Home Forums Hunting & Shooting Gunsmithing Gunsmith lathe. - gear head or belt driven

Getting ready to pull the trigger on a Grizzly lathe for tinkering and barrel work.

I ran across some - gear heads are to complex and not worth it chatter.
What do you guys think?

This one could be fun.

I will make a batch of popcorn.

Hey at least I avoided the used american steel vs. Chinese new stuff issue - although I'd lay fair odd's that will come up too.

I'd go with a gear head lathe.

The big criteria, for me at least, is that the hole through the spindle be sufficiently large to handle all anticipated barrel and action work.

this specific gear head has a foot break on it which is pretty large plus.
it's a 14x40 w/ a 1 9/16ths spindle bore

Grizzly G0709

I asked one of the better smiths here which one he'd pick and he recommended this one due to the foot break, it is the one I was leaning to - but I've never heard anyone complain about gears before..

So I asked, didn't want to bother the smith with follow on questions - but I did think it was weird that someone wouldn't want gears if they do things like cut threads. I know a good deal of people use the G4003G belt driven lathe and are pretty happy with it so ...

Looks like a pretty well thought out design for a "Gunsmith lathe", particularly the 1 9/16" spindle bore and the centering screws on the outboard end of the spindle. I would try to find someone who owns one to get some feedback before I pulled the trigger though. The other issue that comes to mind is getting a machine that big (heavy) moved into where you are going to use it. Be sure to get the front to back measurement so you can measure door width (learned this from experience).

yep the weights got me a bit worried but it's going into a workshop with garage doors so I'm good on the entrance.
It's a concrete slab so I should be ok there as well.

I did find a couple of guys who went with this lathe and they seem extremely happy, it's a step up (at least cost wise) in the Grizzly gunsmith line from the 4003G, and almost all those people who have them are very happy so I think it's a safe bet.

I assume it is a heated space because condensation in an unheated space plays hell with cast iron.

Right now it's not heated....

Hmm....

My woodworking equipment in my unheated garage has suffered enormously despite my best efforts to protect them.

My lathe lives in my basement and has been GTG for a long time.

As a stopgap you may consider building a little enclosure for your new lathe out of 2" foam and using a small spaceheater to moderate the temperature and hence the condensation.
You'll be VERY unhappy when you see rust blooming on your new cast iron ways!

I am in the wet Pacific NW, shop is one mile from salt water.

Lots of insulation (studs are 2x6) and the attic is pumped full of blown in insulation.

Nary a problem with condensation or rust of any type. Been in this shop 20 years. Previous shop was not insulated and rust was a problem.

Insulate your shop! Put in some type of heat, don't use propane or natural gas, both pump moisture into the area. I have a 5000 watt electric mounted on the ceiling and only have to use it when it is pretty cold. 30 minutes of running the heat and the shop is warm and I can turn the heater off.

Damn it, ok insulating the place is going to put a shift in my schedule.

Didn't want to hear that but it's darn important so thanks for keeping me out of trouble

I made the mistake of not having my shop heated, cast iron was red rust in short order. The heat does not need to be much over 50 degrees or so, easy to turn it up before a work session and then back down. Sounds as though you're good to go as far as getting it into your shop. Pipe rollers and a Johnson bar are useful in setting your new lathe in place. Most rental places have Johnson bars, a johnson bar is a heavy duty long handled tool kinda like on half of a hand truck with rugged cast iron casters. Indispensible in getting the lathe up on and down off pipe rollers and off the shipping pallet.

Gearhead lathes tend to be noisy unless the grears are precision
ground, something you will not find on a popular priced Grizzly lathe. Noisy gears along with the inherent torsional vibration produced by a single-phase motor can be annoying as well as producing a less than perfect surface finish on the work piece.
Gear heads usually don't have a slip clutch to save tooling and perhaps a workpiece if you do something stupid.

Belt drives are quieter( especially with multi-link belts) and can be adjusted to allow the belt(s) to slip if a crash occurs.
The belt does not transmit sigle-phase torsional vibration very well.

The primo set-up is a belt drive with a VFD for speed control. This eliminates the single-phase vibration since a 3-phase motor is required. The VFD gives at least a 12:1 speed range, infinitely adjustable. If the lathe is well built and the spindle and motor are properly balanced, it will run quietly and vibration free from a crawl( 10 Hz) to full speed ( 120 Hz).
It is true that spindle torque will be limited at speeds below 30Hz. You can always move the drive belts if needed to get more torque, but in my case I never move the belts on my 13x36 Jet.
Additionally, the VFD is adjustable on the fly and can also brake the spindle in you have a non-threaded spindle nose.

RAN

Keep in mind when you are moving a lathe, especially on rollers, that it is very top heavy and will tip over in a heartbeat.

I almost tiped one over several years ago when moving it, pipe rollers on a concrete floor. Just barely saw it start to tip and we managed to keep it upright, don't ask how, I do not know.

The mention of 3 phase makes me wonder. Most residential areas do not ha ve3 phase available.There are converters to change a 3 phase motor to single phase,but then would you not still get the vibration mentioned?

Doing chambering work , .001-.003 out of alignment can sure screw up a good barrel

Couple of thoughts:
1. Gear "slap" is common on all geared head lathes. As mentioned, the premium USA built machines (long gone) had precision ground headstock gears so this was hardly an issue.
2. The trade off from gears to belts would be metal removal. If only used for smith work, doubt that is a big issue.
3. Digital phase converters (such as Phase Technologies) will often out preform the rural power companies.
4. Finding a pristine, affordable LeBlond, Colchester, Monarch, etc. is beginning to become a serious endeavor.
5. The Taiwanese machines are typically superior to any produced in China. Priced accordingly too.

Does the Grizzly have a taper attachment?

Clemson

I have an acquaintance that also happens to work for one of the major barrel makers. He also builds his own rifles, which I might add, are very accurate and well done. He purchased the Grizzly G0709 recently and is pleased with it.