How do you cut/weld 90* angles?

[Lyaec350]

In box tube or angle? I frequently find myself making square frames for things and I never seem to be happy with the results when I cut both pieces to 45* in the bandsaw and weld them together along the seam....

90* to 0* for box tube? 45* to 45*?

Coped joints for angle? More work but might look nicer in the end...

 

[rickairmedic]

I have always just cut 2 45*s and welded the seam together .


Rick

 

[MXtras]

Ditto. Cut half the desired angle in each of the two pieces.

It's the way to go.

Scott

 

[Lyaec350]

What always ends up happening to me is that the final dimensions vary slightly from what I had intended... is there any good way to make sure that you get the outside dimension exactly where you want it? For example, if you want a frame that is 2 feet by 3 feet, do you cut your pieces to 2*wall thickness than the desired size so that butted together they maintain the proper exterior dimension?

 

[rickairmedic]

I usually just cut my frame a little large and trim as needed to get exactly what I want .


Rick

 

[PurdueSD]

If making a table or box shape. Run the corners verical corners all the way up/ down and run horizontal box tube into the vertical... That way you dont have to cap an open box tube end. Kinda confusing but looks like this.

 

[PAToyota]

I do 45° angles. The secret is making sure that the pieces are clamped together to the final length you need before you start welding.

In other words, if you are making a square frame that is 2' x 2' in length don't cut two pieces, weld them together, cut the third piece, weld it on, cut the final piece, and weld it on.

Cut all four pieces, dry fit them and measure, grind down the ends until it all fits properly, clamp it all up, measure again, tack weld each corner, and measure again. If it is all copacetic, finish the welding.

 

[russlaferrera]

IMO it is difficult to cut metal at a perfect angle. . All sawing methods the blade or wheel will flex. The result is an angle that is not what you wanted..

Proper fitting is required to maintain the desired measurements. I leave a small gap between the pieces . This allows some room to reposition the parts in needed.

I then tack weld the pieces. check to be sure that's where everything supposed to be. Then weld.

 

[Atlascycle]

In Angle make a cope cut, then clamp at 90 and Weld.

 

[brianpgriset]

As your finding out, there are dozens of different ways to do this, but none of them will work unless, like others have mentioned, you measure, measure again, cut, re-measure, clamp, measure, tack, measure, measure, and weld..

 

[Lyaec350]

When you say "grind" the edges down before the dry fit, what kind of grinder are you talking about? Flap disc in angle grinder, abrasive disc in angle grinder, sanding pad in angle grinder, die grinder, etc?

 

[PAToyota]

When you say "grind" the edges down before the dry fit, what kind of grinder are you talking about? Flap disc in angle grinder, abrasive disc in angle grinder, sanding pad in angle grinder, die grinder, etc?

Yes...

Depends on how much needs to be taken off.

 

[TNToy]

The grinding isn't the crucial step. It's getting the parts square, and KEEPING them square, as the heat of the weld causes them to warp.

If you have a welding table similar to the picture above, it's not too difficult.


Hypothetically, lets say you were making a 12" x 12" square out of 4 pieces of tubing. Use a carpenters square to mark the desired outline onto the table with a sharpie. (Draw a 1 foot-wide cube on the top of the table).

Now whether you join the ends at 45s, or 90s, it's the same process. Cut everything to length, and lay it out on the table. Now tack all your pieces together. Still look perfect? Good. TACK THEM TO THE TABLE. In 3-4 places on each side of the square. Now weld the hell out of it. Bust the tack welds loose, flip it over, weld the other side, and clean the tack-welds off of your table with a flap disc.

Done.


If you need a piece bigger than you can draw out on your table, it's trickier. Or let's say you're *building* you're table, in which case you probably don't already have one. When I'm working on the floor, I would usually start by getting 2 pieces (both legs cut about 1/2" too long) welded at a perfect 90. Again, tack the hell out of them before welding. 2 tacks isn't really enough.

Then build another, identical L-shaped assembly. *THEN* join the two together. It's much more precise than trying to go around in a circle to each corner, with all the other pieces shifting around.

 

[GJN]

It helps if you jig the whole (or most) of the frame up using robust corner clamps like these http://www.besseytools.com/products/metal/AngleCorner.php or the Record equivalent. I use eight of the Record 4" clamps all the time - very useful.

The other thing is to tack the whole piece up prior to final welding and then to weld opposing corners in sequence such that any distortion caused welding one corner is corrected by the distortion caused when welding the opposing corner.

For lengths of metal, such as legs, where there is no bracing at one end you may have to set the leg at a slight angle prior to welding such that the heat distortion brings the leg back into plumb. This part is more an art than a science, it's taken me 40 years of welding to realise that unfortunate fact!

 

[Torque1st]

BTW- Here is a tip, when typing press and hold the "Alt" key then type 248 into the numeric pad then let up on the Alt key you get a nice degree symbol: 90°

Just my 2¢ which is "Alt-155"

I leave the parts just a hair small for adjustment then clamp measure and tack then measure again.

 

[proorange]

I have 4 of these and they are great for welding your 90's.

http://www.fabtools.com/product.html

 

[Atlascycle]

I have 4 of these and they are great for welding your 90's.

http://www.fabtools.com/product.html

Those look Awesome. Where did you get them?

 

[proorange]

Here ya go

http://www.ramweldingsupply.com/products-view.mcic?s=1996

 

[russlaferrera]

BTW- Here is a tip, when typing press and hold the "Alt" key then type 248 into the numeric pad then let up on the Alt key you get a nice degree symbol: 90°

Just my 2¢ which is "Alt-155"

I leave the parts just a hair small for adjustment then clamp measure and tack then measure again.

I tried, per your instructions. Pressed down the "ALT" key On the numeric keypad (on the R/S of the keyboard) pressed 2 at 4 the page went to the black hole in cyberspace.

 

[Torque1st]

I tried, per your instructions. Pressed down the "ALT" key On the numeric keypad (on the R/S of the keyboard) pressed 2 at 4 the page went to the black hole in cyberspace.

Was your numlock set? In other words were you typing numbers or cursor commands? Cursor commands will send you to lala land.

This works in many editors even notepad in windows.

Here is a chart as well as instructions:
http://tools.oratory.com/altcodes.html

There are other ways to type many characters also.

Have fun!

 

[KraftwerkMk1Jetta]

This thread couldn't have come at a better time for me. This weekend I plan on making a small rolling "creeper" tool tray that I can roll under the car to keep tools and whatever nuts and bolts handy while working. I'll probably use box tubing to make the frame and casters attached to it in a way as to keep it very low. I'll be sure to follow some of these tips when mocking up and welding the frame. This will just be a small project to practice my novice fabrication skills.

 

[garfunkle24]

As your finding out, there are dozens of different ways to do this, but none of them will work unless, like others have mentioned, you measure, measure again, cut, re-measure, clamp, measure, tack, measure, measure, and weld..

You forgot measure.

Seriously, don't you check if the piece warped/moved during welding? Has no-one ever taught you the importance of measuring stuff?