[magneto259]

Hello all I'm looking for a Maxnc 10 open loop controller board. Mine took a dump. Maxnc wants about $400 for one and I was hoping someone had one new or used for sale or could point me to someone who does. Thanks in advance!

[HillBilly]

1st or 2nd generation?

[Stepper Monkey]

Even if you found a new or used one cheap it's VERY likely just to take a dump again. They do that a lot. There are a couple people on here that went through two or three stock boards before trashing the stock electronics entirely and going with Xylotex or similar.
I'd just get a Xylotex for that machine - it's a cheap reliable board with similar specs to stock, and is a good match for the machine - Gecko's or similar more powerful boards would be a waste of money as the NC10 just isn't rigid enough to take the extra power or speed of a stronger board.

[magneto259]

Hmmmm.....i'm not sure but I believe it is a first generation because its pretty damn old. Are there any distinguishing features that will tell what generation it is? Thanks for the input stepper monkey i'll look into that board. Thanks in advance!

[magneto259]

I just checked out Xylotex's site and their board is much cheaper than the maxnc one combined with the power supply! Do you know if this combo would work with my existing motors? It said you could configure the board the way you needed it to be. Also what software does this require to run? Thanks in advance!

[HillBilly]

1st generation did not include spindle control or 4th axis. There is not much that could go wrong on a 1st gen. If all axis are dead it is probably the transformer or bridge rectifier.

Darek

[magneto259]

Ok its a first generation one then. Because I don't have those features. The board isn't completely dead. Only one of my axis's isn't working correctly the Y axis to be exact. It jerks and moves erratically and only moves in one direction. I've switched the motors around and it is the axis not the motor.

[HillBilly]

If this is what your controller looks like it is a 1st generation. Each axis has a 7400 chip ( 7400 = QUAD AND GATE used as a signal buffer.) and four TIP# output transistors ( I forget the #.) All of these parts are in the $1 each range.

Darek

[magneto259]

Yeah thats what it looks like if i remember correctly. I was wondering if I could just replace the components and see if it will make it work correctly again. I'll have to see if radio shack has the parts or online somewhere.

[magneto259]

I took the controller apart and the solder joints look horrible and it is covered with flux. Is there anyway to test the components to see which ones are bad? Thanks in advance!

[HillBilly]

Here is the pinout of the 7400. Each gate has its 2 inputs tied together on the PCB. If an input is high the output should be low. The 7400 outputs trigger the power transistors.

Darek

[magneto259]

Sweet! thanks for the pinout. It will finally give me a reason to use my logic probe! LOL I'll give it a try here in a bit. Thanks again

[HillBilly]

Here is the pattern of the four outputs. It is half step mode and repeats after 8 steps.

Winding 1a 11000001110000011100000111
Winding 1b 00011100000111000001110000
Winding 2a 01110000011100000111000001
Winding 2b 00000111000001110000011100

Darek

[magneto259]

Sorry about the delay. I never had a chance to use my logic probe yet but i was inspecting the soldering joints and they looked horrible. So I reflowed the solder joints. I hooked it back up and the same problem is happening. I took a few pictures of the board. If anyone can tell if anything is missing or hooked up wrong i'd appreciate it. Thanks in advance.

[samco]

you might want to take a look at this site.. he is one of the emc2 developers. He replaced the resister current limited drives with some home made L297-298 drives.

http://timeguy.com/cradek/cnc

high-voltage stepper motor drivers that use a chopper instead of ballast resistors to limit current, allowing rapid speeds of about 32 inches/min instead of the abysmal 10 that the original drivers allowed.

sam

[awerby]

I started out with one of these, and the people here are giving you good advice - junk it, and get something else. Xylotek is a good choice, also Geckodrives just came out with a new low-power low-cost system that sounds good.

But while you're waiting for the new system to arrive, you can try replacing the transistors. These are Darlington type TIP 120, and they did tend to burn up in use. I think you can still get them at Radio Shack (if you can find someone there who knows what a transistor is). Don't expect it to go very fast, or very long, though...

Andrew Werby
www.computersculpture.com