Thread: Some home made corner clamp tools

Hi guys,

I've struggled through a few SHS and angle frames now without a big flat area to tack them together- so i decided to make something to make the job easier and allow me to clamp and tack a frame completely flat even though i don't have a flat surface to work on.

I first made some really simple corner fixtures out of 100x5 flat bar and some small bits of angle for the upright 90 deg walls. found that welding the uprights to the flat bar caused the ends to distort a bit and my frames were no longer clamping up perfectly level.

So i decided to use a different design, and got some 25x25x3 SHS and two bits of 50x50x5 angle, welded together like in this pic:






Tacked the g-clamps onto the bottom to make things easy.

I ran out of angle after making 3 so made another design again out of a short length of 25x50x3 SS rectangle tube i had lying around. I prefer this design as its easier to get the work piece sitting flush against the upright bits of rectangle tube as opposed to the curved bit in the crotch of the angle. I have to check with a square when clamping up in the other 3, but thats no big deal and probably a good idea anyway.

heres the second design:




Now that i've got these made i kinda wonder why I bothered struggling without them, no matter how uneven the ground or table is once the frame is clamped up tightly it will remain flat and square for tacking.

I think i'll get some more stainless RHS and make 3 more of those clamps, it is in my opinion the better design.

thanks for reading!

Although it's good to make your own stuff and get satisfaction out of it, sometimes it's just easier (and cheaper) to go out and buy stuff you need.

These clamps from supercreep auto do a pretty good job and at only 8 bux each are good value too!

Super Works Clamp - Inside Corner, 90 Degree - Supercheap Auto Australia

Thank you gentlemen - you just sorted out my activities for tomorrow.

The supercreep will solve one issue but not another because they can't handle unequal size stock so ill be making one of Corgans for that

Corgan,
I like it, well the second one anyway. Just a note of the angle iron one, are you sure its not the internal radius of the angle that is giving you the problems? The inside face of angle can be pretty hit and miss. You'd likely be better off setting up off the outside as you have done with the tube.

Stuart

Yeah, it's the internal radius that is the problem. It's not a huge deal, because I can eyeball them fairly straight and quickly check with a square before clamping hard, but the outside angle would definately be better to clamp against. I didn't really want such a small surface (25mm shs) to clamp the pieces down to so that's why i went with the angle oriented that way. (and I wanted the clamping to be vertical to keep the whole frame flat and level, instead of clamping sideways to the walls)

I don't see any advantages using angle for the corner walls over tubing, I just had some 50x50x5 angle in the scrap bin that was begging to get chopped up and made into something

The 2nd version is much better- i just ran out of rectangle tube. i'll make 3 more of them and get some bigger g-clamps to tack onto em to handle bigger stock.

method m- i feel a bit silly seeing that link, I always assumed i'd be paying through the roof to buy 4 decent angle clamps for metal work! do those supercheap ones handle decent size tubing, and do they give plenty of clearance to weld while clamped up? they look pretty good. too late now, lol!

I had a look in supercheap; saw the big corner clamps, but I couldn't work out what they were made of. seemed like solid plastic , just didn't feel heavy enough to be a heavy duty cast metal clamp, so i was a bit iffy. picked up some locking c clamps for 8 bucks each instead

The clamps at supercreep are a light cast aluminium.

You can get 50x50 tubing in there and still have room around them to weld.

Unequal sized pieces will fit in them as the triangle shaped clamp pivots to allow for different shaped items.

Originally Posted by method m

The clamps at supercreep are a light cast aluminium.

You can get 50x50 tubing in there and still have room around them to weld.

Unequal sized pieces will fit in them as the triangle shaped clamp pivots to allow for different shaped items.

Yep I found that out today, I was using one today while welding a 5 mm thin strap to a 25 mm section of SHS. I think I still prefer my set of magnets for basic stuff.

Originally Posted by Corgan

Hi guys,


heres the second design:




Now that i've got these made i kinda wonder why I bothered struggling without them, no matter how uneven the ground or table is once the frame is clamped up tightly it will remain flat and square for tacking.

I think i'll get some more stainless RHS and make 3 more of those clamps, it is in my opinion the better design.

thanks for reading!

Thanks very much Corgan,
I am a metals high school teacher and was looking for a cheap and easy way to hold some student work while they brazed up their miter joints. In the past i have used the Supercheap variety but students can still get twisted frames using this method, which is harder for students to check, whereas your design is a lot easier to check for square than twist. Excellent design is always simple. Myself and the students will be making a few.
Thanks again
JohnD

When I have to make up a frame in the shop (usually about 2200 x 1700) I just use a builders rafter square screwed to some timber to check my right angles. Usually have the space to build it on the floor. Tack all four sides, check diagonals and away we go. Always have some reasonably heavy items on hand to sit on the frame to minimise the twisting. HAve one of the above mentioned Supercheap clamps, used it once. Found it was too much mucking around for larger frames cause I would have to pack the other end of the RHS. Also picked up another corner clamp that one can set the angle ie 45 deg from the field days. On day I might get to use it.

I bought a builders rafter square recently. You must have got luckier than me. Mine is out of square by about 3mm. What is the point of a non square square. It served its prime purpose. It produced profit.

I will make my own.

I usually lay out large frames on the concrete carport floor. This is the only flat piece of concrete on my property. The shed floor has about 5 length wise strips 9m long, some (all) broken across and none level. About 50mm variation in level in places but the worst is just in front of a work (junk) bench and rarely causes problems. Also there is only walking space on each side of ths shed. All the rest is full of important stuff.

Smaller frames go on welding bench or on other welding bench or on........ Anyway I like the look of these clamps and may make some myself. The price at supercreep was $15.99 each when I clicked on the link, which is 60 bucks for 4 and they are only ali. Also the nearest store is 400km from here and I have had my fill of the big smoke for now! Good work.

Dean

Dean

I grabbed four of supercreep ones when they were half price. They're pretty good once you grind off the little bits protruding into the clamp face, but you still have to check the diagonals. They're a bit fiddly though if you're doing lots of corners and I wouldn't pay $16 for them. The picture shows 40x40mm stock. As you can see, checking the diagonals on smaller size stock becomes harder as the centre clamp gets in the way. So I actually like Corgan's ones better - nicely done. Cheers - Mick

Originally Posted by method m

The clamps at supercheep are a light cast aluminium.

You can get 50x50 tubing in there and still have room around them to weld.

Unequal sized pieces will fit in them as the triangle shaped clamp pivots to allow for different shaped items.

@ method m. I agree with your logic, however, in 3 short years, 2009 > 2011, those "supercheap" aluminum clamps are no longer so "supercheap"! They are now $15.99 each, so a set of 4 would be just under $65.00! Unfortunately, I just now found this thread today, November 28, 2011.

So if any of any of you remember "Maxwell Smart" let me quote him...
"I missed it by that much!"
Oh well....

adios!

First off welcome to the forum

It was about 4 months ago they had their huge end of financial year specials on the clamps and a lot of other things, so keep your eye out next year if your chasing clamps as they will probably come around again.
I was the same, my local store only had 1 clamp left by the time I got their, but I bought it, LOL

Dave