Shop Powerfeed

[Doggggboy]

The x axis powerfeed died on the mill.
Precision Mathews does not handle any parts for it.
I've ordered a new board from ebay but the old board still kinda works, just no speed control, it's all or nothing. You can see the fried parts on the board below but I can't read the badly burnt one in the middle. Any guesses?
The board is an AL-510S 120v.

 

[jcdammeyer]

The x axis powerfeed died on the mill.
Precision Mathews does not handle any parts for it.
I've ordered a new board from ebay but the old board still kinda works, just no speed control, it's all or nothing. You can see the fried parts on the board below but I can't read the badly burnt one in the middle. Any guesses?
The board is an AL-510S 120v.

There's likely more than just those damaged. Likely not repairable without a schematic and component list.

 

[Doggggboy]

There's likely more than just those damaged. Likely not repairable without a schematic and component list.

That's kinda what I expected. The only thing that isn't working right now is the speed control.
What happened was I mistakenly, (stupidly, carelessly, thoughtlessly...take your pick) threw it from full up to full down.
It quit on the spot. When I pushed the breaker button to try to reset, it broke. I took it apart and replaced the breaker with another the same size and now everything works but the speed control.

 

[gerritv]

http://www.elrodmachine.com/PDF/ALign%20Power%20Feed%20Instruction%20Manual.pdf

 

[Doggggboy]

http://www.elrodmachine.com/PDF/ALign%20Power%20Feed%20Instruction%20Manual.pdf

Awesome. I just found the same thing on the PM site as well.
Thanks.
No if only I could read a circuit diagram

 

[jcdammeyer]

Awesome. I just found the same thing on the PM site as well.
Thanks.
No if only I could read a circuit diagram

Which unit do you have? An AL-300 or AL 400/500?

 

[Doggggboy]

Which unit do you have? An AL-300 or AL 400/500?

AL-510S for the Z axis 110V. I think it is a little older than the one PM lists.
It's on the Ferro mill I bought from John Conroy.

 

[PeterT]

I don't intentionally change direction instantly on PF but I can foresee instances where it may happen by accident. I'm kind of surprised these designs don't have some kind of safeguard integrated into the board like a hardwired 1-sec pause delay regardless of the shift lever movement, but maybe its not as easy as that.

Which reminds me (unrelated), my lathe Forward/Neutral/Reverse lever is drifting out of detent alignment again despite tweaking. Bad design. I need to come up with something better. It has slipped from motor on Rev to Fwd instantly just like you described. One sad day the magic smoke will come out .

 

[Darren]

I've done instant fwd to reverse feed a few times, although i prefer to kick it to the center position and let the motor stop before changing direction. I didn't know it was a bad thing really, but it didn't seem right. I figured it might break gears if anything, not fry electronics...

 

[Doggggboy]

I've done instant fwd to reverse feed a few times, although i prefer to kick it to the center position and let the motor stop before changing direction. I didn't know it was a bad thing really, but it didn't seem right. I figured it might break gears if anything, not fry electronics...

I guess I'm just lucky that way.

 

[Susquatch]

I've done instant fwd to reverse feed a few times, although i prefer to kick it to the center position and let the motor stop before changing direction. I didn't know it was a bad thing really, but it didn't seem right. I figured it might break gears if anything, not fry electronics...

If I recall correctly, you have a VFD on your lathe. If so, it should handle a full reversal in either position to the other just fine. Basically, the VFD runs the decell cycle before starting the accel cycle both according to whatever accel/decel rate you programmed into it.

 

[Darren]

If I recall correctly, you have a VFD on your lathe. If so, it should handle a full reversal in either position to the other just fine. Basically, the VFD runs the decell cycle before starting the accel cycle both according to whatever accel/decel rate you programmed into it.

I have VFD's on everything pretty much. They love back to front, not a problem.

Here, i think we are talking about the typical Align style power feed for mills. Where you'll be wizzin along, shreddin metal, and then suddenly decide to stop and go the other way. I was worrying about busted gears, but its actually more of a solid state problem.

 

[Susquatch]

I have VFD's on everything pretty much. They love back to front, not a problem.

Here, i think we are talking about the typical Align style power feed for mills. Where you'll be wizzin along, shreddin metal, and then suddenly decide to stop and go the other way. I was worrying about busted gears, but its actually more of a solid state problem.

Ah, I misunderstood.

Personally, I think that flipping direction on the fly is worse on a lathe with all that rotating mass - especially with an up sized motor. And I still think gears are the biggest risk. But a good quality VFD solves that problem.

I think the typical mill has different risks. The lower rotating mass is less likely to break gears, but even so, a VFD solves the problem on a mill too.

In the special case of non vfd electronic speed controls on either lathes or mills, there is a VERY high risk of excessive current flowing for double the normal time during the direction reversal which could damage solid state controls which is probably what happened in this case.

I am glad that the OP was able to find schematics for his control board, but like @jcdammeyer, I'll be surprised if replacing those two resistors fixes the problem. My guess is more likely shorted drivers (SCRs?) that will still look fine but are toasted. But we can all hope otherwise.

 

[slow-poke]

I removed the power feed from my BusyBee A1S, so if anyone needs one let me know.

 

[van123d]

The two burnt parts look like resisters from the dogbone shape. That is an unusual pcb in that the silkscreen appears to be the component values.

Example. 4004 is a 4004 diode. There is a 0.33 next to a likely 0.33uf cap.

What is throwing me off is the 333 number with what appears to be a 400 ohm resister.

Can you take a picture that show more of the resisters so we can try and decipher the code? There are a 103 and 104 number visible but I can’t see the colour bars on the resister. I wonder if those are 10k and 100k resisters?

A photo with other resisters that we can see the colour bars on the resisters as well as their board numbering might help.

If you clean the charring off the board the silk screen is possibly still visible underneath.

 

[Susquatch]

If you clean the charring off the board the silk screen is possibly still visible underneath.

Duhhhhh. I noticed the same correlation but never thought about trying to clean off the soot.

330 & 400 are not so far apart as to rule out their interchangeability. Unless specified otherwise, it might even be within tolerance.

While you are in there with a Q-tip, take a magnifier and have a REALLY good look at the power devices - and also the traces and solder joints for them. Might as well also write down their device numbers too.

 

[Doggggboy]

The two burnt parts look like resisters from the dogbone shape. That is an unusual pcb in that the silkscreen appears to be the component values.

Example. 4004 is a 4004 diode. There is a 0.33 next to a likely 0.33uf cap.

What is throwing me off is the 333 number with what appears to be a 400 ohm resister.

Can you take a picture that show more of the resisters so we can try and decipher the code? There are a 103 and 104 number visible but I can’t see the colour bars on the resister. I wonder if those are 10k and 100k resisters?

A photo with other resisters that we can see the colour bars on the resisters as well as their board numbering might help.

If you clean the charring off the board the silk screen is possibly still visible underneath.

Yeah, I shoulda taken a better picture when I still had it apart. No biggie, it actually comes apart pretty easy once it is off the mill.
I'll get on that this afternoon.
Blondihacks on Youtube has a good video on her powerfeed refurb. It looks like a very similar board but her problem was a dirty variable resistor.

 

[slow-poke]

151 = 150 Ohm
Burnt = 820 Ohm
Check all of the diodes, especially the one at the 150/820 junction
Check the thyristors

 

[Doggggboy]

The two burnt parts look like resisters from the dogbone shape. That is an unusual pcb in that the silkscreen appears to be the component values.

Example. 4004 is a 4004 diode. There is a 0.33 next to a likely 0.33uf cap.

What is throwing me off is the 333 number with what appears to be a 400 ohm resister.

Can you take a picture that show more of the resisters so we can try and decipher the code? There are a 103 and 104 number visible but I can’t see the colour bars on the resister. I wonder if those are 10k and 100k resisters?

A photo with other resisters that we can see the colour bars on the resisters as well as their board numbering might help.

If you clean the charring off the board the silk screen is possibly still visible underneath.

 

[slow-poke]

Creepage Yikes

Clean the board, check the diodes, SCR's, and potentiometer. Replace the 150 and 820 and whatever else let go and you should be good to go.

Digi-Key has S6010LSTP in stock, looks to be about a $10 or less repair, they ship FedEx overnight for $8, delivery next day by noon.

Sounds like shorted SCR(s), does it go full speed in both directions?