Tear apart my suspension setup stand design

My garage floor more resembles a very broad, shallow funnel than a surface plate. I need to fix the alignment on my fun car. Before I can get out the string and rulers I need a set of setup stands.

I was looking at Coleman Racing's Chassis Set-up Stands. They're about $400 shipped.

I decided to investigate the cost of making a set myself and drew something up in CAD last night:

The top plate is 300 mm x 300 mm (slightly less than 12" x 12") and 0.5" thick. The tubing is 1" wide 0.125" wall. The leveling feet are M8 with a 25 mm round pad. The stands are 250 mm tall. I think this is about $250 in materials for a set of four. Most of the expense is the top plate.

I designed it to be able to take the top plate and move it to under the top tubes. The top tube then becomes a fence to capture hub stands. The area the hub stands would sit in would be 10" x 10" which is small. Other chassis stands on the market are about 15" x 15", I think.

This design doesn't nest when stacked. I could remove the bottom horizontal tubes and then they'd stack, somewhat. This also doesn't include any roll on/roll off area. I could make them 300 x 600 mm to include some roll and space for scales, etc. I don't think that's necessary if hub stands are involved, but I don't yet own a set of hubstands. They're just on my shopping list. If I'm using hub stands I think these are the right size, but for working with wheels and tires I think they're small.

What would you change?

Looks nice. Is stacking a priority? I feel like those angles just make fabricating really annoying. Square is quick and easy.

I'm considering making something similar, as seen recently on JG's wednesday night feeds. i'd probably just build something out of wood for $40 or less.

I don't like that the whole top section is held in shear by those welds, I'd have the vertical tubes support that section from beneath. Also, I think 12x12 is a bit small. Warpage of the stands  during weld would also be a concern, but I suppose you have provisions for leveling already. What's your plan for turn/slip plates?

I just built some setup stands myself a couple weeks ago, which I'll readily admit were basically a complete and total ripoff of JG's design . Combo of 2x4s and 2x6s stacked like Jenga pieces, 18" square. My slip plates differ from his, I've just got some pieces of OSB with a couple of greased up linoleum tiles laid on top and 2x4s cut in half lengthwise to keep the car from slipping too far. Seems to work well enough for me.

Furious_E said:

I don't like that the whole top section is held in shear by those welds, I'd have the vertical tubes support that section from beneath.

Nesting would be a requirement for me, so the bottom horizontal square would be enough larger than the top that with the vertical legs welded between them they can stack.  Just notch the top plate for the legs.

Think about putting a railing around the platform at the top to avoid wheels rolling off. 

Seen that happen more than once with airplanes up on scale platforms!

Karacticus said:

Think about putting a railing around the platform at the top to avoid wheels rolling off.

I've got it set up so the top plate can be moved to bolt under the top horizontal tubes. The tubes would act as railing.

Here's version 2. With the difference in price between 12" x 12" plate versus anything bigger, I've tried to maximize the area of the plate I'm using. Here I've moved the fence outside of the plate, which also puts the vertical tubes into the bottom of the top horizontal tubes, removing the welds in shear.

Four adjustable feet will drive you crazy, as one will be holding another at something less than its share of the load.

kb58 said:

Four adjustable feet will drive you crazy, as one will be holding another at something less than its share of the load.

I'd design it with you a fixed foot and two adjustable feet in an equilateral triangle, but I think that could be unstable.

If you want to refine the design, you should listen to suggestions. When I was a young draftsman, I was taught never to marry a line, because chances are you will have to move it. Design is a process of revision. Seach google images for other successful designs. 

Simple is good in design - and more likely to be well made. 

Weld a top square of angle iron (flange up or down) set you plate in it ( half inch is at least three times thicker than you need).  

Weld a bottom square of angle or square tube  an inch and a half larger each way.  Put one post between  top and bottom squares at each corner.  If you make them stackable, you will thank yourself later. 

If you plan on putting the Rolls Royce on it, add a quarter or 3/8 rod on the diagonal on each side. I'd buy your feet first, and remember that you are putting 150-300lbs on each one, I would get something sturdy. 

Michael

version 3

I've simplified the top. The rails around the top are now 2" x 300 mm plate screwed. The design is stackable at the expense of the verticals having compound angles. Luckily they're all the same.

I'm not the biggest fan of where the vertical tubes intersect the top plate's horizontal tubes, but it's not terrible. I'm running a simulation right now.