Folding my own chassis

[Cliff Schecht]

Hey fellas! First off, sorry that I've been so absent since I've moved. The ebay thing really picked up here in Austin and that's been keeping me so busy that I wasn't focusing on building very much.

However, now that I have Techshop around the corner from my house (as well as VERY inexpensive sheet metal available, also near my house!), I've been getting into cutting/notching and folding my own chassis from scratch. I've built a few non guitar amp related items in the sheet metal shop (like a homemade fender eliminator for my Speed Triple 1050, came out great!) but haven't gotten around to an actual chassis til yesterday.

I also have access to Inventor which takes any guesswork out of the process. I draw up a quick 3D model of my chassis, use Inventor to unfold the chassis and print out a 1:1 of the unfolded design which I can glue right to the sheet metal. Note in the unfolded pattern that they also give you the optimal bending order!

This first chassis is a 7"x6"x2" chassis that will become one of my (not-so) infamous mini-Champs. I've built them into 6"x4" chassis but that just gets too crammed for my liking when I'm going for a full 5W output.

Also exciting is I have a nice transformer winding machine. I haven't gotten to build anything with it yet but it's exciting to be venturing into new DIY adventures again!

Obviously this first chassis didn't turn out perfect, one of the sides came out a bit longer but was able to be beat into acquiescence with a dead-blow hammer. Also I was not very aggressive with how I was bending at the corner notches so there is too much of a gap to be able to spot weld the inside corners. I think on my next chassis I will have foldable ears on the inside walls that I can just use the actual spot welder (like how Hammond builds their boxes) as well as aiming for tighter tolerances in those corners.

Also you can see that I didn't remove enough teeth from the sheet metal brake for the last fold and so when I went to fold the last corner in, I ended up digging into the two longer sides of the chassis. It buggered them up a bit but it turned out to not be a huge deal. As the guy who taught my father and myself said about the sheet metal brake, "it's one of those machines that takes a few minutes to learn and many years to master..". No joke there, folding with the brake is an art!

[xtian]

That's COOL. I'm putting you on my to-visit-in-Austin list.

[M Fowler]

Cool some more practice and you will be folding like a pro. Sounds like you have quite an adventure going Cliff, all the best to you.

[Cliff Schecht]

Thanks guys yeah it's been an interesting few months. Took me a little while to get my bearings again and get things rolling. I still honestly have NO customers out here as far as repair work. I'm going to try online avenues to sell some custom one-off builds and see how I do there. I think if I can get a few amp builds a month plus what I'm doing now (a glorified junk peddler) then I'll be making as much or more than what I've heard as offers from engineering companies. Granted it's more work than a 9-5, but I work my own hours and am really only limited by the amount of effort I'm willing to put in. And since I'm now living with TWO magnetics/power experts, it seems some interesting things may be coming out of this neck of the woods soon. Already have a few cool projects in the works!

[Cliff Schecht]

Gonna be a lil' Champ-style circuit with my favorite hacks. I'm digging it so far and the big gaps in the corners will disappear when this goes in a cab .

[tubeswell]

Looking promising there Cliff

[Cantplay]

For future chassis if you add tabs to the front edges of the side panels it will fill the gaps. when the front and rear panel are bent they will touch the tabs.

John

[cbass]

When I done mine I had tabs like john said and boltesd the corners together since I ain't got no welder

[M Fowler]

Aluma weld

[The New Steve H]

That's neat. What kind of brake?

[M Fowler]

Cliff very neat little Champ, you and Milkman now have me wanting to use up some of my salvage transformers to make some of these little amps for stocking stuffers for Christmas.

[Cliff Schecht]

The brake is a massive one made by Jet. Think it does up to 18 gauge. Not really sure how else they specify brakes. Lots of teething options.

The tabs are really easy to add but weird to implement for me still. I'll be doing another chassis soon that will incorporate these tabs. Just drew up a 7x9x2 chassis with foldable/weldable tabs. Here's the folding pattern for that guy.. Look at all of those folds (I'll leave the fat jokes up to your imagination ).

Something else I learned recently, aluminum is not specified by gauge but simply by the thickness. All non-ferrous materials are specified either by their thickness or by some other metric (i.e. ounces for copper). I got corrected by the guys at the local sheet metal supply on this!

[The New Steve H]

I considered getting a brake, but then I thought, "You're crazy enough already."

[cbass]

You can score aluminum and bend without a brake.

[M Fowler]

CBass what did you use angle iron or 2x6?