Saturday, 23 June 2012

3D Printed Wheels. A First Attempt


Today has been an interesting one. After a 'pep talk' from a fellow member of the 2mmSA Oxford Group with regards to my 3D printed wheel centers I then realised that I had enough bits to make a set of replacement wheels for a Graham Farish Pannier Tank. Below is what I managed to achieve in about 5 hours today...

Here are the ingredients for the conversion.
  1. A Graham Farish Pannier Tank Engine
  2. Some 1.5mm steel rod
  3. A couple of etched coupling rods from the 2mmSA (3-205)
  4. 6 x 3D printed spoked wheel centers.
  5. 6 x 9mm Steel wheel rims (courtesy of the 2mmSA)
  6. 6 x 2mmSA Crankpins (I used 3-106 but 3-107 would be better (I didnt have any!))
Step 1 was to press the wheel centers onto the rims. This was done simply by using (a very rusty!) machine vice and the centers were pressed into the rims until the back of the wheel was flush.

Step 2 was to cut 3 lengths of the steel rod for the wheel axles. I cut them with at least 10mm extra than I needed (for holding). I then used my rotary tool to clean up the ends and add a small chamfer to ease pressing on the wheels.

Step 3 was to press the axle onto the wheel. I used my drill press to make sure everything stayed square. I pushed the axle about 5mm through the wheel. I ended up with this...

Step 4 was to press the second wheels onto the axle. I did this by first holding the 5mm length of axle in the check and then pressing the second wheel on until it was on the axle. I then used a small length of tube which was a sliding fit over the axle and using a back-to-back gauge, pressed the wheels together until the gauge was a good fit between the wheels.

Im going to mention the gear now too. I 'salvaged' it from the original wheels as I didnt have an alternative but then found out that it had a bore of 1.6mm! Im not going into too much detail about how I got it to fit the axle (it was a bit of a cobble!) but it was pressed onto the axle of one wheelset before the second wheel was fitted in much the same way.

I then ended up with wheels like in the photo above. The pair nearest the ruler shows the next steps 5 where I cut the axle flush with the wheel (well cut it not quite flush then filed it down), then step 6 where I fitted the crankpins but pushing them through from the back with a bit of superglue to hold them in place.

Step 7 was them to paint them buy first giving the wheels a good clean in some IPA and then once dried I painted them with some Humbrol matt black.

Fitted into the chassis they look like this...

And below is how far I have got today. I still have a bit of work to do soldering the coupling rods in place but you get a good idea of the finished thing...

Julia :)


  1. Julia,


    I like your wheels who did them for you? Im still in the design stage of my pre quartered wheels and these may be an easier/better option.



  2. Hello Damien.

    I designed and drew the wheels then uploaded the designs to a company called Shapeways who printed them for me. The design needs a few tweaks but as far as a proof of concept goes they are fine so far...

    1. Hi Julia,

      im just in the final stages of sending some bits to Shapeways. I have done wheels, boilers, chimneys etc and want to make sure they come out good quality. Did you have yours done with Fine Detail Plastic?

  3. I will be interested to see how long your wheels will last. FUD is a lot more brittle than ABS or nylon that wheel centres and we know that early Gibson wheels cracked a round the hub because of brittle plastic.
    Personally I wouldn't trust FUD with any sort of force fit.

    Bill Bedford

  4. I will be interested too Bill.

    Any plastic which has a low melting point cannot inherently be that stable. The restrictions I have currently is the printing process, in 2mm there just isnt the availability of machines at the right price to get anything better. I am sure that in time things will get better, cheaper, more accurate buy until then this is the best I can manage.

    There is a distinct advantage with 2mm scale though in that the wheels are so much smaller than 4mm so therefore must be much stronger.

    As you say, only time will tell. I know its not the ideal material but using the methods above I didnt encounter any real issues with FUD.

    Thank you for the advice though, I know you have been working on things like this for a while now.

    Julia :)