I am boxing my frame and have it clamped down to a heavy steel table with post supporting it on the ends. Tack welded the top unclamped flipped it over tacked the bottom then ran several small beads(1 inch or so) on the bottom. flipped it back and did the same on top . kept this going till I had it welded entirely. Now it seems to have twisted a little, the side I have done is approx. 3/4 of in inch higher than the side that isnt done. I wonder if anyone has any advice. will it come back in line if I finish the other side? do I need to pull it back straight before I do the other side? would it hurt to use some heat to relax it back to level?
The Ford Model A frame by design was SUPPOSED to flex slightly to keep things from breaking. Although many (including myself) box their frames to increase strength, by doing so also will remove almost all of the flex, putting all the stress on the corner joints. Installing a k-member or X will keep things square, but keep in mind that unless ALL of this is done on a frame table or jig made to keep things straight you will do more harm than good by welding the length of the rails in order to box them. Spend the time to make sure things are securely clamped or welded to the table b4 taking on such a task. When I did mine I bought a digital level, a laser...and due to the taper of the frame from front to rear, ran a simple string down the middle for a centerline to measure off of...Measure 34 times in every conceivable way. Take your time welding, small beads, alternating side to side to prevent excessive heat. Unless you keep it straight while welding you will NOT be able to correct it after finishing.
When i boxed my Model A frame, i had it tacked into a Jig at the front, middle in two places and then at the rear. So had four places along the length of the rails at each side it was tacked in. I welded the center crossmember and a K leg in at the rear before welding the boxing plates. I did it all with a Tig, and did all the top first. I went from one corner to the next, and just kept going around in circles until it was all welded. The Tig was good because it didn't put in nearly as much heat as a Mig would have.. and because it was slow it did take me a couple of days worth of 2 hours or so each to get it done.. which gave it sufficient time to cool in between. After i did the top, i built a rotisserie for the front and rear of the jig, and flipped it upside down and did the same thing. After it was all welded and cooled.. i cut it out and it had not moved at all. Was still within 1/2 mm of being diagonally square and was also flat. It had not twisted at all.
Plumbid. Sounds and looks like exactly what I am doing. Is that a Dagels X member? I got one and I am very happy with it so far. I did end up with a slight twist like I mentioned but I guess I will just pull it all back where I want it and finish setting in the X member after thats in it should be all square again. Posted using the Full Custom H.A.M.B. App!
Now you guys got me worried. I boxed my frame while it was on jack stands. I checked the level from time to time and when I finished and all was OK. It had not moved. Then welded in a Mustang II front suspension and Maverick rear. Everything seemed perfectly straight and sat right. The chassis has been stored for a while, how do I check to make sure it is correct?
Lay flat on level surface and check levels at front, centre and rear. Start at one end and go from there. Being an old body man I would also check all the diagonals to ensure that it is square as well. If twisted it may need a torsional tweek to get it true. If out of square it will need a pull or diagonal push with an hydraulic ram. Easy with the right tools and ability. Chassis may require securing with chains to floor and a slight lift with a trolley jack on the corner that is low. If fully welded it will require a bit more effort that if it was only tack welded together.
Putting proper crossmembers in should take out any twist. Just make sure the frame is clamped down tight and straight then weld in the crossmembers. Those should hold it square, and until you get the crossmembers fully welding in there probably will be some distortion of the frame. Don
Next time tack the top and bottom before you unclamp anything. This should help keep some more of the twist out. Try to keep it in one position as long as possible before flipping it. Hope this helps. Wow post 2000.
I weld up my chassis's in stages,always working opposite the previous welds.If I do a short run on one side starting from the front of the chassis welding towards the rear,I do the opposite rail in the same direction,on the same part of the rail as last side,the same short run,thus using the pull of the welds to counteract each other.Works a treat for me.As said though,tack it down square on all four corners before you start.
I'd have to say that 28A and Barrelnose Pickup hit on one thing that the guys I know who do a lot of frames preach and that is tack everything in place before finish welding anything and work your way around a bit at a time when welding it up so as not to get too much heat built up in one area, I ended up building a twist into the back half of my truck's frame by not following those exact suggestions years ago. The "keep welding till your done" thing doesn't work well on hot rod or custom truck frames if you don't skip around to keep the heat from building up too much in one spot.
Interesting thread... I was working on my frame jig at my shop one day, in walks a straggler...Silicon Valley type, dockers, tasseled loafers, polo shirt. I'm jacking the porta power fitted to the corner of the table, watching the tape, the guy says "Long as it's around an eighth, that's close enough..." "You must be the new boss," I said. "No, I was just looking around at the cars here..." He left as he arrived. I always pull 'em to zero. If it's 1/8", I pull it again. Done. Okay, so a few years later, we are here, our new home. 2.5 car garage, I've made a portable frame table, (shop wasn't built yet) I have my American Stamping deuce rails set up, clamped, bracketed and tacked securely. I am setting the rear 'A' crossmember, having some problem with my centerline. Measure once, Starboard side...good to center. Walk to the other side, weird measurement: 3/16" off! Working from side-to-side, I've had the foresight to have a yardstick on each side...save steps. After an hour of head scratching (and replacing the centerline string with steel strap) I look at my yardsticks...Side by side, at 24" they were 3/16" different! And they were BOTH made in China! LOL
I worked at a collision shop for rail cars a couple years back. We ran into that same issue with tape measures. Boss ended up having to get everyone the same starret tapes so everyone got the same measurement. And if the tab bends in a little bit when you drop it, well that'll throw ya off too. -Pat
YUPPERs to using the same tape measure for the whole job and not having a separate one on each side of the work area. I took that on March 31 after measuring the difference between the wheel mounting surfaces on my 48 front axle and the Jag XJS front suspension . The one in the middle has the hook to use over a nail for framing houses and it doesn't work too when you hook it over a flat surface at the end of what you are measuring.
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