Broke my Grizzly G0765 7x14 lathe - HELP!

Use the same threaded rod with a smaller diameter sleeve to pull the spindle back into place. I have broken more than one gear, usually from grabbing a high rake tool while cutting Delrin. This one pops out of high gear while under a load.

The new steel gears have sharp edges and need to be de-burred before installation. I used needle files and fine sandpaper to ease the corners. The faces of the teeth were very smooth so I don't think they add to the wear. Not having to pull the spindle offsets any slight accelerated wear IMHO.
 
ARhodes01075 said:
Thanks for the pointers. I have some acme threaded rod on hand. It is part of a spring compressor set. I think it is 1/2" diameter. I don't recall how long the rods are. 12" to 14" as I recall. But that may be enough to get the spindle released. I probably have some 1/2" steel plate that I could use instead of a 2x4. I will look for some 3 or 4 inch PVC pipe.

Good suggestion about a steel combo gear on the spindle! Will that cause more wear on the plastic gear on the layshaft than a plastic-on-plastic mesh?

Does the spindle need to be pressed back on or will the nuts on the spindle pull it up properly?

I feel almost up to this procedure once I get the parts for the puller
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It may seem like a lot but you will have a lot more confidence once you've done it. I had to disassemble my lathe to get it into the basement which included pulling most of the gears out of the head stock and I was not sure I would ever get Humpty Dumpty back together again. :grin:
Now it is not my favorite thing to do, but I no longer fear taking the machines apart, after the lathe I did the same with 2 mills, and that seemed like it was no big deal at all.

Take pictures and where possible reassemble the parts as you they come out or at least organize them in the order they go back in. Makes life much easier particularly if you get pulled away from the task. Wire can be useful to keep assemblies together.
 
OK, I have new combo-gears coming from Grizzly. I will have some 1/2" acme-thread rod (2 feet long) coming from Mcmaster, as well as the proper nuts. I was able to use the broken lathe on the "high" speed setting to turn a fitting for the left side of the spindle to pull against with the threaded rod. I have some 1/2" thick 707x aluminum plate for the right side of the puller. I am figuring out what to use as a spacer to go under the plate and against the headstock gearbox. Likely some 3.5" ID steel or aluminum pipe about 12" length.

So... assuming I can successfully pull the spindle to get the broken gears out, what type of grease is going to be compatible with whatever plastic these gears are made from?
 
Firstram said:
No lube needed!
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Well, actually it seems that lube IS needed in the hi/lo gearbox. I finally got a reply from Grizzly about this. They recommend NGLI#2 multipurpose lube. and nothing but that.

Maybe no lube on the crossfeed speed selector gears? I used while lithuim grease on those gears. That grease is supposed to be fine with plastics.
 
RJSakowski said:
Be thankful it was only lathe gears. A year ago, I took out the low range gears on my tractor. It involved splitting the tractor. disassembling the entire transmission and rear end, including removal of the pto, hydraulics, rear wheels, and fuel tank. All that in 100+ temperatures and 90+ RH.
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Well are you saying this was you just before the gearbox gave out ?


;)
 
stupoty said:
Well are you saying this was you just before the gearbox gave out ?
Like

;)
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Not by a long shot. It's a good thing he has a roll cage on that machine because he's going to need it at some point. I chewed some gears dropping from high to low range while doing some yard work.
XT35 Low Range .JPG

Many years ago, I transplanted a 364 c.i. V8 into a 1962 3/4 ton Chevy pickup, replacing a 235 c.i straight six. The 3/4 trucks back then were geard down for working and the truck had a 4.411 rear end and a four speed transmission. You could climb trees in first gear and start out in third gear. Fourth gear would red line the engine at 55mph.

I was passing a slow moving gravel truck on an incline and dropped down into third gear and threw a rod before I had passed the truck.
 
RJSakowski said:
Not by a long shot. It's a good thing he has a roll cage on that machine because he's going to need it at some point. I chewed some gears dropping from high to low range while doing some yard work.
View attachment 331414

Many years ago, I transplanted a 364 c.i. V8 into a 1962 3/4 ton Chevy pickup, replacing a 235 c.i straight six. The 3/4 trucks back then were geard down for working and the truck had a 4.411 rear end and a four speed transmission. You could climb trees in first gear and start out in third gear. Fourth gear would red line the engine at 55mph.

I was passing a slow moving gravel truck on an incline and dropped down into third gear and threw a rod before I had passed the truck.
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My '54 (avatar) has a 4.3 built V6 in it, and that's plenty fast. My '65 C10 truck has a built 350 V8 in it. I don't drive either one of them like I did back when I was a teenager. My first was a '55 Chevy with a 265 Power Pack in it. I changed it over to a Carter AFB carburetor and dropped .411 positraction rear-end in it, and a 3-speed on the floor that came out of a '56 (I think) Corvette. Not much beat me off the line, but my top end wasn't too good. I did manage, however, to spring the speedometer at 110 MPH. We were crazy.

Regards
 
I have the lathe FIXED! I had on hand a 4" OD piece of pipe and some 1/2" Acme thread rod to pull the spindle. But I tried using a light weight rubber mallet to gently but firmly tap it out. It came out easily.

The teeth on both gears for the low speed drive were broken. Mostly on the 12 tooth gear: 5 teeth were sheared off.

I got it back together again. and it works fine.

Afterward I got to thinking: I could 3D print these combo gears pretty easily. My CAD program has a tool to make gear profiles. Just plug in the specs of pitch diameter, number of teeth and pressure angle and voila, a gear is made.

They look great and are very printable. But I need a bit more info to be sure. I will create a new thread on this subject.


ARhodes01075 said:
As the title says, I broke my G0765 7x14 lathe yesterday.
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