The best way to split it and deal with the bow is to leave several small places attached. This requires stopping and starting the cut but it keeps the tube straight while you are splitting it. It will run all over the shop if you start at one end and go straigt thru. Once both sides are split the small places can be cut, it will want to spring apart so be prepared for that. Once the splits are clamped back to back that should cancel out the bow. If its a stich weld at the flange centers, that will pull most stresses back out of the halves. You can do some cool stuff splitting tubes. My frame rails are split tubes and curved to follow the body. The hard part is getting a matched pair.
How about tacking 3 pieces of square/rectangular tubing together before you split them. When you cut them apart, you'll end up with 2 "I-beam" and 2 channel (that maybe bowed) sections. Larry T
Very nice result........looks like lots of effort went into that....but something to be very proud of...looks like you have a jig or guage piece along side the frame rail to guide you....thanks for the comments and pics. I see the rail is split along the body line curve, but not completely it's whole length. do you put this in a large press and bend (cold? heated?) or rig up a port-a-power and bend in place?? inquiring minds want to know! Ray
Wouldn't it be easier to buy C channel to begin with? I'm sure I've seen it in various sizes at the steel supplier I use.
That's just a straight tube staged to show the amount of curve. Where its straight, there is no need to split it. The tubes were bent by clamping the tube (must be longer for leveage) to the table with the split end hanging off. An engine hoist provided the power, and small heats in a "V" shape were made along the 1" flanges. The closer the heats the more bend, its only a 1" flange needs to shrink or stretch if you split a 2" tube. It's very important to heat consistent and evenly on both sides. After splitting, 1/2 of the tube was all ready headed the right way. There is no perceptible distortion as you'd have if it was rolled because the 6 or 4 " sides didn't have to shrink or stretch. For the S bend it was just a matter of flipping it over and pulling it back. As far as a gauge, I drew it up full size and made the steel follow that, I did cut the profile out of some tempered hard board to keep things moving a bit quicker. I took some trial and error to figure it out but all in all it was pretty easy. Scrapped one piece because I had the tube seam to the outside and I didn't like it.
can house of fab or any one tell me why the truck arm tilts when it is bolted to the axle. Is the saddle on the axle designed to make that happen? is that the way the design has to be or can it stay straight? Thanks
The arm (which is "flat") is intersecting the axle (which is a circle), at an outward angle, and at a downward angle as it comes from the inboard pivot point to the outboard axle. If you think back to high school geometry, it should make sense as to why this is happening. Grab an empty paper towel roll and some cardboard and build a quick model to see that the intersection between the arm and the axle is not parallel to the axle centerline.
This makes a lot of sense to me. I will go even further and ask, "If you want steel I-beams, why not just buy I-beams?" Is everyone just too bored and needs an excuse to cut and weld something? Steel: http://www.mcmaster.com/#steel-i-beams/=ggmf5m Aluminum: http://www.mcmaster.com/#aluminum-i-beams/=ggmdq8
as I understand it the mono ball type set up is to prevent bind up in suspinsion I ran a NASCAR late model stock for a few years and that is the explanation that the chassis builder gave me
Structural steel is hot rolled, never square or true and butt ugly. Tube is usually cold rolled, pickled, and pretty nice to work with. If you split it and put it inside out, there's a seam to deal with.
Plus...as has been said...they NEED to be flexable, or better, they NEED to be able to easily twist as the body of the car moves as it goes around corners, goes thru the bumps and undulations in the road during everyday driving. I put a pair of GM arms in my 54 Conestoga (Stude wagon). Except for the narrowness of the Stude frame and having to "make them fit", I'm very happy with the ride they provide. Now..I just have to wait and see how they do at the drag strip.. I would never consider building them out of any "industrial steel" or anything else when they can be bought, and when bought for actual use on a car or truck, why build them out of bridge making steel...!? Not a good idea. Mike
I would also buy them before fabricating them. I was just trying to figure out why people were choosing certain paths for fabrication. Bridges flex too, you know. I wouldn't rule out the use of steel based on the usual application. But I do acknowledge that you need to be aware of the properties of the specific alloy you are using. That's another thing that makes me lean toward buying parts off the shelf. There's a quality control process at work there. When you cut and weld and shape things on your own, you're changing the properties of the steel in those areas. So how do you verify that the properties of the finished product match the properties of the alloy you chose?
On this subject, has anyone used or have experience with the No Limit Engineering kits? They're definitely up there in price, but for those who don't have a ton of time to fabricate every piece they look like a good, well thought out option. Especially after finally taking my 50 Fleetline around the block last week on dearched, reversed eye leaf springs and 4" lowering blocks, the ride was less than pleasant to say the least!
do you have any pics of the front (crossmember). are those nascar arms,chevy arms, or did you make them. Thanks..
I don't see any reason why you couldn't use coilovers. There's a '70 Chevy pickup on Craigslist right now for $400 here in Joplin. Surely they pop up cheap around where you live, too? Buy one, keep the rear suspension, and part out the rest. You'll probably end up making a little money on the deal.
Thanks for the replies XXL and Atomic Dave. I'll have to hit the wrecking yards as I don't think my neighbors would be too cool with me parting out a pickup on our street! If only we had the room because I'm sure you're right about making money on the deal. So do the 60's - 70's truck have coils in front and shocks behind the axle?
just to let you know. there are some shops in n.c. nascar country that sell the arms used. i think they go for about $50.00 a piece. the arms are different, as there is different amounts of pinion angle built into the arm. one of the shops down there was called second chance racing. think that one is gone. know there are others. just dont know the names.
Ive posted my rear suspension up here before but here it is again. I am hoping although not channel, the stepped tubing will have the flex required. I am pretty pleased with its articulation in the garage so far. My only complaint so far is they ate up a fair amount of space under the car....but that only affected shoehorning the exhaust and mufflers into place. Btw, I used Camaro front leaf spring poly bushing for the front, if they dont work, i will just replace with OEM rubber ones.
The front trailing arm brackets are rivited to the cross member no shims but the trailing arm bolts are essentic. My plan is to use the crossmember ( part of it ) and the arms replace springs with airbags and reuse shock mounts and track bar, That being said some changes will have to be made due to space. Im going to weld in a bar to lock the arms in at the correct angle when I remove the stock axle, I should be left with just arms/crossmember/track bar, I had this rear section cut out complete for $100 from local junk yard, I figure I can sell the axle for that much and scrap the frame aswell. as a bonus the stock crossmember acts as a drive shaft loop to. MrC.
That's the route I'm trying to go. No engineering just use what GM designed. I made a deal with a CL A-Hole, we made a deal and agreed on a price; when I asked when and where I could pick them up he seemed to not be interested. When I finally got back in touch with him again he sold the set-up. I told this guy I had cash and was ready to pick up. I guess at the time he had plenty crack, needless to say I'm looking again. I'm sure Mr. C will have his job complete before I find a source for the parts.
I have a 71 c-10 that I want to see double duty/ street-strip. Any thoughts or info on deleting the coils on the arms and going to a coil over set up behind the axle with a full length track bar???
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