Question about building a steel dolly

[grobierno]

Hello, I am 71, a scrap steel artist. I purchased a welder in January and although certainly still learning, have reached the point that I am now using welding to assemble components instead of using brackets and bolts. I hope I qualify to post here, if not please direct me.

My question is not about welding. I want to build what I will call a small dolly, fundamentally (operationally) like a furniture dolly, but with a full floor/deck, and large wheels for exterior terrain and a handle for manual or lawn tractor pulling. I'm looking for guidance regarding steel plate floor thickness as it relates to supports under it. I want to be able to make my sculptures on it and have part of my weight (a knee or two) on it while I'm working.

Dolly Size: 3' x 3' My weight: 215 lbs Typical Sculpture Weight: 50 to 250 lbs

My store-bought welding table top is 2' x 3' and about 5/32" thickness. It has 1-1/2 " x 3/4" x 3/32" rectangular tube supports around the perimeter and one across the middle. So I could use these specs to plan my dolly, but don't know if they are ideal, too little, or overkill for the dolly requireents.

 

[drawoh]

grobierno,

Are you constrained for weight? The heavier your dolly is, the harder it will be for it to tip over. Do you have to lift it?

Do your wheels have to be under the dolly? If they are outside, you have a larger footprint, a lower centre of mass, and more stability.

For stiffness, you need gussets underneath, which I presume, you will weld in place. How thin a piece of steel can you apply a high quality weld bead?

 

[grobierno]

Thanks drawoh,

The die is cast, and I can relate to your last question due to my limited welding experience.

I bought 10ga for the 3' x 3' "floor", and 14ga for the 1" x 2" rectangular tube gussets which will go around the perimeter and also form a cross in the center (like a 4 pane window grid).

When comparing my options for rectangle tube at the metal supply house, I picked 14ga over .0625 for the very reason you referenced.

Because I am not an engineer, I rely on build over weight. This will be 90-some pounds. If I'm using this in 10 years, I'll make a dolly for it.

 

[lucky-guesser]

Assuming you have the vertical space to do so, get your 1x2 bracing tubes such that the 2" face is vertical, that will give you the most strength the resist flexing. Your 10ga plate with 250+ lbs in the center would certainly be prone to bowing on its own, so your tubes will be what prevents that. A simple "+" may be enough, but if you have the material you may want to add more bracing than that. You can always build it with the one cross and see how it feels, and add bracing as needed.

My style of welding is to turn up the voltage and burn it in. Not always pretty, but nothing ever breaks. That said, "burn it in" is more like "burn a hole through it" when using sheet metals like your 14ga. If your art typically uses thinner materials then you are probly used to it, but if you are new to thinner materials then be prepared to turn down your welder, and if nothing else take your time and allow the part to cool as needed.