Hoss's G0704

[Thomasn]

Hoss any update on the release of DVD how to on the G0704?

[BAR553]

The second chinese speed control board blew this weekend. After looking at the motor, it may have been the problem all along. Installed the replacement motor, which has a different part number, and put in the KB Electronics board, the whole machine sounds better. Got about 300 rpm increase over the original speed controller, without touching the pots. Modified the recommended heat sink, to act as the back panel. A nice days project for a beginner, not perfect but learned a lot.

[Isplat]

Can't speak to the quality of the controller yet as I don't have a lot of time on mine.

I think they should be fine since they look like a "carbon copy" of a KBIC albeit with Chinese SCRs, components, and manufacturer's label.

One thing I have noticed running my setup is that the stock motor gets really hot to the touch because it has no real cooling i.e. no fan to speak of. It is also burried in a poorly ventilated cover. So, I'm thinking of ways to mod the motor and stock motor-enclosure to attach a fan for cooling. I think the motor might be cooking itself (frying the windings) and then frying the controllers based on some of the images I've seen posted. I might just ditch the cover altogether; but I like the idea that it keeps some of the swarf and crap out.

Grizzly also shipped a warning with the mill manual about "overheating" the motor by running full tilt continuously. They claim in the notice that some users are "burning up" their motors by running them at maximum continuous speed.

Along these lines, I need to lift a leg of the "power resistor" on the clone board so I can measure what size "HP" resistor is actually installed. I couln't tell from the part number on the resistor.

That would give an indication of how much power the controller is configured to deliver. 3/4HP, 1HP, or what?

-Ian

[hoss2006]

Originally Posted by mrcodewiz I guess I'm not picturing this. The spindle is out along with the lower bearing (minus the race that is pressed into the quill). Only other time I have had to replace races is on motorcycles and with those you place a drift through the steering neck and tap around the rim of the race to push it out. That doesn't seem possible because that lower race is sort of recessed.

I found a couple pics that might help.
The jaws were not tightened up so it could slide thru.
Hoss

[mrcodewiz]

Originally Posted by BAR553 The second chinese speed control board blew this weekend. After looking at the motor, it may have been the problem all along. Installed the replacement motor, which has a different part number, and put in the KB Electronics board, the whole machine sounds better. Got about 300 rpm increase over the original speed controller, without touching the pots. Modified the recommended heat sink, to act as the back panel. A nice days project for a beginner, not perfect but learned a lot.

Which KB board did you buy?

[mrcodewiz]

Originally Posted by hoss2006 I found a couple pics that might help. The jaws were not tightened up so it could slide thru. Hoss

Thanks, Hoss. I think I'm good now. Now I just need to make the upper spacer and wait for the Kluber to show up. Oh and figure out my speed controller/motor issue and THEN maybe I will be back in business.

[DogWood]

Originally Posted by Isplat <snip> One thing I have noticed running my setup is that the stock motor gets really hot to the touch because it has no real cooling i.e. no fan to speak of. It is also burried in a poorly ventilated cover. So, I'm thinking of ways to mod the motor and stock motor-enclosure to attach a fan for cooling. I think the motor might be cooking itself (frying the windings) and then frying the controllers based on some of the images I've seen posted. I might just ditch the cover altogether; but I like the idea that it keeps some of the swarf and crap out. <snip> -Ian

My thoughts exactly Ian, thinking the lack of cooling is a big issue, especially if you leave the motor enclosure in place.

Thinking of either adding a fan or perhaps wrapping a couple loops of copper tubing around it and directing the flood coolant through there.

-Doug

[rcazwillis]

Mine buenws up with the cover off. During breakin it was hot, so l left the cover off hoping it would break in and begin running cooler. Toasted after very little use.

Sent from my DROIDX using Tapatalk

[BAR553]

The board was a KBIC - 125 with the Resistor part# 9843.

See Hoss's post #390 for the advice he gave me, which as usual was spot on.

[diyengineer]

Originally Posted by DogWood My thoughts exactly Ian, thinking the lack of cooling is a big issue, especially if you leave the motor enclosure in place. Thinking of either adding a fan or perhaps wrapping a couple loops of copper tubing around it and directing the flood coolant through there. -Doug

Why not just cut a hole in the top and install a 120MM fan. then the air can blow out the louvers in the back. You can get them in any voltage from 5V-220V. you could even splice it into the motor control power box with switch. easy fix. Might as well install a fan for the control box too.

[DogWood]

Reason I was thinking of using the flood coolant is you're already pumping it, but without some other cooling it might get rather warm on a long cut.

I would be inclined to have the fan on top pull the air out as opposed to blowing, heat rising and all that.

Will probably go with a fan on top, at least for now as it will be away before I can make an enclosure or even CNC it for that matter.

[arizonavideo]

To IAN:
You should have just enough room to mount a 120mm fan on the back of the motor cover facing the Z ways. I would think vary little stuff will get in from their.

None of the motors should be going bad even with long run times. The controller limits the power going to the motor with its current limiting. A good DC motor can run so hot you can't touch it and you can do this for many hours and it will be just fine. What were seeing is a batch of defective motors going bad.

But if you have a good motor and add lots of cooling you can drive it way past the stock HP rating and it might be fine if it has over sized brushes.

This is a good time to see how Grizzly handles a real product defect. Telling people not to run the mills at full speed is a cop out.