| Project by Justus | posted 225 days ago | 762 views | 5 times favorited | 5 comments |  |
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Ever been bothered by wielding annyingly long pipe or bar clamps? Do you also always seem to have the wrong size of clamps? How cool would it be to have a web clamp that actually clamps like a pipe clamp?
The main problem is, that the arms of the pipe clamp do have to sustain some torque, i.e. the pipe should not bend. The straps of a web clamp bend with no effort at all.
The thought did not leave me and after some less succesful prototypes I came up with this version:
The trick is in the shape of the batten where the strap is running around – think of the triangular sections as if they were wheels where the strap in wound on. At university we learned, that the friction put onto a wheel by a rope depends on the tension of the rope and the angle of loop – twice around would be 720° – as an example. By making the strap taking a longer way at the bottom and putting the lock such that the moving strap is pointing upwards, pulling the web together creates the torque necessary to keep the arms on the object to be clamped.
If you need low to medium clamping pressure on very large or otherwise cumbersome objects, this may be your tool.
Glad to have proven my point I rewarded myself with a pair of Bessey parallel clamps.
5 comments so far
W. Paul
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39 posts in 840 days
posted 225 days ago
Forgive me, but I don’t understand the point. Perhaps you can add a picture showing the device in use? The science sounds interesting, though.
-- Paul, Shelbyville, KY; (Ps 145: 1-2)
rtb
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535 posts in 464 days
posted 225 days ago
I see the point exactly and intend to make several. One of the obvious results is that these appear to be alternative to long clamps that might only get used once a year and won’t cost $1.00 an inch. when not in use they will store in a small space. I have added you to my buddy list so I don’t miss any projects or ideas.
Guten tag ( my english spelling is bad enough, so I won’t attempt any german again)
-- RTB. "dumb animals are not stupid they simply can't talk "
Peter O
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982 posts in 625 days
posted 225 days ago
Very smart. And a fitting reward!
-- http://www.north40custom.com -- http://north40studios.etsy.com --
sandhill
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531 posts in 674 days
posted 225 days ago
I see you idea (I think) but how do you keep the board from popping apart /”\ with clamping pressure?
-- Just another day in paradise. I need more tools http://woodworkerslist.com/classifieds/
Justus
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18 posts in 226 days
posted 220 days ago
@rtb—Thank you for the trust you put into my ideas – but be warned not to expect to much of this design. The clamping pressure these devices provide is well sufficient for epoxy-amine 2K glue or polyurethane glues – but they fail with PVAc. Just like my cheap single-hand clamps. There is a reason I bought the Besseys.
@sandhill – right that is the trick with the torque stuff – you need some inward torque so the arms do not pop apart. And you have to put the unit to be clamped onto the supports.
I’ll make some more instructive pics once I get into my studio again (later this week).
Cheers, Justus