Troubleshooting Hawk BM Clamps

[hotshot]

Since there is not a lot on the Hawk stuff out here yet, I thought I would post some information on troubleshooting the blade clamps.  One of the bottom clamps I got with the saw would have definitely caused the prior owner issues, but he apparently gave up and went back to his 788 before he found the issue.  With a little inspection, I think it's pretty obvious what he needed to do to fix the issue.

The first clue something may be wrong

Hard to see down that dark little hole, but there is only threads, and no sign of the set screw

But looking down the knob hole, there is a sign of something else.  This was removed easy enough by poking/loosening it with another blade.

Edited July 25, 2017 by hotshot

[hotshot]

Now for the much newer clamp to use as reference:

Whether or not this is the perfect setting, at a glance you can see that the set screw is forcing the blade towards the center.

Trust me, the arrow is pointing to the end of the set screw

Finally, the set screw is sunken just barely under the surface of the clamp surface.  I'm sure this varies some, but vary little from clamp to clamp.

[SCROLLSAW703]

you hit the nail on the head, hotshot! The holders for the BM, if you look at it, has a machine mark dead center of the bottom of the clamp. The inside end of the set screw should be just over that mark, which in turn will make your set screw flush, or just under the outside edge of the blade holder. 

[tuner]

Very clear and logical, it's a shame a lot of scroller just don't take the time to troubleshoot a problem because a lot of them are fixable without having to be a Mechanic.

[Terry Jay]

This based on my experience with the EX and 788 clamps.

Repeated firm tightening will eventually open the clamp body and produce hockey stick blades.  The same bending can result from having the set screw back out and no longer clear the clamp body/  The Hawk has a hole, not a slot, but as it is aluminum and the screws are steel, it could go egg shaped over time and no align the two set screws.  So, check the set screws, and replace the clamp if the problem continues.

Second issue, reverse the screw positions on the lower clamp, so the set screw is on the right and the operating screw on the left.  This seems to provide a better clamping action with a lot less effort.  Please note, I do mostly stack-cut fret work 3/4" to 1" thick in Alaska Birch and Big Leaf Maple, both not too hard, and I top feed.

Hope this helps a bit.

[hotshot]

1 hour ago, SCROLLSAW703 said:

you hit the nail on the head, hotshot! The holders for the BM, if you look at it, has a machine mark dead center of the bottom of the clamp. The inside end of the set screw should be just over that mark, which in turn will make your set screw flush, or just under the outside edge of the blade holder. 

That should make it trivial to reset it when it moves.  I re-adjusted the older clamp and will see how it does.  If it moves, I'll re-locktite it.

[amazingkevin]

On 7/24/2017 at 8:47 PM, hotshot said:

Now for the much newer clamp to use as reference:

Whether or not this is the perfect setting, at a glance you can see that the set screw is forcing the blade towards the center.

Trust me, the arrow is pointing to the end of the set screw

Finally, the set screw is sunken just barely under the surface of the clamp surface.  I'm sure this varies some, but vary little from clamp to clamp.

Your info is in valuable for us ,Thanks Hotshot!

[hotshot]

On 7/24/2017 at 9:51 PM, Terry Jay said:

reverse the screw positions on the lower clamp, so the set screw is on the right and the operating screw on the left.  

One cool thing about these clamps they are symmetrical.  So, you can place the knob on the left or the right.  So that means if I'm used to using it on one side, and the threads start getting sloppy, I can move the set screw to the other side, turn the clamp around, and continue using it as it was.  I really should have an extra set of clamps for the EX, because last time the threads wore out, even the set screw wouldn't hold, so I was down for a few days while Seyco shipped the new ones.  If that happened on the hawk, I just grab another spare clamp and continue on.

But probably the coolest thing, you pay $20 and you have another clamp and thumbscrew.  I expected them to be a bit more, so I'm glad Bushton didn't take advantage.

Edited July 26, 2017 by hotshot

[Rolf]

tuner, unfortunately many people don't understand anything mechanical and are intimidated my them.

I was blessed to be raised by a German toolmaker., mechanical things are my comfort zone. 

Randy in 12 years I have never worn out one of the newer clamps, and I am heavy handed.

[Rolf]

Great pictures Randy. You really are sharing lots of good information about the Hawk. I hope this helps folks realize just how simple the saws are.