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Notching tubing for cage


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so i had a cage bent up for my datsun. i have to notch all my tubing so that i can tack it in now. it has been suggested to use a hole saw and a sanding drum. also the harbor freight notcher has been brought up. the guy who bent my cage is a professional and he showed me how he did it with a band saw.. i was wondering what people here have had success with and if there are any tips you guys have.

 

:mparty:

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The harbor freight tubing notcher is great if the tubes hit in nice regular angles. When they don't or when the angles are too extreme it is fairly useless. In my case it was worth the $40, but I suppose it depends on your cage layout.

 

I don't know what size tubing you're using, but for my really funky notches I used a cardboard paper towel roll center. It actually slides right onto 1.625" tubing, so that's convenient if that's what you're using.

 

Otherwise I cut the tube to a reasonably close angle with my band saw, then ground the notch out with a 4.5 inch angle grinder. When you get close you can switch to flap sanding disks on the grinder. Trial and error and yeah, it's tedious and takes forever.

 

You could also try one of those tubing notch tools that has all the needles. You press it against the tube and the needles keep the shape of the notch, then you just slide it over your tube and trace it and cut it out. The tools are kind of pricey, but that's probably the best way to go for speed and ease.

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We used a sawsall and a vise to cut the angles approximate, then used grinder and cutoff wheel to cut the rest a little at a time, of course we used a sharpe marker as well. It takes alot of time but the end results is worth it. We had (2) Tubing notches with a drill press but ended up not using it.

 

John

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You can get tube notchers like the ones here: http://www.jd2.com/

 

There are cheaper ones that allow for angle adjustments, usually up to about 50 degrees on most.

 

Use VERY good hole saws (read: expensive), go slow, and use lots of cutting fluid. In Mild Steel you shouldn't have too many problems, but if you were using crome-moly, then you would have a tedious task on your hands.

 

the most difficult part is getting the notch lined up, just right, especially when you have a bent piece that needs to be notched on both ends, for something like a halo bar, or funny car cage, or even just the seat belt crossbar (the bar that goes accross the main hoop behind the seats).

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There are a number of options I've used in the past. I bought a nice holesaw notcher and thought it was really good. Then I discovered you don't need a notcher at all and can simply cut two angles on the tube across the center line.

 

And for really funcky angles you can use a program called tubemitre (search google for it) and then transfer the output to a tube and plasma the end off.

 

But the big problem in all this is being able to measure the angle the tubes come together. Take the time to build a simple protractor for tubing and it will save a lot of time in the end.

 

And for the computer geeks there's a program that calculates all the bends and gives you fishmouth diagrams. I believe it's called bend pack or similar.

 

Cary

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But the big problem in all this is being able to measure the angle the tubes come together. Take the time to build a simple protractor for tubing and it will save a lot of time in the end.

For this I bought a digital protractor from Harbor Freight. It was only $15 I think and works really well, measures angles to .1 degree. I tried to find it on their website just now and couldn't, but I am pretty sure I saw one at the store yesterday when I was there, so they should still be available.

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For this I bought a digital protractor from Harbor Freight. It was only $15 I think and works really well, measures angles to .1 degree. I tried to find it on their website just now and couldn't, but I am pretty sure I saw one at the store yesterday when I was there, so they should still be available.

 

I've been looking for that every time I go there. So far nada. One of these days ...

 

Cary

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hmm.. so i think ill get that digital protractor and while it looks like getting that JD2 tube notcher would be pretty easy, that program for tube coping calculating looks like it would be awesome.. just find your angle. put it, print it out, cut it with a bandsaw and use a grinder on it.

 

thanks a lot for your guys help

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I rednecked it.

 

I have a nice tubing notcher, ~$200 IIRC.

I also have a nice selection of quality hole saws and arbors.

 

I found that testing out the fit on scrap pieces of tubing is the way to go.

Get creative with strings and laser pointers to make sure the little scrap piece is pointing at the junction on the opposite end. This will allow you to get the right fit without screwing up your actual tubing pieces.

 

It is relatively easy to get the tubing notcher set up to copy an existing notch. The plan is.. get it right with a short piece of scrap and then use the scrap to properly set up your notcher.(keep in mind that you will often already have the notcher set up once you get the scrap to fit).

 

I also have another suggestion.

Never cut things(or notch them) to the exact length required. I always sneak up on the correct fit. That allows you to get a perfect fit every time. Try to cut a little oversized. Then you can hand grind the exact fit or you can quickly chuck it back into the notcher to shave a little more off.

 

Mark your tubing... I use a variety of paint markers to put down good visible marks. Then I use a scribe(in the paint) to accurately mark the cut line. Make alignemt marks for all dimensions including rotation.

 

I use typical woodworking type angle finders. I also have an angle finding level. I often use strings and wire. I also used some small square stock cut to various lengths. Laser pointers on magnets helped in a few spots.

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....oh yeah and if your notcher is like mines ('Ol joint jigger), it required a half inch drill which has a lot of torque. I was so preoccupied watching the holesaw go to work when the drill seized into the tubing, the drill came out of my hand and came around and smacked me upside the head.....USE TWO HANDS on that drill! It doesn't really hurt, but you feel real stupid afterwards

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