Archive | January 2012

Please Kopimi

I just want to let everyone know that it’s totally cool to copy me. In fact, please do.

Progress has been made

Here are some things I’ve done in the past couple of months.

First, I decided that 1 1/2″ birch was to narrow and the machine wouldn’t go very far before it crashed and fell over or something. So I replaced it with 3″ poplar.

Most notably, however, I have replaced the old linear actuator system on the x-axis with this stepper and belt from an old scanner I found in the alley. I didn’t really want to do it at first because it’s a unipolar motor (6 wires) as opposed to a bipolar motor (4 wires) like the old motor. A unipolar motor can be turned into a bipolar motor simply by not using the two COMMON wires. I thought it would be a pain in the ass to find the Common wires as well as find the coil wires and group everything together correctly. Then I realized the Common wires were both Brown. So that was easy.

And as a bonus, the motor came with its own mounting bracket!

Here’s the other side of the belt-drive. Once again, it conveniently came with its own bracket and pulley.

That 3/16″ steel rod you see in the back will either be replaced by a 3/8″ aluminum rod in the future or have a partner right below it to stabilize the carriage.

Notice how far apart the y-axis bearings are. I expect this to be much more stable.

 

 

 

This is how the belt is fastened for right now. It will have to be temporary. It’s way to heavy.  I will also need a belt tensioner. I’m working on some ideas for that.

Belt tensioners on Thingiverse:

http://www.thingiverse.com/thing:10274

http://www.thingiverse.com/thing:10082

http://www.thingiverse.com/thing:12733

That’s it for now. I have to go to work.

I’m back

Seems like it’s been a really long time, but it’s only been a couple of months since my last post.

So let’s get up to speed:

I ordered two laser diodes but only one came in. I didn’t take the initiative to contact the seller/s because they appear to be a gigantic factory in China and they’re dirt cheap. So I’ll just order another one if/when I need it. I’d like to get a box of several spares but I don’t know if that will be possible unless I land on some disposable income.

I took the old diode out of the Aixiz module (The process involved a hammer. It wasn’t pretty) and put the new 808nm 300mW diode in, which was a little tricky. I had to use a vice and a piece of wood with a hole drilled in it to protect the pins.

The diode is an open-can model, unlike the old one. This requires a little more care. Can’t allow dust and debris to get in there.

At the moment, I don’t have a good way of testing the diode. The beam is not visible to the naked eye and I don’t even have appropriate safety glasses yet. It also seems that none of the leads are connected by conductive material. I’ve tested it with the ohmmeter and I don’t get a response. I don’t think this means the diode is broken, but it seems odd to me.

I need a driver. The laser has an operating voltage of 2.2V and is rated at 300mW. That means it needs about 2.2V at 136.36mA. The last time I tried to make a driver it didn’t work. Perfboard is not my friend.

In other news, I have decided to replace the x-axis linear actuator system with a much lighter belt-drive system. I will have pictures in the next post.