Clear Acrylic Case for Motor Controllers
 

*NOTE: Some photos are missing from this thread. The evil photo-hosting service just decided they weren't hosting any more and just plain stopped. With SOME of my photos, I had already started switching over to only posting through my own domain. I'll try to update old, broken photo links as I can.*


Hi everyone,

While I think the Open ReVolt project has been fantastic, I've always wanted a case for it that was just a little bit cooler-looking.

I just saw a recent blog entry by somebody who is a member of the same workshop co-op as I that I thought would work perfect for this!

Here's his blog entry - BoxMaker | Milwaukee Makerspace

http://milwaukeemakerspace.org/wp-co...12/01/box3.jpg

In this case, he was just making a box, but if I applied the same idea to make a box that was just missing the bottom, and cut square holes in the ends for the bus-bars, it would make a great case for a controller! (It would be fun to show off the guts, and much easier to see the trouble-shooting LEDs!)

This box was made with the tabs accidentally too big. Since I have access to a laser cutter (I still don't know how to use it!) I could perhaps do the work to design a case and THEN MAKE SURE I SAVE MY WORK! I could make extras to sell as a low-cost kit and/or share the file so that other people could download that and make it themselves on their local laser.

I was also thinking that it would be VERY cool to have the Open ReVolt logo laser etched on the top of the case!

Something like this?

Yep, very similar!

I recently got to use the laser cutter at the Milwaukee Makerspace! Man, is that thing cool!

After just a few minutes of training, I imported the vector art of the Open ReVolt logo and started etching on some scrap plexiglass!

I also figured out how to CUT with the laser cutter. It's not all that powerful, so cutting takes a few passes, but comes out so perfectly clean, with a nice smooth edge!

I made two different versions of Open ReVolt tokens. Just the logo cut out in a round shape. Could be used as a keychain or something I suppose! (I even added a little hole at the top for that!)

http://gallery.me.com/benhdvideoguy/...13320105540001
http://gallery.me.com/benhdvideoguy/...13320105490001

The clear plexiglass was "top-etched" - the side you are looking at is the front. I figured that when I actually do the lid of the motor controller case, I want the logo cut from behind, so the top is smooth, and doesn't get dirt and gunk in the engraved logo. For the orange token, I mirrored the logo art, so that you look THROUGH the smooth side and the logo is cut on the back.

http://gallery.me.com/benhdvideoguy/...13320105660001

I ended up having to go back to the Makerspace this morning (I left my laptop there last night!) I had my travel coffee mug with me, and started wondering if I could laser etch my name on it.

Sure enough, I can. I just had to make sure it wouldn't roll while the laser etched it.

http://gallery.me.com/benhdvideoguy/...13320105550001

I also grabbed the lightning bolt from the Open ReVolt logo and used it on the back side of the coffee cup.

http://gallery.me.com/benhdvideoguy/...13320105630001

A friend of mine there has been doing some work carving plexiglass and edge lighting it with LEDs. It's very similar to what I would like to do with the controller case.

http://gallery.me.com/benhdvideoguy/...13320105470001

I still have to figure out the boxmaker software, choose the material, learn how to power a string of green LEDs, but THEN I can make a really awesome controller case! (Don't worry, I'll be sure to post all the files when I'm done!)

Love this ben!!! Neat.......

LED series parallel array wizard easy as pie. Just need a DC voltage to start with.

Oh, and I design my circuits to be 10mA current or less. Most LEDs are rated for 20mA and underdriving them is a good way to prolong them. When I use superbrights, I use 6mA or less.

-Jay

Thanks for the tips Jay!

For the AC boards I'm just about to send in, It's going to darn near require a clear case. It's got crap sticking out the top, and 2 of the sides. haha.

Might not be as much progress in the near future on this project as I would like.

I broke my ankle this weekend, so I might have to switch over to building a cyborg leg for a while. When I'm done with that, I'll finish up the clear case.

:eek: :eek: :eek: :eek:

Ben, now there must be more of a story here.
How did this happen?

Eric

:eek: OK Ben ---- Story???

Well, here's the thing.

Lead acid motorcycles are cheaper than lithium motorcycles, but they also happen to weigh more. So, when you ditch a PB Bike onto your left ankle, the ankle isn't going to be happy with that!

The worst part is how horribly self-inflicted this is. A camera mount clipped the ground on a slow-speed left-hand turn, scooting the back tire out a hair, completely changing the two-wheel dynamics and INSTANTLY ditching 400 lbs on my left ankle.

Ouch.

I fully understand your pain. But I did it with a 600 lb Harley, but I was wearing leather boots and didn't break anything. What were you wearing, may I ask?

Eric

Jeans, leather ankle boots, and helmet.

Should have been wearing my helmet on my ankle.

Well, I finally did up a "rough draft" of what I'm planning.

Here's about what it will look like.

http://300mpg.org/wp-content/uploads...lustrator1.png

The lines are extra-thick, just so they show up nice for you to see. In the actual layout for the laser, they would be infinitely thin cut-lines.

The logo in the middle will be etched so that the high-lights of it will be white, similar to the plastic "tokens" I posted earlier.

I'm not sure yet exactly how I will embed the LEDs. I suppose that if the case material was thick enough, and the LEDs were skinny, I could drill holes in the edge and poke the LEDs right in there.

By the way, the measurements here aren't exact, so please, nobody say, "hey, that hole has to be one 1/16" to the left!" Because I already know that!

I also just show one round hole for the throttle, 12V power, and pre-charge wires to poke through. I lost my RS232 cable a while back, so I do NOT have a serial port connector cut-out shown on the case.

I originally just put the M-,B+,B- marks on the case just as a note to self, but thinking about it, that would be a really good idea to mark them on the case. I think they should go ABOVE the bus bar holes, to make them easier to read when the controller is mounted.

I also think that I want to power the case LEDs by a separate, dedicated 12V connection to the car's 12V accessory battery, with a small switch under the hood. The only time that I am really going to show off the controller is at car shows and eco-events, where the car will be parked with the main power disconnected.

Looks nice!

Have you experimented at all with heat bending? I don't know how well it would work in this case, but it could reduce the 3 large pieces into 1, and then you'd just lego the end caps on.

I haven't experimented yet with heat bending. I've seen a few projects done with it that looked pretty good.

I guess what I like about cutting flat pieces with a machine is that everything will be nice and square and clean. If I start bending material, it brings in the human factor - me.

One other thing I was thinking would be nice about just going with straight laser-cut is that all the parts are FLAT. I could mail a flat case to Paul or whoever wants one, and they could just assemble/glue/caulk and be done.

One gripe that I had about shipping the controller is that it exactly DOESN'T fit into one of the post office flat rate boxes. It would be nice to design a controller case that fits in a flat cardboard envelope!

Since I'm laid up right now anyways, I tried to put in a little more design work into the controller case.

Here, I laid it out to fit within a 12" x 24" area - which is the cutting size available on the laser that I have access to.

http://300mpg.org/wp-content/uploads...ayout_LEDs.png

I put it so that parts that have straight cuts, overlap with each other, saving the time and laser power of two additional cuts.

Also in this image, I have now added in roughly what I am thinking for LEDs. I'd like to use green LEDs, as they have such a neat look to them. I've never done this before, but I was thinking that if I got smaller ones, I could counter-sink them to embed them right in the clear plastic, where they could be friction fit, or use a drop of super-glue, clear caulk, or something similar.

Here's just a view of the "lid" - the topmost piece.

http://300mpg.org/wp-content/uploads...ser_w-LEDs.png

Note that I mirrored the Open Revolt logo for this. The logo will get cut on the BACK of the plastic, so that it is smooth on the top outside surface. It will stay cleaner and it looks a bit nicer too.

Also on the logo, wherever it is white will be the clear plastic, and wherever it is black will be etched. Please imagine white, lit-up etching wherever the logo is black.

I set a 3/8" hole in the B+ & B- bus bar end for the throttle, power, and pre-charge wires to go through. 3/8 is big enough for a 1/4" spade connector to fit through while a couple other wires are already through the hole.

So, this is what I am thinking so far. Am I missing anything? Any thoughts or suggestions?

I really have no idea how many LEDs I need. I just put a few around all for sides for the heck of it. Maybe I only need them on the two sides closer to the logo?

I also played around with some more "CAD" - cardboard aided design.

Since I don't have a laser cutter at home, I figured a great way to test things out in the physical world from the virtual one is simply to hit "PRINT".

The humble ink-jet printer is a fast and cheap way to prototype anything 8.5"x11" or smaller!

I printed up the ends of the case and cut them out with a scissors, and cut the bus-bar holes with a sharp knife over a cardboard mat.

The great thing about this is I can instantly see what does and doesn't line up! The paper is also great, because any changes or notes can be written right on there. If the bus-bar holes don't quite line up, I can tear or cut the paper to make it work, and then match that up in my drawing software.

I was also able to see what size hole I really would need for all the wires to poke through.

http://300mpg.org/wp-content/uploads...4/DSC_1626.jpg

http://300mpg.org/wp-content/uploads...4/DSC_1630.jpg

http://300mpg.org/wp-content/uploads...4/DSC_1631.jpg

I got a chance to head back to the Makerspace.

That place is HUGE, when you are trying to carry a laptop computer, motor controller, and camera, ON CRUTCHES!

Anyways, I sat down at the laser and set to work. I had some cheap, thinner material right there, so I thought I'd try making a "prototype" clear case out of the cheap and thin stuff.

http://300mpg.org/wp-content/uploads...C_1649_med.jpg

http://300mpg.org/wp-content/uploads...C_1650_med.jpg

http://300mpg.org/wp-content/uploads...C_1651_med.jpg

It turned out OK for just some scrap material cobbled together. Get the whole story over at my blog.

PS: Keep toddlers away from projects.
http://300mpg.org/wp-content/uploads...med_sophie.jpg

I just ordered a few rectangular green LEDs. They are little pairs of two green LEDs that shoot sideways.

Seemed like I might be able to laser-cut the case to fit these LEDs directly. With the legs hanging down, it should be easy to wire them up.

Digi-Key - 67-1324-ND (Manufacturer - SSB-LX02GC)

(Update from last time - the rectangular LEDs aren't very bright. I'm going to try pointing cylindrical LEDs straight at the logo instead.)

The project progresses!

I had a friend cut out the main hunks of plexiglass on his work laser. I tried cutting the .22" thick acrylic on the 25 watt laser, but it just wasn't powerful enough to do it without significant smoke, melting, and other issues. He offered just to cut it for me, so I e-mailed him my Adobe Illustrator file and went from there.

I got the cut pieces back the other day and test fit them. Laser-cut fit was fantastic! Parts went together just like a jigsaw puzzle!

I did sand off the very bottom edge of the one end, as it hit wierd on the heat sink. I also trimmed part of the board on the controller because it stuck out a bit. Heck, the whole controller is sort of out of square!

I put the cut pieces into the laser and engraved the Open Revolt logo into the middle. (Took about 45 minutes - 30% power, 3-passes....)

I then engraved the bus bar marks on the ends and "Open Revolt Motor Controller" on the one side.

http://300mpg.org/wp-content/uploads...7/DSC_2357.jpg
http://300mpg.org/wp-content/uploads...7/DSC_2358.jpg

I've glued the case together as much as I dare to right now. Since bus bars stick out both ends, the whole case does NOT just set over the top of the controller - the end caps have to slide on OVER the bus bars. I decided to glue the top, two sides, and the M- ends. That leaves the end with the B+/B- loose. I should be able to put on that piece and then slide everything else on from the M- end.

I also got to play around with some LEDs. The etching looks AMAZING when edge-lit with LEDs, but only in the dark.... With the lights on, it barely reads.

http://300mpg.org/wp-content/uploads...7/DSC_2371.jpg
http://300mpg.org/wp-content/uploads...7/DSC_2373.jpg

After fiddling with the LEDs a bit, and talking with some of the guys, I decided that I need to use some other, higher power, LEDs. I have also been trying to figure out from the start HOW to attach LEDs to the case and MAKE THEM LOOK GOOD! LEDs usually use a resistor for every two or three LEDs on a 12V system. So, I need at least 4 LEDs, 2 resistors, and some bits of wire, (all with my icky-looking soldering skills) mount them to the case AND make them look good!

Some green LEDs that I found were actually pretty small - about 1/8" in diameter. It seems that I could drill a hole in the case, and point them right into there. Except that plexiglass is so brittle, and the holes would be really close to the edge!

I did some test drill in some scrap material, and found that I could cleanly drill a hole that the LED would fit in.

However, I still do NOT want to wreck my nice end cap that somebody else was nice enough to laser-cut for me!

So, here's what I'm leaning towards right now.....
I will cut ANOTHER piece of plexiglass, drill the holes for the LEDs in that, and then glue it to the end cap when all done.

That way, if I mess up, so what. I can make another. Also, I was thinking that maybe I make a spacer and sandwich together that piece of plexi with a cover, so that it covers the resistors and LED power wiring. Might give it a nice finished look, and the "LED Section" will be a stand-alone, removable unit.

Looks really nice Ben!

Here's the latest update.
I grabbed a couple of scrap LEDs and starting experimenting to see what would work to attach them to another piece of plastic. How about laser-cutting a hole and poking them in there!

This is two LEDs, a 5mm and a 3mm
http://300mpg.org/wp-content/uploads...7/DSC_2692.jpg

Here you can see them against the .22" plexiglass that I used to make the controller case. The 5mm LED is just a little too long to fit inside the thickness of the plexiglass, but the 3mm will embed itself in there just fine.

http://300mpg.org/wp-content/uploads...7/DSC_2693.jpg

I used the laser-cutter at the Milwaukee Makerspace to make a new end piece to experiment with. Although this is a piece of scrap material, which IS NOT the right thickness, it still let me check the hole size and see how LEDs would fit through.
http://300mpg.org/wp-content/uploads...7/DSC_2703.jpg

Here's a screen grab of the cutting layout on the laser cutter. I used my existing pattern of end cap to make a new one (without the castled edge) so that I could add LED holes to a new piece.

http://300mpg.org/wp-content/uploads...more-holes.gif


Here's the new "test" piece just leaned up against the end cap of the controller. I wanted the LEDs to line up to shine sideways through the top material to illuminate the Open Revolt Logo.

After cutting this piece, I realized that I put the holes to line up with the male notches on the end cap. I should have put them over the female notches, as that puts the LEDs more in direct contact with the top piece, so the light transmission should be better.

http://300mpg.org/wp-content/uploads...7/DSC_2705.jpg

I still need to get the actual LEDs I'll be using. The 3mm were nice in how they fit right into the plexiglass. Also, their smaller diameter brought them in from the edge a bit.

I also want to make several layers of plexiglass, so that the LEDs, their associated resistors, and wires are all covered and contained in a way that looks nice.

Looks good Ben!

My suggestion for the LED mounting would be to drill 3mm holes in the female parts of the LID (so the sides cover them) LENGTHWISE. Then the LEDs are pushed into the holes end-on, the LED legs are bent at 90 degrees, and are (mostly) protected by the male castellations on the sides. It's methods like this that Computer Case modders have been using for years now.