PM727 Issues

mak91

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A public service announcement for pm727 owners. Two things you might want to check to prevent future failures. First is the wiring in your control box. Make sure the crimps are good and tight by giving a slight tug on the wire. I had loose crimps which caused heat buildup to the point the insulation melted off the wires and shorted out which eventually fried my motor. The second thing to check are the spindle bearings. Mine were bone dry with no lube which caused bearing failure.
 

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Oh yucko, you should definitely let Matt at PM know about that (if you haven't already)
Mark
 
The electrical issues happened a year or so ago, PM replaced the motor no problem. They said there was no wire harness for the machine even though each individual wire is clear marked. I got some wire/crimps from the hardware store and made my own. The bearings are a recent problem and it was recommended from them that I buy better bearings. I am not sure if they consider their own bearings crap or not but honestly I think a little grease would have gone a long way to preventing this. You are on your own to figure out how to disassemble and replace this stuff. Luckily I have the tools and a 20 ton press to do this with.
 
I am not quite sure who this is, only found customer one in Ringgold, GA, and that machine is about 2 months shy of 3 years old. Is it converted to CNC and running constantly or faster than stock? Thats the only time Ive seen anything like that, just asking because of the comment about we recommended buying better bearings leads me to believe it was converted and / or sped up, that would be why it was recommended to get different bearings. Not how its sounding like you got the machine last week with dry bearings and we told you to go buy bearings. If that is the case, let me know who you talked to here and they are going to have a problem.
It definitely does not hurt to check bearings and is good to do when new, but I have never seen one that was dry like that when new or recently put in to service. If anything they over-grease them from the factory and I am on them about not using too much grease. I would check them about 1 time per year though, or every 500 hours or so of use as a general rule.
 
You are correct, my machine is almost 3 years old and not cnc'd. I am a hobbyist and don't use this machine that often. NSK bearing were recommended as an upgrade when I asked if the bearings were covered under warranty.
 
As a fairly new 727v owner i though the oil in the headblock served to oil the gears and the spindle bearings.. if that is not correct are the instructions for the spindle bearings in the manual?
 
@mak91 I need to replace the spindle bearings/seals. Where did you source yours, and advice changing them?
 
@mak91 I need to replace the spindle bearings/seals. Where did you source yours, and advice changing them?
Which bearings are you going to replace ? If its part number 36 and 50 in the manual bearing numbers 30205 and 30207 there is no seal to worry about. I got them locally from an industrial bearing / hardware store. If you have to change the 6007 bearings part number 6 in the manual things will get interesting. You will have to remove the top cover of the gear box to change them. There are seals related to the 6007 bearing but mine looked good so I didn't change them. Even though the 6007 bearings are inside the gear box they are NOT bathed in oil. PM originally told me they were, they are NOT, they are above the oil and grease packed.

The only tricky thing to taking the spindle out is there is a screw hidden behind a setscrew on the left side of the head. You must remove the set screw and use a flat head screwdriver to loosen up the screw some so the spindle can drop completely out. If you have to replace the 6007 bearings the motor and top plate must come off. There is a plate sitting on top of the 6007 bearings that screws onto the top plate that also must come off. Here are the official instructions that PM emailed me. They leave a lot to be desired but will get you going in the right direction. Also the bearings are available from multiple places just google the bearing numbers like 6007 or 30205 and you'll get lots of hits, go with a name brand and a known seller.

Hello Friend

it is need open that top casting.

1.,open electric box.and Remove side connecting screw with top casting.

2..remove motor.

3.please checking this picture.remove two plug.

4.remove spindle Snap ring and remove this top casting.

5.replace bearing

6.Restore them

if there are any question,please let us know.thanks

best regards

Mr.Chen yuan
 
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