Evaluate my frame table!

[mitch_04]

Playing around with Sketchup and designing a frame table. It's a big 'un, 17' long, 6' wide, and 3' tall. 3X3 square tubing with 3/16 thickness. Main use will be for my '86 C10 (hence the length) but I'm sure it will be used for other projects down the road. Let me know what you think and ideas for improvement.
51949

[dontlifttoshift]

You won't like the width. Both of mine are 5' x 16" and at times that is wider than I want it. If you use 4"x4"x1/4" on the main rails you won't need the trusses. Mine is 3/16 and I wish it was 1/4", it would take some of the "ring" out of it.

Here is a pic of mine, disregard chassis.
http://frameupwheelworks.smugmug.com/Projects/Donny-and-Angelas-32-Ford/i-SgFGcR9/0/M/032%20%282%29-M.jpg

Three legs on each side and three main crossmembers welded in, the rest of the crossmember float so I can put them where I need them for whatever I am working on......or get them out of my way. The legs are built in two sections so I have two different heights available. Casters or adjuster pads are usable at either height.

Make it as simple and as universal as you can, that will ensure that it stays useful. Also remember that you will want to work under it so leave enough room that you can.

Another note on the truss work, the more you weld on the main rails the more likely it is to pull out of level.

One more thing, leave the ends open. My welded in crossmembers are 2 feet back from the end of the mainrails, someday you are going to want to put the motor in the chassis and that crossmember will be in your way.

[Sieg]

Good information and advice Donny. :thumbsup:

[Revved]

Probably some of the best advice i've read about building a frame table. Thanks!

You won't like the width. Both of mine are 5' x 16" and at times that is wider than I want it. If you use 4"x4"x1/4" on the main rails you won't need the trusses. Mine is 3/16 and I wish it was 1/4", it would take some of the "ring" out of it.

Here is a pic of mine, disregard chassis.
http://frameupwheelworks.smugmug.com/Projects/Donny-and-Angelas-32-Ford/i-SgFGcR9/0/M/032%20%282%29-M.jpg

Three legs on each side and three main crossmembers welded in, the rest of the crossmember float so I can put them where I need them for whatever I am working on......or get them out of my way. The legs are built in two sections so I have two different heights available. Casters or adjuster pads are usable at either height.

Make it as simple and as universal as you can, that will ensure that it stays useful. Also remember that you will want to work under it so leave enough room that you can.

Another note on the truss work, the more you weld on the main rails the more likely it is to pull out of level.

One more thing, leave the ends open. My welded in crossmembers are 2 feet back from the end of the mainrails, someday you are going to want to put the motor in the chassis and that crossmember will be in your way.

[raustinss]

Agree times two,beware thou if you leave the ends open and weld the second cross members tubes will pull into each other so either have a temporary piece in there just for the welding process or make it a bolt in crossmember

[mitch_04]

My thinking behind the 6'x17' frame table was so that I could mount the body and components where I wanted them at ride height, then build my frame around the components. The outside of the tires are roughly 6' and the front to back of the body is 17'.

I see what you are saying about the removable crossmembers, I had considered building some for resting where the components will go. IE one below the engine mounts, one below the tranny mount, etc etc.

I have been getting better at designing in Sketchup little by little, I'm starting to think I may be able to design the frame without having all the pieces assembled for a reference like I had originally planned.

[Vince@Meanstreets]

You can plate and have these sections bolt in instead of welded. Don's right it will pull it from level.

[mitch_04]

So how about this...

A basic rectangle frame on top with 1 additional crossmember centered in the middle of the rectangle. 3 legs on each side directly below crossmembers, welded on (carefully), with bolt on girders (correct term?) centering from middle of leg (to keep some room for getting underneath) to the side rails meeting between welded in crossmembers?

Sound like a step in the right direction?

[GregWeld]

There's tons of plans already out there on the internet to copy. I've even seen them with complete materials lists and how to's. Just Google Automotive frame table.

I've seen lots of 'em -- and it appears to me that you're planning on building a tank on it with all the material you're putting into the table. Not trying to flame you here - just sayin' I think you're way overbuilding it and all the extra stuff is just going to get in your way. Keep it simple. With three down legs per side it will be plenty rigid. I agree with Donny -- I'd do .250 wall tubing.

You don't have to keep this within .0001" === cars ride on springs - and the suspension is adjustable... bodies have bushings and shims... plus or minus 1/32" is probably plenty close enough... I'd be more concerned about how parallel the rails are because you'll be pulling measurements off these the length of the car and parallel would be a good thing!

[mitch_04]

I could be overbuilding it, I have a habit of doing that. However, I always like to err on the side over too strong vs finding out halfway through a build that I have flex somewhere! With the bolt on girders, I could remove them to gain access if needed, or if I find out that I have plenty of strength. I'm building this primarily for my C10 which will probably come in close to 4000 lbs.

I have scoured the internet reading different thread and have seen so many different ways of building them. This design was based off of one that I found that made sense to me. I figured I'd start up a thread so I could get some feedback on my design.

Seems like there is more than 1 way to skin a cat... who knew?

[dontlifttoshift]

I promise, you don't need the truss work.

The problem with looking to the internet for frame tables is everyone has different purposes for their tables. If you are building top fuel or nascar chassis you need a surface _plate_ to work off of. This is different than what we need. A fixture table or surface plate needs a level surface, machinists level, and several holes to bolt different tooling to. We are not building space shuttles, we are building prototypes out of cars that usually had a tolerance of plus or minus an 1/8". We need a platform that gives us a solid foundation to measure and build off of, we need access to all sides of the car, we need to be able to adapt, on the fly quickly and easily. If I am building fixtures and tooling, I am not making progress on the car.

The table I pictured is nearly a direct copy of the table that RadRides uses. The first table I had, had a ladder structure on the top made of 2X2 on 2" centers, big gussets at all the legs, crossmembers on the bottom tying the legs together and all of that stuff was just in the way. After using the second table, I realize that you just don't need all the structure.

If you weld your frame to the table, you just increased the strength of both pieces....even if it is just temporarily.

I'll answer the welding question here. The legs are welded on with two welds side to side and the crossmembers are welded with two welds vertically. You want to avoid welding on the corners of the main rails, that is where most warpage will come from. As I stated in an earlier post, I built the second one on the first one. If the center ends up low, that's okay, with adjusters at 6 points, you can jack up the middle and the weight will settle the ends in and you will be level. Less than an 1/8" of pre bow is all it takes.

[mitch_04]

Thanks for all the information, makes me feel a little more confident with less bracing.

[ironworks]

The less you can weld to the top section or rails, the flatter the top surface will stay. The thicker the material the more you can weld to the actual structure without it pulling or moving.


You will never have 4000 lbs on your chassis table unless you add everything to the chassis table for mock up. Dynamat, glass, and interior parts. The chassis table is just used to get the parts to a roller in the fab process typically.

[WSSix]

This is good information. I hope to one day build a table also.

[mitch_04]

I'm glad it's helping others! Some of the threads on frame tables tend to stop without any finality... if that makes any sense. I'll probably do another design in Sketchup, but that's more for the practice than anything.

[mitch_04]

You will never have 4000 lbs on your chassis table unless you add everything to the chassis table for mock up. Dynamat, glass, and interior parts. The chassis table is just used to get the parts to a roller in the fab process typically.

This is one of those duh moments. I do plan on assembling the drivetrain, frame, suspension, and body on the table. However, many of the little things that add up weight won't be added until it's back down.