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Re: For those keeping score ...
Posted: Sat Feb 08, 2020 11:03 am
by rjent
Here is a picture.

- shaft bearings for web.jpg (74.25 KiB) Viewed 15092 times
Re: For those keeping score ...
Posted: Sat Feb 08, 2020 11:58 am
by rogersk
Deleted post. Referred to the wrong shaft. My bad.
Re: For those keeping score ...
Posted: Sat Feb 08, 2020 8:32 pm
by JPG
rjent wrote:Here is a picture.
shaft bearings for web.jpg
I assume the shaft is 0.625"
Now are the bearings 35 mm od and 11mm thick?(MVII size)
Re: For those keeping score ...
Posted: Thu Feb 20, 2020 12:35 am
by rjent
What a magnificent machine! LOL
I got it back together (parts came in), balanced the belts, buttoned it back up and ....
Quiet, powerful, functional again.
I just hope she works for a while.....
Re: For those keeping score ...
Posted: Thu Feb 20, 2020 8:33 am
by JPG
rjent wrote:What a magnificent machine! LOL
I got it back together (parts came in), balanced the belts, buttoned it back up and ....
Quiet, powerful, functional again.
I just hope she works for a while.....
Glad to see you maintained being "positive".
Now about the size, Ya gots a caliper to measure od and thickness?
Re: For those keeping score ...
Posted: Fri Feb 21, 2020 12:06 am
by rjent
JPG wrote:rjent wrote:What a magnificent machine! LOL
I got it back together (parts came in), balanced the belts, buttoned it back up and ....
Quiet, powerful, functional again.
I just hope she works for a while.....
Glad to see you maintained being "positive".
Now about the size, Ya gots a caliper to measure od and thickness?
Yeah, sorry JPG, I will do that tomorrow. I forgot all about you asking that.
If they are the same as the Mark VII the real argument is that this shaft can spin at 16000 RPM (mine does a lot of that) and there is tremendous pressure on the bearings because of the "balancing" by sound set up. I never have liked that process, not very precise IMHO.
It will be interesting to see what the bearing size is. I have another project tomorrow, but I will be sure to measure them...

Re: For those keeping score ...
Posted: Fri Feb 21, 2020 1:41 pm
by rjent
JPG wrote:rjent wrote:What a magnificent machine! LOL
I got it back together (parts came in), balanced the belts, buttoned it back up and ....
Quiet, powerful, functional again.
I just hope she works for a while.....
Glad to see you maintained being "positive".
Now about the size, Ya gots a caliper to measure od and thickness?
Looks like they measure 30 mm x 7 mm
Re: For those keeping score ...
Posted: Fri Feb 21, 2020 3:26 pm
by JPG
rjent wrote:JPG wrote:rjent wrote:What a magnificent machine! LOL
I got it back together (parts came in), balanced the belts, buttoned it back up and ....
Quiet, powerful, functional again.
I just hope she works for a while.....
Glad to see you maintained being "positive".
Now about the size, Ya gots a caliper to measure od and thickness?
Looks like they measure 30 mm x 7 mm
Hmmmm. Smaller than 35 x 11 fer sure!!! Maybe that is why the MVII eccentric is so much larger than the M5/V.
Re: For those keeping score ...
Posted: Sat Feb 22, 2020 9:15 am
by dusty
The bearings on the tho 510/520 idler shafts that I have are
6803RS or 6803Z (30mm x 7mm). I also have an idler shaft for the Mark 7 and they measure the same. They most probably were all manufactured off shore but so what. There is not much these days that is not. I am even suspicious of items marked "USA".
I took a second look at these bearings and may have a correction. I now believe the bearings are 6903 and not 6803. The size between the two bearings (505/510 idle) is at least 1 mm larger in diameter. This means that the bearings must be pulled off toward opposing ends of the shaft. In the case of the Masrk 7 idler shaft the new pulley prevents the bearing from being pulled unless the pulley is removed first

- Mark V and Mark 7 Idler Shafts with bearings
- 20200222_071055[1].jpg (840.32 KiB) Viewed 14771 times