Cases - make your own

[M0n0mania]

I'm looking into making some pedal cases using bent sheet metal, along the lines of EH and Lovetone. I can get hold of a bending tool that will take up to 20 swg, but I'm no engineer. Can anyone tell me if this will be suitable? What guages do EH?Lovetone use? I've seen that a certain amp chassis uses 16swg but presume pedals don't need to be quite so hefty.

[jimbob]

Pure-tube is a good person to ask.

[puretube]

Pure-tube is a good person to ask.

...but I`m a decimal guy and use aluminum: 1.5mm......  :wink:

[M0n0mania]

wow thats about 17.5swg! (16swg=1.42 mm) The 20 swg I'm looking at is a mere 0.81mm. Do you find it really necessary to use such a guage, or is it because its aluminium, might be stronger in steel? What do you use for forming these boxes?

[puretube]

for alu 1.5 is min., imho;
for steel, 1mm is ok (see E-H boxes);
in the pic: left side the thing I bend,
right side I cut with;

[Mark Hammer]

I would think that the required thickness of the metal would depend on the physical size and shape of the case itself, and any other parameters that affect how rigid it will be where it needs to be.

For instance, I started making a case the other night from relatively thin gauge (in comparison to what Ton uses) aluminum.  It is just about the same size as a DOD case, with recessed knobs, but with a stompswitch rather than FET switch.  The plan is to use 1/4" oak slabs from Home Depot as the sides (with a profile cut to fit the formed top), with the top and bottom screwed into the sides from the top and bottom.  With the sides more than stiff enough, the question then becomes whether the case obtains its rigidity from the top more than the sides or sides more than the top.  In this case, the bends for the recessed knob ad a bit more strength to the top, and the narrowness of the planned case places the brunt of the "responsibility" for stiffness on the sides.  I have no doubts that after assembly it will "feel" sort of flimsy when one steps on the switch - much the same way that the doors on better cars just seem to "feel" better when you close them - but it will be as strong as it needs to be.

On the other hand, there is nothing wrong with over-rating mechanical components in a pedal, just as you would electronic ones, right?

If the intent is to make cases of a larger scale, perhaps to accommodate several footswitches, or several effects, or lots more knobs, then clearly much more responsibility for structural rigidity will rest on the shoulders of the top panel, in which case heavier gauge materials are certainly called for.

[Paul Marossy]

If you're worried about it squishing when you step on the switch, you could also put a little bracing under that area for more rigidity. That could be accomplished any number of ways.

[M0n0mania]

Thanks for the help guys, this is really useful. Your bending jig looks more ore less identical to the one I'm looking at (Clarke CMF24) at https://www.machinemart.co.uk/product.asp?p=051210170&r=2044&g=106
Actually looking again they say a max weight of 22swg (0.71mm). I wonder if they underspec their products and are actually capable of much more?

[puretube]

they prob. choose their safest min. for heavy style steel,
and prob. you can do 1mm with it, too,
as long as the jaws can open up for thicker material;
(which is usually possible).
Mine can do 2mm aluminum, but at 50cm width (for amp chassis)
, it takes muscles!

[M0n0mania]

hehe, maybe I'll have to get the drummer round to help then...

[Chico]

I use .064" Al and it works real well

I actually bought a 4'x8' sheet from an Aluminum shop in town.
I made a template of my top and bottom, and cut them out of the sheet in strips.  To do that, I simply clamp a 4 foot guide to the sheet and rip it with a circular saw.  You have to use a blade with more than 60 teeth (mine has 120-I think) and go REAL slow.  Also, you HAVE to wear safety glasses.  Afterwards, I sweep the area with a Shopvac.

A few quick brushes with a file and the cuts come out clean and straight.

I then spray adhesive (3M) my paper box template to my top piece to use as a drilling and bending guide.  The 3M adhesive I use is does not adhere permanently.  After bending, I peel the paper out of the box.

one other thing I do that really helps me.  I bought at the hardware store, a 1 1/4 inch rectangular bar that I cut into a 1' section (arbitrary).

I clamp this bar in my brake over my top and bottom pieces and use it as a guide when I bend the sides of my boxes.  That way, I can precisely control the height of my boxes.

Good luck

[petemoore]

Scoring the bend lines. File, sharp chisel, etc. and a clamped straight edge...by cutting a shallow 'v' in the bend line, on the inside', reduces the bend pressure...I'm sure you figured this one out...also can reduce the cracking' of the outside, ...when bending thicker stock, the outside sometimes develops 'stretch cracks',

[chumpito]

Is there such a thing as a sheet metal bender that will do curved corners instead of sharp ones?

[axr]

there's a local guy that works with steel that builds me my boxes, the material he use is stainless steel.





this how the boxes looks

[puretube]

Is there such a thing as a sheet metal bender that will do curved corners instead of sharp ones?

those depicted benders got 2 screws, that determine the horizontal
opening between the jaws (before bending);
this in the end effects the radius of the bend;
(and in fact is nevvessary to accomodate diff. types of material
and thickness)

[chumpito]

Thanks puretube.  I'll be down to Harbor Freight Tools this weekend then.

[Mark Hammer]

Depending on the actual design of the case, probably one of the hardest things to figure out is what the final shape translates into in terms of cutting out the metal, taking into account the radius of the bend, metal thickness, what will get in the wayof what once bent, and so on.  That is probably one of the nicest parts about the traditional Small-Stone/DrQ/SmallClone/LitleMuff type cases.  The top is a straight piece with two bends, and the sides are pretty straightforward too.

[bioroids]

Pure-tube is a good person to ask.

...but I`m a decimal guy and use aluminum: 1.5mm......  :wink:

Hi!

What kind of aluminum do you use?  I mean the alloy number, like 1050 for example

Thanks and luck!

Miguel

[guitarhacknoise]

besides scoring, could you heat up the bend line with a propane torch and then bend, for ease and to help keep the stretch marks at bay?
or would you then get into the magical world of warpage?
-matthias

[puretube]

Pure-tube is a good person to ask.

...but I`m a decimal guy and use aluminum: 1.5mm......  :wink:

Hi!

What kind of aluminum do you use?  I mean the alloy number, like 1050 for example

Thanks and luck!

Miguel

...not sure, probably s.th. like Al70/Mg30, or harder