me and my buddy want to attempt to create our own tubular bumpers. we have a tube bender and a welder, but what i dont know how to do is cut the specail cuts in the ends of tubes that meat with other tube. do u just use a tourch and cut it the best u can or is there a specific technique. anyone know?

thanks
erik

 

You need a tube notcher

 

Do you have a tube bender or a pipe bender? There's a difference and a cheap harbor freight pipe bender won't bend tubes.

You can also grind out the notch with a bench grinder or angle grinder, but it takes practice and trial and error. The notcher shane linked is the easiest and in the end probably cheaper than ruining good tubing.

 

If you go to the hardware store and buy a bi-metal hole saw that is the same diameter as the tube you are using you can do it without the fancy stuff. You drill into one side of the tube, turn and do the same on the other side. A vise with tube clamps helps alot. Tada, you have notches. you can also get angles from this method.

 

There are many ways to accomplish this.

The easiest way is the standard tube notcher that uses bi-metal hole saws. This method works well but does have its limitations(ie angles deeper than 50 are generally not possible)

Next is a special fixture on a Machine lathe. Works great but is VERY expensive compared to the notcher above.

Another method is using software to obtain the miter angles (win miter is one such program) , and then using a plasma cutter(much cleaner) or a oxy/ace cutting torch.

At my shop we use all three of the above processes with the plasma method being used the least.

It sounds as if you guys are very new to the whole fab business thing , and although I wish you luck I will give you this advice;
Before you sell anyhing to anyone you had better know what you are doing it is simply not right to sell people products that are made half ass plus a lawsuit is very likely.

I have (especially lately) seen people spring up out of nowhere selling "off road" products that have no real background in fabrication passing themselves off as knowing what they are doing- now most things here are not rocket science but can be done properly if you pay your dues , and learn how to do the work correctly ie takes some classes get certifications take courses on metalurgy learn learn learn. If this type of business really interests you try working for a large welding shop etc- this will help you learn correctly. Another thing to remember is part time weldors are usally never that great at welding since they put very few hours in each month compared to those who put in 8+ a day 40+ a week 160+ a month you get the picture.
Again- good luck
Richard Stubbs

 

I just re-read your post , and I now I thinking that all you want to do is make bumper for yourselves so if that is true disregard my rant at the bottom of my above post .

Anyhow if you have any more specific questions you can email me , and I would be more than happy to help you with your questions.
Richard

 

It can be done with a bench grinder as well. Takes a little trial-and-error at first, but once you get the hang of it, it goes pretty quickly. Don't worry about getting a perfect fit, the weld will fill in some discrepancies.

 

What if you wanted to do the sam thing with square tubing? What tool would you use for the notching?

Chris

 

Square to square? A grinder or chop saw.

 

So just 45 degree each edge right?

Chris

 

you can use a chop saw to mate round tubes as well.

 

How would you do that?

Chris

 

like this. sorry for the shotty picture but you should get the idea. cut the red lines/angles on the tube on the right and it will mate to the vertical pipe - not as good as other methods mentioned but it will.

 

That way is going to need alot of weld to fill the gaps left.

 

Round tubes a hole saw works real nice. Square tubing i dont cut at 45 degrees. If the square tubing is 1/8 wall thickness i cut one tube 1/8 inch short. The other tube i cut a notch in it the width of the tube. All square cuts no jerkin around with 45's

 

I like that method Zedex! That must be a lot stronger than just butting them up against each other, right?

Chris

 

How do you do it if it's not a 90° corner?

 

It might be a bit stronger .Corners are very strong any way you do it. I just dont like cutting 45s. And after its done its alot cleaner looking. You can do all the cuts with an angle grinder or hack saw, sawzall. The reason i dont like cutting 45s is because in a cut off saw, the blade diflects off of 45 degrees so the cuts arent accurate . Notching it makes my life alot easier. If the angle isnt 90 degrees you can cut the short tube the angle you want and notch the second tube straight cuts. Take up the difference with a fillet weld. Just fill it in with weld. If your cutting 4x4 tubing for example. Its alot easier notching it than doing 45s. And fitting is a breeze. Small tubing, cutting 45s is usually no probem. Just another option for you to try. When your banging something together on your garage floor you need all the help you can get. Most guys dont have access to a big shop with proper cut off saws so notching helps a bit.

 

take whatever degree angle you want, and cut both peices at half of that angle

for example:
45+45= 90 degrees
30+30=60 degrees, etc

it is possible to cut only one peice of tubing to the ange that you want, but remember, the mating surfaces will not match up perfectly

 

So if a chop saw flexes too much, what's the preferred method of cutting a perfect cut then?

Chris