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Re: [hobbicast] Re: press project

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  • StoneTool
    RT: Thanks for the share............ I work with 50 ton stuff all the time I agree that an aluminum piston will not transmit 50 T to a 1.5 rod without
    Message 1 of 11 , Jan 23, 2013
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      RT:
      Thanks for the share............

      I work with 50 ton stuff all the time

      I agree that an aluminum piston will not transmit 50 T to a
      1.5" rod without deforming unless there is steel to spread the force out
      wider. I like an Aluminum piston because of wear. I've seen too many
      steel pistons gall cylinders when the wear bands don't quite do the
      job. In addition seals for that kind of pressure must run at VERY close
      tolerance. I don't like steel on steel when tolerances are very
      close. Cast iron on steel works well, as does brass or aluminum.
      I share your concerns about things blowing out of presses to the
      extent that I once built a press based on a 1" thick steel table with
      various openings, and the press portion moved up and down so your
      working height was always the table top. The idea was to weld support
      structures right to the table for pressing so everything was rigid.
      It's a good machine and still in service. A 12" centrally located round
      hole with a flange beneath it for reinforcement is the primary work
      area, and press blocks of 1" plate are used to bridge the hole. It also
      has a slot 8" wide and a number of other holes, and the cylinder can be
      located at virtually any point on the surface. It uses a 50 ton
      Owatanna porta power cylinder and electric pump. A rather unique and
      elegant system that cost a lot of money by the time I was done...... I
      don't own it and couldn't afford to build one like it for my own use.
      Threaded rods across between the table sections may be needed on
      the press I'm contemplating to maintain their relationship, though I'm
      looking at other and more convenient means of securing them. Top
      clamping alone is probably not enough. I've examined a lot of
      different ways of doing things from top and bottom eccentric clamping to
      hydraulic clamping with press pressure, to half nuts to other positive
      dogging methods. I haven't nailed down a final design yet.


      Howard

      On 01/23/2013 05:46 PM, redlupmi2 wrote:
      > I'll share my experience.
      >
      > I don't think an aluminum piston will transmit that much pressure to a 1-1/2" steel rod, without deforming. Besides the columnar strength required due to length.
      >
      > My 25T Dake has deformed the end of the 1-1/4" diameter screw many times. And has swelled the ends of CRS 1" dia. push pins to hour glass shape. I was hiding behind the upright as best I could, to avoid possible shrapnel.
      >
      > The 25T Dake has a 3-7/8" dia. bore and 2-1/2" rod, with 1-1/2" adjusting screw with currently 1-1/4" end.
      >
      > Have a 150T Dake 8" dia. bore, also. It is scary when using it, as everything has to be secure, and perpendicular. Any miss alignment and those big blocks travel a loooooooooog way when anything slips.
      >
      > 4"id x 5"OD tubing is readily available from my usual source Bailey Sales Knoxville, TN. (They sell components too) But looks like 1-1/4" wall is used by the ones using 10k psi and required to stand behind or beside their products.
      >
      > As for securing the piston to the rod for a double ended cylinder, I would have an interference fit (.001/inch) between the piston and rod, with a three piece ring to slip into the appropriate groove machined in the rod, and secured by a counterbore in the piston. The three piece ring has to withstand the shearing force of the pressure applied to the piston.
      >
      > Heat piston, quickly slip on rod, while securing three piece ring. I've worked on lower pressure double end cylinders the piston was only secured by the interference fit. And these cylinders were required to push and pull, where your design only requires high pressure one direction.
      >
      > If in doubt, could install a spiral lock retaining ring above the piston for peace of mind.
      >
      > Plan carefully, and work safely.
      >
      > R.T. :D
      >
      > --- In hobbicast@yahoogroups.com, StoneTool wrote:
      >> I've been contemplating a shop press project that is rather unique.
      >> The press consists of a set of legs on the floor to support it, and a
      >> vertical post, with two parallel channels extending outward toward you,
      >> and fairly high up. Two frames consisting of a top channel, a pair of
      >> vertical square tubes, and a bottom tube hang from the two horizontal
      >> channels that extend from the main post. Each of these frames is half
      >> of the press frame, and has a channel table that can be raised or
      >> lowered to the correct height. Because these frames are independent
      >> and free floating, they can be slid to any spacing or angle desired.
      >> Clamping bars above the top channels of these frames clamp them firmly
      >> down to the two channels they hang from so they do not move once
      >> placed. The two channels these frames hang from have the press cylinder
      >> attached between them in a fixed location (center).
      >>
      >> Now that the above is clear as mud ;-)........... on to the
      >> casting portion of the project:
      >>
      >> 1: The material required to build a 4" cylinder capable of 10,000 PSI
      >> is quite expensive and not locally available. I propose to use
      >> ordinary 3/8" wall 4" honed tubing, place it inside considerably larger
      >> diameter ordinary pipe, say 6", and pour the intervening space full of
      >> aluminum
      >>
      >>
      >> 2: This cylinder will have a ram that passes completely through both
      >> ends, with the piston in the middle or thereabouts. The problem here
      >> is that I need to attach a piston capable of transmitting 50 tons to the
      >> ram. That means either I must use a stepped shaft so the piston has a
      >> ledge to press on, which means turning the upper portion down and having
      >> it ground for the high pressure seal, or start with a 4" shaft and turn
      >> it down, leaving the center portion as the piston............ A LOT of
      >> material to remove.
      >>
      >> The third option is to take a 1.5" shaft, and turn a groove into it
      >> to accept a heavy snap ring or something of the sort, and simply pour
      >> the ram right on the shaft. This of course means designing the mold so
      >> I can turn out a pocket in the aluminum ram to accept a pressure seal or
      >> just a high pressure O-ring. No big deal.
      >>
      >>
      >> Option3 appeals to me.............. any thoughts?
      >>
      >> * Now to the why of it. The first part, the press design is pretty
      >> obvious, but the ram design may not be as obvious to some. Here are the
      >> reasons.
      >>
      >> 1: Keeping the spacing between the support points constant as the
      >> cylinder extends. That is to say that with an ordinary cylinder, as the
      >> ram approaches the end bushing any play is magnified. If you have a
      >> couple thousandths of an inch at the top of the stroke, there will be
      >> quite a bit by the time it is extended.
      >>
      >> 2: Impact......... I want a press where I can have an impact weight on
      >> top....... lifted by air and dropped, and transmit that impact all the
      >> way down through the ram. With impact, you can move something at 10
      >> tons that would otherwise take the full 50 tons....... and not break it.
      >>
      >>
      >> I would draw up a sketch, but I'm not much of a draftsman........ I
      >> know what I want, and have a very clear picture in my head of
      >> it............ enough to build it. I tend to do things that way.
      >>
      >>
      >> Howard
      >>
      >
      >
      >
      > ------------------------------------
      >
      > For discussion of Metal Casting and related issues
      > this list does not accept attachments.
      >
      > Files area and list services are at:
      > http://groups.yahoo.com/group/hobbicast
      >
      > For additional files and photos and off topic discussions
      > check out these two affiliated sites:
      > http://groups.yahoo.com/group/sandcrabs
      > http://groups.yahoo.com/group/Hobbicast1
      >
      > Please visit our sponsor: Budget Casting Supply
      > http://budgetcastingsupply.com/
      >
      > List Owner:
      > owly@...
      >
      > Yahoo! Groups Links
      >
      >
      >
      >
    • redlupmi2
      Glad to know you have experience with 50 ton presses. Some pay a high price for the experience. A local hydraulic cylinder builder takes a steel piston and
      Message 2 of 11 , Jan 24, 2013
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        Glad to know you have experience with 50 ton presses. Some pay a high price for the experience.

        A local hydraulic cylinder builder takes a steel piston and brazes a layer of brass or welds a layer of silicon bronze to the OD of some of their pistons then machines to finish size.

        R.T. :D

        --- In hobbicast@yahoogroups.com, StoneTool wrote:
        >
        > RT:
        > Thanks for the share............
        >
        > I work with 50 ton stuff all the time
        >
        > I agree that an aluminum piston will not transmit 50 T to a
        > 1.5" rod without deforming unless there is steel to spread the force out
        > wider. I like an Aluminum piston because of wear. I've seen too many
        > steel pistons gall cylinders when the wear bands don't quite do the
        > job. In addition seals for that kind of pressure must run at VERY close
        > tolerance. I don't like steel on steel when tolerances are very
        > close. Cast iron on steel works well, as does brass or aluminum.
        > I share your concerns about things blowing out of presses to the
        > extent that I once built a press based on a 1" thick steel table with
        > various openings, and the press portion moved up and down so your
        > working height was always the table top. The idea was to weld support
        > structures right to the table for pressing so everything was rigid.
        > It's a good machine and still in service. A 12" centrally located round
        > hole with a flange beneath it for reinforcement is the primary work
        > area, and press blocks of 1" plate are used to bridge the hole. It also
        > has a slot 8" wide and a number of other holes, and the cylinder can be
        > located at virtually any point on the surface. It uses a 50 ton
        > Owatanna porta power cylinder and electric pump. A rather unique and
        > elegant system that cost a lot of money by the time I was done...... I
        > don't own it and couldn't afford to build one like it for my own use.
        > Threaded rods across between the table sections may be needed on
        > the press I'm contemplating to maintain their relationship, though I'm
        > looking at other and more convenient means of securing them. Top
        > clamping alone is probably not enough. I've examined a lot of
        > different ways of doing things from top and bottom eccentric clamping to
        > hydraulic clamping with press pressure, to half nuts to other positive
        > dogging methods. I haven't nailed down a final design yet.
        >
        >
        > Howard
        >
        > On 01/23/2013 05:46 PM, redlupmi2 wrote:
        > > I'll share my experience.
        > >
        > > I don't think an aluminum piston will transmit that much pressure to a 1-1/2" steel rod, without deforming. Besides the columnar strength required due to length.
        > >
        > > My 25T Dake has deformed the end of the 1-1/4" diameter screw many times. And has swelled the ends of CRS 1" dia. push pins to hour glass shape. I was hiding behind the upright as best I could, to avoid possible shrapnel.
        > >
        > > The 25T Dake has a 3-7/8" dia. bore and 2-1/2" rod, with 1-1/2" adjusting screw with currently 1-1/4" end.
        > >
        > > Have a 150T Dake 8" dia. bore, also. It is scary when using it, as everything has to be secure, and perpendicular. Any miss alignment and those big blocks travel a loooooooooog way when anything slips.
        > >
        > > 4"id x 5"OD tubing is readily available from my usual source Bailey Sales Knoxville, TN. (They sell components too) But looks like 1-1/4" wall is used by the ones using 10k psi and required to stand behind or beside their products.
        > >
        > > As for securing the piston to the rod for a double ended cylinder, I would have an interference fit (.001/inch) between the piston and rod, with a three piece ring to slip into the appropriate groove machined in the rod, and secured by a counterbore in the piston. The three piece ring has to withstand the shearing force of the pressure applied to the piston.
        > >
        > > Heat piston, quickly slip on rod, while securing three piece ring. I've worked on lower pressure double end cylinders the piston was only secured by the interference fit. And these cylinders were required to push and pull, where your design only requires high pressure one direction.
        > >
        > > If in doubt, could install a spiral lock retaining ring above the piston for peace of mind.
        > >
        > > Plan carefully, and work safely.
        > >
        > > R.T. :D
        > >
        > > --- In hobbicast@yahoogroups.com, StoneTool wrote:
        > >> I've been contemplating a shop press project that is rather unique.
        > >> The press consists of a set of legs on the floor to support it, and a
        > >> vertical post, with two parallel channels extending outward toward you,
        > >> and fairly high up. Two frames consisting of a top channel, a pair of
        > >> vertical square tubes, and a bottom tube hang from the two horizontal
        > >> channels that extend from the main post. Each of these frames is half
        > >> of the press frame, and has a channel table that can be raised or
        > >> lowered to the correct height. Because these frames are independent
        > >> and free floating, they can be slid to any spacing or angle desired.
        > >> Clamping bars above the top channels of these frames clamp them firmly
        > >> down to the two channels they hang from so they do not move once
        > >> placed. The two channels these frames hang from have the press cylinder
        > >> attached between them in a fixed location (center).
        > >>
        > >> Now that the above is clear as mud ;-)........... on to the
        > >> casting portion of the project:
        > >>
        > >> 1: The material required to build a 4" cylinder capable of 10,000 PSI
        > >> is quite expensive and not locally available. I propose to use
        > >> ordinary 3/8" wall 4" honed tubing, place it inside considerably larger
        > >> diameter ordinary pipe, say 6", and pour the intervening space full of
        > >> aluminum
        > >>
        > >>
        > >> 2: This cylinder will have a ram that passes completely through both
        > >> ends, with the piston in the middle or thereabouts. The problem here
        > >> is that I need to attach a piston capable of transmitting 50 tons to the
        > >> ram. That means either I must use a stepped shaft so the piston has a
        > >> ledge to press on, which means turning the upper portion down and having
        > >> it ground for the high pressure seal, or start with a 4" shaft and turn
        > >> it down, leaving the center portion as the piston............ A LOT of
        > >> material to remove.
        > >>
        > >> The third option is to take a 1.5" shaft, and turn a groove into it
        > >> to accept a heavy snap ring or something of the sort, and simply pour
        > >> the ram right on the shaft. This of course means designing the mold so
        > >> I can turn out a pocket in the aluminum ram to accept a pressure seal or
        > >> just a high pressure O-ring. No big deal.
        > >>
        > >>
        > >> Option3 appeals to me.............. any thoughts?
        > >>
        > >> * Now to the why of it. The first part, the press design is pretty
        > >> obvious, but the ram design may not be as obvious to some. Here are the
        > >> reasons.
        > >>
        > >> 1: Keeping the spacing between the support points constant as the
        > >> cylinder extends. That is to say that with an ordinary cylinder, as the
        > >> ram approaches the end bushing any play is magnified. If you have a
        > >> couple thousandths of an inch at the top of the stroke, there will be
        > >> quite a bit by the time it is extended.
        > >>
        > >> 2: Impact......... I want a press where I can have an impact weight on
        > >> top....... lifted by air and dropped, and transmit that impact all the
        > >> way down through the ram. With impact, you can move something at 10
        > >> tons that would otherwise take the full 50 tons....... and not break it.
        > >>
        > >>
        > >> I would draw up a sketch, but I'm not much of a draftsman........ I
        > >> know what I want, and have a very clear picture in my head of
        > >> it............ enough to build it. I tend to do things that way.
        > >>
        > >>
        > >> Howard
        > >>
        > >
        > >
        > >
        > > ------------------------------------
        > >
        > > For discussion of Metal Casting and related issues
        > > this list does not accept attachments.
        > >
        > > Files area and list services are at:
        > > http://groups.yahoo.com/group/hobbicast
        > >
        > > For additional files and photos and off topic discussions
        > > check out these two affiliated sites:
        > > http://groups.yahoo.com/group/sandcrabs
        > > http://groups.yahoo.com/group/Hobbicast1
        > >
        > > Please visit our sponsor: Budget Casting Supply
        > > http://budgetcastingsupply.com/
        > >
        > > List Owner:
        > > owly@...
        > >
        > > Yahoo! Groups Links
        > >
        > >
        > >
        > >
        >
      • StoneTool
        I have a 50 ton ram with 8 stroke that has a solid brass ram & piston............ Howard
        Message 3 of 11 , Jan 24, 2013
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          I have a 50 ton ram with 8" stroke that has a solid brass ram &
          piston............


          Howard

          On 01/24/2013 03:23 PM, redlupmi2 wrote:
          > Glad to know you have experience with 50 ton presses. Some pay a high price for the experience.
          >
          > A local hydraulic cylinder builder takes a steel piston and brazes a layer of brass or welds a layer of silicon bronze to the OD of some of their pistons then machines to finish size.
          >
          > R.T. :D
          >
          > --- In hobbicast@yahoogroups.com, StoneTool wrote:
          >> RT:
          >> Thanks for the share............
          >>
          >> I work with 50 ton stuff all the time
          >>
          >> I agree that an aluminum piston will not transmit 50 T to a
          >> 1.5" rod without deforming unless there is steel to spread the force out
          >> wider. I like an Aluminum piston because of wear. I've seen too many
          >> steel pistons gall cylinders when the wear bands don't quite do the
          >> job. In addition seals for that kind of pressure must run at VERY close
          >> tolerance. I don't like steel on steel when tolerances are very
          >> close. Cast iron on steel works well, as does brass or aluminum.
          >> I share your concerns about things blowing out of presses to the
          >> extent that I once built a press based on a 1" thick steel table with
          >> various openings, and the press portion moved up and down so your
          >> working height was always the table top. The idea was to weld support
          >> structures right to the table for pressing so everything was rigid.
          >> It's a good machine and still in service. A 12" centrally located round
          >> hole with a flange beneath it for reinforcement is the primary work
          >> area, and press blocks of 1" plate are used to bridge the hole. It also
          >> has a slot 8" wide and a number of other holes, and the cylinder can be
          >> located at virtually any point on the surface. It uses a 50 ton
          >> Owatanna porta power cylinder and electric pump. A rather unique and
          >> elegant system that cost a lot of money by the time I was done...... I
          >> don't own it and couldn't afford to build one like it for my own use.
          >> Threaded rods across between the table sections may be needed on
          >> the press I'm contemplating to maintain their relationship, though I'm
          >> looking at other and more convenient means of securing them. Top
          >> clamping alone is probably not enough. I've examined a lot of
          >> different ways of doing things from top and bottom eccentric clamping to
          >> hydraulic clamping with press pressure, to half nuts to other positive
          >> dogging methods. I haven't nailed down a final design yet.
          >>
          >>
          >> Howard
          >>
          >> On 01/23/2013 05:46 PM, redlupmi2 wrote:
          >>> I'll share my experience.
          >>>
          >>> I don't think an aluminum piston will transmit that much pressure to a 1-1/2" steel rod, without deforming. Besides the columnar strength required due to length.
          >>>
          >>> My 25T Dake has deformed the end of the 1-1/4" diameter screw many times. And has swelled the ends of CRS 1" dia. push pins to hour glass shape. I was hiding behind the upright as best I could, to avoid possible shrapnel.
          >>>
          >>> The 25T Dake has a 3-7/8" dia. bore and 2-1/2" rod, with 1-1/2" adjusting screw with currently 1-1/4" end.
          >>>
          >>> Have a 150T Dake 8" dia. bore, also. It is scary when using it, as everything has to be secure, and perpendicular. Any miss alignment and those big blocks travel a loooooooooog way when anything slips.
          >>>
          >>> 4"id x 5"OD tubing is readily available from my usual source Bailey Sales Knoxville, TN. (They sell components too) But looks like 1-1/4" wall is used by the ones using 10k psi and required to stand behind or beside their products.
          >>>
          >>> As for securing the piston to the rod for a double ended cylinder, I would have an interference fit (.001/inch) between the piston and rod, with a three piece ring to slip into the appropriate groove machined in the rod, and secured by a counterbore in the piston. The three piece ring has to withstand the shearing force of the pressure applied to the piston.
          >>>
          >>> Heat piston, quickly slip on rod, while securing three piece ring. I've worked on lower pressure double end cylinders the piston was only secured by the interference fit. And these cylinders were required to push and pull, where your design only requires high pressure one direction.
          >>>
          >>> If in doubt, could install a spiral lock retaining ring above the piston for peace of mind.
          >>>
          >>> Plan carefully, and work safely.
          >>>
          >>> R.T. :D
          >>>
          >>> --- In hobbicast@yahoogroups.com, StoneTool wrote:
          >>>> I've been contemplating a shop press project that is rather unique.
          >>>> The press consists of a set of legs on the floor to support it, and a
          >>>> vertical post, with two parallel channels extending outward toward you,
          >>>> and fairly high up. Two frames consisting of a top channel, a pair of
          >>>> vertical square tubes, and a bottom tube hang from the two horizontal
          >>>> channels that extend from the main post. Each of these frames is half
          >>>> of the press frame, and has a channel table that can be raised or
          >>>> lowered to the correct height. Because these frames are independent
          >>>> and free floating, they can be slid to any spacing or angle desired.
          >>>> Clamping bars above the top channels of these frames clamp them firmly
          >>>> down to the two channels they hang from so they do not move once
          >>>> placed. The two channels these frames hang from have the press cylinder
          >>>> attached between them in a fixed location (center).
          >>>>
          >>>> Now that the above is clear as mud ;-)........... on to the
          >>>> casting portion of the project:
          >>>>
          >>>> 1: The material required to build a 4" cylinder capable of 10,000 PSI
          >>>> is quite expensive and not locally available. I propose to use
          >>>> ordinary 3/8" wall 4" honed tubing, place it inside considerably larger
          >>>> diameter ordinary pipe, say 6", and pour the intervening space full of
          >>>> aluminum
          >>>>
          >>>>
          >>>> 2: This cylinder will have a ram that passes completely through both
          >>>> ends, with the piston in the middle or thereabouts. The problem here
          >>>> is that I need to attach a piston capable of transmitting 50 tons to the
          >>>> ram. That means either I must use a stepped shaft so the piston has a
          >>>> ledge to press on, which means turning the upper portion down and having
          >>>> it ground for the high pressure seal, or start with a 4" shaft and turn
          >>>> it down, leaving the center portion as the piston............ A LOT of
          >>>> material to remove.
          >>>>
          >>>> The third option is to take a 1.5" shaft, and turn a groove into it
          >>>> to accept a heavy snap ring or something of the sort, and simply pour
          >>>> the ram right on the shaft. This of course means designing the mold so
          >>>> I can turn out a pocket in the aluminum ram to accept a pressure seal or
          >>>> just a high pressure O-ring. No big deal.
          >>>>
          >>>>
          >>>> Option3 appeals to me.............. any thoughts?
          >>>>
          >>>> * Now to the why of it. The first part, the press design is pretty
          >>>> obvious, but the ram design may not be as obvious to some. Here are the
          >>>> reasons.
          >>>>
          >>>> 1: Keeping the spacing between the support points constant as the
          >>>> cylinder extends. That is to say that with an ordinary cylinder, as the
          >>>> ram approaches the end bushing any play is magnified. If you have a
          >>>> couple thousandths of an inch at the top of the stroke, there will be
          >>>> quite a bit by the time it is extended.
          >>>>
          >>>> 2: Impact......... I want a press where I can have an impact weight on
          >>>> top....... lifted by air and dropped, and transmit that impact all the
          >>>> way down through the ram. With impact, you can move something at 10
          >>>> tons that would otherwise take the full 50 tons....... and not break it.
          >>>>
          >>>>
          >>>> I would draw up a sketch, but I'm not much of a draftsman........ I
          >>>> know what I want, and have a very clear picture in my head of
          >>>> it............ enough to build it. I tend to do things that way.
          >>>>
          >>>>
          >>>> Howard
          >>>>
          >>>
          >>>
          >>> ------------------------------------
          >>>
          >>> For discussion of Metal Casting and related issues
          >>> this list does not accept attachments.
          >>>
          >>> Files area and list services are at:
          >>> http://groups.yahoo.com/group/hobbicast
          >>>
          >>> For additional files and photos and off topic discussions
          >>> check out these two affiliated sites:
          >>> http://groups.yahoo.com/group/sandcrabs
          >>> http://groups.yahoo.com/group/Hobbicast1
          >>>
          >>> Please visit our sponsor: Budget Casting Supply
          >>> http://budgetcastingsupply.com/
          >>>
          >>> List Owner:
          >>> owly@...
          >>>
          >>> Yahoo! Groups Links
          >>>
          >>>
          >>>
          >>>
          >
          >
          >
          > ------------------------------------
          >
          > For discussion of Metal Casting and related issues
          > this list does not accept attachments.
          >
          > Files area and list services are at:
          > http://groups.yahoo.com/group/hobbicast
          >
          > For additional files and photos and off topic discussions
          > check out these two affiliated sites:
          > http://groups.yahoo.com/group/sandcrabs
          > http://groups.yahoo.com/group/Hobbicast1
          >
          > Please visit our sponsor: Budget Casting Supply
          > http://budgetcastingsupply.com/
          >
          > List Owner:
          > owly@...
          >
          > Yahoo! Groups Links
          >
          >
          >
          >
        • Steven DePhillips
          Here is a company that sells hydraulic cylinders and stuff at reasonable prices they also have surplus cylinders at even less.  I use them for a lot of my
          Message 4 of 11 , Jan 25, 2013
          • 0 Attachment
            Here is a company that sells hydraulic cylinders and stuff at reasonable prices they also have surplus cylinders at even less.  I use them for a lot of my projects  http://www.baileynet.com/%c2%a0  They are in Tennessee  so i don't know ho much the shipping to you would be.  I live in Georgia so its not too bad.


            ________________________________
            From: StoneTool <owly@...>
            To: hobbicast@yahoogroups.com
            Sent: Thursday, January 24, 2013 10:51 PM
            Subject: Re: [hobbicast] Re: press project


             
            I have a 50 ton ram with 8" stroke that has a solid brass ram &
            piston............

            Howard

            On 01/24/2013 03:23 PM, redlupmi2 wrote:
            > Glad to know you have experience with 50 ton presses. Some pay a high price for the experience.
            >
            > A local hydraulic cylinder builder takes a steel piston and brazes a layer of brass or welds a layer of silicon bronze to the OD of some of their pistons then machines to finish size.
            >
            > R.T. :D
            >
            > --- In hobbicast@yahoogroups.com, StoneTool wrote:
            >> RT:
            >> Thanks for the share............
            >>
            >> I work with 50 ton stuff all the time
            >>
            >> I agree that an aluminum piston will not transmit 50 T to a
            >> 1.5" rod without deforming unless there is steel to spread the force out
            >> wider. I like an Aluminum piston because of wear. I've seen too many
            >> steel pistons gall cylinders when the wear bands don't quite do the
            >> job. In addition seals for that kind of pressure must run at VERY close
            >> tolerance. I don't like steel on steel when tolerances are very
            >> close. Cast iron on steel works well, as does brass or aluminum.
            >> I share your concerns about things blowing out of presses to the
            >> extent that I once built a press based on a 1" thick steel table with
            >> various openings, and the press portion moved up and down so your
            >> working height was always the table top. The idea was to weld support
            >> structures right to the table for pressing so everything was rigid.
            >> It's a good machine and still in service. A 12" centrally located round
            >> hole with a flange beneath it for reinforcement is the primary work
            >> area, and press blocks of 1" plate are used to bridge the hole. It also
            >> has a slot 8" wide and a number of other holes, and the cylinder can be
            >> located at virtually any point on the surface. It uses a 50 ton
            >> Owatanna porta power cylinder and electric pump. A rather unique and
            >> elegant system that cost a lot of money by the time I was done...... I
            >> don't own it and couldn't afford to build one like it for my own use.
            >> Threaded rods across between the table sections may be needed on
            >> the press I'm contemplating to maintain their relationship, though I'm
            >> looking at other and more convenient means of securing them. Top
            >> clamping alone is probably not enough. I've examined a lot of
            >> different ways of doing things from top and bottom eccentric clamping to
            >> hydraulic clamping with press pressure, to half nuts to other positive
            >> dogging methods. I haven't nailed down a final design yet.
            >>
            >>
            >> Howard
            >>
            >> On 01/23/2013 05:46 PM, redlupmi2 wrote:
            >>> I'll share my experience.
            >>>
            >>> I don't think an aluminum piston will transmit that much pressure to a 1-1/2" steel rod, without deforming. Besides the columnar strength required due to length.
            >>>
            >>> My 25T Dake has deformed the end of the 1-1/4" diameter screw many times. And has swelled the ends of CRS 1" dia. push pins to hour glass shape. I was hiding behind the upright as best I could, to avoid possible shrapnel.
            >>>
            >>> The 25T Dake has a 3-7/8" dia. bore and 2-1/2" rod, with 1-1/2" adjusting screw with currently 1-1/4" end.
            >>>
            >>> Have a 150T Dake 8" dia. bore, also. It is scary when using it, as everything has to be secure, and perpendicular. Any miss alignment and those big blocks travel a loooooooooog way when anything slips.
            >>>
            >>> 4"id x 5"OD tubing is readily available from my usual source Bailey Sales Knoxville, TN. (They sell components too) But looks like 1-1/4" wall is used by the ones using 10k psi and required to stand behind or beside their products.
            >>>
            >>> As for securing the piston to the rod for a double ended cylinder, I would have an interference fit (.001/inch) between the piston and rod, with a three piece ring to slip into the appropriate groove machined in the rod, and secured by a counterbore in the piston. The three piece ring has to withstand the shearing force of the pressure applied to the piston.
            >>>
            >>> Heat piston, quickly slip on rod, while securing three piece ring. I've worked on lower pressure double end cylinders the piston was only secured by the interference fit. And these cylinders were required to push and pull, where your design only requires high pressure one direction.
            >>>
            >>> If in doubt, could install a spiral lock retaining ring above the piston for peace of mind.
            >>>
            >>> Plan carefully, and work safely.
            >>>
            >>> R.T. :D
            >>>
            >>> --- In hobbicast@yahoogroups.com, StoneTool wrote:
            >>>> I've been contemplating a shop press project that is rather unique.
            >>>> The press consists of a set of legs on the floor to support it, and a
            >>>> vertical post, with two parallel channels extending outward toward you,
            >>>> and fairly high up. Two frames consisting of a top channel, a pair of
            >>>> vertical square tubes, and a bottom tube hang from the two horizontal
            >>>> channels that extend from the main post. Each of these frames is half
            >>>> of the press frame, and has a channel table that can be raised or
            >>>> lowered to the correct height. Because these frames are independent
            >>>> and free floating, they can be slid to any spacing or angle desired.
            >>>> Clamping bars above the top channels of these frames clamp them firmly
            >>>> down to the two channels they hang from so they do not move once
            >>>> placed. The two channels these frames hang from have the press cylinder
            >>>> attached between them in a fixed location (center).
            >>>>
            >>>> Now that the above is clear as mud ;-)........... on to the
            >>>> casting portion of the project:
            >>>>
            >>>> 1: The material required to build a 4" cylinder capable of 10,000 PSI
            >>>> is quite expensive and not locally available. I propose to use
            >>>> ordinary 3/8" wall 4" honed tubing, place it inside considerably larger
            >>>> diameter ordinary pipe, say 6", and pour the intervening space full of
            >>>> aluminum
            >>>>
            >>>>
            >>>> 2: This cylinder will have a ram that passes completely through both
            >>>> ends, with the piston in the middle or thereabouts. The problem here
            >>>> is that I need to attach a piston capable of transmitting 50 tons to the
            >>>> ram. That means either I must use a stepped shaft so the piston has a
            >>>> ledge to press on, which means turning the upper portion down and having
            >>>> it ground for the high pressure seal, or start with a 4" shaft and turn
            >>>> it down, leaving the center portion as the piston............ A LOT of
            >>>> material to remove.
            >>>>
            >>>> The third option is to take a 1.5" shaft, and turn a groove into it
            >>>> to accept a heavy snap ring or something of the sort, and simply pour
            >>>> the ram right on the shaft. This of course means designing the mold so
            >>>> I can turn out a pocket in the aluminum ram to accept a pressure seal or
            >>>> just a high pressure O-ring. No big deal.
            >>>>
            >>>>
            >>>> Option3 appeals to me.............. any thoughts?
            >>>>
            >>>> * Now to the why of it. The first part, the press design is pretty
            >>>> obvious, but the ram design may not be as obvious to some. Here are the
            >>>> reasons.
            >>>>
            >>>> 1: Keeping the spacing between the support points constant as the
            >>>> cylinder extends. That is to say that with an ordinary cylinder, as the
            >>>> ram approaches the end bushing any play is magnified. If you have a
            >>>> couple thousandths of an inch at the top of the stroke, there will be
            >>>> quite a bit by the time it is extended.
            >>>>
            >>>> 2: Impact......... I want a press where I can have an impact weight on
            >>>> top....... lifted by air and dropped, and transmit that impact all the
            >>>> way down through the ram. With impact, you can move something at 10
            >>>> tons that would otherwise take the full 50 tons....... and not break it.
            >>>>
            >>>>
            >>>> I would draw up a sketch, but I'm not much of a draftsman........ I
            >>>> know what I want, and have a very clear picture in my head of
            >>>> it............ enough to build it. I tend to do things that way.
            >>>>
            >>>>
            >>>> Howard
            >>>>
            >>>
            >>>
            >>> ------------------------------------
            >>>
            >>> For discussion of Metal Casting and related issues
            >>> this list does not accept attachments.
            >>>
            >>> Files area and list services are at:
            >>> http://groups.yahoo.com/group/hobbicast
            >>>
            >>> For additional files and photos and off topic discussions
            >>> check out these two affiliated sites:
            >>> http://groups.yahoo.com/group/sandcrabs
            >>> http://groups.yahoo.com/group/Hobbicast1
            >>>
            >>> Please visit our sponsor: Budget Casting Supply
            >>> http://budgetcastingsupply.com/
            >>>
            >>> List Owner:
            >>> owly@...
            >>>
            >>> Yahoo! Groups Links
            >>>
            >>>
            >>>
            >>>
            >
            >
            >
            > ------------------------------------
            >
            > For discussion of Metal Casting and related issues
            > this list does not accept attachments.
            >
            > Files area and list services are at:
            > http://groups.yahoo.com/group/hobbicast
            >
            > For additional files and photos and off topic discussions
            > check out these two affiliated sites:
            > http://groups.yahoo.com/group/sandcrabs
            > http://groups.yahoo.com/group/Hobbicast1
            >
            > Please visit our sponsor: Budget Casting Supply
            > http://budgetcastingsupply.com/
            >
            > List Owner:
            > owly@...
            >
            > Yahoo! Groups Links
            >
            >
            >
            >




            [Non-text portions of this message have been removed]
          • StoneTool
            Steven: I do business with Bailey all the time........ My cylinder design is significantly different from anything I can readily buy off the shelf. The ram
            Message 5 of 11 , Jan 25, 2013
            • 0 Attachment
              Steven:
              I do business with Bailey all the time........

              My cylinder design is significantly different from anything I can
              readily buy off the shelf. The ram passing completely through the
              cylinder is an important feature for several reasons. I want to be
              able to impact the press by jarring the top of the ram, and I also want
              the stability of having two bushings that remain at the same spacing,
              rather than the single lower bushing and the ram, which approach each
              other as the ram extends. That reducing spacing as the ram extends
              results in more side play as you work further extended. The 10000 psi
              pressure range matters in terms of size. It would take an 8" cylinder
              to accomplish the same thing on "conventional pressures". I can get 4"
              x 4.75" material at the local hydraulic shop where I have an account and
              get fairly decent prices.


              Howard



              On 01/25/2013 08:10 AM, Steven DePhillips wrote:
              > Here is a company that sells hydraulic cylinders and stuff at reasonable prices they also have surplus cylinders at even less. I use them for a lot of my projects http://www.baileynet.com/ They are in Tennessee so i don't know ho much the shipping to you would be. I live in Georgia so its not too bad.
              >
              >
              > ________________________________
              > From: StoneTool<owly@...>
              > To: hobbicast@yahoogroups.com
              > Sent: Thursday, January 24, 2013 10:51 PM
              > Subject: Re: [hobbicast] Re: press project
              >
              >
              >
              > I have a 50 ton ram with 8" stroke that has a solid brass ram&
              > piston............
              >
              > Howard
              >
              > On 01/24/2013 03:23 PM, redlupmi2 wrote:
              >> Glad to know you have experience with 50 ton presses. Some pay a high price for the experience.
              >>
              >> A local hydraulic cylinder builder takes a steel piston and brazes a layer of brass or welds a layer of silicon bronze to the OD of some of their pistons then machines to finish size.
              >>
              >> R.T. :D
              >>
              >> --- In hobbicast@yahoogroups.com, StoneTool wrote:
              >>> RT:
              >>> Thanks for the share............
              >>>
              >>> I work with 50 ton stuff all the time
              >>>
              >>> I agree that an aluminum piston will not transmit 50 T to a
              >>> 1.5" rod without deforming unless there is steel to spread the force out
              >>> wider. I like an Aluminum piston because of wear. I've seen too many
              >>> steel pistons gall cylinders when the wear bands don't quite do the
              >>> job. In addition seals for that kind of pressure must run at VERY close
              >>> tolerance. I don't like steel on steel when tolerances are very
              >>> close. Cast iron on steel works well, as does brass or aluminum.
              >>> I share your concerns about things blowing out of presses to the
              >>> extent that I once built a press based on a 1" thick steel table with
              >>> various openings, and the press portion moved up and down so your
              >>> working height was always the table top. The idea was to weld support
              >>> structures right to the table for pressing so everything was rigid.
              >>> It's a good machine and still in service. A 12" centrally located round
              >>> hole with a flange beneath it for reinforcement is the primary work
              >>> area, and press blocks of 1" plate are used to bridge the hole. It also
              >>> has a slot 8" wide and a number of other holes, and the cylinder can be
              >>> located at virtually any point on the surface. It uses a 50 ton
              >>> Owatanna porta power cylinder and electric pump. A rather unique and
              >>> elegant system that cost a lot of money by the time I was done...... I
              >>> don't own it and couldn't afford to build one like it for my own use.
              >>> Threaded rods across between the table sections may be needed on
              >>> the press I'm contemplating to maintain their relationship, though I'm
              >>> looking at other and more convenient means of securing them. Top
              >>> clamping alone is probably not enough. I've examined a lot of
              >>> different ways of doing things from top and bottom eccentric clamping to
              >>> hydraulic clamping with press pressure, to half nuts to other positive
              >>> dogging methods. I haven't nailed down a final design yet.
              >>>
              >>>
              >>> Howard
              >>>
              >>> On 01/23/2013 05:46 PM, redlupmi2 wrote:
              >>>> I'll share my experience.
              >>>>
              >>>> I don't think an aluminum piston will transmit that much pressure to a 1-1/2" steel rod, without deforming. Besides the columnar strength required due to length.
              >>>>
              >>>> My 25T Dake has deformed the end of the 1-1/4" diameter screw many times. And has swelled the ends of CRS 1" dia. push pins to hour glass shape. I was hiding behind the upright as best I could, to avoid possible shrapnel.
              >>>>
              >>>> The 25T Dake has a 3-7/8" dia. bore and 2-1/2" rod, with 1-1/2" adjusting screw with currently 1-1/4" end.
              >>>>
              >>>> Have a 150T Dake 8" dia. bore, also. It is scary when using it, as everything has to be secure, and perpendicular. Any miss alignment and those big blocks travel a loooooooooog way when anything slips.
              >>>>
              >>>> 4"id x 5"OD tubing is readily available from my usual source Bailey Sales Knoxville, TN. (They sell components too) But looks like 1-1/4" wall is used by the ones using 10k psi and required to stand behind or beside their products.
              >>>>
              >>>> As for securing the piston to the rod for a double ended cylinder, I would have an interference fit (.001/inch) between the piston and rod, with a three piece ring to slip into the appropriate groove machined in the rod, and secured by a counterbore in the piston. The three piece ring has to withstand the shearing force of the pressure applied to the piston.
              >>>>
              >>>> Heat piston, quickly slip on rod, while securing three piece ring. I've worked on lower pressure double end cylinders the piston was only secured by the interference fit. And these cylinders were required to push and pull, where your design only requires high pressure one direction.
              >>>>
              >>>> If in doubt, could install a spiral lock retaining ring above the piston for peace of mind.
              >>>>
              >>>> Plan carefully, and work safely.
              >>>>
              >>>> R.T. :D
              >>>>
              >>>> --- In hobbicast@yahoogroups.com, StoneTool wrote:
              >>>>> I've been contemplating a shop press project that is rather unique.
              >>>>> The press consists of a set of legs on the floor to support it, and a
              >>>>> vertical post, with two parallel channels extending outward toward you,
              >>>>> and fairly high up. Two frames consisting of a top channel, a pair of
              >>>>> vertical square tubes, and a bottom tube hang from the two horizontal
              >>>>> channels that extend from the main post. Each of these frames is half
              >>>>> of the press frame, and has a channel table that can be raised or
              >>>>> lowered to the correct height. Because these frames are independent
              >>>>> and free floating, they can be slid to any spacing or angle desired.
              >>>>> Clamping bars above the top channels of these frames clamp them firmly
              >>>>> down to the two channels they hang from so they do not move once
              >>>>> placed. The two channels these frames hang from have the press cylinder
              >>>>> attached between them in a fixed location (center).
              >>>>>
              >>>>> Now that the above is clear as mud ;-)........... on to the
              >>>>> casting portion of the project:
              >>>>>
              >>>>> 1: The material required to build a 4" cylinder capable of 10,000 PSI
              >>>>> is quite expensive and not locally available. I propose to use
              >>>>> ordinary 3/8" wall 4" honed tubing, place it inside considerably larger
              >>>>> diameter ordinary pipe, say 6", and pour the intervening space full of
              >>>>> aluminum
              >>>>>
              >>>>>
              >>>>> 2: This cylinder will have a ram that passes completely through both
              >>>>> ends, with the piston in the middle or thereabouts. The problem here
              >>>>> is that I need to attach a piston capable of transmitting 50 tons to the
              >>>>> ram. That means either I must use a stepped shaft so the piston has a
              >>>>> ledge to press on, which means turning the upper portion down and having
              >>>>> it ground for the high pressure seal, or start with a 4" shaft and turn
              >>>>> it down, leaving the center portion as the piston............ A LOT of
              >>>>> material to remove.
              >>>>>
              >>>>> The third option is to take a 1.5" shaft, and turn a groove into it
              >>>>> to accept a heavy snap ring or something of the sort, and simply pour
              >>>>> the ram right on the shaft. This of course means designing the mold so
              >>>>> I can turn out a pocket in the aluminum ram to accept a pressure seal or
              >>>>> just a high pressure O-ring. No big deal.
              >>>>>
              >>>>>
              >>>>> Option3 appeals to me.............. any thoughts?
              >>>>>
              >>>>> * Now to the why of it. The first part, the press design is pretty
              >>>>> obvious, but the ram design may not be as obvious to some. Here are the
              >>>>> reasons.
              >>>>>
              >>>>> 1: Keeping the spacing between the support points constant as the
              >>>>> cylinder extends. That is to say that with an ordinary cylinder, as the
              >>>>> ram approaches the end bushing any play is magnified. If you have a
              >>>>> couple thousandths of an inch at the top of the stroke, there will be
              >>>>> quite a bit by the time it is extended.
              >>>>>
              >>>>> 2: Impact......... I want a press where I can have an impact weight on
              >>>>> top....... lifted by air and dropped, and transmit that impact all the
              >>>>> way down through the ram. With impact, you can move something at 10
              >>>>> tons that would otherwise take the full 50 tons....... and not break it.
              >>>>>
              >>>>>
              >>>>> I would draw up a sketch, but I'm not much of a draftsman........ I
              >>>>> know what I want, and have a very clear picture in my head of
              >>>>> it............ enough to build it. I tend to do things that way.
              >>>>>
              >>>>>
              >>>>> Howard
              >>>>>
              >>>>
              >>>> ------------------------------------
              >>>>
              >>>> For discussion of Metal Casting and related issues
              >>>> this list does not accept attachments.
              >>>>
              >>>> Files area and list services are at:
              >>>> http://groups.yahoo.com/group/hobbicast
              >>>>
              >>>> For additional files and photos and off topic discussions
              >>>> check out these two affiliated sites:
              >>>> http://groups.yahoo.com/group/sandcrabs
              >>>> http://groups.yahoo.com/group/Hobbicast1
              >>>>
              >>>> Please visit our sponsor: Budget Casting Supply
              >>>> http://budgetcastingsupply.com/
              >>>>
              >>>> List Owner:
              >>>> owly@...
              >>>>
              >>>> Yahoo! Groups Links
              >>>>
              >>>>
              >>>>
              >>>>
              >>
              >>
              >> ------------------------------------
              >>
              >> For discussion of Metal Casting and related issues
              >> this list does not accept attachments.
              >>
              >> Files area and list services are at:
              >> http://groups.yahoo.com/group/hobbicast
              >>
              >> For additional files and photos and off topic discussions
              >> check out these two affiliated sites:
              >> http://groups.yahoo.com/group/sandcrabs
              >> http://groups.yahoo.com/group/Hobbicast1
              >>
              >> Please visit our sponsor: Budget Casting Supply
              >> http://budgetcastingsupply.com/
              >>
              >> List Owner:
              >> owly@...
              >>
              >> Yahoo! Groups Links
              >>
              >>
              >>
              >>
              >
              >
              >
              > [Non-text portions of this message have been removed]
              >
              >
              >
              > ------------------------------------
              >
              > For discussion of Metal Casting and related issues
              > this list does not accept attachments.
              >
              > Files area and list services are at:
              > http://groups.yahoo.com/group/hobbicast
              >
              > For additional files and photos and off topic discussions
              > check out these two affiliated sites:
              > http://groups.yahoo.com/group/sandcrabs
              > http://groups.yahoo.com/group/Hobbicast1
              >
              > Please visit our sponsor: Budget Casting Supply
              > http://budgetcastingsupply.com/
              >
              > List Owner:
              > owly@...
              >
              > Yahoo! Groups Links
              >
              >
              >
              >
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