PDA

View Full Version : What is the best way to bend tubing?



Stamepde
01-22-2005, 09:23 PM
Without crushing it, sizes from 1" to 2".

Thanks.

3 Phase Lightbulb
01-22-2005, 10:30 PM
12 TON HYDRAULIC PIPE BENDER


http://www.harborfreight.com/cpi/photos/32800-32899/32888.gif

Bends 6 different diameter pipes from 1/2" to 2".

It's $99 from HF:

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=32888

I have the 16 ton version which does more than 2" but if you only need up to 2" this should work good. I used mine to bend the frame for my Psychokart.

-3Ph

Jesse168
01-22-2005, 10:31 PM
One of the first machine shop I worked for was owned by a fella that was more a blacksmith than a machinist. We had to bend some large tubing. We didn't have a tubing bender so he packed the tubing with sand then heated it and bent it around a piece of large pipe that was close to the radious he wanted.

3 Phase Lightbulb
01-22-2005, 10:40 PM
I would REALLY like to build a more capable pipe bender that doesn't get in its own way (Your limited to what you can bend with the design above).

Does anyone have any large pipe bending systems that they want to talk about?

-3Ph

cliff69
01-22-2005, 11:10 PM
I am in the early process of gathering parts to build a hydraulic tubing bender of the compression type that will bend light wall tubing to 4" and 2.5" to 3" .120 wall. I am going to use the ram and wiper type dies in which the ram takes up the slack and then the wipers fold back around the ram die. I am using a 5hp hydraulic power unit I have had for some time, the main fram is a piece of 12" I-beam and the dies will be made from 5" thick SAE1090 blocks appoximately 7" long for the wipers and various radiuses for the ram dies. Main reason is to build car chasisis parts, exhaust and intake tubiing (some of the intakes are 4" for intercooler and turbo cold side pipes)

3 Phase Lightbulb
01-22-2005, 11:17 PM
<font face="Verdana, Arial" size="2">Originally posted by cliff69:
Main reason is to build car chasisis parts, exhaust and intake tubiing (some of the intakes are 4" for intercooler and turbo cold side pipes)</font>

Yup, that's exactly what I want one for too. I want to build some custom motorcycle frames, a custom car chassis, and be able to bend up exhaust.

-3Ph

audrey
01-23-2005, 12:00 AM
Buy a Van Sant number three Bender. We got one and its ok. Audrey

rockrat
01-23-2005, 08:47 AM
Would it be possible to copy the computerized / hydraulic benders that are used in manufacturing and add dials / gaging / stop screws where there would have been encoders? We have a Pines and a (cant remember the name) at work. It seems like one could use long bars to generate the force needed to make the bends.

As for the HF benders, a gent a work bought one and tells me that he has to use sand in the pipe to keep it from kinking. I wonder if they cut the radii deep enough in the forms to cover the sidewalls of the tubing.
rocks 2ยข

[This message has been edited by rockrat (edited 01-23-2005).]

ibewgypsie
01-23-2005, 09:27 AM
Howdy.. Almost awake here.. Still sleepy eyes.

I recently digitized the model3 bender. Laying one made over the original it is a few thousandths off here and there thou. All the points are located. If a man was real gentle or plotted it out on autocad 1:1 he could center punch the marks and drill them out right through the paper. If he got in a hurry nope. I have built things from printed circuit boards to streetrod parts like this. Bender holes are not inline but a curved set of holes. (sneaky way to stop copies)

My model 3 got copied for my own use. I have the original I will post on ebay this week for "back child support". I put a driveshaft up from the floor, and made a few other changes from the "near perfect" design. A rolling bender makes much stronger bends as it does not contort, crush or twist the tubing. A piece of tubing's structural strength comes from it's shape ya know. You can build your own dies if you are stubborn enough. cut them out of plate and laminate them for various thickness tubing. Since the bender has holes, they all stay in time, you don't even have to weld up the dies. Or you can just do what I did and purchase the $225 dies. The plate if you have to buy it will cost that much. I can sell you shoptime on the cnc too if you are the lazy type. Betty sure drills them holes faster than I can by hand.

All us "home engineers need to remember to gusset the heck outa everything" Can't bee too strong for the street, you can be too heavy for the track thou. 14 ga Sheetmetal gusset is usually enough.

Yesterday, I thought I had lost all my gcode files. My computer would not boot up in the shop. I got it out on the bench to see what was wrong, no clue, took it apart. While it was aparts and I was lookin, I cut the case in half, switched the cdroms/harddrives/floppy end around next to the cables going out the back. Welded it back up reinstalled mb/drives and put it back into the cnc and it worked, I added the extra cdwriter drive then. Soon I'll keep all them pesky gcode files on cd.

Ain't nothing funnyier looking than a 300lb man on his hands and knees praying to a busted computer. I can sit and reach both ends of the shop puter now. The way the box is made on the cnc both ends come out in a clean area. I plan on "stainless sheeting" the front of the machine today. My fancy painjob is getting roughed up so I'll make her some underpants. (around the front)

COmputerized punch-bender is up. Scale is back on it, piranaha 8" break die is mounted in there. It'll bend 1/2" thick metal to exacting reproduction. I can post pictures if anyone is interested. Next midnight job? digitizing the "fad tee" kit brackets.

See Lo-buck tools for a decent homebuilt rolling bender. It swivels.
David

ibewgypsie
01-23-2005, 09:37 AM
Ohh..

Using a 3/4"/1" electrical bender, I have built about everything I have with the model3. A big foot, a long handle and a flat floor helps. Use a bigger piece of pipe to adjust the bends. (slip over the bent end)

If you have not ever used one, try that first if you are dealing with small things like go carts. I bought a steel rigid brand bender for $10 at a auction. My set? I bought for my electrical contracting company in the early 80s. I bent a sidecar up for a friend in the late 80s with these benders.

David

seajays2
01-23-2005, 12:00 PM
Check out the plans for sale here:http://www.mechwerks.com/MechWerks_home.htm

DR
01-23-2005, 01:07 PM
To do quality bends you'll have better luck with a draw type bender than the compression type shown above in the HF ad.

I have a Parker tube bender. They mention in the instructions to use a mandrel whenever the ratio of wall thickness to OD is less than .07. For instance, in the case of 4"OD with .120 wall the ratio would be .120/4=.03. This would be a difficult bend to make without an internal mandrel. If the dies and mandrel had to be purchased to do this bend it wouldn't surprise me if you'd be well over $5K in dies alone.