Axle Bearings -best mod ever!

[sed6]

I just finished a marathon session of adding approximately 160 bearings to my rolling stock. I am positively blown away by the results! It took hours and hours to do but cost only about $35 and the result is cars that seem to glide over the rails. 

I used the standard MR52ZZ bearings that others have used. They measure 2x5x2.5mm. These fit the older Lego 1.98mm axles with the pointed end, the newer 2.00mm axles with the blunt end and your custom .078 inch (1.98mm) music wire axles. I used all three types for this project.

Variances in tolerance will sometimes require a hammer to tap the bearings on to the thinner axles, but the thicker ones require quite a pounding for each. I drilled a hole in a board to the correct depth to help seat the bearings when hammering. I used the yellow brick to verify the correct depth on each end and the jig ensures everything is centered. 

The hammering DOES damage the bearings! Don't be fooled. BUT, it doesn't matter. My cheap Chinese bearings went from icy smooth to "spins very well" after hammering. My cars now roll for yards with just a flick. A few (2-3?) bearings were destroyed; they became notchy and wouldn't spin freely after hammering. So off they came and into the trash they went. At less than $.20 each I could afford to toss a few. 

I never plan to reverse this mod, nor sell these parts so I don't care about cutting those two tiny tabs off. That said, this mod could be done and could be reversed without removing those tabs. If anyone's interested how let me know. I also used a tiny drop of thin CA to hold the bearings to the truck. That prevents them from popping out and from shifting left or right and rubbing against the inside of the truck. 

Did I mention I'm thrilled? I can now pull all my cars, at once, around the tightest curves and switches with a single train motor. Three of my engines have twin train motors specifically because they needed the traction provided by four driving wheels. I'm guessing that my battery life will improve also. Now I can start designing longer trains and adding more cars!

Hope you like. 

Edited May 12, 2019 by sed6
cnat spele

[Roadmonkeytj]

Very nice ... I bet a small arbor press would have made short work of all them lol! Seems to be simple enough... Could you not mount the bearings further out and save from cutting those tabs? Did you get any mushrooming of the axles from hammering?

[dxpert]

Would you be willing to share the specific site that you got the batting’s from? Either through post or via private message?

great idea, I’d very much like to do something similar.

Nice work!

[sed6]

15 hours ago, Roadmonkeytj said:

Very nice ... I bet a small arbor press would have made short work of all them lol! Seems to be simple enough... Could you not mount the bearings further out and save from cutting those tabs? Did you get any mushrooming of the axles from hammering?

Indeed a press would have been great! As for mushrooming, not really. The lego axles are hardened so any mushrooming wasn't noticable. The tabs need to be cut because of the depth the axles need to sit. The bearings make the axles about 1.5 mm closer to the track, causing the axles to be pinched by those tabs and not spin, so they need to be removed. Their is a way to do it without removing the tabs, but it's a lot more work with more room for error. 

11 hours ago, dxpert said:

Would you be willing to share the specific site that you got the batting’s from? Either through post or via private message?

great idea, I’d very much like to do something similar.

Nice work!

I bought the bearings on ebay and then the seller doubled his price after I ordered mine. However I included a screen shot above of three other sellers selling them in different size batches.

Glad you all like!

Edited May 13, 2019 by sed6

[JopieK]

@dxpert: I know from another (CNC DIY) project that those MR52ZZ is the specification of the type of bearing so just by that you can find them all over the internet including Aliexpress ;)

[sed6]

To clarify the cutting of the tabs, and to address how to do this without cutting the tabs...

Looking at the picture above, the tabs are circled in red. Without the bearing mod the axles are trapped under the tabs to keep them from falling out. You can see with the bearings installed the axle wants to sit at the same level as the tabs. The tabs will the pinch the axle and prevent it from spinning. There are two solutions, cut the tabs off like I did or trim down the green areas. 

If you don't want to cut the tabs off, you'll need to lower the axles another 1mm or so to get them under the tab. This can be accomplished by trimming the two spots circled in green. Those are the two spots the bearings rest on. If you can trim those two spots 1mm down so the bearings rest lower, the axle will be lower and not pinched by the tabs. 

There are potential problems with that method. Trimming those two green spots down 1mm exactly isn't going to be easy. In my mind the only way to do it would be with a router and a jig of some sort. If you go too deep with that cut the truck could be ruined for this mod. 

Edit: I don't know if ruined is the right word. I'm counting on those shelves in green to be at the right height to hold the bearings. If you cut the green shelf too deep I suppose you could just move the bearing to the right depth and use glue and luck to hold them in the right place...

Edited May 13, 2019 by sed6

[coinoperator]

18 hours ago, sed6 said:

The hammering DOES damage the bearings

Freeze the axle's and heat the bearings * , quickly push them on with a tiny pipe that just fits over the axle.

*don't overdo, they will loose their hardening over 250 degrees celcius.

[sed6]

13 minutes ago, coinoperator said:

Freeze the axle's and heat the bearings * , quickly push them on with a tiny pipe that just fits over the axle.

*don't overdo, they will loose their hardening over 250 degrees celcius.

Excellent tip! I did just this and it worked for some axle/bearing combinations. For most it did not, probably because of tolerances. Eventually it became too big a hassle to keep the parts hot or frozen and I resorted to the hammer for the rest. 

[duifkelego]

The most simple solutions are often the best.

With some of these bearings I had from earlier experiments I modded some wheels this way and did some testing. It works nicely for me.

Thanks very much for the tip ! This is going to make a difference in my train building.  no more weight wories  \o/

Going to try hooking up a wire to the bearing outer case and using this as power pickup too , I think.

[Roadmonkeytj]

6 hours ago, duifkelego said:

Going to try hooking up a wire to the bearing outer case and using this as power pickup too , I think.

Do not install metal wheels on both sides of the same axle or you will create a short circuit

[DameVeraLynn]

These look like a great idea. However, I'm a little squeamish about cutting up Lego (and also short of the necessary time to do it, plus probably the necessary skill!), so I'm interested in buying some that have been pre-prepared.

Does anyone know of a European seller of a similar item?

Edited December 8, 2019 by DameVeraLynn

[zephyr1934]

You don't need to cut up lego, the bearings also fit in technic holes (well, with a little force). A few places are selling the parts assembled, e.g., here. If you just need the axles, you can get them here. Right now you would have to glue the wheels on the end of the axles (assuming you are using RC/PF era wheels) but word on the street is that someone is working on a press-on variant of the wheel.

[Giottist]

I can confirm Seds experiences, with the difference that no "hammering" or so is needed. The diameter of the steel axles is a question of hundredth of a millimeter. Steel rods made of 11CrV3 or 1.2210 aka "Silver Steel" with a diameter of 2mm and a tolerance of h9 fit perfect to the chinese ball bearings. This material is extremly hard and stainless, I had to cut it with an 80 cm bolt cutter but then the material can be grinded easily to the exact length with a carborundum abrasive wheel. It takes about 5 minutes work per axle and it's worth

So try out the original LEGO axles and throw them away  (or sell them at Ebay)  if they do not fit at the first attempt. Silver steel rods 2mm h9 offer a high precision alternative.

Edited December 9, 2019 by Giottist

[bricks n bolts]

I found that if you are using original Lego axles it is too hard to hammer both the bearings in place on the axle whilst simultaneously hammering them into a technic brick hole, but with the Bricktracks axles it was no problem getting the bearings onto the axles and no hammering was needed at least on the axle side (didn't get taxed for one bag to the UK by the way.. @DameVeraLynn and you get 50 axles, not sure if you buy more).

Haven't tried it but if you want to add to wheel holders without cutting there is this post which outlines a method to do that.