Testing DIY enclosures

[irregularshed]

Thought I’d show off the proof-of-concept test build I did today before I take it further for my controller build.

Doesn’t look like much…

Nice texture though…

Aha!

Basically, I need a custom box. There’s nothing I can use off the shelf, and it needs to be easy to work with and as modular as possible. The other day I had a big-brain moment; 3D print edges for foamcore board, and cover the foamcore in something to make it look nicer. Then, I found “tarmac” textured adhesive vinyl online and realised how much it looks like my guitar amp. So, I’ve worked through a few designs today for the connectors and, well, it looks perfect for what I’m doing!

I’m going to build up generic bits for anyone to edit and use. Saves having a printer running for 3 days straight for a case

[juggle]

Nice! I’m a big fan of foamcore and have done a bunch of projects with it. I even designed an improved needle cutter and build a MPCNC specifically for working with it. I actually redesigned and upgraded the needle cutter again after that: https://www.thingiverse.com/thing:2450613 I need to do it again to update it to fit the latest version of the MPCNC…but I’ve been lazy about upgrading my MPCNC. I really want to…but…it works. So I hate to tear it apart just to upgrade it

This is one of the fancier things I designed and built out of foamcore, a little rack for ink samples:

Once nice trick I found - leaving a flap of paper off the edge that you can then wrap around the edge to finish it cleanly:

I also made these sun viewers for the eclipse in 2017:

They were a big hit with my daughters school class

I mostly use the super cheap foam from the dollar store. I’ve used some fancier foam but find I like the versatility of the cheap stuff better.

I’ve also done a number of experiments with laminating it for extra strength. I was trying to come up with a cheap material for a shrouded quadcopter I designed:

The ply was beautiful…but not nearly strong enough and didn’t survive even mild crashes

Carbon Fiber would be great…but is nasty to cut and sheets big enough to cut this out of are crazy expensive and most of it would just go to waste.

Laminating with the cheap fiberglass you can get a walmart gives it a LOT more strength…but makes it a lot heavier. And the polyester resin they sell will melt the foam so you have to use good epoxy instead. But if you’re not worried about weight it’s cheap and makes for some VERY strong material.

I got some more expensive but much lighter fiberglass (0.56oz and 1.5oz and was getting some very promising results:

I also experimented with using “red rosin paper” from the hardware store. It’s $13 for a 3’ by 160ft roll so pretty cheap…but works really well as a laminating material on foam if you’re not worried about weight.

The big trick to doing good laminations is to use peel ply. Just cheap polyester fabric (i.e. suit lining - get the cheapest you can find) since the epoxy won’t stick to it - but will wick through it. So basically you have foam - laminate/epoxy - peel ply - layers of paper towels. And then weight it down. The excess epoxy will wick through the peel ply and into the paper towels leaving you with a nice smooth clean laminate that doesn’t have excess resin in it.

Might be worth trying if you need some extra strength in your build!

[BlackDeath]

If you guys want that effect for your existing wood cases, I’ve used this stuff called TuffCab for my big subwoofers:

Smoothing TuffCab texture with 9 inch roller

Tuff Cab Strukturlack - Verarbeitung mit Grobschaum Strukturrolle (Part 1)

It’s actually freaking awesome. You can get it on Amazon, kind of expensive but I only used half of a bucket to do two MASSIVE cabs. One small tub should do all the cases you ever build.

[Farabide]

Great find! Thanks. Looks like tolex without all the faffing about.

[Bitnik]

Sorry, can’t resist.

The Thin Blue Line - Fannying about

[irregularshed]

Ok, your needle cutter is fantastic! Might have to have a go at one of them, because cutting with my knife is nasty - never perfectly clean edges, which isn’t a huge problem when it’s getting covered but still feels a bit cheap. Last time I worked with it I used my hot air soldering station thing set at a lowish temperature to melt the edges a bit tidier.

It’s funny you mentioning laminating it, fibreglass etc. I started doing something like that during the summer to make a kitchen for the car (it’s an MPV) using XPS insulation sheets, like this guy… https://youtu.be/IJv0pEjvC34
… But then 2020 carried on being 2020 and so I’ve not finished it yet. (Yet.)

[irregularshed]

Ooh, I’ll keep that stuff in mind for the future!

[juggle]

Yeah, foam seems to dull blades FAST and then they just tear. Drove me crazy. The needle was a friends idea who got the idea from a youtube video he saw. It works on thicker foam as well if you make the needle long enough and cut slow enough. I’ve cut 1" xps with it but it’s a bit tedious and a hot wire is a lot quicker (but harder to be accurate with) for that!

The needle can also cut cardboard…but…be prepared for more needle failures with that. Be sure to wear eye protection since they can go flying when they fail

You may also want to look for the “timsav” foam cutter. It was a kid someone was offering last year for awhile but the plans are still out there. He based the cutting head on my needle cutter design but instead of a full gantry style CNC he did a simplified setup that’s great for low impact stuff like the needle cutter and laser - it’s just 2 rails. One for X and one for Y. The X rail is fixed while the Y has a wheel at the far end it rides on. Great for limited space and keeping the costs down.

But if you have the room for it the MPCNC is great. And being able to swap tools is so useful. I have a 3w laser I use for engraving and cutting thin woods, a router for cutting wood and plastic (my machine is too big to be stiff enough to cut metal but smaller machines do it no problem), a drag knife for cutting vinyl decals, a bigger drag knife I made just to try out (it works…but…is of limited utility to me and generating gcode for it with proper corner movements is tricky), the needle cutter, and a couple of improvised pen mounts for drawing things. My machine is an early MPCNC design (The official design has been redone for better stiffness 2 or 3 times since I built mine) and designed to take up to 2’x3’ material since I mostly work with 20x30" sheets of foam board.

If you have a 3d printer it’s pretty cheap and easy to build. All told it’s about $300 and it’s saved me far more than that over the past few years with the things I’ve been able to fabricate for myself with it!