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AARRGGHH!! Stew Mac Cam Clamps!
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10101&t=55077		 Page 1 of 1
Author:  Pat Foster [ Tue Jun 14, 2022 6:24 pm ]
Post subject:  AARRGGHH!! Stew Mac Cam Clamps!
I got about a dozen SM large and small cam clamps in a big lot buy. The shaft has serrated edges; they drive me nuts when releasing them, often requiring tapping to get them to let go. Has anybody modified them to remove this "feature"?
Author:  bobgramann [ Tue Jun 14, 2022 9:12 pm ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
Attachment:
B574D51F-D3AD-4AE7-BBCC-88D8BFAFA8D0.jpeg
The last time I bought clamps from them was a few years ago. You can see the shaft in the photo. These haven’t caused me any issues. Like you say, when it doesn’t release, a tap on the heel of the moveable jaw frees it. I have clamps from other sources that behave the same. Even the Klemsia clamps stick occasionally.

StewMac will readily take them back. But then, you won’t have them.
Author:  joshnothing [ Tue Jun 14, 2022 10:30 pm ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
I’ve had stuck-on-arrival cam clamps from SM, Dubuque, Klemmsia and Lie Nielsen. Both serrated and non-serrated bars. It’s frustrating but I find once they’ve been used a few times they wear in and tend to stop sticking.


Sent from my iPhone using Tapatalk
Author:  J De Rocher [ Wed Jun 15, 2022 12:58 am ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
I have cam clamps from StewMac and another brand. Some clamps of each brand tend to lock and not want to release. The shafts of both brands have those serrations. I don't know if the resistance to releasing I see is the same problem you're seeing, but maybe this would work for your clamps too. I put my thumb on the back end of the lower jaw of a locked clamp like in the photo and press down with the tip of my thumb on the top edge of the lower jaw in the direction of the end of the shaft. That releases them easily with no tapping needed.

Attachment:
IMG_9737.jpg
Author:  DennisK [ Wed Jun 15, 2022 3:35 am ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
Bob's photo looks the same as my Miro Moose cam clamps. They can be a little sticky, especially the deep reach ones, but it does decrease with use. My small ones have more trouble with slipping, after 12 years of heavy use. I've filed the serrations deeper a couple times before, and I think they're due for another tune-up. Cleaning off the grunge also helps, so perhaps rubbing wax or something on the serrations to gum them up would reduce the sticking :)

And as Jay says, pull the jaws apart behind the bar to release. Avoid squeezing it tightly together back there unless you need maximum clamping pressure and are willing to accept the struggle getting it back off.
Author:  WudWerkr [ Wed Jun 15, 2022 8:55 am ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
Pat Foster wrote:
I got about a dozen SM large and small cam clamps in a big lot buy. The shaft has serrated edges; they drive me nuts when releasing them, often requiring tapping to get them to let go. Has anybody modified them to remove this "feature"?



They will wear in a bit , Look at it from the other side. NOT wanting to hold is a way bigger frusteration gaah
Author:  Pat Foster [ Wed Jun 15, 2022 11:18 am ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
All the clamps in the lot I bought about 8 years ago were well used. The non-SM clamps are sometimes a bit sticky when releasing but never need tapping, but the SM clamps it seems are sticky every time. I haven't had any problems with slipping. I'm thinking the relationship in the locations of the two pins on the sliding jaw might be a factor there. Looking at it with force vector geometry (or is that trig?), it would seem the closer they are together, the less likely they are to slip, and possibly more likely to stick. More to think about.

Thanks for the feedback.
Author:  Barry Daniels [ Wed Jun 15, 2022 11:30 am ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
I made my first cam clamps in 1976 using the Irving Sloane book and they don't have serrations. Never had slipping problems. I think the serrations may be an over-engineering thing.
Author:  WudWerkr [ Wed Jun 15, 2022 12:17 pm ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
Pat Foster wrote:
All the clamps in the lot I bought about 8 years ago were well used. The non-SM clamps are sometimes a bit sticky when releasing but never need tapping, but the SM clamps it seems are sticky every time. I haven't had any problems with slipping. I'm thinking the relationship in the locations of the two pins on the sliding jaw might be a factor there. Looking at it with force vector geometry (or is that trig?), it would seem the closer they are together, the less likely they are to slip, and possibly more likely to stick. More to think about.

Thanks for the feedback.



misread the orig thought they were newer clamps Sorry
Author:  Pat Foster [ Wed Jun 15, 2022 2:30 pm ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
Barry Daniels wrote:
I made my first cam clamps in 1976 using the Irving Sloane book and they don't have serrations. Never had slipping problems. I think the serrations may be an over-engineering thing.


If that was the Sloan repair book, maybe I'll dig that out to see where the two rolled pins are located.
Author:  Barry Daniels [ Wed Jun 15, 2022 2:43 pm ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
It was the "How to build a Steel String Guitar" book.
Author:  guitarjtb [ Thu Jun 16, 2022 8:15 am ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
One of my pet peeves, for years, was a cam clamp getting stuck closed, when I hung it on the clamp rack. I would get my large screw driver and insert it in the little gap on the back side of the bar. I would twist the screw driver, and the cam clamp would pop open. Worked great. Then someone on this forum posted a hint that this could be avoided by raising the cam lever before closing the clamp. One of those "Duh, I can't believe I didn't think of that" moments". I still use the screw driver method, when I forget to raise the lever.
Author:  doncaparker [ Thu Jun 16, 2022 8:36 am ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
I store mine by clamping them onto pieces of 3/4” plywood screwed to a plywood wall on my clamp cart. They don’t get stuck closed that way.
Author:  bftobin [ Fri Jun 24, 2022 7:42 am ]
Post subject:  Re: AARRGGHH!! Stew Mac Cam Clamps!
I made some of mine around the same time as Barry. Most of them have aluminum shafts and sometimes do get jammed. I also needed to make up some extras in a hurry and used birch for the jaws and hard maple shafts. The all wood ones never seem to jam. I was a little concerned about how durable they would be, but they're holding up just fine.
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