Frame Rail

I’ve been working on building the frame rails since my last post on Thursday. I picked up the steel from Discount Steel on Wednesday, the day before Thanksgiving. I inventoried the order when I got to the shop and noticed that there was an error with my order. I sent Discount Steel my CAD drawing of the frame rail and it was broken down into two major sections, the front and rear section of a frame rail. The frame rail is almost 16 feet long and it’s too long for their machine to cut as one piece, so I had to make the rail as a front and rear section. Each section has an inside shape and an outside shape. The outside shape has all the through holes for the frame brackets to mount to, but in my order I received 4 inside rear sections of the frame. Since I didn’t notice this until Thanksgiving, and they were closed on Friday, I had to wait until Monday to talk to them.

In the mean time, I can get started on the front section of the frame rails.

Starting with the outside shape of the front frame rail I first cleaned off any oil residue using some carburetor cleaner and then hit it with my Dual-Action (DA) sander. This puts a scratch coat on the steel and helps paint bond to it better. Plus it just looks better this way.

First task was to weld the captive nuts to the inside of the frame part.

I realized after I welded the nuts on the frame, that I should have transferred some holes onto the outside part of the frame. When I’m building this frame I’m going to build a truss like structure between the two axles. This will help strengthen the frame where it needs it most. I drew this in my drawing as a series of triangles that are inside the frame between the front and rear axle center lines. Because this is inside the frame, I can weld the truss structure to the outside of the frame, but it’s going to hard to weld it to the inside since it would cover up the truss structure. What I decided to do was to cut out a series of holes where the truss structure would be visible. This would then allow me to weld the inside part of the frame to the internal truss structure. What I needed to do is to make sure the truss structure was in the proper location. What I needed to do was to transfer punch these holes from the inside part of the frame to the interior side of the outside frame part. Since I had already welded up the captive nuts, this took a little extra effort to get it done.

Transfer Punching Truss Holes

Internal Truss Structure

But before I could get to the internal truss structure, I had to weld the top and bottom pieces to the outside frame rail part. But before I could weld up the top and bottom pieces, I needed to drill some holes for the front bumper mount.

Front Bumper Mount

Two of the holes for the front bumper will be inside the frame rail, so I need to weld up some more captive nuts.

Front Bumper Captive Nuts

Now that I had to top part of the front frame section ready, I could start to weld it to the outside part.

Prepping Front Frame Top

Top and bottom welded up.

Front Frame Top and Bottom

As I was welding up the top and bottom parts, I was having a hard time keeping the parts perpendicular to one another. Through the thickest part of the frame rail, it just be 6 inches wide. After I finished tack welding the top and bottom pieces I was about 1/4 inch off. I made up a little tool to push the sides away and then use the truss structure to help the frame keep its shape until the inside piece can be added.

Spreader Tool

After I welded up the truss structure I gave it a coat of Weld Through primer.

Primer Applied to Frame Front

 

 

 

 

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Bed Mount

The project for today was to weld the bed mounts. These were interesting to draw because I didn’t have to worry too much about hole alignment and this was the one bracket that I could risk doing as one piece and calculating the bend allowance.

Here’s what the part started out looking like:

Bed Mount Cutout

How I designed this part was that I needed the part to end up being 2 1/8 inches wide. With it being made out of 1/8 inch plate, this would result in a 1 7/8 inside dimension. Using a formula I found on the web

Bend Allowance = Angle * (Pi / 180) * (Radius + K-Factor * Thickness)

I needed to bend the material 90 degrees and using a 1/4″ radius of 1/8″ thick material. Using these values the formula looks like:

0.278 = 90 * (3.14 / 180) * (.125 + .42 * .125)

Where 3.14 is the value of Pi, 0.125 is the decimal value of 1/8″. I’m using the inside radius of 1/8″ and material thickness of 1/8″ and using the K-Factor of .42. K-Factor is the portion of the material where there will be stretching or shrinking.

Solving for this results in a distance of 0.278 inches. This is close to 9/32 inches or a little bit more than 1/4 of an inch.

How I refected this in my drawing was that I drew the inside shape, then added the bend allowance and then drew the side shape. Because I don’t have a press brake and this piece is about 5 inches long, I made a 1/8 wide cutout and left two tabs about 1/4″ wide.

This allows me to bend the part by hand and then weld up the edge. Here’s how it looks as I start to bend up the part.

Bed Mount First Bend

Flipping it over I can bend up the other side.

Bed Mount Sides Bend

All that’s remaining is the top part. Here I didn’t make a relief cut, I should have, and I did put in a relief cut for the side radius, but I put it a bit too high so it didn’t really help me make this bend. After a lot of hammering here’s what the part looks like.

Bed Mount Fully Bent

Here’s how the part compares to the original:

Bed Mount Comparison

After I was done with welding up the part and grinding the welds, I wanted to see how close I was to my original specs. I got the radius spot on at 1/4 inch, but I’m about 1/8 inch too wide. It doesn’t matter for this part, but I’ve figured out where I’ve gone wrong with my measurements and I’ll correct it in my TurboCAD drawing.

Bed Mount Bend Radius

Bed Mount Dimensions

Bed Mount Corrections

 

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Rear Cab Mount

This is the 2nd project I started. I drew 3 different versions of this part to be cut out.

Rear Cab Mount

The top version is designed to be bent in a press. In this part I’ve used the “bend allowance” to locate the two holes in the side wings. The two holes that are vertically aligned, these are the holes that bolt to the frame rail. The cab will bolt through the holes in the wings. These holes in the wings need to align perfectly.

The first version I’ll bend up to see if I measured it correctly. The second version without the holes in the wing, I’ll just bend up, and then drill the hole through the two side pieces. This way I’ll make sure the holes line up.

The third version is a weld up one and that’s the project I did next.

Weldable Rear Cab Mount

Here I’ve layed the part out on my worktable. The side pieces are held upright and square to the table by using two small magnets. The aluminum square at the top of the photo is used to align the top edges of the 3 parts. Running through the two side pieces is a 3/8″ center punch, just to make sure I aligned the holes.

After welding it together, here’s what I ended up with. Not bad.

Welded Rear Cab Mount

I’m not sure you can tell in the photo, but here is mistake #2. The holes that allow this part to be bolted to the frame, are off by about and  1/8 of an inch. I’ll have to check how the cab bolts to this part to see if there is enough play or if I’ll have to remake this part.

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Body Mount Bracket

This is the first project I started after getting my steel shipment. In the first photo you’ll see how I drew this out as 5 separate pieces. Reason being, this piece bolts to the frame rail using 6 bolts and they must align along the frame rail length as well as along the top edge of the frame rail.

You can see in the photo how the original piece is bent into a c-channel shape along it’s length, and then bent perpendicular to establish the tabs that were originally riveted to the frame. What I was up against was that I had to make sure that when I bent this up, that the holes had the correct width spacing as well as vertical spacing. I found a formula online about how to calculate what’s called “bend allowance”, but I wasn’t sure I could get this absolutely right, so I made it up into 5 pieces that would be welded together.

First step was to weld the c-channel shape by welding the side pieces to the top:

Body Mount Tack Welded

Body Mount Partially Welded

Even after all my careful measurements, I still made a mistake. Here’s one of the tabs which allow the body mount to be bolted to the frame rail. I’m not sure where I messed up but you can see I was way off. I’ll have to make this part from hand and not used the laser cut parts.

Body Mount Oops

Here I’ve bolted part of the body mount to the original frame rail. The next steps are to bolt the two tab pieces to the frame rail and then tack weld the tabs to the body mount side pieces. This will ensure that the part will bolt back up to the frame rail. Assuming I have the measurements right on the laser cut pieces. As I write this I think I’ll wait to bolt it up to my manufactured part instead of trying to bolt it to the original. Once I’ve tacked it together on my new frame rail I can double check it against the original to see how far off I was.

Body mount bolted to frame rail

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November 2011 Progress

It’s been a while since I posted but I wanted to catch everyone up to where I’m at in the build process.

When I started off writing this post I was going to go into detail about what’s happened over the last 6 months or so, but this just became too much work.

Suffice to say I’m starting over.

What happened was that I cut built my own frame by cutting pieces out of 1/8″ steel plate using my plasma cutter. Thing were going along well until I put too much heat into the welds and ended up warping the frame rails. I thought I could straighten them out with some heat from the oxy torch but not to my satisfaction, or more likely, I don’t have the necessary skills to do this.

So I’ve decided to start over, but this time I’m going to put a little more thought into it.

Over the last few months I’ve been corresponding with a fellow car nut from Ireland who is also interested in building a ’56 Ford F-100. Problem is, he doesn’t have access to an original frame. Ian turned me on to a builder Paul Horton ( www.welderseries.com ) who has an interesting way of making parts for your hotrod.

These little tabs on each piece help locate the parts relative to each other. Kind of like the paper models I used to put together where you put Tab A into Slot B.

Taking inspiration from this approach I set about making some CAD drawing of the ’56 F100 frame I do have. I started off tracing the outline of the frame onto a sheet of 1/4″ 4′ x 8′ plywood. Since the frame is almost 16′ long I had to trace it as a front and rear section. From this outline I could start taking dimensions to holes that I needed to keep. I’d center punch the hole into the plywood and then take measurements from this indentation. What was really a challenge was all the curves on the frame. I really struggled with this until I remember some high school geometry around tangents and circle radius being perpendicular to the circumference. What I did marked every frame transition from a flat part into a curved part. At this transition, I would draw a perpendicular line or ray. When the curve stopped, I would draw another perpendicular line or ray. Where these two lines met, that would be the centerpoint of the arc. I could then measure this distance and the angle to know how to draw this arc in the TurboCAD.

Here you can see what the plywood ended up looking like when I was through (it’s hard to read all that’s there):

From this tracing I started transfering the dimensions into TurboCAD. After spending several weeks doing it over and over again I came out with something that I felt was close enough to what I needed. And after checking with a local steel company (www.discountsteel.com) around how much it would cost to have this cut out, I sent the plans off.

Today I picked up the parts and boy does this look fantastic. Here are some pictures showing how the front and rear sections will go tother as well as a few pictures for other brackets that are used on the frame.

Frame Front Section

Frame Rear Section

For some reason the rear section messed up. I ended up with two inside parts instead of an inside/outside part. I checked the drawing I sent and both pieces are there. I’m not sure how this happened. I’ll have to check with the DiscountSteel to see if they had to make any modifications to my drawing.

 

Frame Fishmouth

Here you can see how the front and rear sections will be joined together. I’d be hard pressed to be able to produce this accurate of a cut using the plasma cutter by hand.

Weldable Body Mount

The main body mount to the frame. I’ll go into details on why I made this as 5 pieces instead of one in a future post.

 

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Shop air

After getting the cutting torch and drill press I was in the mood to solve another problem I was having at the shop. Not enough air.

I have a 30 gallon Craftsman compressor that I bought a few years ago for the house. When I moved into the shop I took the compressor with me with the idea that I would eventually replace it with a larger compressor.

When my dad and I had our shop we had a 5 HP 60 gallon compressor and a media blast cabinet. It was great but the compressor wasn’t a true 5 HP and it would struggle to keep up with the compressor, or keep a dual-action sander running. So I was looking for a real 5 HP or larger.

I wanted a Champion compressor, but those things are really expensive and buying new would really cut into my truck budget. But since Karen turned me on to Craigslist, I thought I’d look for a slightly used one.

Boy did I luck out. Not long after I started looking, a used Champion came up for sale on Craigslist. It was in Garland and was just refurbished by an air compressor company and looked to be in great shape. I took an hour off for lunch with the idea of driving over there and making what I thought was an obscene offer. Well they took my offer and now I had to get my new compressor over to the shop in Fort Worth.

When I got to the shop I was able to locate a neighbor who had a fork lift and they were kind enough to unload it for me in the shop.

Compressor

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Cutting torch & drill press

Last week I had finished prepping the sides to the frame rails and was ready to lay down the 2” x 1/8” flat-bar that would serve as the top and bottom of each frame rail. After trying to bend the flat-bar I realized I would need some heat to make the job easier and to keep the flat-bar in shape while I tack welded it together.

After pricing what a new oxy/acetylene torch was going to run, Karen started looking for me on Craigslist. She found a guy in Cresson, TX who was selling one. He also had a 18” Delta Drill press for sale which I also needed. I only had this small 10” drill press at the shop and while it was functional, it just didn’t have enough oomph to do what I needed it to do.

Since Monday I was off for Marlin Luther King Day, we drove out to Cresson to pick up the new tools.

He told me he was near the “old Pate Museum” and I asked why he used “old”. He told me that the family has shut down the museum at the end of 2010. A couple of months back I was thinking about going out to visit the Pate Museum. I remember going to Pate with my family when they used to have the Pate Swap Meet held out there. I must have spent a lot of summers in my childhood going to Pate. It was always my favorite swap meet and it must have been my dad’s because I remember us going numerous times.

We picked up the tools and dropped them off at the shop before heading home.

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