Reply with QuoteMine has been working perfectly. Now I am just holding onto the grizzly one as a spare in case of emergency.Originally Posted by SgtSpyder
I’m not going to wait on Grizzly, got things to make. I ordered a KBMM-125 yesterday. Should be an easy replace to get the mill running.
Mine has been working perfectly. Now I am just holding onto the grizzly one as a spare in case of emergency.
Got the KBMM-125 this week, going to put in tomorrow. I’ve been looking over the Grizzly wiring diagrams and it doesn’t look like they have the tach signal inputted back in too the SCR controller. That was a little surprising, I’d like to bring the tach signal in to the KBMM-125 but the manual seems to lack some of the info about the sensor. Does anyone have details on the sensor?
Wired up the KBMM-125 today, didn’t go well. Keep blowing fuses to the main board. The motor spins, just not very fast. Pulled out the meter, best the voltage the controller could do to the motor was 18vdc. But at that voltage, amperage was hitting the 10 amp current limit I set at the KBMM-125 trimpot. I’m thinking there is no way this motor should be pulling that kind of amperage when free spinning with no load.
Looks like I’m calling grizzly tomorrow and see about getting a new motor.
You need a DC tach on the motor, the J2 jumper has to be set for tach and the tach voltage /1k rev should either be 7v or 50v, if between these two then the output has to be tailored with a resistor, the manual shows how.
You can check the motor with an automotive battery, the motor should spin up and be steady rpm and no excessive current, once up to speed, in both directions.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Couple questions. Were you in high gear or low gear and does your spindle feel like it has too much resistance? Mine was the same way - it would pull 8 amps right off the bat but if I ran it in low for 10 minutes, the bearings would warm up and the no-load draw would go down to 3 or so.
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I wanted to try use the tach signal that the G0704 has on the spindle. I just don’t have any info on the signal for the tach sensor or what signal comes out of the little controller it has.
I didn't connect the belt to the spindle, its just free spinning.
Are the bearings in your spindle or the motor heating up... I'm assuming the spindle since you referenced it above. Just want to make sure.
-Dave
Unrelated to Sgt's problem as I missed that he didn't even have it engaged to anything (that is absolutely not right) but on mine it was the big bearing that is outside the quill sleeve - not the spindle bearing.
Well the mill is still not running. Called grizzly to get an ETA on the replacement motor, they said around the beginning of May.
Picked up a brand new tread mill motor off eBay for 60 bucks. Trying to figure out a way to securely mount it without having the mill running to make parts.
Maybe its time for duck tape and safety wire.
I got an email Tuesday saying mine should be in late May. It also said "The new motors and circuits boards should be of an improved design once they arrive from the factory."
I have too much in this thing to send it back now so I'm just moving forward with the parts of the conversion that do not need a functional mill.
A Grizzly Motor Quick Fix
I just received my new G0704 and there are warning labels and an addendum sheet to the manual warning the operator not to run the motor at full RPM for extended periods of time or they will risk burning out the motor.
How's that for a fix?!?!?!?!?
They added that warning many months ago long before this new batch of machines with a supposedly new supplier of motors.I just received my new G0704 and there are warning labels and an addendum sheet to the manual warning the operator not to run the motor at full RPM for extended periods of time or they will risk burning out the motor.
How's that for a fix?!?!?!?!?
Hoss
Gosh, you've... really got some nice toys here. - Roy Batty -- [URL]http://www.g0704.com[/URL]
No matter how you spin the facts the idea of adding the label as some kind of fix to the motor issue is just a big joke. If the motor can’t handle the advertised speed then Grizzly needs own up to it and take action. At the beginning of this motor ordeal I was on Grizzly’s side and was sure they would make things right I just needed to be patient. Time has worn away those patients. Don’t think I’m going to buy anything else from Grizzly.
Grizzly didn’t say anything to me about going with a different motor supplier. They said they were looking at modifying the ends of the motor and the fan inside so it flowed air a little better. But I’m sure someone else can call them and get a completely different story about the motors.
What I do know is that my mill motor blew back in March and I still haven’t gotten a replacement.
Ok in the attempt to add real data to the G0704 motor issues I’m posting some pictures of my old blown motor next to my new motor that I finely received from Grizzly this week. I’ve been told by Grizzly and also read here in a few places that the motors were going to be changed in some way or come from a different supplier.
They look the same to me except for the labels and part numbers being different. It also looks like they’ve moved the that little POS fan in the motor closer to the vent holes.
Decide for yourself.
Old motor on the Left, New motor on the right.
From what I have seen I don't think the motors are not up to the job but some were just defective. Something put too much pressure on the windings and they shorted.
If they fixed that they should never fail under light to normal use.
Under max power over a long run things may be different but this is not the kind of failures people have posted about.
You could drill out the holes in the top motor plate to allow more air in and adding a 120mm fan to the back side of the motor housing cover would be a nice thing too.
I don't think the outside of the motor is where the failures were stemming from.
What they did to the inside is what matters don't you think?
Hoss
Gosh, you've... really got some nice toys here. - Roy Batty -- [URL]http://www.g0704.com[/URL]
Adding a PC case fan to the top of the motor is a good idea. I had a 120mm fan on my old motor for several months before it failed. Being that I have the motor apart now I may go ahead and open up those holes. I’d actually like to remove the crappy little fan and just use an external one, but the armature was probably balanced with the on.
I expected the outside of the motor to be different. Grizzly told me that the motors were possibly getting to warm and because of heat they were going the change it to improve air flow for cooling.I don't think the outside of the motor is where the failures were stemming from.
What they did to the inside is what matters don't you think?
Hoss
Here are pictures of the insides.
New motor.
This shows the timing between the brushes and the magnets, looks unchanged.
Old motor.
Last edited by SgtSpyder; 07-11-2011 at 01:25 AM.
From the pics the new motor looks like it has larger wire windings than the old.
Hoss
Gosh, you've... really got some nice toys here. - Roy Batty -- [URL]http://www.g0704.com[/URL]
Not a G0704, but a PM25... I think I blew the pot as when I turn the mill on - It goes full bore and then trips the breaker. Upon inspection of the control board, nothing appears fried (Scrs or otherwise) - Test the pot and I get out of range readings. Anyone experience a similar issue with the pot on either their G0704 or PM25? Thanks.
