Got my little prototyping machines up and running.

[Chris333]

Over time those belts will loosen. You might want to air erase the pulley so the belts grip longer.

[narrowminded]

Over time those belts will loosen. You might want to air erase the pulley so the belts grip longer.

Yes, stretch is often an issue in these services and was known as a potential issue going in.  Especially if they were Buna or other commonly available off the shelf O rings, even some of the specialty ones.  Also depending on the force being transmitted which in this case just isn't much.  The belts were made specifically for this application and of a compound, durometer, and cross section specific to this service.  They are actually custom from start to finish.  They are resistant to that effect, start fairly loose and will cause trouble if too tight.  And due to position in the train, they are tolerant of what little stretch/ set occurs.  (It's nice to have access to "experts" in various industries from my previous life in industry.)    They are oil resistant, can be washed in alcohol, most solvents, soap and water, and unless stretched more than about 10% in service, should be good for a long, long, time.

This and motors were two of my early concerns and consumed the bulk of my attention, extensively testing various options before to move ahead with flushing out the balance of the design as it exists.  Testing of drive configurations even included extremely thin cross section flat belts that I ground in a lathe, starting with hose stretched over a mandrel.  (And there's another one that I haven't totally dismissed yet and will keep under hat as I may find use for it yet.)    I also recognize that a belt will meet with some resistance from those with legitimate concerns from historical experience with "belts" (that were not much more than rubber bands) but my testing at literally thousands of hours on one of these belts specifically made for this have those concerns covered to my total satisfaction.  And finally, worst case, it can be replaced.  The recommended tool would be a toothpick and "don't stretch the bejeesus  out of it".  I already have literally thousands of them on hand from a minimum run.  You get a lot of little belts out of one batch of mixed up concoction.    And they have a material shelf life of easily 15 years and in reasonable atmospheric conditions, much longer.  How much?  I don't know nor did my "expert".  In proper storage, "a really long time" was his answer to that question.   And a zip lock bag on the shelf in the cupboard was considered "proper storage".   One drawback is, if you need another size, which I will probably wish for one or two more as the configurations in mind are pursued, then get your wallet ready.  If you need a bunch (read thousands and up) it's tolerable per piece but for just a few or on a whim.... OUCH!

You'll have to see one of these as they come together.  I always figured you'd be one to get a kick out of this from my earliest searches that had your exquisite stuff popping up everywhere.    You still have some of my favorite bits and scenes. 

[mmagliaro]

narrowminded, You get an A+ for patience, engineering, and excellent precision assembly!   
Let's all take a step back and think about how much work, and rework, and testing, and experimentation it took for that power truck to get this far.  REALLY nice work, man!

That little power truck could have so many applications.    I'm thinking a true, workable, steam 0-4-0.  With the added tender pickup, there would be no concerns about switch frogs.  How possible is it to put 33" wheels on that thing and use it as a powered steam tender truck?

[Maletrain]

Really nice work!

I am thinking coal mine electric loco.  Yout tipper cars are already that application.  Where did you get those cars?  They look better than what I have seen elsewhere.  Are they Shapeways prints?  How can I get some - with wheels?

[u18b]

I'm impressed with all of it, but I REALLY like the powered mechanism.

Where can I find more info of what you did there.

I have 2 or 3 critters I need to make one day.

[narrowminded]

narrowminded, You get an A+ for patience, engineering, and excellent precision assembly!   
Let's all take a step back and think about how much work, and rework, and testing, and experimentation it took for that power truck to get this far.  REALLY nice work, man!

That little power truck could have so many applications.    I'm thinking a true, workable, steam 0-4-0.  With the added tender pickup, there would be no concerns about switch frogs.  How possible is it to put 33" wheels on that thing and use it as a powered steam tender truck?

Thanks Max.  That's high praises from you and I appreciate it.  I've voiced a similar appreciation watching your projects even if that didn't always come across clearly.

I have a few hundred 33" and 24" nickel silver wheels already run for both Nn3 (Z) and N scale and also have 26" in N for my PCC project (and a few sets of tungsten wheels for testing. An extra gram + on a set of four.)   As I go, if the demand is there, I can have whatever size wheels folks might want and VERY in spec. 

None of the wheels I now have on hand have the faces finished other than flat machined as it is intended to machine those details as needed.  If they are hidden they may be left plain faced (keep all of the weight possible) but when visible they will be at least dished and from there will be 24" with drilled holes, a taper with a small hex in the center for the PCC, and whatever else is needed, actually.  I may still be able to machine spoked wheels depending on size but that's not on my current schedule and unless it's for me and/ or done in quantity, it may be a little too pricey.  (I've seen what people think is a "lot" and can include myself in that group, probably more than my knowledge should allow.)  

I still have the mining loco body (or bodies) to detail and choose materials and construction methods for but I wasn't really sure what the final chassis was going to have going, especially in final dimension and weight, and where a gram or two might be the difference between perfect and pretty good.  To the extent possible I'm going for function first and cost second.  It would be nice to have all of the desired weight in the chassis and be able to use a 3D print, resin, or even molded plastic but I may really want/ need metal.  I'm testing weights vs: performance at each step and each configuration and I'm often right at the cusp.  At the point where even a gram or a few will be the difference between really reliable and maybe pretty good  I will continue to opt for really reliable.  As this shows, I'm still very much in the development stages BUT I can finally move things along whereas, until now, I've seen months go by while I was waiting for a small detail cut, part, or small change to test, with progress stalled until that was tried and proven.  Then the next detail and a few more months wait.  I had to do something.

[narrowminded]

Really nice work!

I am thinking coal mine electric loco.  Yout tipper cars are already that application.  Where did you get those cars?  They look better than what I have seen elsewhere.  Are they Shapeways prints?  How can I get some - with wheels?

Coal mine loco is EXACTLY what started all of this.   And those are Shapeways prints from Roy Stevens.  They are very delicate but work well and have tracked well through switches and all with no more weight than a set of metal wheels.  Fox Valley is what I used, 33" Z scale. 

I really like the style but being that they are made to Nn3/ Z standards, the couplers are actually very high for what I'm doing as the couplers will wind up hanging way high, almost into the operator's cubby hole.  They should only be a foot or even less from the rails and Z is at... I forget right now but it's a lot more.   What i need is to arrive at a variety of cars with link and pin coupler at a standard height for my stuff and then have the option for those who really need to use standard height.  A Z height coupler won't look right on a typical trolley/ battery mine loco. 

I've actually come up with a link and pin with automatic coupling capability on the loco.  Possible to drop a string of tippers, pick up some man trip cars, or pickup some little flats for maintenance or underground supplies.  You could actually run ops.   It's slick to see it and it's simple, too.  But I'm talking ahead of myself here.  But it has been done and tested.  OK, time to shutup.

[peteski]

  It would be nice to have all of the desired weight in the chassis and be able to use a 3D print, resin, or even molded plastic but I may really want/ need metal.  I'm testing weights vs: performance at each step and each configuration and I'm often right at the cusp.  At the point where even a gram or a few will be the difference between really reliable and maybe pretty good  I will continue to opt for really reliable. 

You could design the loco body on your computer, have it 3D-printed in wax, then use lost-wax investment casting to cast if in brass. @robert3985 had some N scale items investment-cast and he made it sound fairly easy and affordable. Brass is quite dense so the body should add a decent amount of weight to the model.  Or maybe even cast it from lead?

[narrowminded]

You could design the loco body on your computer, have it 3D-printed in wax, then use lost-wax investment casting to cast if in brass. @robert3985 had some N scale items investment-cast and he made it sound fairly easy and affordable. Brass is quite dense so the body should add a decent amount of weight to the model.  Or maybe even cast it from lead?

I've considered that and if I was just making one or two might find it very acceptable but honestly, I'm not too comfortable with the detail quality of that process and deathly afraid of having an outside supplier in the mix that doesn't "need" what I suspect will be some smaller orders on such a key part of the whole thing and repeatable over time.  And in these small sizes, if it still means adding detail parts or much hand cleanup at all, which is likely, then maybe it's worth a little more effort up front and in house?  This is my feelings here but also, by style, based in general manufacturing experience.  At this specialty product level you should make every effort not to sub your main product.  Excess needs, sure, but not the entire ability.  That seems fundamental to me.  When it's working all seems fine and in fact IS fine but when it goes wrong it can be disastrous.

I'd love to be able to use a 3D print, especially if that newer Shapeways material proves viable but in the event that I choose to go metal I'm seriously considering lead free pewter and also making machined metal permanent molds.  And totally in house.  Maybe assembled from sides or the more complex approach with retractable die parts.  It really goes with volume as the tooling is the cost and each method has its break even point.  Unfortunately, the good processes are often higher than the market that exists... or is it?  I will have to decide one of these days. 

I might even try the rubber mold route but not having direct experience with that, am concerned as it runs right at the edge of the material limits and I get very mixed reports on that when I research it.  For a few prototypes it might be useable but in any quantity, even just double digits?  Not so sure.  I have also seen widely varying cosmetic qualities in the pewter cast parts I have seen.  It'll be worth a try as I have a vacuum pot, a lead pot, a pressure pot, several flower pots... (oops) and will surely have at least some parts to do in the whole mess that can utilize that process.  So even if it doesn't prove out for this it won't be a wasted effort.  All part of the learning curve.  I'd love to be able to pick the brain of someone truly experienced in the different pewter processes but I'm getting to the point where I may just have to jump into the pool and will get my answers in pretty short order.  At this point that might be the quickest way past that hurdle.  And as I said, the effort won't be wasted as I'm sure those processes will be viable for at least some things I'm doing.  I'm still up in the air on this but have a decent shopping list of processes to choose from. 

I've followed most all of the Shapeways threads with an ear to the skuttlebutt.  Some of it won't hurt me in my application but some might.  And I really am not satisfied at all with FUD for the loco body.  Especially the material strength.  I will probably use 3D for little cars that are free standing, relatively low cost, almost throw away pieces, but not on the much more involved loco.  Maybe I'm also showing where my obsession has fallen.

Thanks for your interest Pete.  You have demonstrated a really good understanding of a lot of technical "things" so i'm always happy to hear your thoughts.  I do appreciate any and all suggestions. 

[narrowminded]

Nice .. what equipment did you get?

Sorry I didn't answer this yet but I'm actually struggling a little with what would be a worthwhile or useful response.  The basic machines are a Proxxon MD-70 (high speed spindle main reason for that choice, then size and price), a drill press stand and Proxxon motor (also high speed spindle) with X-Y table, same as on the mill, and a Seig 7" lathe.  Also a little 1/2 ton arbor press that's getting trued and squared ends as well as adjustable travel stops to accept all sorts of small, specially designed original tools for punching, forming, broaching, and whatever else enters the imagination, including maybe a simple press job.

But really, while those machines matter at some level I would suggest that they are like buying a kit and that they need finished.  And with both of these hobby machines there is some literal truth to that, especially the Chinese made lathe.  Basics are there but it needed virtually disassembled and re-assembled with many small alignment issues, gritty dirt EVERYWHERE it should NOT be, even shimming the table feed gear box and and moving the whole lead screw positioning to get it running true and proper.   It's really understanding what and how machine tools work, acquired through study and unavoidably, experience. 

That dictates what many tools will be needed to make the machines usable and that cost will be at least the price of the machines and maybe some more.  I spent more there but am using these for some varied and pretty precise work.  Cutters, drills, centers, 3 jaw and four jaw chucks, collet closer for the lathe and mill, quick change lathe tool post and holders, indexable carbide insert holders and inserts as needed.  Parting tools, table locks, travel stops, indicators, digital readouts, power table feed, boring bars, live tool holder for the lathe, rotary table(s) and second X-Y table to use in conjunction with the rotary tables (and sometimes the arbor press).  Measuring tools including pin gauges, every thousandth from .010"  through 1/4", over 100 carbide 1/8" shank drill sizes up to about 1/4" size in increments of .002" or less, and etc, etc.  Then customizing them as needed with adjustable stops for the vise, home made edge finder and indicator mount  for cutter and part setup as none exist that are small enough to work in the small windows that these have.  (BTW, that could be a business to itself and no, Little Machine Shop doesn't have any but sure could sell them if they did.) 

As my main shop customer said in this discussion as I was telling him what I was doing, "Hobby machines aren't the problem making good parts. It's hobby machinists that are."  That's short and brutally to the point but it's also pretty much the truth.  And that's NOT to be arrogant about it but it is just facing the facts of the matter.  Something that's an acquired skill has a never ending learning curve and it's not an affront to anybody who is on the early end of that curve to suggest that they might not be able to get the same results from a machine, regardless of the basic machine quality, without the experience.  That concept holds true across many facets of life.  And in fact, he and I were both there at one point and part of why I get called by him is couched in this statement.  I'm older and have been there many times.  I've seen his progress in leaps and bounds over the ten or so years that we have collaborated on projects.  We have many laughs over our past experiences that we never admit happened to us, but "I know a guy.."   And I taught him that, too.

I would encourage anybody who has an inkling to give machining a go to do so.  Expect to have a lot to learn, find a mentor if you can, and don't be afraid to ask her a lot of questions.

[nkalanaga]

Looking at that GP20D on the Weekend Update page, and at my "modern" narrow gauge, I wonder if you could make replacement trucks for N standard gauge mechanisms?  An RS-1/2/3 was very similar to Alco's multi-gauge export diesels, and RSD-style trucks for Nn3 would make the mechanisms just as useful for modelers.

[narrowminded]

Looking at that GP20D on the Weekend Update page, and at my "modern" narrow gauge, I wonder if you could make replacement trucks for N standard gauge mechanisms?  An RS-1/2/3 was very similar to Alco's multi-gauge export diesels, and RSD-style trucks for Nn3 would make the mechanisms just as useful for modelers.

Never say never and I do have various RS units.  I'll give it a look but have a lot on my plate right now just finishing what I started a couple of years ago.  Did you have a particular model(s) that you'd like to try?  I may have one and could look at it specifically.  Maybe a whole new truck but also might rework existing parts with a new sub frame/ insert type deal using the existing frame, installation method, and drive components.  It can probably be done but at what effort?   

[Nato]

        This is wonderful wonderful work. Nate Goodman (Nato). 

[sd45elect2000]

https://www.shapeways.com/product/QFKWTQAKF/cnsm-battery-loco-455-456?optionId=14304668

https://www.shapeways.com/product/X7EQNMB9B/cnsm-electric-loco-452?optionId=16319979

I need to motorize these little guys, Any chance ?

Randy Stahl

[narrowminded]

https://www.shapeways.com/product/QFKWTQAKF/cnsm-battery-loco-455-456?optionId=14304668

https://www.shapeways.com/product/X7EQNMB9B/cnsm-electric-loco-452?optionId=16319979

I need to motorize these little guys, Any chance ?

Randy Stahl

That looks like a good candidate.  And if not the current one in development, the next version that will be lower yet.  I should get one and try it.  Is that special still on?