Loading ...
Sorry, an error occurred while loading the content.

RE: [GrizHFMinimill] Milling titanium on a small mill

Expand Messages
  • gerry waclawiak
    I ve never machined titanium and wouldn t mind having a go but it s quite hard to come by here in the UK, certainly not a case of calling in on the local hobby
    Message 1 of 9 , May 21, 2013
    • 0 Attachment
      I've never machined titanium and wouldn't mind having a go but it's quite hard to come by here in the UK, certainly not a case of calling in on the local hobby shop.

      I came across someone selling offcuts at a recent model engineering show but it was very expensive, several times what a piece of aluminium cost so I don't think I'll be trying it any time soon

      Gerry W
      Leeds UK




      To: GrizHFMinimill@yahoogroups.com
      From: ian_new@...
      Date: Tue, 21 May 2013 01:03:07 -0700
      Subject: Re: [GrizHFMinimill] Milling titanium on a small mill

       

      Hi Kevin,
       
      My experience of machining titanium is a little different.  I have played with it but never worked with it commercially.
       
      In my experience titanium is not difficult to machine. It has a similar in strength to steel (but with a low Young's Modulus and at less than half the weight) so if you approach the job as if it were a piece of stainless steel rather than a piece of aluminium you will have good results.

      It has low thermal conductivity so benefits from using flood cooling and so you must keep tools sharp and take care that tools cut and don't rub. This will help prevent galling in flutes and chips welding to the cutting edge causing BUE problems.

      It cuts equally well with HSS or carbide tooling (C1 - C4 grades are supposed to be best but I have no experience of this). Having said this, the failure mode of the cutting edge tends to be in chipping and as carbide tools are more prone to this they are usually less satisfactory than HSS.

      It tends to be 'gummy' in the same way as aluminium so care is needed when taking interrupted cuts (i.e. when milling). It is best to use down cutting (or climb milling) so the exit of the cut is on the thinning edge of the chip which encourages the chip to break free rather than stick to the cutting edge.

      Of course you will probably be using some sort of alloy rather than the pure metal so the above comments might not be appropriate.

      Ian.

      From: "chrlsmcd@..." <chrlsmcd@...>
      To: "GrizHFMinimill@yahoogroups.com" <GrizHFMinimill@yahoogroups.com>
      Sent: Monday, 20 May 2013, 23:48
      Subject: Re: [GrizHFMinimill] Milling titanium on a small mill
       
      We mill ti at work. I would be surprised of you can pull this off ( but deep down I really hope you can). Coolant, carbide, relatively aggressive feed rates. Ti likes to smear and gall. Treat it like a 316 stainless. I have seen the mills ignite chips when someone forgets to turn on the coolant but never seen a piece of stock go. When you finish throw it in a pan of coke, hook 10 9v batteries in series and anodize it royal blue :)

      On May 20, 2013, at 6:34 PM, "kaje7777" <kevin.quiggle@...> wrote:
       
      I'm looking for advice: A friend of mine came across a small piece of titanium, and asked me if I could make something (a small luthier's plane) out of it for him. I think I can do this with just a few simple cuts, but I'm not sure it's a good idea with the tools I have in hand (though I'm will to get carbide end mills, drills, or whatever if necessary).

      Here is what has me worried: As a first simple experiment, I tried fly cutting one surface with a carbide tool. While this worked, the chips tended to ignite even if I took really shallow (0.002") cuts. Aside from the issue of having flaming titanium chips flying everywhere, I'm also concerned that the larger piece might actually ignite from the friction, raising the possibility of having 290 grams of incandescent titanium on my hands.

      I've done a bit of web searching, but haven't found much: A couple of youtube videos and a few statements to the effect that it can be done, but no discussion of how.

      So: Can this be done safely, and if so, what do I need to do?

      P.S.

      Here are the youtube videos I found:

      https://www.youtube.com/watch?v=shWo6h5vF3E
      https://www.youtube.com/watch?v=9Ut4FNlEy_A


    • cnc sales (hanermo)
      I havent done it personally but many many clients of mine machined titanium. It was not considered difficult at all, similar to stainless. It needs slow rpm
      Message 2 of 9 , May 21, 2013
      • 0 Attachment
        I havent done it personally but many many clients of mine machined titanium.
        It was not considered difficult at all, similar to stainless.

        It needs slow rpm and lots of torque for heavy MRR, but with our little
        tools I doubt that is an issue.


        --
        -hanermo
      • a3sigma
        As Ian suggests, the type of alloy makes a huge difference. In a 30 year career at NASA, I ve machined a lot of titanium. The most common alloy used in
        Message 3 of 9 , May 21, 2013
        • 0 Attachment
          As Ian suggests, the type of alloy makes a huge difference. In a 30 year career at NASA, I've machined a lot of titanium. The most common alloy used in aerospace, Ti6Al4V, is not so different from stainless steel. Some others are hellishly tough to machine.

          However, I strongly advise against doing anything with "mystery metal". If the chips are igniting, there is a real possibily you've got a magnesium alloy. That, and other metals, can be dangerous to work with and require expert knowledge and technique. There can be serious issues with reactivity and toxicity.

          Knowing what you're working with is as important as knowing what you're doing. And you can't know what you're doing, unless you know what you're doing it to.

          David Clark in Southern Maryland, USA



          --- In GrizHFMinimill@yahoogroups.com, Ian Newman <ian_new@...> wrote:
          >
          > Hi Kevin,
          >  
          > My experience of machining titanium is a little different.  I have played with it but never worked with it commercially.
          >  
          > In my experience titanium is not difficult to machine. It has a similar in strength to steel (but with a low Young's Modulus and at less than half the weight) so if you approach the job as if it were a piece of stainless steel rather than a piece of aluminium you will have good results.
          >
          > It has low thermal conductivity so benefits from using flood cooling and so you must keep tools sharp and take care that tools cut and don't rub. This will help prevent galling in flutes and chips welding to the cutting edge causing BUE problems.
          >
          > It cuts equally well with HSS or carbide tooling (C1 - C4 grades are supposed to be best but I have no experience of this). Having said this, the failure mode of the cutting edge tends to be in chipping and as carbide tools are more prone to this they are usually less satisfactory than HSS.
          >
          > It tends to be 'gummy' in the same way as aluminium so care is needed when taking interrupted cuts (i.e. when milling). It is best to use down cutting (or climb milling) so the exit of the cut is on the thinning edge of the chip which encourages the chip to break free rather than stick to the cutting edge.
          >
          > Of course you will probably be using some sort of alloy rather than the pure metal so the above comments might not be appropriate.
          >
          > Ian.
          >
          >
          >
          > ________________________________
          > From: "chrlsmcd@..." <chrlsmcd@...>
          > To: "GrizHFMinimill@yahoogroups.com" <GrizHFMinimill@yahoogroups.com>
          > Sent: Monday, 20 May 2013, 23:48
          > Subject: Re: [GrizHFMinimill] Milling titanium on a small mill
          >
          >
          >  
          >
          > We mill ti at work. I would be surprised of you can pull this off ( but deep down I really hope you can). Coolant, carbide, relatively aggressive feed rates. Ti likes to smear and gall. Treat it like a 316 stainless. I have seen the mills ignite chips when someone forgets to turn on the coolant but never seen a piece of stock go. When you finish throw it in a pan of coke, hook 10 9v batteries in series and anodize it royal blue :)
          >
          > On May 20, 2013, at 6:34 PM, "kaje7777" <kevin.quiggle@...> wrote:
          >  
          > >I'm looking for advice: A friend of mine came across a small piece of titanium, and asked me if I could make something (a small luthier's plane) out of it for him. I think I can do this with just a few simple cuts, but I'm not sure it's a good idea with the tools I have in hand (though I'm will to get carbide end mills, drills, or whatever if necessary).
          > >
          > >Here is what has me worried: As a first simple experiment, I tried fly cutting one surface with a carbide tool. While this worked, the chips tended to ignite even if I took really shallow (0.002") cuts. Aside from the issue of having flaming titanium chips flying everywhere, I'm also concerned that the larger piece might actually ignite from the friction, raising the possibility of having 290 grams of incandescent titanium on my hands.
          > >
          > >I've done a bit of web searching, but haven't found much: A couple of youtube videos and a few statements to the effect that it can be done, but no discussion of how.
          > >
          > >So: Can this be done safely, and if so, what do I need to do?
          > >
          > >P.S.
          > >
          > >Here are the youtube videos I found:
          > >
          > >https://www.youtube.com/watch?v=shWo6h5vF3E
          > >https://www.youtube.com/watch?v=9Ut4FNlEy_A
          > >
          > >
          >
        • Malcolm Parker-Lisberg
          I have a friend who had fun machining Uranium hemispheres (you know what they are used for) He burnt down the workshop. That place in Hampshire, southern
          Message 4 of 9 , May 21, 2013
          • 0 Attachment
            I have a friend who had fun machining Uranium hemispheres (you know what they are used for) He burnt down the workshop. That place in Hampshire, southern England, still has a bad safety record and it was in the news for another fire last week.

            Malcolm

            I don't suffer from insanity I enjoy it!
            Mene, mene, tekel, upharsin
            The writing is on the wall.

            --- On Tue, 5/21/13, a3sigma <dcclark111@...> wrote:

            From: a3sigma <dcclark111@...>
            Subject: [GrizHFMinimill] Re: Milling titanium on a small mill
            To: GrizHFMinimill@yahoogroups.com
            Date: Tuesday, May 21, 2013, 2:49 PM

             

            As Ian suggests, the type of alloy makes a huge difference. In a 30 year career at NASA, I've machined a lot of titanium. The most common alloy used in aerospace, Ti6Al4V, is not so different from stainless steel. Some others are hellishly tough to machine.

            However, I strongly advise against doing anything with "mystery metal". If the chips are igniting, there is a real possibily you've got a magnesium alloy. That, and other metals, can be dangerous to work with and require expert knowledge and technique. There can be serious issues with reactivity and toxicity.

            Knowing what you're working with is as important as knowing what you're doing. And you can't know what you're doing, unless you know what you're doing it to.

            David Clark in Southern Maryland, USA

            --- In GrizHFMinimill@yahoogroups.com, Ian Newman <ian_new@...> wrote:
            >
            > Hi Kevin,
            >  
            > My experience of machining titanium is a little different.  I have played with it but never worked with it commercially.
            >  
            > In my experience titanium is not difficult to machine. It has a similar in strength to steel (but with a low Young's Modulus and at less than half the weight) so if you approach the job as if it were a piece of stainless steel rather than a piece of aluminium you will have good results.
            >
            > It has low thermal conductivity so benefits from using flood cooling and so you must keep tools sharp and take care that tools cut and don't rub. This will help prevent galling in flutes and chips welding to the cutting edge causing BUE problems.
            >
            > It cuts equally well with HSS or carbide tooling (C1 - C4 grades are supposed to be best but I have no experience of this). Having said this, the failure mode of the cutting edge tends to be in chipping and as carbide tools are more prone to this they are usually less satisfactory than HSS.
            >
            > It tends to be 'gummy' in the same way as aluminium so care is needed when taking interrupted cuts (i.e. when milling). It is best to use down cutting (or climb milling) so the exit of the cut is on the thinning edge of the chip which encourages the chip to break free rather than stick to the cutting edge.
            >
            > Of course you will probably be using some sort of alloy rather than the pure metal so the above comments might not be appropriate.
            >
            > Ian.
            >
            >
            >
            > ________________________________
            > From: "chrlsmcd@..." <chrlsmcd@...>
            > To: "GrizHFMinimill@yahoogroups.com" <GrizHFMinimill@yahoogroups.com>
            > Sent: Monday, 20 May 2013, 23:48
            > Subject: Re: [GrizHFMinimill] Milling titanium on a small mill
            >
            >
            >  
            >
            > We mill ti at work. I would be surprised of you can pull this off ( but deep down I really hope you can). Coolant, carbide, relatively aggressive feed rates. Ti likes to smear and gall. Treat it like a 316 stainless. I have seen the mills ignite chips when someone forgets to turn on the coolant but never seen a piece of stock go. When you finish throw it in a pan of coke, hook 10 9v batteries in series and anodize it royal blue :)
            >
            > On May 20, 2013, at 6:34 PM, "kaje7777" <kevin.quiggle@...> wrote:
            >  
            > >I'm looking for advice: A friend of mine came across a small piece of titanium, and asked me if I could make something (a small luthier's plane) out of it for him. I think I can do this with just a few simple cuts, but I'm not sure it's a good idea with the tools I have in hand (though I'm will to get carbide end mills, drills, or whatever if necessary).
            > >
            > >Here is what has me worried: As a first simple experiment, I tried fly cutting one surface with a carbide tool. While this worked, the chips tended to ignite even if I took really shallow (0.002") cuts. Aside from the issue of having flaming titanium chips flying everywhere, I'm also concerned that the larger piece might actually ignite from the friction, raising the possibility of having 290 grams of incandescent titanium on my hands.
            > >
            > >I've done a bit of web searching, but haven't found much: A couple of youtube videos and a few statements to the effect that it can be done, but no discussion of how.
            > >
            > >So: Can this be done safely, and if so, what do I need to do?
            > >
            > >P.S.
            > >
            > >Here are the youtube videos I found:
            > >
            > >https://www.youtube.com/watch?v=shWo6h5vF3E
            > >https://www.youtube.com/watch?v=9Ut4FNlEy_A
            > >
            > >
            >

          • kaje7777
            Thanks for the comments all - I feel somewhat encouraged. I was thinking that some kind of coolant might be the answer, but I don t have flood cooling on my
            Message 5 of 9 , May 21, 2013
            • 0 Attachment
              Thanks for the comments all - I feel somewhat encouraged.

              I was thinking that some kind of coolant might be the answer, but I don't have flood cooling on my mini-mill, or even a misting system. Assuming I did use some kind of coolant, I assume I need to use something water-based so it doesn't catch fire on me.

              I don't want to have to buy a coolant system for just this one job. Does anyone have any alternate suggestions?

              P.S.

              I noticed in the youtube videos I linked to that the author was using a minimill with no coolant, and did not seem to be having any problems with chip ignition. Is this just the difference between using an end mill as opposed to a fly cutter, or am I missing something?

              --- In GrizHFMinimill@yahoogroups.com, "cnc sales (hanermo)" <gcode.fi@...> wrote:
              >
              > I havent done it personally but many many clients of mine machined titanium.
              > It was not considered difficult at all, similar to stainless.
              >
              > It needs slow rpm and lots of torque for heavy MRR, but with our little
              > tools I doubt that is an issue.
              >
              >
              > --
              > -hanermo
              >
            • kaje7777
              You raise some excellent points. In fact, I had some doubts that the metal was even titanium initially, but I did a rough density measurement and it came out
              Message 6 of 9 , May 22, 2013
              • 0 Attachment
                You raise some excellent points. In fact, I had some doubts that the metal was even titanium initially, but I did a rough density measurement and it came out about right. (I got a very approximate 4.6 as opposed to 4.43 for Ti6Al4V. My volume measurement was pretty rough, but I think close enough to say the metal is really Ti (or a Ti alloy).

                On the other hand, the ignition of the chips was spectacular enough that I stopped milling pretty quickly.

                I'll definitely have to give this some serious thought.

                Thanks again for the advice.



                --- In GrizHFMinimill@yahoogroups.com, "a3sigma" <dcclark111@...> wrote:
                >
                > As Ian suggests, the type of alloy makes a huge difference. In a 30 year career at NASA, I've machined a lot of titanium. The most common alloy used in aerospace, Ti6Al4V, is not so different from stainless steel. Some others are hellishly tough to machine.
                >
                > However, I strongly advise against doing anything with "mystery metal". If the chips are igniting, there is a real possibily you've got a magnesium alloy. That, and other metals, can be dangerous to work with and require expert knowledge and technique. There can be serious issues with reactivity and toxicity.
                >
                > Knowing what you're working with is as important as knowing what you're doing. And you can't know what you're doing, unless you know what you're doing it to.
                >
                > David Clark in Southern Maryland, USA
                >
                >
                >
                > --- In GrizHFMinimill@yahoogroups.com, Ian Newman <ian_new@> wrote:
                > >
              Your message has been successfully submitted and would be delivered to recipients shortly.