Aussie Lapidary Forum

LAPIDARY => Saws and Diamond Blades => Topic started by: Gemmie on September 21, 2018, 05:34:09 PM

Title: Replacing bearings on diamond saw
Post by: Gemmie on September 21, 2018, 05:34:09 PM
The bearings on my Robilt diamond saw need replacing but I can't get the shaft out! Is there a trick to it? Any advice welcome, thanks, Gemmie.
Title: Re: Replacing bearings on diamond saw
Post by: Rusted on September 22, 2018, 07:32:32 AM
Probably no trick, they are just well engineered so the bearings are a press fit, meaning you will need a hydraulic press to get them off.
Dont belt them with a hammer, you will mushroom the end of the shaft and cause yourself a lot of grief.

Dismantle as much as you can, see if you can get a number off the bearings and buy a new set, then take the lot to an engineering shop and get them to press the old ones off and the new ones on.
Title: Re: Replacing bearings on diamond saw
Post by: Gemmie on September 23, 2018, 01:17:23 PM
Thanks Rusted! All I can get off is the pulley. Can see the outer bearing and number but likely it will have a bearing on the inside as well, no idea what that looks like. Then there is a bush on the inside, the diamond blade rests against that. If I hold this bush with pliers, I can only just turn the axle by hand but the bush won't move sideways.
Title: Re: Replacing bearings on diamond saw
Post by: Rusted on September 23, 2018, 03:13:24 PM
Buy two of the bearings by the number you have. I doubt very much if Robilt would have used odd sized bearings for each end.
Most sizeable towns have a bearing shop.

Clean up any rust /paint or crud on the shaft with a bit of wet and dry, also the raised pimple where the grub screw from the pulley marked the shaft. Probably need to gently file that.

Next take the shaft and housing to an engineering shop, it probably won't take much under a press to get everything to pieces.

Replace both bearings even if you think one sounds OK, they usually do until they are placed under load.
Title: Re: Replacing bearings on diamond saw
Post by: Robol on September 23, 2018, 05:17:50 PM
When I replaced mine I bought a bearing puller from Supa Cheap Auto. I bought the large one for around $25.00. I suggest you mark the shaft at the edge of the bearing. If I had done that it would have saved some messing around when it was going back together.
Title: Re: Replacing bearings on diamond saw
Post by: Gemmie on September 24, 2018, 05:57:03 PM
I had another go today and to my surprise I could move the bush over using a big screw driver and that's when I could see the circlip on the axle, right against the inside bearing. Very hard to get off!!
Carefully tapped the axle out with outside bearing still attached, then tapped out the inside bearing and after a trip to town and $23 later, brand new bearings and new circlip.
Outside bearing glued in for good measure!
Title: Re: Replacing bearings on diamond saw
Post by: Rusted on September 24, 2018, 07:24:56 PM
Excellent news Gemmie.