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Re: what HOn3 brass is good?

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  • Laurie McLean
    Rob, HOn3 old brass are good however finding the better running & not worn or faulty is the trick. Try before you buy is my suggestion. Even the old open
    Message 1 of 19 , Jul 1 12:51 AM
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      Rob, HOn3 old brass are good however finding the better running &
      not worn or faulty is the trick. "Try before you buy" is my
      suggestion. Even the old open frame motored locos are good &
      remotoring with a can makes them better. I do not believe flywheels
      make that much difference in HOn3 - a personal thought. The room
      required means a smaller less powerful motor. All wheel pick-up
      started with Blackstones K27 & hopefully all mfr's will follow but
      who knows?
      HOn3 has until now required the modeler to gain the skills necessary
      to "tweak" the locos to get reliability. Annoying things in old
      brass locos were intermittent shorts, poor electrical pick-up,
      binding of moving parts & many more such things. This was the "norm"
      & overcoming these faults made it necessary to learn how to fix the
      many possible problems.
      With the check list you have stated it is a good starting point to
      find the right loco. Running tight curves & long wheel base (2-8-2)
      locos is asking too much from old brass. The tightest curve for the
      majority of 2-8-2 (all drivers flanged) is 20 inches radius & this
      is what most HOn3'ers seem to agree upon - those I know.
      Disappointment starts when tight curves hinder the capability of a
      given loco to operate smoothly on track. Trackwork & how it is layed
      also comes into the equasion.
      So, to put it simply buy from a good hobby shop & test it before you
      buy. The best tests to carry out on a brass loco is to run it around
      a layout over turnouts & around curves. This will show if it shorts
      out on DC but this can't be done at most hobby shops.
      Buying from unknown sources where you can't return it means you are
      stuck with it - often these could be problem items.

      Hope this helps - not looking for critism just trying to be of help.

      Regards

      Laurie
      http://www.nmra.org.au/Layout_Tours/Laurie_McLean/index.html



      --- In HOn3@yahoogroups.com, "Rob" <rdressel@...> wrote:
      >
      >
      > I realize there aren't any new ones coming out, but what of the
      > older stock, like PFM, Westside, United, etc, whom makes great
      > K27's//37's. Other HOn3 ?. There are others I haven't mentioned.
      but
      > anyone go ahead and chime in:
      >
      > My requirements for good running include:
      >
      > 1. realistic speeds for the engine modeled.
      > 2. Flywheel included? nec for smooth operation.
      > 3. all wheel pickup?
      > 4. slow speeds.
      > 5. good pulling ability.
      > 6. good details or better.
      > 7. reliable non rubber band drives?
      > 8. reasonable running on Model rr curves?
      >
    • Dale Buxton
      ... From: Rob My requirements for good running include: 1. realistic speeds for the engine modeled. 2. Flywheel included? nec for smooth
      Message 2 of 19 , Jul 1 5:02 AM
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        --- On Mon, 6/30/08, Rob <rdressel@...> wrote:

        From: Rob <rdressel@...>

        My requirements for good running include:

        1. realistic speeds for the engine modeled.
        2. Flywheel included? nec for smooth operation.
        3. all wheel pickup?
        4. slow speeds.
        5. good pulling ability.
        6. good details or better.
        7. reliable non rubber band drives?
        8. reasonable running on Model rr curves?

        Micro Motors with gear-heads will remedy items 1, 2, 3, 4, and 5 almost by them selves with major plus to number 4. Item 6 is a function of the when the model was produced, with the best detail being from the last ten years or so. 7 has never been observed by me in my 50 plus years and 8 is only a problem of you start going below 22 inch radius with 2-8-2’s or larger wheel bases.

        Item (2) really catches my eye though!

        I know that there are those here that will strongly disagree with this point and have all sorts of trick ways to overcome the problems involved. I can almost hear the keyboards warming up now, but here goes. This little exercise involves physics that can not be argued with and a little trip to visit a guy named Newton and one of his laws of motion, namely; A body in motion tends to stay in motion and a body at rest tends to stay at rest. Gravity and friction have profound effects on bodies in motion. With these laws of physics in mind, it is best to put that flywheel on a double shaft micro-motor with a gear-head on the opposite shaft to whatever final drive to the drivers you have in place or in mind.

        Here is why. Mass and motion are what makes the fly-wheel do it’s work. In our case, instead of work being defined as horsepower it is much more relevant to have our work expressed as ounce/inches. This is not very much work to begin with. So having a high efficiency motor with a low drag and no clogging of the winding segments while in rotation, or what it is referred to in the industry as magnetic-detent, removes much of the drag to the centrifugal force of a fly-wheel in motion than less efficient types of motors would exhibit. The flywheel must also at least equal or better the mass of the motors windings if it is expected continue to spin the drive shaft after power is cut or interrupted for any useable amount of coasting.

        Old Pitman style iron-core motors have too much internal drag and detent to make a flywheel with anything less than the core and windings total mass worth the time of adding a fly-wheel. Many can motors (which also have an iron-core) also share this problem. You need very large fly-wheels to even begin to get effective momentum with these motors. With HOn3 space is always at a premium, so large fly-wheels are push out of the picture from the get-go! Very small open frame motors (Pitman style) and small can motors have so little oz./in. torque at the output shaft and so much proportional friction to their size at the bearings, that they can scarcely power their own cores through even a portion of the windings revolution after power interruption. Putting a fly-wheel in this situation only marginally improves the motors momentum after power is cut or interrupted. There is also the problem of matching the fly-wheel to the motors work capacity and not over
        matching it’s capacity.

        All of these kinds of things are why a little German fellow invented the Micro-Mo in the first place! He quite correctly concluded that friction at mini and micro sizes in electric motors was the most problematic to motor efficiencies at low RPM. The corless motor solved part of that problem. The motor still had nominal and maximum output efficiencies that had to be dealt with and these motors do their most efficient work at higher RPM’s. This is where mating a coreless with a gear-head came in. By mating a gear-head to the coreless motor, the motor was able to be powered up to it’s most efficient RPM and the output shaft could be made to work at a slower RPM than the motor would normally work at efficiently. These a ranges of RPM’s at the output shaft are far slower than Pitman’s and can motors ever imagined working at.

        In our little RR worlds all one needs to do is use one of these high-efficiency coreless motors with a gear-head added on to the main output shaft. The motor will now operate in more of it’s most efficient power range and may not even need a fly-wheel to correct momentary power interruptions. But, by adding a nominally sized fly-wheel to the opposite output shaft, the higher RPM of the un-geared end to the motor can utilize those RPM’s and convert them into centrifugal motion and that in turn into coasting motion when power is momentarily interrupted.

        Putting a fly-wheel in the mechanism just for the sake of having it there will not improve a poor running motors efficiency. Its more like just putting lipstick on a pig. It’s still just a pig.

        I have a pretty firm grasp of this material and am not looking for or needing any criticism here. I just want to help get some facts on the subject out there to help.

        Dale
      • Mark Kasprowicz
        Dale, Interesting mail. I ve added flywheels to any re-motor job I have done simply to give momentary continuity to the motor s rotation when the power supply
        Message 3 of 19 , Jul 1 7:25 AM
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          Dale,

          Interesting mail. I've added flywheels to any re-motor job I have done simply to give
          momentary continuity to the motor's rotation when the power supply is interrupted for a very
          short space of time ie dirt on track. It's the mechanical equivalent of a 'stay alive capacitor'
          which I also fi,t space allowing.
          Is there no merit to a flywheel in this situation and am i wasting, time and brass (in both
          senses of the word)?

          Mark
        • Glenn476
          I have an old PFM SP #9 that is really a good runner--I replaced the motor in the tender with a 1630 Sagami with a flywheel--just fits in the Whaleback tender.
          Message 4 of 19 , Jul 1 8:31 AM
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            I have an old PFM SP #9 that is really a good runner--I replaced the motor
            in the tender with a 1630 Sagami with a flywheel--just fits in the Whaleback
            tender. gj
            ----- Original Message -----
            From: "Dale Buxton"
          • Rich Strebendt
            ... My experience with brass models is that they are great for static display, but are very poor performers on a layout. Brass is manufactured for collectors
            Message 5 of 19 , Jul 1 8:40 AM
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              --- In HOn3@yahoogroups.com, "Rob" <rdressel@...> wrote:
              >
              >
              > I realize there aren't any new ones coming out, but what of the
              > older stock, like PFM, Westside, United, etc, whom makes great
              > K27's//37's. Other HOn3 ?. There are others I haven't mentioned. but
              > anyone go ahead and chime in:
              >
              > My requirements for good running include:
              >
              > 1. realistic speeds for the engine modeled.
              > 2. Flywheel included? nec for smooth operation.
              > 3. all wheel pickup?
              > 4. slow speeds.
              > 5. good pulling ability.
              > 6. good details or better.
              > 7. reliable non rubber band drives?
              > 8. reasonable running on Model rr curves?
              >

              My experience with brass models is that they are great for static
              display, but are very poor performers on a layout. Brass is
              manufactured for collectors and speculators, not for layout operators.
              If you want something that looks pretty and your wallet can take the
              punishment, by all means buy brass. If you want something that runs
              at realistic speeds, operates smoothly at all speeds, pulls reasonably
              long trains on reasonably built layouts, buy white metal and plastic.

              Rich Strebendt
            • Jonathan Zook
              I ll chime in with some of my limited experiences with brass. I ll admit, I only own one brass locomotive, but I spent hours at Caboose Hobbies testing
              Message 6 of 19 , Jul 1 9:47 AM
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                I'll chime in with some of my limited experiences with brass. I'll
                admit, I only own one brass locomotive, but I spent hours at Caboose
                Hobbies testing various brass locomotives from their consignment
                cabinet. Some ran really very well, and some hardly ran at all. It
                was amusing to see that the ones that ran well were often less
                expensive than the ones that didn't run so well. For example, I
                compared a Custom Brass C-21 (the one I eventually purchased) to a
                Precision Scale C-21, and the Precision Scale loco was jerky at best
                on the test track. We constantly had to give it a nudge to make it
                move in either direction. The cost difference between the two was
                nearly $300. There was also a noticeable difference in the
                performance (for the better) of brass locos that were refitted with
                can motors. The staff I worked with at Caboose noted that the
                locomotives which didn't run well probably needed to be cleaned and
                lubricated.

                I purchased a nice running NJ Custom Brass C-21. It was re-motored
                and re-geared by it's previous owner and it's a great little
                locomotive. I cleaned it up and lubricated it, and it pretty much
                runs perfectly on DC power. I ran it on our groups sectional layout
                (now completely dismantled), and the locomotive never once shorted out
                on curves or running through turnouts (#4's and #6's). This little
                guy may be the exception rather than the rule for NJ Custom Brass
                offerings, based on other posts about these models. However, it does
                prove that brass locomotives can be good, reliable runners.

                Now, for some other thoughts. There are at least two manufacturers
                currently importing HOn3 brass models, Precision Scale and Division
                Point. Their prices are hefty, and they're not releasing models which
                any frequency, but they do exist. Caboose lists a Division Point K-27
                #461 with the RGS herald for $1332. I talked with Duncan about this
                model, and he explained that it's pretty much a work of art. It has
                all wheel pickup, a lighted cab, and incredible amounts of detail. On
                top of all of that, it runs as good as any Blackstone or MMI K-27.
                The challenge is that it runs on DC only from the manufacturer, so a
                DCC decoder would have to be installed by the purchaser.

                All that being said, I think brass locomotives are viable as part of a
                fleet on any layout. Sure, they're higher in maintenance and they
                need continuous TLC, but I find that to be part of the fun in the hobby.

                So, there's my 2 cents worth.

                Jon Z.
              • k27freak
                Just a short roundup: - I have 6 Sunset Brass engines, 3 K-27 2, 3 K-36 s - They ran well right out of the box with some minor adustments: (Loosening Pony +
                Message 7 of 19 , Jul 1 11:28 AM
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                  Just a short roundup:

                  - I have 6 Sunset Brass engines, 3 K-27'2, 3 K-36's
                  - They ran well right out of the box with some minor adustments:
                  (Loosening Pony + Trailer trucks, polishing the Tender bolsters
                  & Tender Trucks, cutting one of the springs of the Tender Trucks a
                  little to keep them on the rails at all time.
                  - The slow speed performance is ok, maintenance is easy , they're
                  robust (ask my 4 year old daughter) and I still favor them over any
                  Blackstone or even PSC engine.
                  - That I did was add Faulhaber Motors with Flywheels to all of them.
                  They run even smoother than ever before. My Blackstone K-27 is a
                  coffee mill compared to them
                  - My PSC K-37 needed a lot of work to get her roadworthy, and sh e
                  still isn't fully functional IMHO.

                  - If you want to buy Brass ; Insist on a test drive at your dealer.
                  If the engine runs well, with no wobbling or binding right out of
                  the box, go for it, you can still "pimp" her later with a new
                  Motor and Flywheel.


                  My 2 cents...

                  Boris
                • Rob
                  Thank you Gentlemen, Pretty much what I expected of Brass locomotives, since I have some in N scale that pretty much covers the same issues. My feeling on
                  Message 8 of 19 , Jul 1 11:48 AM
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                    Thank you Gentlemen,

                    Pretty much what I expected of Brass locomotives, since I have some
                    in N scale that pretty much covers the same issues.

                    My feeling on flywheels, they add internia to a motor that doesn't
                    really have much. They (flywheels) also smooth out motor responses,
                    important on layouts with less than optimum clean track. Braking is
                    much more realistic with a flywheel than without.

                    As far as motors go Micro mo makes some great ones.

                    Rob
                  • Jim Vail
                    Totally wrong on that one. Much of the old brass locomotives by Westside, PSC, Overland, etc. runs smooth, quiet and out pulls the newer composite
                    Message 9 of 19 , Jul 1 12:21 PM
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                      Totally wrong on that one. Much of the old brass locomotives by
                      Westside, PSC, Overland, etc. runs smooth, quiet and out pulls the newer
                      composite construction locomotives. The new ready-to-run locomotives
                      are great - and I have and run quite a few. But the older brass
                      locomotives are great too (and I also run many of those.). They are all
                      good locomotives and they all have their proper place on a running model
                      railroad.

                      Jim Vail
                      >
                      >
                      > >
                      >
                      > My experience with brass models is that they are great for static
                      > display, but are very poor performers on a layout. Brass is
                      > manufactured for collectors and speculators, not for layout operators.
                      > If you want something that looks pretty and your wallet can take the
                      > punishment, by all means buy brass. If you want something that runs
                      > at realistic speeds, operates smoothly at all speeds, pulls reasonably
                      > long trains on reasonably built layouts, buy white metal and plastic.
                      >
                      > Rich Strebendt
                      >
                      >
                    • John Stutz
                      Mark asks if flywheels do any good. I believe thy do. But their effectiveness is a matter of mass, and particularly diameter, so it is the larger locomotives
                      Message 10 of 19 , Jul 1 12:22 PM
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                        Mark asks if flywheels do any good. I believe thy do. But their
                        effectiveness is a matter of mass, and particularly diameter, so it is
                        the larger locomotives that are most helped. And if the motor tends to
                        cog, they may hinder starting. So you also need either a coreless
                        micromotor, or a skew wound armature in a can motor. Some of the older
                        straight armature Skagami's, particularly in the smaller sizes, were
                        worse than contemporary open frame motors in this respect.

                        As an example, I have a Westside K-36, the one supplied with a wimpy
                        12mm coreless motor. I mounted a pair of 16mm flywheels on an extended
                        worm shaft, with a 24V 1624 Faulhaber to keep speed down with the 24:1
                        gear ratio. This engine runs dead smooth on only occasionally cleaned
                        track. From full speed, when the power is switched off, the engine
                        coasts it own length. Best of all, it is dead quiet, except for wheels
                        on the rail joints, with just a hint of side rod clank. Of course, it
                        was a very smooth runner to start with, which is more important than the
                        drive line changes.

                        Dale gives some very sound reasons for using micromotors fitted with
                        gearheads to get the speed down. I have tried them, and confirm Dale's
                        results. The double shafted Faulhabers with flywheels on the motor
                        shaft extension, available from Steffen at Stoner Creek, give
                        exceedingly good performance. Dale did not mention the gear noise
                        problem. At speed, with the plastic gearheads of 25 years ago, these
                        locomotives gave a good imitation of an angry bumblebee. The modern
                        gearheads are quieter, but still too noisy for my taste.

                        Hence my experiments with the higher voltage rated micromotors. The
                        alternative is to use a compound gearset with initial worm reduction to
                        keep the gear noise down. NWSL offers a 50:1 gearbox suitable for small
                        HOn3 and N locomotives. It is a little short for mounting flywheels,
                        but should work well with motor and flywheel in the tender. Several
                        English sources offer gearbox kits with ratios in the range of
                        48-108:1. These might need to be altered to suit our ideas. The larger
                        ratios are comparable to using a 3.45:1 gearhead with a 30:1 worm drive,
                        but a ratio of around 70:1 might be better. With a micromotor, and a
                        flywheel on the worm shaft, they could give performance comparable to
                        the gearhead combination. Eliminating the length of the gearhead will
                        allow fitting a much longer flywheel. This is probably the best overall
                        approach for both operating and acoustical performance. It should be
                        relatively straightforward for outside framed engines, but is
                        problematic with inside framed HOn3 engines. And not many of us are
                        really interested in fitting new gears, let alone making our own gear
                        boxes.

                        John Stutz
                      • Mark Kasprowicz
                        ... Glenn, No, I do not think that is true. I have a mix of PFM, Custom Brass, Westside, PSC, Balboa, and Division point locos (and a few others which aged
                        Message 11 of 19 , Jul 1 8:00 PM
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                          > I think that in the seventies Brass turned from good layout-grade models to
                          > collectors'/museum models.
                          Glenn,
                          No, I do not think that is true. I have a mix of PFM, Custom Brass, Westside, PSC, Balboa,
                          and Division point locos (and a few others which aged memory doesn't give me access to at
                          this moment) which pretty well cpvers the 70's to the present day and I think it's either
                          simply down to luck as to whether you get a good running loco (the classic monday
                          morning, Friday afternoon loco) or there are inherent design faults that affects the whole
                          range to a greater or lessor degree. i have some great running locos and some that were
                          pretty bad but could be fixed.
                          I agree with the concept of try before you buy BUT most of the test tracks I have seen are
                          straight with no turnouts or curves which is usually where any problem manifests itself.
                          Also don't assume that a loco that runs OK of Dc with do the same on DCC where the
                          short circuit tolerance is much much smaller.
                          Apart from the very worst of cases, given time, skill, patience and good help, I believe that
                          locos from whatever vintage can be made to work well, perhaps not perfectly, but well
                          enough.
                          One thing i would say about Division point locos, despite their claims, they do NOT have
                          all wheel pickup. My K-28 has pickup on only two of the drivers on the insulated side.
                          Mark
                        • Glenn476
                          my comment was based on a mix of locos I have had direct experience with--either my own or ones I have overhauled and painted. The only importer I haven t
                          Message 12 of 19 , Jul 2 12:08 AM
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                            my comment was based on a mix of locos I have had direct experience
                            with--either my own or ones I have overhauled and painted. The only
                            importer I haven't dealt with that you list is DP. I even have a PSC/Iron
                            Horse K-37 in On3 that a dealer could not unload at cost for five
                            years--After he almost gave it away I wound up with it --found the problem,
                            fixed it. A SamHongSa loco--usually top notch.

                            But my point is that way back--while the locos didn't carry all the detail
                            that today's do, they were designed and made to run, and run well. gj
                            ----- Original Message -----
                            From: "Mark Kasprowicz" <marowicz@...>
                          • Dale Buxton
                            I think it is important to inject here that the Balboa and NJ HOn3 C-21’s where both made by Katsumi. NJ somehow got the rights to import these models when
                            Message 13 of 19 , Jul 2 2:54 AM
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                              I think it is important to inject here that the Balboa and NJ HOn3 C-21’s where both made by Katsumi. NJ somehow got the rights to import these models when Balboa closed it’s doors. The Balboa version is more of a composite of No’s 360 and 361. While NJ actually had Katsumi do the individual tenders and details specific to No’s 360 and 361. Both models have the same exact mechanical problems in design and execution though. The biggest of which is that the counter weight/crankpin connections were soldered on they axle ends and not pressed on. Those solder joints kept breaking loose because of other poor design choices at Katsumi. Like the following: The frames flexed too much; The driver springs were too stiff; The pillow blocks on the axles were round and really should have been square to keep those springs better aligned; The cover plates that held the drivers in the frame where too soft and flexed too much; The rubber tube between the motor
                              shaft and gearbox shaft was too stiff; The motor had three or four mounting screws. If any of these started to move out of perfect alignment the resulting bind would almost always bust those soldered crankpin connections loose.

                              There was a guy (Tom Napp) from Boulder, CO that used work in an aerospace lab, I think it was Ball Aerospace. He had access to fancy tools and equipment that most of us never will and he used to rebuild these models with can motors and would braze the crankpin connections on with silver solder. He used to advertise this in the Gazette about 25 plus years a go. If you have a Balboa or NJ C-21 that is rebuilt with a can motor and it runs smoothly there is a very good chance Tom rebuilt it.

                              After reading Jim Vail’s tune up points on the PSC C-21’s it becomes clear to me that those models really were pointed directly at the collectors and no one else. Especially not operators! To be begin with, there were only 42 of each engine produced. There were also numerous little fiddley-bits of detail parts that made collectors go Oooo and Ahhh but many of those parts were just oversize enough or hanging in places that made operation almost impossible and electrical shorts that would make a guy want to pitch rocks at them. From what I hear though, if you have great patience and electo-mechanical skills, they can be made to run quite smoothly but are seriously under powered. Nope… These are collectors models and not ones for operators.

                              Dale
                            • ebt18
                              Dale, What would you recommend for RPM on a coreless motor with gearhead? When I shop for can motors, they provide the RPM but I don t know enough about motor
                              Message 14 of 19 , Jul 2 3:52 AM
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                                Dale,

                                What would you recommend for RPM on a coreless motor with gearhead?
                                When I shop for can motors, they provide the RPM but I don't know
                                enough about motor speed to make a good decision.

                                Russ

                                --- In HOn3@yahoogroups.com, Dale Buxton <the_one_tuatha_ddana@...>
                                wrote:
                                >
                                >
                                > This is where mating a coreless with a gear-head came in. By mating a
                                gear-head to the coreless motor, the motor was able to be powered up to
                                it’s most efficient RPM and the output shaft could be made to work at
                                a slower RPM than the motor would normally work at efficiently. These a
                                ranges of RPM’s at the output shaft are far slower than Pitman’s
                                and can motors ever imagined working at.
                                >
                                >
                              • ebt18
                                I have three Hallmark brass EBT engines -- #14, #18 and the M-1 motorcar. The steamers have a reputation for being good runners, even though they were
                                Message 15 of 19 , Jul 2 3:57 AM
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                                  I have three Hallmark brass EBT engines -- #14, #18 and the M-1
                                  motorcar. The steamers have a reputation for being good runners, even
                                  though they were imported 20 years ago. I would agree with the
                                  sentiment here expressed that you have to pick and choose your brass --
                                  but in some cases (like the EBT) you really only have one other choice,
                                  and that's to build your own. I don't see Blackstone manufacturing any
                                  of the EBT mikados in this lifetime.

                                  Russ

                                  --- In HOn3@yahoogroups.com, Jim Vail <akacoot@...> wrote:
                                  >
                                  > Totally wrong on that one. Much of the old brass locomotives by
                                  > Westside, PSC, Overland, etc. runs smooth, quiet and out pulls the
                                  newer
                                  > composite construction locomotives. The new ready-to-run locomotives
                                  > are great - and I have and run quite a few. But the older brass
                                  > locomotives are great too (and I also run many of those.). They are
                                  all
                                  > good locomotives and they all have their proper place on a running
                                  model
                                  > railroad.
                                  >
                                • John Stutz
                                  ... Depends on how fast you want to go, and how big a motor you can fit in. Small short ones tend to go faster, while fat long ones tend to run slower.
                                  Message 16 of 19 , Jul 2 5:42 PM
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                                    ebt18 wrote:
                                    >
                                    > Dale,
                                    >
                                    > What would you recommend for RPM on a coreless motor with gearhead?
                                    > When I shop for can motors, they provide the RPM but I don't know
                                    > enough about motor speed to make a good decision.
                                    >
                                    > Russ
                                    >









                                    Depends on how fast you want to go, and how big a motor you can fit
                                    in. Small short ones tend to go faster, while fat long ones tend to
                                    run slower.

                                    Faulhaber micromotor specs are at
                                    http://www.faulhaber-group.com/n110828/n.html -> products -> coreless motors

                                    As an example, suppose you have 44 inch diameter drivers and want to do
                                    40mph at 12V. One mile per hour is 88ft per minute. You want an axle
                                    rpm equal to the speed in feet per minutes, divided by driver
                                    circumference in feet: (88 * 40 ) / ( 3.14 * 44/12) = 306rpm. It is
                                    the same calculation for real feet or scale feet, so long as you
                                    consistently use one or the other. Now assume this is an old PFM K,
                                    with their standard 30:1 worm drive. You want a worm shaft speed of 306
                                    * 30 = 9080. For useful size Faulhabers, the no-load speeds run from
                                    8000 to 16000rpm, and you can expect to make 80-90% of no-load speed at
                                    the rated voltage under load, so a 1331 or 1524, directly coupled,
                                    should do nicely. These are nominal speeds for the size families.
                                    Check the specification sheets for actual 12V motor no-load speeds.

                                    Gearheads only come into play if you want significantly lower top
                                    speeds, or are limited to the smaller motors or to low final worm
                                    ratios. There the problem is the lower limit on gearhead ratios: 3.45:1
                                    for the offset spur gearheads, 4:1 for planetary gearheads, and 6.3:1
                                    for centered spur gearheads. It can be hard to get a fast enough over
                                    the track speed, without going to a very fast motor and potentially very
                                    noisy gearhead. The NWSL 50:1 gearbox may be a big help here, at
                                    least for the smaller motors. Note that the spur gearheads slip over
                                    the motors, adding about 1mm to the overall diameter. The NWSL 15:1
                                    Flea gearbox may also be of use.

                                    A better solution may be to go to a 15V or 24V rated motor. Coreless
                                    motor speeds are very linear with the applied voltage, so one rated at
                                    10,000rpm at 15V will do about 8,000rpm at 12V, and it won't be
                                    overloaded if you actually have 14V on the track. You won't be running
                                    at maximum efficiency, but these things draw very small currents, and so
                                    long as you use the largest that will fit into your engine, overloading
                                    is unlikely. With direct drives, an idler gearbox that places the
                                    motor level, will allow putting flywheels on the worm shaft. Also, with
                                    direct drives it will be a good idea to use a shaft coupling that allows
                                    for lengthwise relative motion, since the motor bearings are not
                                    intended to stand up to worm thrusts.

                                    Sources are a problem. You can buy OEM, but prices are high. Steffen
                                    at Stoner Creek offers a considerable range of conversions designed for
                                    specific HOn3 and HO engines, some bare and some with gearheads, and
                                    most with flywheels on extended motor shafts. He is the only source I
                                    know of for the double shafted Faulhabers. The Schwendlers at
                                    Coronado Scale Models in Phoenix once stocked and may still handle
                                    Faulhabers, and should be considered if you want to specify your own.
                                    Roundbell now has several conversion sets available, some of which can
                                    doubtless be adapted to other locomotives. His are all direct drive,
                                    using voltage de-rating to get a good speed range. Motorman offers a
                                    variable range of surplus micromotors from a variety of sources. he
                                    also offers to rebuild gearheads for specific ratios. Nigel Lawton
                                    (England) offers his own line of 6 and 10 mm motors suitable for very
                                    small equipment. His web site describes some very interesting
                                    applications. And if you live in any of the high tech areas, it is
                                    well worthwhile to periodically check out the local surplus stores.
                                    Just make sure you know what you are buying before putting your money
                                    down. I have a bunch of 6V micromotors, if anyone is interested.

                                    John Stutz
                                  • Craig Symington
                                    Russ ... I created this tool for myself to help with this very question... http://www.riograndesouthern.com/RidgwayShops/DriveTrainCalc.aspx Craig Symington.
                                    Message 17 of 19 , Jul 2 5:49 PM
                                    • 0 Attachment
                                      Russ

                                      > What would you recommend for RPM on a coreless motor with gearhead?
                                      > When I shop for can motors, they provide the RPM but I don't know
                                      > enough about motor speed to make a good decision.

                                      I created this tool for myself to help with this very question...

                                      http://www.riograndesouthern.com/RidgwayShops/DriveTrainCalc.aspx

                                      Craig Symington.
                                      http://www.riograndesouthern.com/
                                    • Dale Buxton
                                      Thanks Craig,   I just back channeled this very valuable and useful link to Russ. And thank you again for creating and sharing it!   Dale Buxton ... From:
                                      Message 18 of 19 , Jul 2 10:42 PM
                                      • 0 Attachment
                                        Thanks Craig,
                                         
                                        I just back channeled this very valuable and useful link to Russ. And thank you again for creating and sharing it!
                                         
                                        Dale Buxton

                                        --- On Wed, 7/2/08, Craig Symington <rgsnut@...> wrote:

                                        From: Craig Symington <rgsnut@...>
                                        Subject: [HOn3] Drivetrain Calculator
                                        To: HOn3@yahoogroups.com
                                        Date: Wednesday, July 2, 2008, 6:49 PM







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