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Belt Sander Backup Plate Warped

Posted: Tue Nov 02, 2021 7:22 pm
by DavidMcM
I just bought a brand new 6" belt sander and the backup plate is warped about 0.05" on one side only. One of the backup plate mounting points on the casting with the Shopsmith logo is lower than the others. The casting does not appear to be damaged but I am not sure. Has anyone else seen this? Is this a common problem?

I could shim the backup plate but don't think I should have to with a new sander.


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Re: Belt Sander Backup Plate Warped

Posted: Tue Nov 02, 2021 7:25 pm
by garys
I would shim it and get it as close to perfect as you can. You will appreciate it being straight once you use it.

Re: Belt Sander Backup Plate Warped

Posted: Tue Nov 02, 2021 9:38 pm
by JPG
I think CS needs to take a crack at answering that question.

Re: Belt Sander Backup Plate Warped

Posted: Wed Nov 03, 2021 11:17 am
by chapmanruss
I agree with JPG. Since it is brand new you should not have to correct it yourself. Contact Customer Service who will likely have you send it back to be repaired or replaced. Hopefully you still have the box it came in to return it in. It will make packing it for return easier.

Re: Belt Sander Backup Plate Warped

Posted: Wed Nov 03, 2021 12:22 pm
by dusty
I agree but I will have to check my own just to see what I see. I do not recall ever checking it and i use my belt sander a lot. but not to straighten long pieces which is when it would likely be noticed.

Re: Belt Sander Backup Plate Warped

Posted: Wed Nov 03, 2021 12:55 pm
by DavidMcM
@Dusty, I would really appreciate it if you could check the flatness of your backup plate. I’m very curious if is is a common casting issue. Thanks to everyone else for your comments. I did send the sander back to Shopsmith.

Re: Belt Sander Backup Plate Warped

Posted: Thu Nov 04, 2021 3:24 pm
by davebodner
I just checked my belt sander of unknown vintage and dubious condition. Mine doesn't appear to have that problem.

Re: Belt Sander Backup Plate Warped

Posted: Thu Nov 04, 2021 4:01 pm
by chapmanruss
My Belt Sander was made in 1977 and I don't recall if I had ever checked that before. I checked it yesterday and found a slight amount, much less than David's, of the same problem. I added shim washers to the top 2 mounting holes and corrected it. My Belt Sander has 2 washers stacked between the plate and the tinnerman clips on the mounting castings for each of the six mounting holes. These washers, 12 in total, are not shown in the online parts diagram or my Manual dated 1/89. They are shown in the 3 Manuals I have dated 7/72 and earlier. My reason for bringing this up is are these washers still included in later Belt Sanders. It looks like they are present in the picture David showed in his first post. I had another Belt Sander made in 1989 I restored but I can't remember for sure if it had the washers for spacers behind the plate and the 1/89 manual would be the correct one for it. While I had mine apart, I didn't check the mounting castings as David showed in his picture to see if they are out of line too.

Re: Belt Sander Backup Plate Warped

Posted: Thu Nov 04, 2021 4:58 pm
by DLB
chapmanruss wrote: Thu Nov 04, 2021 4:01 pm My Belt Sander was made in 1977 and I don't recall if I had ever checked that before. I checked it yesterday and found a slight amount, much less than David's, of the same problem. I added shim washers to the top 2 mounting holes and corrected it. My Belt Sander has 2 washers stacked between the plate and the tinnerman clips on the mounting castings for each of the six mounting holes. These washers, 12 in total, are not shown in the online parts diagram or my Manual dated 1/89. They are shown in the 3 Manuals I have dated 7/72 and earlier. My reason for bringing this up is are these washers still included in later Belt Sanders. It looks like they are present in the picture David showed in his first post. I had another Belt Sander made in 1989 I restored but I can't remember for sure if it had the washers for spacers behind the plate and the 1/89 manual would be the correct one for it. While I had mine apart, I didn't check the mounting castings as David showed in his picture to see if they are out of line too.
The washers are in my 6/82 manual. Item 29, PN 502965, 11/32" flat washer (12).

- David

Re: Belt Sander Backup Plate Warped

Posted: Thu Nov 04, 2021 8:45 pm
by DavidMcM
Thanks to everyone for your replies. I heard back from Shopsmith and they said one of the casting mounting points was high so they filed it down a bit and are sending it back. I was considering shiming it myself but we will see how it looks when I get it back with the mounting point filed. I'm not sure what the best solution is (filing vs. shimming) for others with this problem.

There were no washers included under the backup plate when I received the new belt sander.

The good news is with the Shopsmith belt sander design, it is pretty easy to correct the problem with shims as others have pointed out.