Thread: Angle Clamps - how hard can it be?

At the complete other end of the scale, I bought 4 corner (2 axis) clamps from supercheap about 3 years ago. On special for $8 each. Not even sure what they're made of - cast aluminium, plastic, something light. Anyway, they've been really good. Obviously they aren't rigid enough to combat distortion, but for jigging things up they've been fantastic.

Jody did a bit of a review on the stronghand 3-axis clamp. Looks nice.

The Record M141 clamps are very good, I bought 8 back when they were around the $20-$30 mark and use them incessantly. I suspect they are a lot more money these days but you might find them in estate sales.

At the other end of the spectrum I've lashed out on a 2m x 1m nitrided Stronghand table. Jigging stuff up on that is a dream.

Originally Posted by WelderMick

Jody did a bit of a review on the stronghand 3-axis clamp. Looks nice.

They do look nice, trouble is our local welding supplier wants nearly $400 EACH for them!

Originally Posted by Gavin Newman

They do look nice, trouble is our local welding supplier wants nearly $400 EACH for them!

When I enquired at the fancy shop I think that's what they normally stock, although they didn't have any. The one I got was $182 plus $16 freight, I think the 3-axis was pretty much twice that.

I use the elcheapo magnets all the time, purely to tack up, once everything is tacked together and square, keeping it square, is a matter of getting the welding sequence right, sometimes yes, sometimes NO. Tacking a brace across the job also helps.
Kryn

I've got some Bessey WSM-9 clamps. I bought them from overseas, for a lot less than they go for here. 2-axis only, but I generally don't do 3-axis in one go anyway.

Originally Posted by KBs PensNmore

I use the elcheapo magnets all the time, purely to tack up, once everything is tacked together and square, keeping it square, is a matter of getting the welding sequence right, sometimes yes, sometimes NO. Tacking a brace across the job also helps.
Kryn

Up to this point I've been setting up the joint using magnets, but even the smallest tack will pull the joint out of square. So then you peen the tack, or just belt the pieces to get them square again, and move on to welding out the join, but in the absence of clamping, the join can still move out of square.

I've had some success starting with the pieces a bit wider than 90 degrees, I've also used bits of MIG wire to pack out and hold the angle, but all this just chews up time. Even when you get the corners square, such as for a simple 700x2000 frame in 40 SHS I did for an awning, the fillet weld inside each corner caused the long sides to bow inwards, requiring the addition of another piece halfway to maintain the 700 width.

Haven't actually tried this clamp yet, but I'm hoping it'll speed up the process considerably.

Originally Posted by RustyArc

requiring the addition of another piece halfway to maintain the 700 width.

Which leads me to a strategy that I use a lot - just clamping or temporarily tacking spacers along the length, so that it doesn't bow in the first place. I use my el cheapo angle clamps to just hold the joint, but rely on spacers and immovable objects to keep things aligned. Ratchet straps come in handy too.
You're right about the time factor though - how good would it be if metal didn't distort.

After reading the information in this thread I decided to look around for some of these for some projects. The best I could find in Australia were about $213 each delivered and up to $400 each! I have ordered two from Amazon for US$282.67 (AU$320 approx) delivered. Have bought a few tools etc from Amazon lately and their selection of items available to Australia is a bit odd. Not all you would think could be sent are available but sometimes other sellers listed with Amazon can supply an item when Amazon won't. Just check shipping charges first before completing order.
All items ordered earlier this year have arrived in good time in good order.
Of course the AU$ exchange rate not as good now as previously.

I would suggest that a different approach may be of benefit.
Assuming that you are making a square frame with four mitered corners. Cut your miters, be as accurate as you can, but if anything you want any gap in the assembled miter to be on the inside of the joint. Now set out your frame on a flat surface that is free of twist or use packers to remove any twist. Place two tacks on the outside corner of each joint, one top and one bottom. You should now have a four sided frame that you can move on the hinged corners. Take your tape measure and equalise your diagonals, taking care that you do not measure over a tack which will skew your results. One the diagonals are to your satisfaction, place a tack on the inside of the first joint, (I find on the top inner edge is the easiest location). Now do the joint next to the first and work around the frame. Check your diagonals. Finally, weld the frame. The miter welds must only be welded from inside to outside. This minimises distortion as the forces are trying to bow the frame outwards, rather than inwards.
On light rhs, don't be afraid of correcting some distortion post welding if need be, simply holding the frame over a solid floor with the long diagonal vertical and dropping/slamming the corner downwards will often be sufficient to correct minor distortion.
Distortion is part of welding, (if you think steel rhs is bad, try some stainless!), and is best managed by correct joint design, (butt tee joints distort less than miters), and welding sequence, (don't alternate between diagonal corners as this will maximise distortion and weld outside corner, mitre from inside to out before finally welding the inside corner). Naturally, place all members in the frame and tack in place before the first full weld is run.
As Kryn posted, a diagonal brace or two is a good thing on heavier work as straightening these sections takes more brute force than a home workshop can offer.

It,s not very hard at all.
Make a simple one. An angle clamp from angle section. Who would have thought.

Yes! I know someone will say "what about the internal radius".

I say make the angle fixture with the toes facing out. Cope the joint, check for square and tack in the three obvious places. Tacked is good enough, no further welding and no further distortion.

I have a simple fixture which I use to make up frames and just use a vice grip or C clamps to secure work to fixture.I will find for a photo, after the shift from the old garage to the nearly finished Garaj Mahal if the blasted electricians turn up to finish what they started.

For those a piece of work up tacking up, tack everything up before welding it out and you have a much better day, particularly if you oppose your sequences of welding as opposing distortion forces tend to cancel each other.

Originally Posted by Karl Robbers

I would suggest that a different approach may be of benefit.
Assuming that you are making a square frame with four mitered corners. Cut your miters, be as accurate as you can, but if anything you want any gap in the assembled miter to be on the inside of the joint. Now set out your frame on a flat surface that is free of twist or use packers to remove any twist. Place two tacks on the outside corner of each joint, one top and one bottom. You should now have a four sided frame that you can move on the hinged corners. Take your tape measure and equalise your diagonals, taking care that you do not measure over a tack which will skew your results. One the diagonals are to your satisfaction, place a tack on the inside of the first joint, (I find on the top inner edge is the easiest location). Now do the joint next to the first and work around the frame. Check your diagonals. Finally, weld the frame. The miter welds must only be welded from inside to outside. This minimises distortion as the forces are trying to bow the frame outwards, rather than inwards.

For the awning frame, this is pretty much what I did, except I couldn't be arsed changing the angle on the bandsaw so I did butt joins, but the procedure was as you advise, all corners tacked, checked diagonals, tack more and weld out. What caught me there was the bowing in of the 2m sides, which I'm pretty sure only happened when I did the internal fillets, which were the last 4 welds I did. I have to do 4 more of these awnings, and I think the major difference in my approach, apart from using the angle clamp, will be bracing the sides such that I hope I won't need to install a spacer.

It is interesting to hear about the preferred direction to weld mitres - will need to remember that.

All that said, I also do a lot of fabrication that isn't a square frame, just lots of bits of RHS that need to be welded square to each other. Hopefully the clamp will make that a quicker process.

Originally Posted by Grahame Collins

Make a simple one. An angle clamp from angle section. Who would have thought.

Well, now I have a nice angle clamp, I can make more angle clamps

Similar to Jody's SHS distortion video, I'm curious how you might sequence:

- one mitre
- four mitres in a frame, like Rusty's job

I wonder if a similar approach would work. Maybe one mitre in one direction, then the back side mitre in the opposite direction. If doing one joint, outside corner then inside corner fillet last. If doing four joints, all mitre cuts welded out opposite style, then all four outside corners, then all four fillets. How does that sound?