Archive | October 2011

Replacement Parts

At the suggestion of some very helpful redditors, I just ordered a couple of new laser diodes. (one for back-up) This time it’s an IR diode. 808nm, 300mW. The blu-ray diode was (bless her heart) 405nm, 100mW. In other words, the new one will have three times the cutting power but I won’t be able to see it without a camera. I have a feeling safety is going to be an issue.

Also , the new diodes are insanely cheap!

I bought a new multimeter from Radio Shack for about $20. You’d expect them to have the courtesy to include batteries for twenty bucks, but they didn’t. They take AAAs too. I hate AAAs I have a ton of AAs and 9Vs. What’s the point anyway? Why should there be two different sizes for what is essentially the same thing? I believe the sole purpose of the difference between AA and AAA is to piss people off.

Anyway, once I find some AAAs around here, I’m sure the new multimeter will do fine.

Tomorrow, I need to look into a new current regulator. I’d do it right now, but it’s about 1:30am and I have class in the morning.

Advertisements

Successful Failure

That’s what this blog should be called.

So, I got it up and running…for a while anyway.

Riding along the 3/8″ threaded rod and 1/16″ steel bar is the laser carrier. Made of good ol’ 1 1/2″ birch with a hole drilled through it and a 3/8″ nut inside, it has room for improvement. When cutting a piece of electrical tape, it wobbles quite noticeably, resulting in a kind of zigzag cut. I think I need to go to the hardware store this weekend and get another 1/16″  metal bar to stick on there, taking advantage of the stability of a triangle.

The Y-axis on the other hand, moves straight as an arrow…that is, when the bearings don’t fall of the tracks and the motor shaft doesn’t slide around in the rubber-hose-motor-coupler. zip-ties don’t seem to do the trick for that one.

Running the show is the Arduino Diecemila hooked up to two EasyDriver version 4.4 stepper motor drivers from Spark Fun Electronics. As reported by other users, the A3967 get’s considerably hot, so I screwed on a heat-sink from a…stereo, I think. There’s a computer fan sitting on top of it now.

The wiring is like so:

…except I’m using 8.4V instead of 12. It seems to work fine.

I can’t remember where I got this image, but it’s not mine. If it’s yours just let me know and I’ll give you credit. Since you’re using open-source hardware, I get this eerie feeling that you don’t care, but I’m in no position to make assumptions…In any case it’s a very nice image. Good job.

If you plan on getting some of those motors from All Electronics, the wire configuration is:

A1: Red

A2: Yellow

B3: Blue

B4: Orange

I got some basic code to work and the motors move fine. I still have a TON of software stuff to work out. I need something that will interpret GCode into Arduino and make it do everything it’s suppose to. I also need something to convert images into GCode.

Image==>GCode==>Arduino. That’s how this needs to work.

Anyway, all that would be fine if it weren’t for the fact that my current regulator quit on me, consequently burning out my laser diode. Quite depressing. I also need to get a new multimeter (not from Wally-World this time) because it seems to think 12V is around 43V. I thought it was the power supply for a while, and then I tested another 12V supply. It also read 43V. Verdict: cheap and shitty multimeter is cheap and shitty.

Ugh…doing some shopping this weekend.

I forgot to mention…

I got the motors (Minebea # 23KM-K217-P2V) from allelectronics.com for $12 each. It’s a great website. I highly recommend it.

 

 

 

 

 

 

Also, about that giant red stain on my workbench…I know it looks bad, but I promise I still have most of my digits.

REMINDER: Always wear safety glasses. Can’t let the blood spray into your eyes or you’ll go blind and you won’t be able to find the first aid kit.

…okay, it’s just wood stain from another project.

X-Axis assembly

I wasn’t able to screw the motor on in any good way, so I just went for zip ties. Same piece of rubber hose for the motor coupler as on the Y-axis. The linear Actuator is the same 3/8″ threaded rod as on the Y-axis. The 3/16″ metal rod above the actuator is there to stabilize the laser carrier.

By the way, This is really starting to look to me like a legit CNC machine.

As for the structure, I just have to make the laser carrier and connect the electronics. Then it’s on to the software side.

Y-Axis Motor mount

Here we have the Y-axis motormount, which consists of a 1/16″ thick piece of aluminum, 3 1/4″ wide and about 4″ long, bent 90°. The hole for the motor shaft is about 5/16″. There are two 2″ X 1/8″ screws at the top held in place by nuts. The springs are there to hold the mount at the correct height for the Y-axis threaded rod.

Time to work on the X-axis.

This project has legs.

As you can see, I’ve installed four 1/4″  X 4″bolts in the Platten to hold the structure up.

The bearings have been inserted into two 3/4″ pieces of birch about 8″ long. Between the two boards is a 2′ long piece of threaded rod, in the middle of which is another board with a bolt glued into it and another threaded rod. The black rubber tube on the end is for the shaft of the Y-axis stepper motor. The opposite end of that rod still needs to be fastened to the bottom of the platten to hold it up.

However, I am having some second thoughts on the design. As it is, it doesn’t seem to work very well when the Y-axis rod is in the middle. I’ll know more once I have it installed, but having the motor on the right or left side might work better.

The bearings don’t slide too easily. I can tell they might need some silicone, teflon, grease, or something.

In the next post I’ll show you my Y-axis motor bracket and possibly the synthesizer I just finished.

By the way, sorry about that sideways pic, but I don’t really feel like fixing it.