Author Topic: Bending tube NEEP HELP!! (Read 4015 times)

gotrocks · « **on:** Aug 10, 2006, 01:09:49 AM »

ok so I'm little worried that my rock buggy isn't going to be done in time for the roundup

. So now I'm frantically trying to get my runner ready in time

. I decided that I've wheeled a few to many times now without a good roll cage and it was time to get something in there that is safer than the crappy 4runner roll bar. I have a protools standup hydro bender that my friend is letting me use and it isn't exactly the easiest to bend with. It doesn't have a degree ring and is kinda hard to bend things and keep them all straight. The problem that I'm having is knowing where to start and stop my bends. I read the tube bending 101 on the pirate board A LOT and still with the info on there can't seem to get my tubes to fallow my design that I've laid out on the floor. I have a degree meter and really cool protrator that I've been using but it seems like my tube is stretching in the bends and once they stretch they throw all of my measurements off. ANyone have some advice that they could give me. This really is my first attempt at bending up tube and I hate to wasting everying inch of the tube because its costing me that much more money.

Here's what the bender looks like if you don't know which one I"m talking about.

Rockdiver · « **Reply #1 on:** Aug 10, 2006, 09:58:01 PM »

Try this Cut a piece of pipe 36 inches Make a line at 12 inches put that line at the edge of the die and then bend to 90 degrees.
Then Place the Bent 90 on a square and then measure both sides . On Mine the 12 in side gains 8 in and loses 3.75 on the 24 in side. Hope this helps

Rockdiver · « **Reply #2 on:** Aug 10, 2006, 10:00:06 PM »

Just realized your bender might not bend 90 Not sure my info will help you

Rockdiver · « **Reply #3 on:** Aug 10, 2006, 10:16:43 PM »

Here is the link to Pro tools instructions showing what I was trying to explain
http://www.pro-tools.com/pdf/200.pdf
Happy Bending

TheBandit · « **Reply #4 on:** Aug 10, 2006, 10:17:18 PM »

The most important thing is to know where your bend starts. This is tough to nail down, but start by putting a piece of tube into your bender. There is a set screw on the main die u-strap. Tighten it against the tube to keep it from moving anywhere. You should NOT be lubricating the tube or any of the die or backing block surfaces on this type of bender. Put a bend into the tubing at least 5 degrees. Look closely at tubing from the side and note where it starts to neck down. The beginning of the bend is just before it necks down. This is the last part of the straight section of tube with the original outter diameter of the tubing. MARK THIS LOCATION ON YOUR DIE.

Once you have that figured out, continue to bend a 90. This type of bender should be cable of doing a 90 even after a little springback. Make sure the piece you bent is exactly 90 degrees. Then you can find the start and stop points of the bend the same way I mentioned above (just where the tubing starts to neck down) and use this piece for layout purposes.

Nailing down the start location of the bend on the tube and marking it appropriately on the die is very important. Also, if you are using the Pirate4x4 Tube Bending 101 article as a guide, it's also critical to mark these correctly on your dummy piece of 90 degree tubing.

One thing you may find hard to deal with is springback. My advice is that after you have finished pumping the jack on the bender and you think you are at the right angle, release pressure on the jack but leave the tubing in the die (do not loosen the set screw on the u-strap). Measure the angle of the tubing to make sure you have your final angle correct. If you do not release pressure on the tubing, you will not be measuring the sprung back angle the tube and your part will be the wrong angle when you take it out of the bender. If you have to remove the tubing from the bender, be careful to realign your start point with the start point marked on the die.

Once you've got that figured out and you've laid out your part on the floor, start at the center and work your way outward.

A helpful forum with a lot of knowledgeable tube bending folks is www.offroadfabnet.com If you are still having trouble, you might try posting over there too.

gotrocks · « **Reply #5 on:** Aug 11, 2006, 01:02:59 AM »

well I got a better idea of how to bend today. I though A LOT about how I was doing it and figured out what my problem was. don't give me to hard of a time about this but I forgot to take into consideration that due to the stretching of the tube in a bend I'm not able to get all of my bend start and stops marked on my tube before I do the first bend. After I figured this out my bends all started to come together. I bought a really cool clear protrator that has foot long measuring marked and the center line. By putting this down on my layout that I drew on the floor I was able to get my angle of each bend. I also have a magnetic angle meter that I placed on the tube and got the exact degree I was looking for with that. I did what the Pirate bending 101 guide told me and sure enough my start and stop points I had drawn out were perfect. I'll post some pictures tomorrow evening of the progress on the cage. It really looks good and I even figured out how to get compound bends in as well. I was able to bend my main hoop and 1 door bar. The door bar is the best and tightest one I've seen so far.

Chopperman · « **Reply #6 on:** Aug 18, 2006, 09:33:45 PM »

Quote from: TheBandit on Aug 10, 2006, 10:17:18 PM

The most important thing is to know where your bend starts. This is tough to nail down, but start by putting a piece of tube into your bender. There is a set screw on the main die u-strap. Tighten it against the tube to keep it from moving anywhere. You should NOT be lubricating the tube or any of the die or backing block surfaces on this type of bender. Put a bend into the tubing at least 5 degrees. Look closely at tubing from the side and note where it starts to neck down. The beginning of the bend is just before it necks down. This is the last part of the straight section of tube with the original outter diameter of the tubing. MARK THIS LOCATION ON YOUR DIE.

Once you have that figured out, continue to bend a 90. This type of bender should be cable of doing a 90 even after a little springback. Make sure the piece you bent is exactly 90 degrees. Then you can find the start and stop points of the bend the same way I mentioned above (just where the tubing starts to neck down) and use this piece for layout purposes.

Nailing down the start location of the bend on the tube and marking it appropriately on the die is very important. Also, if you are using the Pirate4x4 Tube Bending 101 article as a guide, it's also critical to mark these correctly on your dummy piece of 90 degree tubing.

One thing you may find hard to deal with is springback. My advice is that after you have finished pumping the jack on the bender and you think you are at the right angle, release pressure on the jack but leave the tubing in the die (do not loosen the set screw on the u-strap). Measure the angle of the tubing to make sure you have your final angle correct. If you do not release pressure on the tubing, you will not be measuring the sprung back angle the tube and your part will be the wrong angle when you take it out of the bender. If you have to remove the tubing from the bender, be careful to realign your start point with the start point marked on the die.

Once you've got that figured out and you've laid out your part on the floor, start at the center and work your way outward.

A helpful forum with a lot of knowledgeable tube bending folks is www.offroadfabnet.com If you are still having trouble, you might try posting over there too.

what he said

jimbo74 · « **Reply #7 on:** Aug 18, 2006, 09:56:12 PM »

glad to hear you got it somewhat figured out

Rockdiver · « **Reply #8 on:** Aug 19, 2006, 01:20:02 PM »

Cool deal Cant wait to see it

gotrocks · « **Reply #9 on:** Aug 21, 2006, 09:52:13 AM »

I will post some pictures tonight. It really is looking pretty good. I'm not going to say that I'm awesome at bending tube yet but it is looking really clean and fitting tight so far.

SuperDave · « **Reply #10 on:** Aug 21, 2006, 10:34:38 AM »

This helped me get started... http://www.pirate4x4.com/tech/bendin_tube/

Skinny_Pedal · « **Reply #11 on:** Aug 23, 2006, 07:16:44 PM »

lay out a pattern. find your tangent and offset lines. will never have a problem bending tube

gotrocks · « **Reply #12 on:** Aug 24, 2006, 08:42:25 AM »

after figuring out how to lay out my patter better we started to make some good bends. Check out my makeshift plumb bob. I like to call it my ear bob.