XXL-sized LEGO compatible steam driver. This one is a Boxpok type, inspired by the drivers on the Pennsylvania Railroad T1 Duplex locomotive, but it should serve for other locomotives with similar drivers as well. This one has a groove for a rubber traction tire. Imortant if you want to drive your model through the driving wheels and not, say, though a LEGO train motor in the tender of your model. Tires are not included with the model. I recommend large, thin plumbing o-rings, which can be found at most hardware stores. This version of the wheel has a larger counterweight.
Thanks for your interest in my train wheels! I am offering these parts at Shapeway's cost, i.e. no profit to me, because they are intended to fit and function as LEGO elements but, because I do not have control over the production process, I cannot make any guarantee regarding the fit and finish of any individual piece. I have made every effort in the design stage to make the axle and pin holes sized correctly, but variations in the 3d printed result will occur. As a result, you may receive a part that will not fit well on an axle or pin. Also, the black parts are dyed, and the dye does not always take perfectly, especially if there is any residue of the printing process left behind. Again, I do not control any aspect of production, and cannot know the condition of the specific part you will receive.
That being said, I have had a decent success rate with test models fitting and functioning and, as I have had several requests for these wheels, I am offering them here. I do hope they will work for you but, again, I cannot guarantee that.
As an additional note, XXL sized wheels, while I think they are the right scale for many LEGO steam engine models, are a little too big for standard R40 LEGO curve track. If one were to use them in a flanged-blind-flanged arrangement to make, for example, a Pacific type locomotive, the two flanged wheels will be so far apart that they will bind in curves. The XXL wheels do work well when two flanged wheels are placed next to one another but, for other arrangements, you will need to look into after market wider radius curves if you are looking to run with these wheels.
All that said, you are welcome to let me know if these wheels worked for you, or if you have requests for future models. I only work on these wheels occasionally in my spare time, so I make no promises that I will actually get around to making people's requests, but I will update requesters if I do. Thanks!