Hello All,
After trying to source replacements for cracked axles and worm gear couplers on several diesel locomotives- -both in and out of production, without success I began thinking...
...Yes, I know that can be dangerous!
My question to fellow forum members:
Do you think these parts could be 3D printed?
Thoughts?
Recommendations on 3D printing services?
Thank you in advance for your comments.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
I don't know anything about the printing, but you said you had cracked worm gears as well?
Would you mind sharing with us wjat locos you need parts for?
What printed things I have bought, I searched for a dealer on Shapeway's web site.
Mike.
My You Tube
mbinsewi...you said you had cracked worm gears as well? Would you mind sharing with us what locos you need parts for?
The failed part(s) is/are not the brass worm gears.
It's the plastic coupler, press fit on the metal worm gear shafts to the dogbone, that fails.
They are all Bachmann diesels: GP40s & GP30s.
Bachmann doesn't sell the worm gear assembly with the plastic coupler- -the failed part- -as a separate item.
This part is included in the larger assembly of the Truck Gearbox (HO GP40/GP50/Universal).
At $6.50 each, to harvest the replacement worm gear and coupler, adds up.
I have four GP40s and three GP30s that have had at least one of these worm gear couplers cracked and needed replacement.
Now I have eight of these Truck Gearbox assemblies, minus the worm gear couplers that I have no use for.
I contacted Bachmann to see if the worm gear coupler assembly was available in bulk.
The response was that just buying the singular part was not an option and directed me to the entire Truck Gearbox assembly, which is currently sold out.
I also have an Athearn Blue Box SW 1500 with cracked plastic axles (Part #40023- -discontinued).
The wheels press into the plastic axles but the diameter of the O.E.M. axles are larger than anything currently available from Athearn.
I ordered what I thought would be a substitute from them but they don't fit.
That's why I'm considering 3D printing of these specific parts.
Again, thank you for your question, and...
The Athearn site says preorder, Due late May, 2021. ATH60024 Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
jjdamnitIt's the plastic coupler, press fit on the metal worm gear shafts to the dogbone, that fails.
Have you looked at the A-Line drive shaft parts?
https://ppw-aline.com/collections/miscellaneous-re-powering-parts
Scroll down.
Athearn SW universals:
https://www.shapeways.com/product/UN6A8NTEG/assembly-drive-athearn-sw7-replacement-driveshaft?optionId=65766288&li=marketplace
Good Luck, Ed
You might also want to consider NWSL. Given the volume, it justifies a phone call (I assume they still answer the phone - the previous owner did).
In all cases, it will not be cheap.
Simon
Thank you for all your great responses.
RR_MelThe Athearn site says preorder, Due late May, 2021. ATH60024
As I posted...
jjdamnitThe wheels press into the plastic axles but the diameter of the O.E.M. axles are larger than anything currently available from Athearn. I ordered what I thought would be a substitute from them but they don't fit.
Unfortunately, the current replacement parts from Athearn are not a viable option.
gmpullmanHave you looked at the A-Line drive shaft parts?
Yes, I have three sets of them and nothing is compatible.
I apologize if I didn't make it clear that I have two separate problems from two manufacturers:
The first is with Bachmann.
It's the plastic coupler from the worm gear shaft(s) to the dog bone drive shaft(s) that has cracked.
This coupler is not available as a separate O.E.M. part.
Bachmann only sells this part in a larger sub-assembly, which is currently out of stock.
I only need this specific press-fit coupler, not the entire sub-assembly that I have harvested this specific part from, and have a surplus of un-needed gear towers.
The second is with Athearn.
Which is the plastic axel.
The older 42-inch wheels have a larger diameter spindle, that presses into the geared axel, than any currently available replacement parts, is cracked.
I have purchased several replacement wheelsets from Athearn and none of them fit- -adding to the useless parts bin, and lost monies.
This is why I am exploring the options of 3D printing these specific parts.
mbinsewi...on Shapeway's web site.
Thank you for this suggestion and I will look into this option.
snjroyYou might also want to consider NWSL. Given the volume, it justifies a phone call (I assume they still answer the phone - the previous owner did).
I looked at their website and was further frustrated by the lack of visual information. I know what these parts look like but the written descriptions are not helpful.
I apologize if my responses are terse and show my frustrations.
snjroyIn all cases, it will not be cheap.
Yes, I realize this. The first run is always the most costly.
But, if other modelers are encountering the same problems, producing in bulk might be a viable cost solution.
I do not want to be a "distributor" of aftermarket components, I just want to run reliable motive power.
Again, thank you for all your great responses, keep them coming and...
I found some Model Power axle gears on Shapeways (about 5 yrs ago) and one cracked as I attempted to install it the other only ran a few hours (over a weeks time) and cracked. I finally got some that worked (still OK) I think from NWSL.I read on another forum to drill out the Shapeways gears and use super glue (CA) on the shaft, haven’t tried that myself. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
RR_Mel...to drill out the Shapeways gears and use super glue (CA) on the shaft, haven’t tried that myself.
Thank you for your suggestion.
I'm thinking, even with 3D printed parts, there will be some hand tooling to get them to fit.
Again, keep the great comments/suggestions coming.
If the older axles are larger in diameter than the 60024 gear you might tri drilling it out and using CA.CA is amazing, I glued a axle gear on my Bachmann 2-6-0 G gauge locomotive back in 2005 and it still works like new. The locomotive was under warranty and Bachmann sent me a replacement wheel set with the gear but since it’s still working OK it is still in the package. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
I just want to begin by thanking all of you for your great suggestions and invoking all of your knowledge.
RR_MelIf the older axles are larger in diameter than the 60024 gear you might tr(y) S.I.C. drilling it out and using CA.
I considered this but the amount of material on the newer axels won't allow me to bore out the needed clearance for the older axel shafts without failure of the thinner walls after "machining".
This is why I'm considering, despite the initial price of tooling, 3D printing options.
Thank you for all your input and...
With all of the dog bone types of connectors that NWSL has you can build your own dog bone- the sets are not that expensive. Just measure you shaft size and go from there.
I think that I keep 5 or 6 sizes in my parts bin for re-motoring jobs.
Swap the wheels out with the smaller 40" wheels, since it's a switcher and shouldn't have 42" wheels anyway? Can use Athearn parts, I did an Athearn switcher years ago with NWSL's replacement wheels, which I'm not sure they make any more. Though these were sized to press fit the stock Athearn axle gears.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Being a printing process rather than a forming process, would 3D printed gears and axels actually be strong enough?
It takes an iron man to play with a toy iron horse.
woodoneWith all of the dog bone types of connectors that NWSL has you can build your own dog bone- the sets are not that expensive. Just measure you(r) S.I.C, shaft size and go from there.
Yes, you'd think that would be true.
As I've previously posted, the current NWSL webpage only has written descriptions...
jjdamnit snjroy You might also want to consider NWSL. Given the volume, it justifies a phone call (I assume they still answer the phone - the previous owner did).
But...
jjdamnitI looked at their (NWSL) website and was further frustrated by the lack of visual information. I know what these parts look like but the written descriptions were not helpful.
Shapeways seems to be the folks to reach out to and see if this is possible.
MisterBeasleyBeing a printing process rather than a forming process, would 3D printed gears and axels actually be strong enough?
Great point!
That's why I'm reaching out to see if a material in 3D printing will be sufficient.
Thank you for all your input and keep the suggestions rolling in.
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
Hello Railfans!
Heres my experience with this very subject and 3d printing....
Can it be done? Yes. I have made for myself a replacement set of 3d printed axles for the Bachmann 2-8-0.
Did they work? Yes, to a degree. While the new parts served their function, the inherent bad design of this type is still a problem. Slippage will eventually reoccur even if it doesnt crack the new parts. Even replacement axles of commercial grade with eventually experience the original problem. Its plainly a bad design.
Are 3d axle replacements durable enough? Yes. They can take the load just as the originals do. But again, up to a point. the flaws of the design still overcome the advantages of replacement. Do know you can select the hardness of plastic you print.
Pro vs Con: Unless you are set up yourself to 3d print, it is more practical to search out and aquire commercial versions. If not found or not available, then someone like Shapeways ( i hear) or other company may be able to help. These are such small parts they might not be cheap for a company to make just one set. Its time intensive to design, populate, print, then test a part.
Only if you are able to print these up yourself would this be an economical process. Once you have the original you can reproduce as needed because but again, the flaw will always exist in this type of design. Youll likely print a few during the lifetime of the loco.
Lastly, consider a straight axle to an axle with a gear (or teeth rather), its a bit more complex part to produce at such a small scale, even for 3d printing. Though it can be done. To produce a commercial quality gear, you would have to print below 'normal' print sizes.
Best of luck!
PMR
Seems to me the problems with these gears cracking over time is due to the selection of the original plastics used. POM or the more commonly used acetal are used in gears due to cost, dimensional stability and lubricity.
There are two types of acetal (as well as most polymers) homopolymer and copolymer. Duponts Delrin is a homopolymer and they were first to market. The homopolymers are inherently less expensive than copolymers, are stiffer and are subject to cracking and crack propagation over time.
Copolymers do cost $0.10 or so per pound more, have a lower modulus, are therefore more forgiving to cracking over time.
Manufacturers could do everyone a favor and specify any of the many unfilled copolymers available instead of the historically used homopolymer.
Just a thought....
Lee
Erie Lackawanna in GeorgiaSeems to me the problems with these gears cracking over time is due to the selection of the original plastics used.
This seems to be the crux of the problem.
Lee 1234Versatile Plastic material at Shapeways is plenty tough.
Thank you for the recommendation on printing material.
Lee 1234 Athearn 40023 is the part number of the old outside frame drive wheel assembly.
According to the original Athearn Assembly Instructions included in the box of the unit I am attempting to rebuild 41023/24 are the Truck Units for the Powered Locomotives. It also notes that the 41022 units are for the dummy locomotives.
The 40023 wheels sets are used on the F-7, GP-9, GP-30, GP-35, SDP-40, SD-45, and the SW-1500 Cow & Calf according to the original documentation.
Thank you for your suggestions.
40023 is the complete wheelset, 2 stub axle wheels and the gear. You don't need all that if just the gear is cracked. And those are definitely the older outside bearing truck type. If your loco has the bronze bushings between the wheel and the truck sideframe, those aren't the right gears, the ones you need should still be available. The whole truck can be repalced if you have the older ones - the plastic sideframes are much nicer than the old metal ones anyway. Far as I know, th only old Athearn BB loco that never got changed over was the Trainmaster, probably because of the uinique offset 3 axle trucks.
rrinker...(T)he ones you need should still be available.
I've searched the Athearn/Horizon Hobby (Athearn's parts supplier) to no avail.
Not to be facetious but...where?
If you have a known source I'm all ears!
rrinkerThe whole truck can be replaced (SIC) if you have the older ones - the plastic side frames are much nicer than the old metal ones anyway.
The tabs on the truck assemblies I am dealing with extend farther into the frame than the assemblies currently available.
I don't believe that the newer truck assemblies will fit the frame I have without major modification to the frame.
Athearn does offer HO Drive Axle Gear [ATH60024]. These might work for the cracked gears.
However, I still have the cracked Bachmann worm gear couplers to contend with.
Again, thank you for your suggestions.
Maybe try the Bachmann Forums.
mbinsewiMaybe try the Bachmann Forums.
I am a member of the Bachmann Forums.
The problem is...
Bachmann has admitted that the plastic couplers between the metal worm gear shafts and the dog bone drive shafts are only available as a part of a major sub-assembly.
Which are currently "Unavailable".
The reason I began this thread was to explore the possibility of having these unavailable replacement parts replicated by 3D printing.
Thank you for all your suggestions and comments, keep them coming, and...
jjdamnitThe reason I began this thread was to explore the possibility of having these unavailable replacement parts replicated by 3D printing.
Make it in metal, cross-drill and insert pins of correct dimensions for the pivots. It will not shear, it will not break, it will not twist or distort.
jjdamnitI am a member of the Bachmann Forums.
OK, so do the Shapeway, or what ever printing thing you have found. or want to do.
Simple. Just do it.
So far, nobody has jumped up, that does 3D printing, and said " Hey JJ I can do that!"
So search it out. all of us that have responed to your post have given you the resources that have been "go to" places to find what you want.
So, go for it, and explore.
Contact James at James train parts. He has made several replacement gears for primarily n gauge but can whip it out in no time if he wants to produce it.
ndbprrContact James at James train parts.
Excellent resource!
Thank you for the link.
I just reached out to him in regards to both parts.
I contacted James at James train parts for a consultation on 3D printing for the parts I need.
Unfortunately, he is located in the U.K.
Noting wrong with overseas sources but the cost of tooling, printing, and shipping is currently cost-prohibitive.
I took another look at the solutions A-Line offers. I've ordered three components that might work:
I have several A-Line Universal Coupling Kits. The problem is the couplers are designed for a 3/32-inch shaft while the Bachmann shafts are 2-mm.
With the addition of the Brass Sleeves hopefully, I can finally find a solution to the failing Bachmann components.
So far, every Bachmann GP series worm gear coupler in my roster has failed and needed replacement. I've gotten proficient at quickly replacing this defective part, but only when replacements are available.
Currently, Bachmann only offers a complete powered truck. The Gear Tower is listed as "Out Of Stock".
I will keep all of you informed of my progress and will hopefully provide others with a viable and permanent solution to Bachmann's shortcomings.