Page 1 of 1

Mark 7 lower saw blade guard clamp

Posted: Wed May 01, 2019 10:19 am
by AB2SS
I've had my Mark 7 for just over a week. Already the lower saw blade guard clamp has lost some of it's grip. When I tighten the allen screw as tight as it will go, there's about 1/4" of rotational play in the guard. Have others encountered this? Solution?

Thanks,
Kirk

Re: Mark 7 lower saw blade guard clamp

Posted: Wed May 01, 2019 11:16 am
by wa2crk
I haven't looked at mine lately but I think there should be a washer under the head of the screw. If there is not, then try one and see if it corrects the problem
Bill V.

Re: Mark 7 lower saw blade guard clamp

Posted: Wed May 01, 2019 12:19 pm
by chapmanruss
There is a lock "split" washer under the cap screw but that should not make a difference in clamping it it to the quill. it is there to keep it from coming loose. Does it lock tight on the quill but move the 1/4" when in place? Is the quill locked? Until locked the quill has a slight amount of rotational movement.

Re: Mark 7 lower saw blade guard clamp

Posted: Sat May 04, 2019 12:47 pm
by algale
The lower blade guard clamps on the quill housing, not the quill itself. So quill backlash shouldn't be the source of the observed rotational movement of the blade guard.

My lower blade guard has always had some rotational give to it after clamping. I notice this most often when I lower the main table without sighting under the table to make sure the main table's tie bar guard is going to clear the lower blade guard. At that point, the tie bar guard usually hangs up on lower the blade guard as I try to lower the main table and when I raise the table to correct the problem I usually notice that the lower blade guard has rotated slightly from the force of the tie bar guard coming down on it.

In operation, I don't think a little rotational give is a problem. The bottom of the main table is going to sit down on the spring loaded part of the lower blade guard and this will keep the blade guard reasonably level and prevent significant rotation of the blade guard.

If the clamp is slipping longitudinally along the quill housing, however, that would be a safety issue because it would mean the guard might slip off.

Re: Mark 7 lower saw blade guard clamp

Posted: Sat May 04, 2019 9:48 pm
by JPG
The quill 'housing' IS 'the quill'.

The quill 'shaft' IS 'the shaft'.

:) ;) :cool:

Re: Mark 7 lower saw blade guard clamp

Posted: Sat May 04, 2019 10:12 pm
by jsburger
JPG wrote:The quill 'housing' IS 'the quill'.

The quill 'shaft' IS 'the shaft'.

:) ;) :cool:
The quill has a slight rotational movement because the dog nose on the set screw that keeps the quill from coming out is smaller than the groove in the quill that it rides in. So the quill has a slight bit of rotation and when the lower saw guard is installed that rotational amount is amplified by the size of the guard. It is all normal.

Re: Mark 7 lower saw blade guard clamp

Posted: Sun May 05, 2019 1:16 pm
by JPG
AB2SS wrote:I've had my Mark 7 for just over a week. Already the lower saw blade guard clamp has lost some of it's grip. When I tighten the allen screw as tight as it will go, there's about 1/4" of rotational play in the guard. Have others encountered this? Solution?

Thanks,
Kirk
Very few screws require such gorilla tactics.

Be advised that excessive tightening can cause much misery later.

This also applies to wingnuts and other clamping thingies on the SS. :)