HELP! LMS mini mill (SX2) won't retart after overload fault

hman said:
It looks very like you'll have to replace that board ... multiple component failures! Hopefully, this will be under warranty. In any case, ain't it nice that at least SOME failures announce themselves plainly? :lmao:
Best wishes!
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Heard back from Chris again, he's going to send out another board under warranty. That dude is great. He really stands behind his product and is helping me out even though this was probably my fault. I will make sure i give him more of our business.


wrmiller19 said:
I was going to say that it sounds like you popped a FET, but after looking at your board, I'd say that was obvious.

Not knowing how long the machine was running, what cutter size, DOC, etc., I don't know if you overheated the board or not. But it kinda looks like it.

The duty cycle on these little machines is probably very low. For prolonged usage I would add airflow over the control board/heat sinks to better handle the extra power dissipation requirements. Maybe even larger heat sinks on the FETs.

Bill
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This happened around 6-6:30 in the evening and I had been making chips most of the day. It wasn't a real deep cut - 5/8" 2 flute end mill .06" DOC with about 50-60% engagement while I was roughing out the slot. Nothing crazy but I had been doing similar work for a least a couple hours. Duty cycle was not something I had considered when I picked this mill, probably a critical oversight. I will definitely look into adding an exhaust fan to the back housing to keep the air moving in there.


All that being said, I'm starting to regret a little bit that I didn't go for the G0704/759 when i was looking at mills. More machine is always mo' better, right?
 
I've never gone larger than a 1/2" end mill in the LMS, and that was a rougher to keep loading on the machine down. Mostly I stayed with 3/8" and smaller. But that's just me. :)

You're not alone in the 'larger is better' arena. Which is why my LMS machine is just sitting around looking forlorn while the PM25 gets all the work. The LMS was 'almost' big enough for what I need, but not quite. Unfortunately, I had to use it for a bit before I came to that conclusion. Such is life.

Bill
 
Glad you got it figured out and that LMS is standing behind their product. I remember pushing my duty cycle last year on a deep cut steel project and felt the motor to see if it was getting hot after an hour or so. It was starting to get pretty warm so I setup a room fan to provide additional airflow and it helped.

With this in mind, I recently picked up a surplus 3" 125v box fan ($5) like a computer uses to aid cooling, but it sounds like I should be using it to draw air through the control box instead of blowing it across the motor. I never even considered the temp of the control board components.

I run 3/4" bits once in a while, but my go to bits for hoggin are 5/8" 3 flute (alum) and 4 flute (steel) in both finish and roughing. A quality 3 flute roughing bit eats aluminum like butter @ .060" per pass with no problem.
 
If you add a fan to a control box, it might be a good idea to put some kind of air filter to keep out dust and other crud.

John
 
John_Dennis said:
If you add a fan to a control box, it might be a good idea to put some kind of air filter to keep out dust and other crud.

John
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The control box has filtered vents but no forced air so I think I would wire up a motor to blow air out of the box and have the makeup air come in through the existing filtered holes.
 
Fabrickator said:
I run 3/4" bits once in a while, but my go to bits for hoggin are 5/8" 3 flute (alum) and 4 flute (steel) in both finish and roughing. A quality 3 flute roughing bit eats aluminum like butter @ .060" per pass with no problem.
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Something like this maybe?
 
believe it or not, sometimes you can replace the obviously scorched parts on a board and it will run again. I have replaced the diode in my air conditioner control board a couple of times and gotten it fully functional. There is no way for most people to check the chips, but resistors diodes and transistors ect can be checked with a good volt meter.

John
 
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