Printed gears?

[wm3798]

I'm curious if anyone has had any success using a 3D printer to create gears. I have a growing collection of steam locomotive Hulk's that suffer from cracked gear syndrome. I would be willing to provide donor parts for scanning and would be happy to test the results. I can't help but think there would be a market for this to resurrect the huge volume of models that are out there laying in junk boxes.

At the same time I don't think it would be cost-effective for a manufacturer to have to go into production for large quantities of them.

 But I don't know enough about 3D printing to know whether something as refined and precise as a gear can be successfully replicated.

Any thoughts?

[C855B]

Yes: https://jamestrainparts.com/shop/replacement-gears/

James has been doing them for a while, in Shapeways "fine detail". I think it would be a natural for the Photoners among us. IMO the Photon resin is stronger and smoother, and much more suitable for this application. It certainly holds precision dimensions well.

The primary challenge is the R&D. The cracked gear problem in the first place is poor engineering of the original plastic relative to being jammed on a metal shaft. A thousandth of an inch can make the difference between a press fit that runs reliably today and one that cracks months or years down the road.

[wm3798]

Excellent!  Thanks!  Not unreasonably priced for an experiment...
There are a lot more Bachmann designs, though, that still need attention.  I'm thinking their early Spectrum diesels, Plus F units, and the ubiquitous 0-4-0 ...

[wm3798]

My order has been processed!  The OOPS man will be here any day with the replacements...  Then I can go back to driving myself crazy trying to get a Bachmann White Box to be worth the cost of the box...

I'll keep you posted on my progress.
Lee

[Sharky_McSharknose]

Excellent!  Thanks!  Not unreasonably priced for an experiment...
There are a lot more Bachmann designs, though, that still need attention.  I'm thinking their early Spectrum diesels, Plus F units, and the ubiquitous 0-4-0 ...

Add the early-run E-R Models Sharknose units to that list since they were made in a Bachmann factory. I wonder what kind of engineering could be done with 3D printed gears to reduce the gear "growl" these units are known for.

[C855B]

Wow. Shapeways in a week!

Yes - I'm really curious how these work. James did a gear insert for the C855 conversion to extend the driveshaft and it's been good so far.

[narrowminded]

Excellent!  Thanks!  Not unreasonably priced for an experiment...
There are a lot more Bachmann designs, though, that still need attention.  I'm thinking their early Spectrum diesels, Plus F units, and the ubiquitous 0-4-0 ...

Most Bachmann gears (and many others) are mod 3.0 and as a result, if the tooth count is correct the gear can be used, often as is but can also be modified to fit.  An example of interchangeable axle gears that I know work is the Plymouth 3 axle and the 0-4-0. 

I suspect there are just one to maybe three axle gears that would cover the majority of Bachmann locos but I don't know that for sure nor do I have many Bachmann units to measure but If someone does I think it would be worth a look.   And for those that don't have a direct replacement, if you can get the gear teeth right it wouldn't be a huge effort to machine, sleeve, or whatever straight machining it would take to adapt one.

[wm3798]

I have an 040 that I love, and another that's got the shakes.  I'll take it apart to see what's in there.

[narrowminded]

I have an 040 that I love, and another that's got the shakes.  I'll take it apart to see what's in there.

Is one of them the one I sent you for a project?

[wm3798]

Is one of them the one I sent you for a project?

That's the one I love!  I added some weight to it, fashioned some pick ups to use with a new Bachmann all wheel pick up tender, and it runs like a champ!  Slow speed is good, and it glides through insulated frogs with no questions asked.  The other one came from a collection I picked up cheap with low expectations, so if I can fix the cracked gear issue, I'll be happy to modify it into a second reliable runner for the short train roster.

Lee

[narrowminded]

That's the one I love!  I added some weight to it, fashioned some pick ups to use with a new Bachmann all wheel pick up tender, and it runs like a champ!  Slow speed is good, and it glides through insulated frogs with no questions asked.  The other one came from a collection I picked up cheap with low expectations, so if I can fix the cracked gear issue, I'll be happy to modify it into a second reliable runner for the short train roster.

Lee

That might be one of the ones I discovered the Plymouth gear thing with.  I have a few more of those that I inherited.

[Lemosteam]

That's the one I love!  I added some weight to it, fashioned some pick ups to use with a new Bachmann all wheel pick up tender, and it runs like a champ!  Slow speed is good, and it glides through insulated frogs with no questions asked.  The other one came from a collection I picked up cheap with low expectations, so if I can fix the cracked gear issue, I'll be happy to modify it into a second reliable runner for the short train roster.

Lee

Lee, can you share a pic?  s it the one with the full blown PRR A5 valve gear?

[wm3798]

Reporting back...  I installed the new gears, and after a little fiddling with the quartering, I got it to run fairly smoothly... for about a lap and a half.  Couldn't keep the axle nubs to stay in the front gear.  Same problem I had with the stock gears.  I haven't taken it apart to see what's up, but if the shapeways gear cracked, then it's just going in the parts bin. 
It's a shame, really.  It runs smoothly when it runs, but after a little bit, the quartering goes out and that's the end of that.

I guess you just can't overcome a bad design.

Here's the little 0-4-0 that @narrowminded sent me.  I modified the drawbar post with some pickups on each side, and traded in the stock tender for a new one with all wheel pick up.  After adding some bits of weight where I could hide them, she runs like a Swiss watch and can haul 10 cars (newer ones with low friction axles) around the layout for hours.



Lee

[narrowminded]

Here's the little 0-4-0 that @narrowminded sent me...
Lee

That's the one that uses the same gears as a Plymouth 3 axle, and probably many more of the Bachmanns.

[glakedylan]

That's the one that uses the same gears as a Plymouth 3 axle, and probably many more of the Bachmanns.

THESE????

[/size][/font] Gear -Large (N MDT Plymouth) [/t][/c]$2.80 Add: [/size] Max: 10 [/size][/size][/font] [/t][/size][/size][/size][/font] Gear -Small (N MDT Plymouth) [/c]$1.10 Add: Max: 10 Thanks G[/size][/size][/size][/font]