G0773 Lathe / Mill Combo

[BROCKWOOD]

Another good mod for any lathe is to add holders for everyday tools. T Handles will always need to be close (but nut in the chuck when not in hand). My lil combo uses 6mm for most everything, so I included it in my holder design. I made it using 1/2" electrical thin wall conduit.

 

[BROCKWOOD]

I've actually had this lathe 3 years last April. Now I've done it. Really! By all appearances, I've fried the lathe motor. Made a pass, turned it off, set up for a new pass, turned it on & HMMMMM. Maybe a start cap, so I turned the chuck. Nope. Every manual for every machine states, "leave room to access from the rear." Of course I didn't. It's a 2 car garage full of car parts.

Specs call for 115V 1700RPM. Grizzly doesn't seem to offer it anymore (was just checking my options). Seems nobody does 1700RPM & Grizzly is into 1ph 220V for similar offerings these days.

Gotta get the motor out & see if it is repairable or rebuildable. Pics as I gain access. Of course getting all strain off the motor to retry spinning it up to speed proved useless.



Couple pics of diving into the belly.

 

[Mitch Alsup]

You are going to have to move it away from the wall.

But it is likely that the start or run capacitors have turned to toast and that the motor is not completely dead.

Good luck.

 

[Aaron_W]

That is a bummer, 3 years seems a short life for a motor unless you run it a lot. Hope it is a relatively simple fix.

If not it 1725rpm seems to be a fairly common motor speed, I wouldn't think they are so picky that an extra 25 would be an issue. My lathe has a Baldor 1725 rpm motor that can be wired 115 or 230v.

 

[BROCKWOOD]

Just looked at what it would take to move it all out from the wall. Gotta see what I can do to avoid that. In the end Mitch is right for best results etc. I'm not sure that 1 of the motor bolts is even accessible with the lathe mounted to the table.

Aaron brings up a good point about motor RPM vs Speeds & Feeds. At 1st blush, speeds must be affected, right? Going from 1700 to 1725 RPM isn't much, but still should ......... Math best left to ponder at a later date.

So, here is the lay of the land.



Needs a reorganization anyway.

 

[BROCKWOOD]

Well, I knew I wanted to take the motor out to at least clean & inspect it. (Was leaning on it being bad.) And I knew I wanted to make the motor serviceable without unbolting the lathe from the table or moving the table. Plans are to add an inline connector to the wiring as it exits the motor & to use studs with nuts in place of the 4 motor mounting bolts. As an inquiring mind, I went ahead & pulled the F / R switch to see how it works. Motor wires had to come off anyway.



I've cut out the Mill portion of the diagram. It's on a completely different circuit now (as discussed earlier). That switch & connection are labeled AUX. The F / R switch (CCW / CW) has 4 jumpers that do not show up in the stock diagram. That is how the switch comes. I've added them to the diagram. So here is how the switch works.



I do believe we have solved the puzzle. 1 of the plastic spring retainers had melted just enough to prevent Z2 from ever making contact.



This switch is 1 - 2 months away if I order today. Really looking for a better switch that is much easier to get. Any ideas?

 

[BROCKWOOD]

Old switch is rebuilt (from the pile of parts seen above) & ready to go - short term. Contacts are burnished & the melted plastic cut away for smooth contact + make / break functionality. Next it was on to pulling wires through the conduit they are routed in to get to the motor. Turns out the Z2 wire has melted to the wire casing for the chuck guard limit switch down inside the conduit. Gonna need bigger wires with that better rotary switch. I don't need to go up by much - 1 better wire size with good insulation & really just wanting all this to be good for 20Amps min.

Thoughts & recommendations are always welcome?

 

[FOMOGO]

12 gauge fine stranded wire should be fine for your application. Mike

 

[BROCKWOOD]

Thanks Mike. I have 12 gauge stranded rounded up. There is a piece of conduit that runs through the gearbox. Looks like water pipe - only very thin. Well, it did not like the heat that had built up. Wiring sheaths stuck to it like glue. I have a thick wall cold water pvc pipe. But I'm leaning toward cutting down a piece of electrical PVC into a trough for the bigger wires to lay in.

Been looking at barrel switches. Exact replacement is just going to burn up again. KEDU makes a higher amp version - but nothing on the shelf here in the states that I could find. Dayton / Eaton have readily available barrel switches, but I am not able to picture how it would wire directly in place of what I have. Lots to ponder.

 

[BROCKWOOD]

The GE SB-1 switch comes in just about any configuration you can imagine. Still available new & much higher than what is listed on EBay. I happen to have saved a few old versions. Just change cams to fit your application. Might have to make my own cams though. Too cold in the shop, so mapping this out for current & future projects is fun.