Spot Weld Design

[projectbluebird]

What is the best way to design a spot weld?

I am thinking of designing an enclosure that will be cut from sheet steel, bent, and spot welded to itself. It needs to be fairly rigid. I thought about using a two part box, but because of the thickness of the sheet, I feel that machine screws would not be strong enough. Using sheet steel also puts the part on the thin side for regular welding techniques.

A one piece part will also be faster to assemble with the base.

The approach I am currently thinking is using tabs and multiple spot welds. I realize that that brings up tolerance issues with bend radii, but is there a better way to do it?

(I'll try to work up a design and post it later, I don't feel like I'm explaining it very well)

[Tech2]

Are you doing a five or six side box? If six I'd go with our box wizard and PEM fasteners.

[projectbluebird]

5 sided box, being screwed to a stout piece of wood.

[Tech2]

Why do you feel you need any reinforcement? You have essentially zero degrees of bend freedom when screwed to a rigid wood board.

[projectbluebird]

Essentially this will be a base for a heated element for forming wood for violins. It needs to be sturdy because people will be pulling with most of their weight to form the wood around the heating element. I have another design that would be much simpler to fabricate, but because of the holes in the ends, I wonder how much lateral bending resistance they will provide.

[Tech2]

I believe a version with the vent holes and four flanges would be very sturdy without the welds.