Jump to content
Sign in to follow this  
c64orinoco

Shapeways for old parts

Recommended Posts

Does anyone have any experience with getting old parts made by Shapeways?

The spur gear A on my 80's Sand Rover has a chipped tooth; running it last weekend was a bit harrowing as the gears skipped quite badly. I worried I'll completely strip a gear if I keep running it like this.

I have found some STL files for the gear train, and I'm thinking of gettign them made by Shapeways.

Has anyone done this? What is the right material to select for a spur gear?

Share this post


Link to post
Share on other sites

It somewhat depends upon how good the stl file is - the old adage of "put rubbish, get rubbish out" definitely applies to 3D printing.

The versatile plastic is great for decorative parts, but I couldn't promise it would hold up for any length of time for a structural or drive component. For that I'd be wanting to use one of the SLA materials, such as the Accura Extreme 200. The issue with that is of course the price, so you might be better off trying to find a replacement vintage part.

Hope that helps - feel free to ask anything else. :) 

Share this post


Link to post
Share on other sites

It was the situation you would register with shapeways, open your own shop, upload the STL files and then you could see how much per part it would cost, I haven't done that for a couple of years

Share this post


Link to post
Share on other sites

Yup - although I don't think you even have to open a shop - just register and upload your files

 

Share this post


Link to post
Share on other sites

If you decide to print the STL file on shapeways, I would recommend buying only 1 gear at first to see if it actually fits and is really the right size.

Depending on the person that created the STL file and their level of experience in designing and printing gears for printing by Shapeways, the exact dimensions of the gear when printed may or may not work perfectly.   Since the STL file you found may not have been created for Shapeways specifically, the gear may be slightly too small with thin teeth.

My personal experience:

I designed some gears using software that correctly generated the tooth profile for 32P gears and had them printed by Shapeways.

The first one I printed was raw from some software that generated a proper 2D gear profile mesh which was imported into Blender and made into the proper 3D gear shape by me.  It looked perfect in CAD with the proper tooth size and profile and the gear dimensions were perfect (within 0.1mm anyway which is the limit of resolution on Shapeways plastic prints).  But when I received the gear from Shapeways, the overall size of the gear was slightly smaller than it needed to be and the teeth themselves were too thin.   The printing process had shrunk the teeth.  It's just the nature of 3D printing.  The gear "fit" into the gearbox, but the mesh was too light due to the smaller teeth and smaller overall diameter of the gear itself.

So I started to modify the gear in Blender.  I increased the tooth profile and made the teeth thicker and increased the diameter. I created 5 different sizes, increasing dimensions by 0.1mm or 0.2mm each time in order to see how Shapeways interpreted my changes. Then I printed all 5 designs.  Sure enough, I found the right dimensions that resulted in a printed gear that very closely matched the original in both diameter and tooth size and shape.  I still have the gear installed in one of my cars today just to see how it wears.  But man, it was a chore and rather expensive, like $100 for all of the trial prints+shipping all said and done.  I mostly did it just to see if it could be done and to see how strong the gear was.  IMO, 3D printing gears is a viable solution for the non-racer.  I haven't done any torture testing.

Maybe there are much better ways to design gears for printing by Shapeways and I don't know about them.  If so, I'd love to learn about them.  Because the sizing trial method I used was not what I would call fun or cheap.

  • Like 1

Share this post


Link to post
Share on other sites

... and next time you reorder the fitting gear its again another size. Its in the nature of 3D prints. But maybe fella @Tizer wants to say anything about? He is the shapeways dude here on TC.

Share this post


Link to post
Share on other sites
1 minute ago, Collin said:

... and next time you reorder the fitting gear its again another size. Its in the nature of 3D prints. But maybe fella @Tizer wants to say anything about? He is the shapeways dude here on TC.

I haven't experienced that yet.  But I've only ordered 2 of the gears so not much to go on.  I suppose depending on which physical 3D printer printed your parts, they could come out differently.

Share this post


Link to post
Share on other sites

there are always some tollerances on X/Y/Z axis and you never know how your part is in position inside the printer. Unless you force shapeways to do position as you want to.

  • Like 1

Share this post


Link to post
Share on other sites
8 hours ago, jonboy1 said:

The issue with that is of course the price, so you might be better off trying to find a replacement vintage part.

An original 1983 Sand Rover spur gear A is pure unobtainium.

I might try the local 3D printers before committing to Shapeways. I only considered them because of access to stronger materials than I can get locally.

Share this post


Link to post
Share on other sites

I've got a fair bit of experience with 3d printing gears , I modelled up a complete parts set for the original Yokomo Dogfighter including the entire gear set , its very trial and error to get the mesh just right to say the least , different materials contract on cooling in different ways ,  having said that the durable plastic that shapeways use is pretty strong and their sintered powder printing method is very accurate , my experience is with FDM based hobby grade printers .

It will really come down to the file , if it was created for FDM printers then it could be dimensionally wrong if shrinkage was taken into account , if it was modeled up using exact measurements from a real gear it may be better or if it was made using a cad programme that has a gear making tool inbuilt it could be better or worse .... It really will be a case of try it and see , sorry .

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...