540 motor bearings

[Toolmaker72 507]

Was wondering if there are replacement ball race bearing for the standard bronze type fitted in the vintage 27 turn stock motors?

Standard motor shafts are 1/8” but I can only find bearings with a 3mm inner diameter 

[Superluminal 3750]

I dont think so - its not that the bearings arent available for this its just that unless the motor was designed with a fully removable end bell (like a Superstock for instance) the normal motors like the standard silver can or Sport Tuned will be ruined by trying to pull out the swaged in tabs that hold the end bell in place.

[Superluminal 3750]

The bearings to do it if you try are an odd size. I replaced the bushes in a Superstock BZ motor a little while ago. Will try and find the thread posted with the bearing sizes.

 

 

Edited March 14, 2020 by Superluminal
Added link

[Toolmaker72 507]

8 hours ago, Superluminal said:

The bearings to do it if you try are an odd size. I replaced the bushes in a Superstock BZ motor a little while ago. Will try and find the thread posted with the bearing sizes.

 

 

Cheers 🥂!  It’s the removable rear housing type motors I’m looking to change the bearings. The link to the bearings works also.  I’ll dig out the motors I have for a quick measure before ordering but they look to be correct 👍😊

[Toolmaker72 507]

Tapped the bearings out, both the same size either end and ordered a few for my motors. I noticed the 19 turn epic already have ball race bearings.  The 27 turn epics all have bronze bearings.

They tapped out easily enough using the back of a 5.4mm drill. As my name suggests, I’ll make a correct little tool to remove and replace the bearings properly 🙂

[Toolmaker72 507]

Made the little tools.  The rod with the 2 turned diameters removes the old bearings. The rod with the single turned diameter pushes the new bearings in 😊

donor motor back together again

[Toolmaker72 507]

Ball race bearings fitted to my 27 turn stock motors now.  Running them with no load on my dc adjustable power supply as before and after current.  Roughly 1.5amps less draw compared to original bronze bush bearings. In theory extra run time.  Really happy with the results 🙂

[Juggular 4964]

Yes, as you say, run time should increase.  I was surprised to learn that the RPM doesn't change much, though.  But I'm always all for more efficiency.  

For posterity, the size of a 540 bearing is 1/8 x 3/8 x 5/32. (I thought it would be in metric, but it was imperial)

Ebay sells them for about $8 USD for ten pieces.    

 

[Toolmaker72 507]

The motor shaft diameter is an imperial size rather than a converted metric size but if you can’t find the imperial  fraction dimension try looking up 0.125x0.375x0.156 as a decimalised imperial size.  
As you say, not expensive 🙂.

with regards to motor rpm,  electric motors simply pull more amps to maintain a given rpm.  So less friction in the bearings means less amperage per rpm, rather than increased rpm with more amps.  I think that makes sense. The extra volts gives more rpm hence running a 2s or 3s lipo battery or 7.2v or 8.4v nimh battery for more rpm.