Hello everyone. Just joined this awesome message board but have used it for reference for a long time. Im Adam out of Houston,TX. Hope this thread works out as well as being informative to others and myself. I have a 32 frame built with ASC rails, been boxed, and cross members installed. I am going to need to pinch in the front in the cowl area. The body is a Henry steel 31 Model A. I am planning on the famous channel by dropping the body down and resting it on the frame right on the sub rails. In order to do this, I am going to notch and shorten the feet of the cowl. I started looking at the frame and I noticed there is a twist. It's about a 5 degree twist on both sides. Please see attached images. My questions are: 1. Are the frame rails supposed to have that inward slant? 2. Will my plan of pinching sound right for those that have done it. The plan: bolting the frame to my frame table. I will weld two pieces of plate inside of frame around location where the pinch will be. I'm going to support both of the rails with a piece of square tubing directly below the pinch area. After heating both the area of the pinch as well as directly behind the front cross member, I'm going to pull in each rail with a hydraulic pull back ram. One rail first and then the other. 3. For mock up, I put the body on the frame but am curious if there is a proven position out there. Where I had the body, the rear axle tubes lined up directly beneath the vertical center bead on the rear wheel panel behind th rear wheels. There are two body mount nuts that are exposed in front of the cowl. The 3rd body mount nut is about an inch away from the hole in the body. Is that about where everyone lines up their bodies? 4. If the inward slant is normal for that frame, should I pinch it and still maintain the sland or should I square it by pulling in the top rail first and then finishing up with the pinch. Look forward to hearing back from everyone and thank you.
Is the side really slanted, or is the bottom flange of the frame just not 90 degrees to the side? No, it's not supposed to slant. You should talk to your frame builder and ask why he built it like that (slanted side or bottom flange). Some guys put a 30/31 body on a 32 frame with no pinching required. They may bring the cowl sides out a little, but that is a lot easier than pinching the frame. Do you think you could do that?
Alchemy and High Plains Drifter...thank you both for your replies. Yes, the side is slanted at than angle. Both flanges are 90 degrees to the side. I believe I can pull the cowl out as an alternative to the pinch but I'm not sure if the mini channel will allow me to not pinch. Both top and bottom rails are the same.
Looks like they set the boxing plate inside the rail on bottom and outside the rail on top. Right or wrong its pretty common. It gives you some help with the weld pool location so you aren't welding completely vertical welds.
From your pics you are measuring the angle on the inside. Have you checked on the outside of the frame and is it the same degree? I know on the set of ASC frame rails I purchased that in places the top lip is wider or narrower than the bottom lip. So they have to be trimmed to spec and also bent some to get a true 90 degree angle top and bottom before welding in boxing plates. And I am a firm believer in a frame table to get everything true and square before starting to weld. And yes my ASC rails have a little twist but more towards the front horns which I will work out on the frame table. Posted using the Full Custom H.A.M.B. App!
Wooster..thanks for your comments. You too PurdueSD. I have checked and it is out that much on the outside. The frame looks as if someone took a frame with perfectly square in relation to perfectly level table rails and forced a giant "v" between them. The only reason why I ask this, in addition to affecting the way I pinch, is that the P&J master cylinder/clutch cylinder that I'm going to use has a mounting plate with an angle to it where it welds to the frame. So the plate is not square. But even mocking the plate up, it twists the cylinder assembly up.
Bottom line...the frame side should be vertical, inside and out. The only non-vertical part is the bit in the swage on the outside. But the top and bottom edges of that section of the frame are still in the same vertical plane.
That'd my guess as well. Fitting oversized boxing plates goes a hell of a lot quicker that way too. Quick measure will tell if that's the case and I'm pretty sure it will. Other wise the frame rails stamped bends for legs are not 90* parallel. Depending on your own personal level of "anal" it might make you pucker but as long as the welds weren't ground completely off I don't see a problem. Edit: just saw the remark about the outside being off too. So if that the case, the frame will have a different out side measurement top side than bottom side / bottom bigger by 1/2".
I guess I'm going to have to figure a way to straighten it. P I don't doubt that the reason I have to pinch is because the frame is not square. Had the top of the frame rail been in line with the bottom, I think the body would have dropped right down. I figure that in order to line it up, I'm going to have to pull the top of the frame in by 3/8" on each side. Problem is the frame is that way from front to rear. For that front area, I was planning on pulling the frame with plate welded on in the area of the pinch. I'm going to drill a hole at the top of the plate so that more pulling force will be focused there... Does that sound about right for all of those that have pinched?
I believe I saw somewhere that they pie cut the inside of the frame to pinch it. Maybe it was for a 29 A body? Ago
Ago, I saw the same thread. I believe someone said that the pie cut was to make the ASC rails easier to bend after being heated.
I doubt you will be able to pull your pinch in without some cutting. If left whole, the boxed rails will pucker somewhere.
I ended up measuring the frame rail spacing this morning, right between the 2nd and 3rd bolt body mount holes. The top of the frame is 32 1/2" and the bottom is 32 1/8". So it is not straight and vertical. Any idea on how to fix this issue??
What I been fighting lately with JW Garage boxed rails is that the top and bottom flanges are not 90 degrees to the side plate and the left rail measures 2 inch's wide and the right rail is 1 7/8 wide. That makes it very difficult to get every thing lined up and square. When I get done it isn't real noticeable but slight compromises have to be made. I have addressed these problems to them so we'll see with my next batch of boxed rails? I have boxed a lot of ASC rails in the past and we were very fussy about these things in out shop.
The last ASC frame I did the rails were wider on the top and narrower on the bottom. Had it on my frame jig everything was right on except for the wider & narrower rails. When I boxed them the top rail stuck out further than the bottom, no big deal you really dont see the top anyway. This was like 5 years ago, almost sounds like their not making them consistent?
Krylon32... Thanks for your insight on the issue. It appears that perhaps ASC is off on their stamping? Either way, I would think that by assembling the chassis in a jig the chassis would at least be square, even if the boxing plates are at opposing angles. The problem I'm going to have is pinching this mess. I guess it will be a 2 part procedure. First, I'm going to have to square the rails up. Both rails are cocked out both inside and outside. Then, I will need to pinch them. Kinda hard to find info on all this.
HPD... I'm not sure it that is the issue. The thickness of the rails is consistent from side to side. The issue I'm having is the rails are cocked outward, making the distance side to side different between top and bottom. Crazy hu?
Well I can tell you that with a life time of fabrication, lining up 2 corkscrews can be done. Any type of stamping or structural steel is not going to be the epitome dimensional trueness. Cold rolled comes close, as close as you'll ever need in most cases. So making frames and other symmetrical items where aesthetics and both inside and outside dimensions are critical is a dance of compromise or a lot of work way before the first tack is laid. Usually such things are machined. Unless someone trued the bends and trimmed the legs it's not going to be perfect. If you wanted perfect, and paid for perfect I'd send that fucking thing back. I'm guessing you couldn't ever pay enough for perfect though. If you got the cheapest you could find , well there's plenty of advice against this practice and it's as old as the moon. So your frame is 3/8" out. Which is correct to the drawing, and are the mounting holes correct? If the top is undersized and bottom correct the body will still fit. If the top is correct and the bottom is oversized the body will still fit. Is the 3/8" all to one side or is it 3/16" each side? All to one side might give you a bunch if trouble, if it's split it's just a compromise.
Also when we were boxing ASC rails we had a fixture that worked with our plasma cutter that trimmed the top and bottom legs to consistent width. We did the trimming after we straightened the legs.
31Vicky...the 3/8" over is on each side, so a total of 3/4". Both the top and bottom are correct, its not an issue of being under or oversized side to side. Its like you said earlier with the corkscrew. There is a taper because the frame rails are at opposing angles. Since you said that lining up two corkscrews can be done, what would you do in a case like this? I see a few options. First, in order to pinch the frame, the rails will have to be trued. The amount that needs to be pinched on each side can be taken in and measured on both the top and bottom.. Or second, I can pinch the frame but leave the taper in the rails. I would just have to measure in for the pinch at the top since it is the widest distance. Would there be a benefit to doing one way over another?
All right, a post above you said you had 32 1/8 vs 32 1/2- that's 3/8 difference. Now you say is 3/4" difference ? 3/4" is large bit beyond acceptable. If its 3/4" out the best thing you can do is grab the phone. How about a few general shots of the whole frame
31Vicky....Yes, when I gave the two measurements, that was from outside frame rail to outside frame rail topside and outside frame rail to outside framerail bottomside. The top measurement will need to come in by 3/8" on each side to fit under the cab and that's streaching it. More would be better. I can get some general shots of the frame for ya. So grab the phone??
So then You are including the amount that needs pinched when calling for the 3/4" movement needed (3/8 each side) correct ?
I used ASC rails when I built my 34 frame - had to make a couple sets of 'tools' to enable me to push/pull the rails to get things in the right location --> not only being perpendicular to the table, but also the various widths that the frame should be. In some areas I had to widen the frame rails out (bow them - made big threaded bars to do that), in other areas, needed to pull it back in (chain setups - could tighten top/bottom to square in the process). I can tell you that the contours were off quite a bit in the whole middle area of the frame - just too straight and not matching a stock frame (which I have to compare to). It took some pretty heavy duty tools to apply enough force to reform them to be correct and to spec. The X-Member is what held things in place (once welded). Here are some pictures of my home-made 'tools' - they worked out well and I'm sure I'll be using them again! B&S These are used to pull the frame rails in - and I can use the threaded rods to change the amount top-to-bottom. I found that this was definitely necessary! These are used to move the frame rails out. I put one on the top lip and one on the bottom - then use the big adjusting nuts to make things square and the correct width. Once correct, then tack weld to the frame jig uprights. All of this was done BEFORE I put the boxing plates in - as it would have been impossible afterwards. Hope this helps somebody! B&S
Those are pretty sweet B&S, I'm building my frame table now and was just thinking about how to build just those types of fixtures. Thanks much Posted using the Full Custom H.A.M.B. App!
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