Built a car dolly using 80/20 slotted aluminum!

[mikey]

So I wanted to make a nice dolly for maneuvering my formula car around the shop. I found some great heavy duty (750lb rating each) swivel casters at casterconnection.com. I attempted to build the dolly from wood at first, but when finished it had a warp/twist to it that prevented all the wheels from sitting level. Me standing on it wasn't enough to square it up, I used a lot of screws in it!

The weight of the car might have been enough, but overall wasn't thrilled with it so I started looking at 80/20 aluminum as an option since I do not weld. Two sources popped up online - 8020.net and tnutz.com. The latter had much better prices so I got two pieces of 1545 series for the ends (24" long each) and 1530 (60" long) for the center. I had everything cut to order so all I needed was my tape measure and a 3/16 allen wrench to assemble it when it arrived!

This first design ended up being very hefty, about 30 lbs of aluminum and the casters weight 5 lbs each so overall 50lbs for the cart.
The design did allow for adjustability of the cross beam distance as a note. The height is 8 inches, which is what fits under the car when lifted with the quick jacks. I could easily add vertically to this and create a taller cart on this same base.

So then I wanted to know how lightweight I could build one. After all, my aborted wooden attempt certainly was a lot lighter! I found a nifty beam deflection calculator on the 8020.net site and did some math with the goal of building the lightest version I could. 8020.net offers light and ultra-light versions of the 15 series so I bought the beams from them the second time around. The website gives you the weight among other characteristics when you click on each profile type, so I knew exactly what the final project should weigh before deciding if it was worth re-buying parts using the UL profile. End result was I shaved nearly 20 lbs off in total.



This stuff really is like man-sized erector set! I found rubber tread strip inserts for the slots also which help cushion and grip the car floor. You can get lots of different fasteners, hinges, adapters, inserts, etc. You can get pieces pre-cut, with angles, drilled and countersunk, etc. You can use the inner cavity as a pressure chamber - which would be handy if making a workbench as an idea.

All this cost less than buying an aluminum fabricated rolling cart and it's modular and re-configurable into different dimensions later if I want, with re-use of parts as an option. Pretty cool if you ask me LOL!

Anyway, just wanted to share, hopefully some will find this helpful if you struggle like me and can't weld or you just want to make cool things.

Cheers!
Mikey

[romoman]

Very nice. If you ever make it through modern factories, you'll see that 80/20 is the industrial erector set!

[DanW]

Gives me ideas for alignment/cornerweight platform....

[mikey]

Gives me ideas for alignment/cornerweight platform....

for sure! 8020.net has all kinds of floor to frame accessories, or I'm sure you could adapt just about anything to the modular frame that you want. design for length and width modularity and it'll be the last chassis setup pad you ever have to buy.

[Steve Demeter]

Sweet Idea/ Looks really nice

[billtebbutt]

Mikey,

I just love the fact that you built a wooden one, which probably would have worked just fine for almost all of us, but it just wasn't "right". Then you built an ally one but that one (beautiful as it was!) was just too heavy. And then you engineered a lightweight ally one with substantial weight savings that was "just right".

You are the Apex formula-car-rolling-stand-fabricator equivalent of Goldilocks. My hat is off to you sir!

best,
bt

[mikey]

Derek would probably say the same thing.. he sold me a car that he ran (very fast I'm told by his peers) at vintage events for years without issues and yet here I am, finding excuses to make lots of updates. Once an engineer always an engineer


If anybody wants the wooden one (minus casters), come pickup for free. Before I get bored and decide to salvage all the wood screws out of it ha ha

[DanW]

Derek would probably say the same thing.. he sold me a car that he ran (very fast I'm told by his peers) at vintage events for years without issues and yet here I am, finding excuses to make lots of updates. Once an engineer always an engineer

Occupational hazard...

[Jorma]

I agree with the "adult erector set" moniker. I just got my first taste of 80/20 building my sim rig. I'm really glad it did it that way instead of buying a pre-made chassis as I changed my type of real race car (GT to Prototype) and all I had to do was reconfigure and buy a new steering wheel. I really enjoyed working with it.
Mike M.

[lowside67]

In case anybody is interested, this is a design I was working on for a more traditional height working stand. After consulting with some folks, I opted to spec a double wide beam across the stand to allow for 2x attachment points at each end without resorting to expensive brackets, this adds a LOT more strength to prevent the stand from toppling forward/backward when you are rolling it at a minimal cost. It was sized to allow me to use existing castors I have at home. I haven't built it yet but think it would be fun so will probably go this route when my car gets here.

-Mark

[Ralph Z.]

And the total cost less casters?

[Joefisherff]

Any way by flipping the side supports and moving them inward of the end supports that you could make the length adjustable? I like to adjust mine based on if the engine is in the car or out of the car.

[lowside67]

In case anybody is interested, this is a design I was working on for a more traditional height working stand. After consulting with some folks, I opted to spec a double wide beam across the stand to allow for 2x attachment points at each end without resorting to expensive brackets, this adds a LOT more strength to prevent the stand from toppling forward/backward when you are rolling it at a minimal cost. It was sized to allow me to use existing castors I have at home. I haven't built it yet but think it would be fun so will probably go this route when my car gets here.

-Mark

Materials:
4x 30" 1.5x1.5 (Suggested #1515-ULS 1.5” X 1.5” T-SLOTTED EXTRUSION ULTRA LITE SMOOTH)
2x 69" 1.5x3.0 (Suggested #1530-ULS 1.5” X 3” T-SLOTTED EXTRUSION ULTRA LITE SMOOTH)
16x #3380 15 S END FASTENER W/5/16-18 SCREW
24x #3320 5/16-18 X 11/16” FBHSCS & ECON T-NUT
8x #4376 15 S 3 HOLE INSIDE CORNER BRACKET
8x #4302 15 S 2 HOLE INSIDE CORNER BRACKET

I was also working on a slightly cheaper version that basically replaced the bottom skids & brackets (which are the expensive part) wih two pieces of aluminum angle per end. Didn't finish fleshing that out as I didn't like the look.

Total price was ~$355cdn without any drilling or tapping services (I will do myself). The prices in Canada are not representative of what you would pay in the US. There are also alternative brackets that are possible - I needed ones that would accommodate the spacing on my castors which is why I chose those specific ones.

-Mark

[R. Pare]

In case anybody is interested, this is a design I was working on for a more traditional height working stand. After consulting with some folks, I opted to spec a double wide beam across the stand to allow for 2x attachment points at each end without resorting to expensive brackets, this adds a LOT more strength to prevent the stand from toppling forward/backward when you are rolling it at a minimal cost. It was sized to allow me to use existing castors I have at home. I haven't built it yet but think it would be fun so will probably go this route when my car gets here.

-Mark

Use the large triangular corner braces for the double wide beams - the torque loads on the fasteners if you hit a screw or something else on the floor when the cart is loaded with a car will be tremendous. The same for the end cross pieces - lateral strength there is also important.

[lowside67]

Any way by flipping the side supports and moving them inward of the end supports that you could make the length adjustable? I like to adjust mine based on if the engine is in the car or out of the car.

Sure, but you'd need to replace the uprights with ones with 3 slots then instead of 2 since you'd need slots on the front, back, and inside.

-Mark

[lowside67]

Use the large triangular corner braces for the double wide beams - the torque loads on the fasteners if you hit a screw or something else on the floor when the cart is loaded with a car will be tremendous. The same for the end cross pieces - lateral strength there is also important.

I spent a lot of time looking at this chart. If you hit a screw on the floor while rolling, the load the main front-back beam will take is cantilevered. With 8x total end fasteners across the beams, this is a pretty significant level of strength for this application. This is the reason why I made the design in this way rather than putting the beams on the inside similar to the MK designs approach.

-Mark

[problemchild]

Being a function over style guy, I would have used wood, and spent resources on actually racing ........ but if you are going to build the ultimate car stand, I would really think the Bosch product would be the ticket.

[holmberg]

Being a function over style guy, I would have used wood, and spent resources on actually racing ........ but if you are going to build the ultimate car stand, I would really think the Bosch product would be the ticket.

Are you referring to this product line?

Bosch Rexroth Aluminum Structural Framing

What is it you like about it? Why is it better?


Greg

[problemchild]

What is it you like about it? Why is it better?

I was being facetious. Bosch is to 8020 what 7-Up is to no-name lemon soda, Rolex is to Timex, etc. When I used to build custom automated machinery, some customers would insist on Bosch framing. You would not get the job if you spec'd 80-20.

[Beartrax]

"This stuff really is like man-sized erector set!" - I love it! I spent a good portion of my youth building Erector Sets.

[DanW]

Being a function over style guy, I would have used wood, and spent resources on actually racing ........ but if you are going to build the ultimate car stand, I would really think the Bosch product would be the ticket.

Greg,

Understood. My setup platform is wood too. I shim with vinyl floor tiles at each corner, the ramps are 2x12s. At my age, fishing everything out of the garage rafters to do a setup is a workout.

Regards,
Dan

[swiftdrivr]

Greg,

Understood. My setup platform is wood too. I shim with vinyl floor tiles at each corner, the ramps are 2x12s. At my age, fishing everything out of the garage rafters to do a setup is a workout.

Regards,
Dan

I was thinking the same thing. Aluminum runners would weigh a ton less than my doubled 2 x 12s. If Canadian Money is anywhere close to USD, one back injury would cover the cost.

[problemchild]

Why would you be using 12x2s? If you don't have scales, then just use floor tiles to shim the floor so left and right sides are the same height at each end. If you do have scales, do it like the stock car guys and have an 18" long pad behind each scale, so you can roll the car off and on, once jacked on to the scales.

[Rick Iverson]

I have plans for the one I made.

Gives me ideas for alignment/cornerweight platform....

[Rick Kirchner]

with respect to the discussion regarding torque on the joints when rolling the car:

I built a rolling stand that is pretty much a copy of Doug Brenner's design but I use two thinner beams across the bottom. They are lighter and allow for using the bottom of the stand to hold bins for parts and tools.

I used some casters I had laying about, adequate but without much margin. They had a bigger problem I did not anticipate - relatively soft rubber tires. They were solid, but you could definitely see a difference in "patch" between the front and back when loaded.

As a result, it's pretty tough to get the thing to change direction at the back. One day after shoving it about, I thought I perceived some motion of the car and caught it starting to tip over! The torque had caused the tops of the rear casters to start bending, loads increased to that side, and the metal around the weld was peeling off gradually as a result.

Luckily I had designed it so that the rear support was captured between the rear skid blocks. That kept the car from sliding off. I had to jam some junk under it to keep the tilt from progressing further while I repositioned the crane and removed he car.

I bought some bigger casters with 100% margin with harder tires and it's still a bitch to get the thing to change direction.

So a couple of conclusions: make sure you use big enough casters, at least 500lb rated each at the rear. Try to find casters with minimum caster, which should help in changing direction. If your shop floor has no cracks, the harder the tire the better.

[EYERACE]

I know someone - not me - who found one of those things that's about waist high....and one rolls it around a Homey Despot and it's completely flat across the top.....often painted orange for some strange reason........found it out behind the Despot with bummed up wheels near a lot of other garbage......funny how it fit into the back of a truck bed.