SAB-250 grinder wheel wobble

[Chris]

Hi,

I recently bought an old Tormek SAB-250 that does not seem to be in great shape. The grinding stone has a noticeable wobble, which I have  tried to show in the attached YouTube video. My guess is that the nylon bushings are worn out or that the axle itself.

Has anyone experienced the same issue and managed to fix it by replacing the bushings and axle?

[Ken S]

Welcome to the forum, Chris. I am not familiar with a Tormek SAB-250 model. I suggest that you email support (support@tormek.se) The head of support is a veteran employee who may well have been part of the crew which built your Tormek. Be sure to include the video with your email.

Please share your reply on the forum.

Ken

[RickKrung]

Does the wheel actually wobble on the shaft, or is the wobble due to the shape of the wheel itself?  If the wheel is loose on the shaft and wobbles, it may be that the arbor hole has worn and/or is no longer round.  If it does not wobble on the shaft, and the sides of the wheel wobble, as shown in your video, that would appear to be the result of the shape of the wheel. 

I've read a few times here in the forum the opinion that side wobble, even as much as shown in your video does not really adversely affect sharpening, as long as the outside diameter (OD) of the wheel can be trued, presumably using the Tormek Truing Tool.  Do you have one of those and have you tried truing OD, which is the only surface that matters on that type of stone. 

[Ken S]

The latest version of the TT-50 truingtool is definitely worth having.

Ken

[Herman Trivilino]

Does the honing wheel wobble in sync with the grindstone? If so, it's likely a bent main shaft.

[Chris]

Thank you all for the replies. I've sent an email to Tormek support regarding this issue and am currently waiting for their response. I'm glad to hear it might still work for sharpening even though it's wobbling. I might give it a shot if I can't get it sorted out in the end.

It's equipped with some kind of truing tool, probably an older version of the TT-50—so truing might also be needed. I just checked whether the honing wheel synchronized the wobble with the grinding stone, and it did. Most likely a bent main shaft just as Herman suggested.

[John Hancock Sr]

You should be able to check a couple of things. Remove the grinding wheel and see if there is any play in either end of the shaft. It should be rock solid. If there is any lateral play then the bearings or shaft are worn. Set up something, such as blocks or such under the grinding stone end of the shaft that comes up to the almost touch the underside of the shaft without touching. Say with one or two mm lower. Then watching the gap rotate the shaft. If it is bent you should see a change in the gap whilst rotating the shaft. This is also another way of checking to see if the bearings are worn. Joggle the honing wheel and see if there is any variation in the gap.

To check for wear on the shaft remove it completely and check the area where it contacts the nylon bushings. You can see any wear since it will form a ridge where it contacts the nylon bushings.