Custom Lego Train Axle Holders

[Sixpence]

For a while now I've been working on creating replacement axel holders for lego train wheels.

It all started when I got back into the hobby and ran out of train wheels. Looking around my local area (Australia, Queensland) the 1 or 2 clubs that used to be around disappeared so there wasn't anyone I could trade or buy them off. I then remembered brick link but I couldn't get the cost down to below $5-8 pre-unit shipped. When you want 100 or 50 or 24 of the $8-5 a peace starts getting really expensive.  I then tried to order them from lego but they weren't shipping bricks and peace due to the outbreak. Shortly after trying to order directly from lego, they also discontinued the part I wanted.

So a few months of design later, I now have a number of wheel axle configurations. I printed the last prototypes this week and I was a little surprised that they felt smoother than the official ones. Although having said that my existing lego wheels are all 9V or RC so they are really old. 

I have a version with no sides, a version that is designed to imitate the existing one from lego and one that has studs on the side that is primarily for snot builds (8/9/10 wide).

 

I'm now moving into a phase where I'd be sending them out to an ABS plastic print farm because they take between an hour and 1hr+45min to print.

Initially, I wasn't going to sell them but I was wondering if there might be a demand? If there was a demand what colours other than back people might be interested in?

Other Questions Welcome.

 

 

Edited November 16, 2020 by Sixpence

[Legownz]

These look really cool! I'm sure there would be a demand for LBG for people looking to do Super Chiefs. Maybe red too?

[ejayb]

@Sixpence, are you still running these? Did you make any changes?

[ALCO]

Nice work there! A good portion of the serious train builders here in North America use MR55ZZ ball-bearings pressed into 1x2 technic bricks with 2 holes for brick-built trucks/bogies. The bearings drastically reduce rolling resistance especially for heavier cars that are built to 1:48 scale (generally 8w). There are a couple suppliers for these parts, they can be found on www.bricktraindepot.com or www.brickmodelrailroader.com. I'm not sure they ship to Australia though. The bearings are pretty easy to find on AliExpress and the axles and wheels 3rd party manufacture can be found on www.bricktracks.com. I have built some of these myself and it takes some work. But I also bought 200 wheels from Lego when the new wheels and folders came out on the Hidden Side train.

[Sixpence]

On 12/27/2020 at 3:21 PM, ejayb said:

@Sixpence, are you still running these? Did you make any changes?

Yes, I have made a few changes.

• I've started printing into two separate parts to
  • reduce print waste
  •  fix an underside separation issue where the material was splitting due to being printed on the support material. This won't be possible for the models with the sides so I'll have to live with a slightly higher defective rate or let the 3D print farm solve the issue with better slicer settings

• slightly revised end cap to hold the wheelsets in

• I'd probably start considering having 3 studs on the side stud model but now that I've sorted out a spacing issue

My current testbed of 20th Century BR/QR Rail wagons seems to be doing ok using them. They're not for sale yet as I haven't found the right 3D print farm partner yet and still trying to finish testing to make sure I've resolved a squeaking issue. 

21 hours ago, ALCO said:

Nice work there! A good portion of the serious train builders here in North America use MR55ZZ ball-bearings pressed into 1x2 technic bricks with 2 holes for brick-built trucks/bogies. The bearings drastically reduce rolling resistance especially for heavier cars that are built to 1:48 scale (generally 8w). There are a couple suppliers for these parts, they can be found on www.bricktraindepot.com or www.brickmodelrailroader.com. I'm not sure they ship to Australia though. The bearings are pretty easy to find on AliExpress and the axles and wheels 3rd party manufacture can be found on www.bricktracks.com. I have built some of these myself and it takes some work. But I also bought 200 wheels from Lego when the new wheels and folders came out on the Hidden Side train.

It probably wouldn't be too hard to modify what I have to accept ball-bearings. Probably wouldn't be too hard to do a 1 by 1 or 2 by 1 brick with the correct size hole/s either. Although something that small might be a little hard to keep stuck to the print bed.  The hole widening of a technical axel hold looks like a really painful process and one that would be much easier to print. I've found that there are a few places on eBay and AliExpress that sell the right sized ball bearings - although I believe the model number is MR52ZZ. I'm familiar with BT as I'm using BT wheels as I can't get the FDM wheel prints to stop warping - I'd have to move to a resin printer I think to fix that issue and be able to print straight axel holes. Although I can print the Big Ben Bricks wheels clones I designed and they stay flat so it's probably a thinness issue but I digress. There is only one reason not to use ball bearings I can foresee and that is I can run 4 wheelsets inline because of the side to side movement without ball bearings holding the axel in place.

General Project Update

I've had a little trouble getting some test parts out of lego for couplings which have stalled my testing efforts (this part). Two of the earliest axel holders I printed (revision 8 units) developed a squeak which I'm a little concerned about and why I want to test a little more. Although the design changed slightly since then so I'm hoping that it's just an issue with the early print runs. This seems likely because swapping into a revision 10 or 9 looks to have solved the issue. It's only happened with 2 out of 40 units but the majority are either a revision 9 or 10 which haven't failed in the same way yet despite only being printed a week or two apart.

3D print farm wise I'm still looking, as the local place, I was going to use seams to have closed down. There are a few other locations within my area but they look a little iffy.

I've got a few other 3D print lego train-based projects running in the meantime; which once parts start arriving I should be able to start talking about. I'll give the ball bearings ago and I'll probably find a print farm somewhere in 2021.

 

Edited December 29, 2020 by Sixpence

[Sixpence]

So Just a small update the ball bearings arrived last week and I've had a chance to update the design to use them.

Features include:

• an ejection slot so that ball bearings can be replaced or serviced outside the frame
• non-cracking friction fit 
• printed with a slightly smaller 0.3mm nozzle to improve accuracy - which means the studs now have a slightly better clutch when used with official lego parts

I've also had a number of original non-ball-bearing sets start to squeak so that design won't be moving forward. I'm really happy with how the ball bearings behave; so that is what I'm going with.

See images hidden below

Spoiler

 

Edited February 1, 2021 by Sixpence

[Sixpence]

So after a redesign and some testing here's the final model:

Available from here: https://www.thingiverse.com/thing:4840051

I'm not selling the physical item as I just don't have the capacity. The models are however available for download (Link above). If you don't have a 3d printer you can use either a local service or one of Thingiverse's 3D print partners. If you need ball bearings you'd be looking for "MR52ZZ 2x5x2.5mm". The wheels are from bricktracks and come in a few different colours.

 

Edited April 26, 2021 by Sixpence