Any Experience w/ Straight Edge Clamps?

Bill Satko

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Methow Valley
Such as ProGrip Back to Back. Looking for knowledge such as: any deflection side to side in the middle and does the clamp secure to the work without moving? Anything else I should know?

Basically I am looking for information as to how well these products work and which ones work best.
 
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I got this one from Sears for Christmas it's 50 inches, as you can see it's still in the package so I haven't tried it yet, but I have to break down some plywood for a project so I hope it will work well.

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I have a 50" and steered dad onto a set of three at a blowout price from Rockler back awhile. Dad also has a back-to-back that he inherited from a neighbor. I also have a short one that I use as a quick fence on my 10" bandsaw. The older unit is much stouter (no surprise there) but, the current crop of eemersontool products are very usable. My short one is the "A-series" profile with the raised track while the set dad has and my 50" are all the AIO (all-in-one) "Contractor" profile with the recessed tracks. All are quite rigid but, they are an aluminum extrusion. The closed box design makes then much stiffer than other versions I have tried. I use them as a guide and not as a clamp but the grip pressure available is pretty surprising. In my use I have always had success with them and am glad to have them.
 
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I have a 24 and 50 inch TruGrip "Clamp 'n Tool Guide."

I use them regularly as a router guide when cutting dadoes, since the router follows the irregularity of the plywood, and with a good dado I can clamp out the irregularity during assembly. They have worked well for over 10 years.

I do not use them as clamps. The jaws are only about 1/2 inch high, so all the pressure is on the top of the work, not across the entire face of the pieces being clamped. In fact, taller jaws would be nice, because sometimes I would like to put the dado/rabbet (3/8" high and deep) in the back of a cabinet before I do the shelf dadoes, but that only leaves a small amount of area to clamp.

My usual test... if I had to replace my shop, what would I buy? This pair of clamps (or at least the 24 inch one) would be replaced.
 
Thanks everyone! I have all sorts of F-Clamps, Cabinet Clamps and even a Festool Track System, but wanted a quick way to secure work to my bench top and have a guide at the same time for doing things like routing dados. Not really thinking of using them for gluing up boards or cabinets. That is why the double clamp was looking appealing to me. If I do decide to get them, it will probably be 24" or 36" set.
 
I have a pair of the back to back models, and have used them occasionally to hold panels or things like cutting boards on my Workmate. (Although in most cases, the Workmate on its own can do the same thing.)
 
about holding work securely to the bench---I will add this method which I have used for many years. I purchased a vacuum pump and made my own vacuum clamps. I find that I use system regularly and I consider the system one of my most valuable tools. The cost is not prohibitive and well worth checking out. The comment about holding stock on the bench top prompted this post.
 
about holding work securely to the bench---I will add this method which I have used for many years. I purchased a vacuum pump and made my own vacuum clamps. I find that I use system regularly and I consider the system one of my most valuable tools. The cost is not prohibitive and well worth checking out. The comment about holding stock on the bench top prompted this post.

hey marv you have any pictures of how you made your vacumn clamps? would like to see how you do it. thanks
 
Back in the day, Larry, I taught a class on vacuum clamping. Had to create the syllabus from scratch. Was nothing out there 18 years ago. Dirt simple if you understand the concepts. Straight edge clamps clamp to a solid surface like your bench and your work piece is clamped by them. A vacuum clamp in this configuration is simply a 'plate' that have an area surrounded with closed cell tape. There is a hole within that area that is connected via an air hose to a vacuum pump. Fasten the plate to a solid surface (bench), lay your workpiece on top of the plate, making sure air cannot get into the vacuum area. Turn on the pump. Your work piece is securely held down and you can rout, sand, carve, etc. with no interference from surface clamps. You can easily make the plates from non-porous substrate to suit the occasion. I have a trunk full of them - somewhere. :)

Weakest dimension is sideways. If you plan to exert sideways force, use a physical reference pin to block it. This is the secret to CNC clamping as well. If you use a porous material like MDF, you will need to seal it. Vacuum pressure works because one side of the workpiece has a different air pressure exerted on it that the other. So the atmosphere pushes down to hold things down. Actually it works in any dimension. Interesting, fun stuff, learning how to use a vacuum pump in the shop. If there is a family gathering in your neck of the woods next summer, maybe I could do some demos on the technology. Hoping Jonathan will be well enough to go forward on that. Love to see his horses at work and play. Can't go to New York. No place for a single white woman traveling alone. Certainly not one quite as sprightly as she once was. Sorry, Allen. BTDT. Not again.
 
Back in the day, Larry, I taught a class on vacuum clamping. Had to create the syllabus from scratch. Was nothing out there 18 years ago. Dirt simple if you understand the concepts. Straight edge clamps clamp to a solid surface like your bench and your work piece is clamped by them. A vacuum clamp in this configuration is simply a 'plate' that have an area surrounded with closed cell tape. There is a hole within that area that is connected via an air hose to a vacuum pump. Fasten the plate to a solid surface (bench), lay your workpiece on top of the plate, making sure air cannot get into the vacuum area. Turn on the pump. Your work piece is securely held down and you can rout, sand, carve, etc. with no interference from surface clamps. You can easily make the plates from non-porous substrate to suit the occasion. I have a trunk full of them - somewhere. :)

Weakest dimension is sideways. If you plan to exert sideways force, use a physical reference pin to block it. This is the secret to CNC clamping as well. If you use a porous material like MDF, you will need to seal it. Vacuum pressure works because one side of the workpiece has a different air pressure exerted on it that the other. So the atmosphere pushes down to hold things down. Actually it works in any dimension. Interesting, fun stuff, learning how to use a vacuum pump in the shop. If there is a family gathering in your neck of the woods next summer, maybe I could do some demos on the technology. Hoping Jonathan will be well enough to go forward on that. Love to see his horses at work and play. Can't go to New York. No place for a single white woman traveling alone. Certainly not one quite as sprightly as she once was. Sorry, Allen. BTDT. Not again.

Why do you need to seal the mdf when you use it on a cnc? At work we use 3/4" mdf as a spoil board that the plywood we cut is set on and then we turn on the vacuum pump and it immediately sucks the plywood tight to the mdf. Nothing is sealed on the mdf and we regularly fly cut it to flatten it back out again after cutting about 40 or so sheets.
 
Your machine and vacuum pump can handle a high rate of cubic feet per minute. The little systems we were building could not. That made unsealed MDF unsuitable. Air was gonna come in from somewhere. If air comes in, the vacuum goes away, and so does the clamping pressure.
 
I built a vacuum path to a hole in the middle of my work table, planning to use it for vacuum clamping. It collected so much fine sawdust that it plugged the filter on the vacuum pump, which was designed as a last resort to keep dirty air from a vacuum bag out of the pump. It was not designed to filter out benchtop grunge. It was a horrible job to clean. I gave up on vacuum clamping until I could devise a better filter system to protect my vacuum pump; I never got around to doing it.

Bottom line, be sure you have some way to filter out the grunge. Perhaps as simple as an empty chamber that the air passes through, dropping sawdust, before it gets to the pump. If you have a vacuum pump with a tank, the tank will probably fill that role.
 
Your machine and vacuum pump can handle a high rate of cubic feet per minute. The little systems we were building could not. That made unsealed MDF unsuitable. Air was gonna come in from somewhere. If air comes in, the vacuum goes away, and so does the clamping pressure.

Yea I guess the 40 hp vacuum pump we use for our cnc is just a touch bigger than the average hobbyist has.:rofl::rofl::rofl:
 
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