Tutorial for a Four-Motor Compact Laser Spirograph

Hi there, though I don't post much here on laserpointerforums, I have browsed a lot and gained a ton of information from the numerous posts. I first came here with questions about a 5mW green laser over a year ago, and today I've decided to say thanks and post a guide to a tutorial I created on Instructables.com, using four home-chemical treated front surface mirrors, a 150mW RayFoss 532nm laser, and four 3v DC hobby motors, with five switches to boot. I've come a long way thanks to this board, and figured I should give something in return.

I've seen guides on three-motor spirographs here on laserpointerforums, as well as an ultra-compact 2-motor spirograph for a blu-ray laser. I decided to make one with four motors for some ultra-complex patterns, and it turned out great. I just figured I would say thanks a bunch, and check it out if you're interested:

Four-Motor Laser Spirograph
YouTube Video of Four-Motor Spirograph

Very nice. I'll have to give it, or something like it a try some time!

WOW this looks really awesome! But also looks a little too complex for my building skill... but I really wanna try to build it..

edit: I'm trying to think of ways to make it more universal for other laser pointers. I was thinking of having an extended entry tube that is atleast 3 or 4 inches long, and about 1 inch in diameter, that way just about any laser pointer can simply just site in the tube. I'm trying to think of a way to make it compatible with the Arctic Laser.
2'' diameter mirrors might be needed for this. If you think about it, the size of the laser will effect the height of the laser beam traveling through the tube and bouncing off the mirrors, I'd think 2'' should be enough if your laser sits taller or shorter.

This is something I'm really thinking about doing, but to be honest I've really never built anything like this.

Very nice, I've been thinking about making a spiro for a while. Might just give this a go!

Also- a quick (but very important) note.

If you're gonna use somewhat large mirrors, use plastic or acrylic ones. Not glass FSRs.

If you use something that's mounted too wonky, or use a glass mirror, you will spend most of your time dealing with vibration problems.

Also, make the mirrors as big as you can. It'll save you a lot of effort during alignment.

goninanbl00d said:

Also- a quick (but very important) note.

If you're gonna use somewhat large mirrors, use plastic or acrylic ones. Not glass FSRs.

If you use something that's mounted too wonky, or use a glass mirror, you will spend most of your time dealing with vibration problems.

Also, make the mirrors as big as you can. It'll save you a lot of effort during alignment.

Click to expand...

Yeah I was thinkng large glass FS mirrors could make some vibration problems, but I thought properly mounting the motors (and properly mounting the mirrors) would solve it.

Properly mounting the mirrors will cause more, not less, vibration.

The vibration will simply be coupled to the chassis/board and the whole board will start shaking.

I've torn my 'graph apart multiple times due to vibration issues.

The mirrors aren't large- they're 1x1cm square and 4mm thick. And they're only going at about 2500rpm, yet the plate that I've got it all attached to slowly snakes across my table while I'm using it.

I've found putting a sliver of gum-based pencil eraser between the motor and the chassis works well.

You want to avoid any unnecessary physical contact between the motor and the body if you have vibration problems.

Also, another tip- the bevel in each mirror does need to be visible to the naked eye. What looks like a perfectly flat mirror is still in fact at an angle, and will draw a circle.

Excessive angling will only create more vibration, and unless you're aiming for large patterns at short range, there is no need for it.

I've been thinking about doing a four-motor spiro for a while. Now you've got me thinking about five...

-Trevor

@ goninanbl00d
I used acrylic mirrors in my spirograph. Since I didn't feel like paying for front surface mirrors, I got a bag of 24 cheapy 1" acrylic mirrors and chemical treated the backs to expose the raw aluminum. One can of aircraft-stripper later, my projections have minimal scatter. Not only are the mirrors lighter and less apt to vibration, but cheaper too

@twhite828

If you do end up making a five-motor spirograph, PM me some images or videos of the results, I'd love to see how it turns out - likely an incredibly intricate projection if you can get any decent control over it. Good luck.

QuackMasterDan said:

@twhite828

If you do end up making a five-motor spirograph, PM me some images or videos of the results, I'd love to see how it turns out - likely an incredibly intricate projection if you can get any decent control over it. Good luck.

Click to expand...

Yeah, it's probably not going to be fun to align... I suspect this wasn't exactly a cakewalk to get working either.

I'll let you know how it goes.

-Trevor

FYI, larger, flatter mirrors make for easier alignment. Keep that in mind and it should be a cakewalk.

Your tut. is worthy of a +rep. good job--very professional for sure..

I like the safety switch you have on there, I use those on some of my builds when I want it to look particularity intimidating :eg:. Looks great!!

i have the same switch
where can i get some mirrors like that localy?
cheap shops etc
cheers

EDIT: Hahaha nevermind i stole my sisters make-up mirror from one of those little opening up things

I caught this tutorial last night, the spiro looks fantastic!

I've been playing around with several ideas for the motor speed controls. Since I'm more of a scrounger than a buyer (I'll take apart something that I haven't used in over a year to find parts rather than buy it), I took apart 2 old Nintendo GameCube controller and removed the joysticks and "rumble" motors. I was able to set up the 2 motors on the X and Y axis and can control both with a single 360 joystick.

It doesn't work perfectly (the motors only ran one at a time originally so I had to cut some metal to expand the stick's movement and the control doesn't allow the speed to increase gradually) but I think having 2 stick controls for 4 motors would be an interesting twist in the design.

Edit: The controllers mentioned above were not official Nintendo brand controllers. I just opened an official one and I can't detach the weight in the "rumble" motor and the joystick cannot be used on its own with DC power. I may end up taking a trip to RadioShack, after all...