X2 died. Must revive!

[voltsandbolts]

Before I start troubleshooting. I was running my X2 and when I finished with a slot. I noticed the pot would not reduce the spindle speed. E-stop worked. I started the mill again and it went right to max speed with the pot in the minimum position. I tried to turn it off and on again and it was dead. I am guessing the strain of a full speed start caused the fuse to blow.

I can’t be the first this has happened to ( I did search and read but no clear answer), so what was the fix? New pot?

Thanks for any info you can offer.

Rob.

[Crevice Reamer]

Sounds like a shorted speed pot. If you really fried anything in the speed control board, here is a relatively cheap replacement that is also an upgrade to half again more spindle rpm and torque--It also comes WITH a new speed potentiometer, but you have to add (from the same source) fuses and HP resistor:

http://state-electric.com/_product_15408/KBIC-120

Or you could get normal performance with THIS one for only $30:

http://www.surpluscenter.com/item.as...tname=electric

CR.

[Mike Nash]

It could quite possibly be a shorted mosfet.

Check out Uncle Rabid for cheap repairs. See bottom of page for X2.
http://www.unclerabid.com/Repairs.html

Also see http://www.littlemachineshop.com for lots of useful info. (I got the first link from there as I didn't remember the url.)

[voltsandbolts]

Thanks for the info guys. But being the geek I am I would love to see the schematic for the controller, has anyone scratched one out? I want to take a shot at fixing it before I replace it, I got nothing to lose!

Rob.

[Mike Nash]

There are schematics on the various 7x and minimill yahoo groups under files or photos. There is more than one version also. Below is another group with some files.

http://groups.yahoo.com/group/mlathe...eed%20Control/

[voltsandbolts]

Thanks Mike.

[blades]

I just today received the speed controller from www.surpluscenter.com and it looks pretty decent. It's labeled as a treadmill speed controller, and has the 3 terminals for the pot, 2 for AC input, and 2 for the 130v DC motor output. All terminals are pretty hefty spade type terminals, and it's attached to a very generous sized aluminum extrusion that also acts as heat sink for the power transistors. All in all, it's a really decent looking unit for $30. Haven't hooked it up yet.

This unit came recommended from Hoss, so I don't forsee any issues with it. If he's happy with it, then I'm sure I will be also. I believe he mentioned that when using this controller, you don't have the green light, just the amber one. Not an issue for me, as I'm putting all my controls into one wall-mounted custom box, which will hold the speed controller, CNC board & power supply, and have all motor controlls on the front of the box. Will post pics when it's done.

[Crevice Reamer]

Excellent, blades! Sounds like you are doing some good work. What happened to your OLD X2 speed board?

CR.

[blades]

Originally Posted by Crevice Reamer Excellent, blades! Sounds like you are doing some good work. What happened to your OLD X2 speed board? CR.

Thanks Crevice, I decided to dedicate the board to display my own personal fireworks show. The metal box I'm putting everything in is directly grounded from the ground wire of the 110 plug. I used small metal standoffs to mount the board to the box, utilizing the 3 mounting holes in the speed control board. Evidently, I must have unwittingly grounded to something that wasn't supposed to be grounded, because after everything was wired up, I opened the power switch and POW!
Upon closer investigation, there is evidence of an arc between one of the mounting holes and the board. Physically, I see 2 capacitors that are blown, but I'd have to believe there is more damage than just those. If I get a chance, I'll post pics of it tonight.

Apologies to voltsandbolts: don't want to hijack your thread, just wanted to pass along info that may save other innocent boards.

[Crevice Reamer]

Thanks for the warning blades! Who knew it was so easy to blow a speed board? There but for your experience could go us all.

CR.

[blades]

Here's the victim, you can see evidence of the arc by the mounting hole, and the 1 capacitor that's obviously toasted, the other being on the bottom left (you can barely see the top is deformed). I hooked the board back up, but it didn't show any signs of life. As I mentioned before, I assume there's more than just the 2 capacitors damaged.



On a brighter note, here's the new board.

[dang]

I've already replaced my X2's circuit board with that treadmill board. It works gangbusters! It's a great alternative! That said, the fuse is always the 1st thing to go under any sort of load. Personally, I blow out at least two fuses every week. I ordered from China in bulk, off ebay. So that should always be checked and replaced 1st. After that comes the treadmill board replacement and then the motor.