Adjustable double bearing blocks

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rungemach
Posts: 460
Joined: Mon Aug 02, 2010 8:24 am
Location: Sarasota, Florida

Adjustable double bearing blocks

Post by rungemach »

I had been working on upgrading an extended table pro plus which use the same bearing arrangement as the Hd's on the y axis ( I am told).

The difficulty was in too much play in the bearings causing gantry rocking and I noticed the double bearings used do not have the backlash adjustment that many of the offshore single bearing blocks do. In looking around a bit it seems that most double bearing blocks do not have this adjustment feautre.

The "adjustment mechanism" on the single blocks is a tapped hole and a set screw. The set screw presses the bearing shell slightly inward to make the bearings tighter on the shaft and take out the free play from manufacturing tolerances.

I modified the double section bearings to have the same adjustability. You can now dial them exactly to the rod that they are placed on.

This would probably void your warranty, so proceed with care if you do this. Remember to keep everything clean as you go.

The bearing assemblies are easily pushed out of the block once the retainers are removed (2 screws each).
Two holes were drilled in the block (at the center of each bearing assembly at the high point of the bore) and Tapped 10-20 thread. (in my case).
Its best to use a drill press to get the holes square, not angled into the blocks.
The inside bore is checked for burrs from the drilling and tapping and the bearing assemblies are put back in the bores and centered. (this can be done by hand)
The setscrews are put in and the bearing is placed back on the rod.
The setcrews are tightened just to the point of friction in the bearing, and backed off slightly for free movement. A nut allows the set screw to be locked in place without using threadlock , and readjusted easily later.

Hope this helps any of you with rocking gantries as in this thread,

http://www.cncsharktalk.com/viewtopic.php?f=9&t=1431
Attachments
completed bearing block with setscrews
completed bearing block with setscrews
bearing block and bearing assemblies
bearing block and bearing assemblies

hdtheater
Posts: 263
Joined: Mon Aug 23, 2010 8:14 am

Re: Adjustable double bearing blocks

Post by hdtheater »

Very nice!
Thanks,

-Eric

Facebook.com/inspireddesignstx

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