[mrcodewiz]

I finally tried to use my G0704 tonight (really the first time since I bought it other than the break-in). It seemed to be doing OK except I thought it kind of smelled - couldn't really tell where it was coming from. Well, about 10 minutes into my work, I heard the RPMs vary a little, then a pop and it tripped the surge protector which shut the whole works down.

It will turn back on and the motor will spin but there seems to be too much noise and fireworks. Here is a short video I made of what it's doing now. The view is from the top of the motor down - its really interesting after about 12 seconds when you can hear the RPM varying and some smoke and noises that it probably shouldn't be making. Any ideas on what I should do?

[nomedia="http://www.youtube.com/watch?v=7JdrL8MFrWs"]YouTube - 00000[/nomedia]

[mrcodewiz]

I don't think the brushes should look like this either.

[john-100]

I think you need a new armature

is the machine still under warranty ?

if not, search for motor armature at littlemachineshop.com for example
for a picture of what it should look like

if copper segments is burnt away at the gaps between them
the armature will need replacing

to test the armature windings when removed from the motor
connect an ac voltage ( 6v or so ) across the commutator
and measure the voltage between adjacent segments should be the same

shorted turns will cause variations in the readings

John

[mrcodewiz]

Yeah, it's still under warranty. At first I thought I may just try to clean it up on the lathe:



But looking further, it looks like some of the windings may be damaged.



Guess I will be calling Grizzly on Monday to see if I can get another motor.

[john-100]

yes a phone call to Grizzly is your first step

in the first picture you can see the gap between some of the segments are wider than they should be

and in the second picture one burnt winding

no testing required with this one

the next question is does the speed control still work

with my minilathe I used a 100w tungsten filament bulb as a dummy load
while testing the speed control

good luck


John

[mrcodewiz]

Hmmm... the speed controller seemed to work. It is wired directly into my BOB and it still turned it on and off and changed speed.

[TOTALLYRC]

Don't feel bad a friend of mine had the same thing happen to his machine.
Along with several other problems he has had to have Grizzly make 4 shipments to replace the dead crap with working crap.

It will finally work in the end.

Mike

[mrcodewiz]

Well, I talked to Grizzly this morning. They want me to inspect the controller prior to putting in the order for the motor to make sure it isn't damaged. I'm not sure what to look for other than 'something not looking right'. It also doesn't sound like they have any motors anyway so I guess I'm stuck for the time being.

[mrcodewiz]

Are the stock motors 90VDC and 1800 RPM? If so, I wonder if this would be a decent upgrade:

Automation Direct Motor

[photomankc]

90V is correct I believe but not sure about the RPM. Looks like a nice motor though. Bit spendy.

ETA: The shaft is a good bit fatter, and the mounting holes are on a larger diameter too than even the 800watt motor on the PM25. The outside diameter is larger as well. Would take some work to get it mounted.

[mrcodewiz]

Ah yeah, it's a 5/8 shaft. Do you know what the stock one is? I will keep looking.

[photomankc]

Ah yeah, it's a 5/8 shaft. Do you know what the stock one is? I will keep looking.

Shaft on my 800watt is 12mm, just a hair under. That may be bigger still than the 600watt. I don't have the plans in hand that had the G0704 motor in them. I can take a look tonight.

[mrcodewiz]

I guess if I go with the belt conversion the shaft size won't really matter. It is pretty expensive though.

[mrcodewiz]

Would a 2HP(ish) 90V treadmill motor be a suitable replacement? It seems like most of them have much higher RPMS (4000+).

[hoss2006]

the stock motor is 5000 rpm with a 10 mm shaft.
Hoss

[hoss2006]

Would a 2HP(ish) 90V treadmill motor be a suitable replacement? It seems like most of them have much higher RPMS (4000+).

I just picked up one from this Ebay seller.
motor items - Get great deals on Incline Motors, Treadmill Motor Chokes items on eBay Stores!
They rate them at 2 - 2.75 HP but that's at 180 VDC ish.
He has a photo of his motors label and you can see that they run around 1.3-1.5 HP continous at 90-100 VDC
depending on motor which is a perfect size for this mill.
Gonna take some mods and fan work to get it to fit.
Hoss

[mrcodewiz]

Ah, good deal. Thanks, hoss. I am going to try to get a delivery estimate from Grizzly today - if it's more than a couple weeks out, I will just go with one from this guy.

thanks again

[mrcodewiz]

Well, its going to be at least a month. Do you think either of these would be a good replacement?

Motor 1

Motor 2

[mrcodewiz]

OK, I'm going to buy one of those treadmill motors today. Does it matter that the treadmill motor is 3 wire (red/black/green) and the grizzly motor is 2 wire? Can I just wire it up with the red/black?

[TOTALLYRC]

The green wire is normally ground so I don't see a problem but I would check to be sure.

Mike