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

This is what I meant by circular bushing. That's the solid steel shaft at the heart of the tool. This bushing is very precisely fitted to that shaft and in turn, the bushing OD is very precisely fitted to a cutout in the "nose" of the tool (second photo) body. The reason being (obviously) that a regular bushing, with enough slop to allow the shaft to pivot, would have two problems. First, the slop in general. Second, the case where the muzzle didn't need to be moved side to side or up or down, in which case, the steel shaft would be "floating" in the slop. The round bushing cures alla' that.

Mr. Davidson's tool used a hollow center shaft to allow for cutting fluid under pressure... however he didn't end up doing that. I had a piece of solid shaft on hand so that's what I used.

On the tool body, the first bushing needs to be a tight slide fit. That's custom to each lathe I would think. I used aluminum but bronze would be better. The second, leftmost bushing engages the mouth of the spindle which is almost always going to be dinged up from guys sliding stuff through. So that one, I went for a jam fit. Aluminum is appropriate for that.

The centering bushing is necessary for reasons that will be apparent if you build it without one, as I originally did. My next trick is to add a couple springs between that bushing and the tool body... pull the bushing to the left, to tension the springs, then tighten down the thumbscrew. Now, you have positive spring pressure keeping the bronze center on the steel shaft engaged against the muzzle while you make your adjustments. Instead of using your belly as I've been doing.






Edit: here's a pic maybe showing more clearly what the centering bushing does for you.

The bright spots to the right of the silver jacking screws are landing pads for the outboard spider screws, to lock the tool body in place in the spindle.

I made brass tipped screws to keep the center shaft pretty.







I can't wait to actually use the [bleep]' thing! I've got 3 actions slated for rebarreling this winter/spring. The practicing gunsmiths here must just be rolling their eyes at all this effort to make a big lathe usable for through-the-headstock work! Thing is, I bought the lathe to make parts on- I do lots of larger diameter stuff that was really taxing on the Logan- but this Webb is just so nice, stable, solid, and precise that I can't see using the skinny little Logan if I can use this instead!

Yep I didn't get into machining parts at hot to do gun work but it just worked out that way.
Anything to make a buck man. Thanks for the infoI web archived the thread so I can refer back to it in a few months.

Ok - what do you mean when you say a deep head stock and is it good or bad.

And that link you posted show 7k, which is more that the Griz?

What he is implying is his spindle length is long making it a little harder to do barrel work through the spindle as opposed to between centers over the bed using a steady rest. Both ways work. A short spindle or headstock can make barrel work a snap with just an added spider at the back with a four jaw up front. Dial it in at both ends and your running. The longer spindle though usually comes on the heavier and bigger machines and that too has it's advantages. Alas there is rarely THE perfect tool...

I compromised on my lathe purchase with a 14x50 Clausing. It has a spindle length right around 22" and will work nicely if all I ever do are 24" barrels but that won't always happen, so I will just have to change methods a little bit to do short barrels. Not a big hill to climb and was worth it in my case as I got a smoking deal on this fully tooled set up that will do some larger work as well. Still anticipating South Bends release of their new Heavy 10 that should happen this year....

Here is a link to as good a tutorial as you can buy showing different ways methods and tooling. It may help you on your way to choosing tools. And to stay on subject a belt driven machine is still an excellent choice just get a cam lock spindle for ease of changing chucks.

http://www.midwayusa.com/Product/29...le-barrel-fitting-book-by-john-l-hinnant

okie,
I believe my Clausing may be the sames as yours. I have a cathead on both ends and can do 22" barrels. I believe I could do 20" if I got a little creative.

I believe your right Butch and have contemplated a cathead in lieu of a four jaw. Mine is a 1500 series.

I'm way out of my pay grade here and have never chambered a barrel so please take this as just an enthusiastic guy a bit ahead of where you are in the process, expounding. As always I welcome correction if I say something wrong here; just trying to learn from the masters, not pretend to be one.

The chambering method popularized by Gritters uses a cathead or spider (4-screw chuck) on the outboard end of the spindle to adjust the axial position of the barrel relative to the axis of rotation of the spindle, to put the throat of the new chamber AND a point a few inches further down the bore into perfect (sic) concentricity with the spindle.

That may or may not mean that the muzzle is actually centered in the spindle. It's different than working between centers in that way.

If the headstock is too "deep" to allow this, IE the barrel muzzle is buried inside the headstock somewhere, then you've got a problem. For instance with a 24" barrel, I'm needing to literally reach about 8" into a 2" pipe (the spindle) to reach that muzzle! And, then I need to be able to very precisely adjust the position of that muzzle and then, lock everything in place. That's what my tool does.

The Grizzly lathe you are looking at specifically has a short headstock and even comes with that outboard spider installed by the factory. I needed a bigger lathe for non-gunsmithing work, and big iron has other advantages, so I've been working to find ways to use my machine through the headstock.

As to price, I paid $4200 for my Webb.... not $7900. One reason I was so hot to snag it. But, it had the downside you hear about with buying used "American Iron", meaning it had a past life as a machine someone bought to do production on (most likely). My Webb is definitely a used machine. It appears to have been spared actual abuse and to have been well-lubricated when it was in hard use; the ways are in great shape and everything is tight and smooth.

I think a great case for buying new Chinese can be made. I was vaguely planning on buying the big Griz gunsmithing lathe, the G0509 16x40. Then you've got a NEW machine to start with (duh).... No worries about past use and abuse. However, it's my opinion that something like my lathe, or several other USA or Euro machines, are fundamentally FAR superior designs and executions than modern Chinese stuff. My lathe just exudes quality manufacturing by people who really, really cared and were trying really hard. For that matter so does my 10x54 Taiwanese mill! To this point- the Grizzly mill I had for a while, exuded none of that for what it's worth. The fit and finish were pretty sloppy and in general it seemed thrown together.

With all that said, the type of work you are talking about doing, hobbyist gunsmithing, is easy duty for a lathe. Plus, most of it is working from a fixed position on the ways, and you don't need to turn long shafts to high precision, nor hog metal in direct competition with the shop across the street.... I would just reiterate what I said earlier, which is to check spindle runout very soon after purchase, and be prepared to send it back if it exceeds .000X". I don't know what an allowable "X" should be. I only say this because of what a guy I know fairly well related to me recently about the very lathe you are buying. But yours might be fine!

All the best, and I hope I haven't tromped on your thread.

That's funny right there. A real lathe setup should have an isolated slab for itself. The owners manual for my lathe recommends cutting a hole in the slab a little bigger than the lathe footprint and pouring a new slab, 2' thick with an expansion joint around it!

My shop has 4000 # concrete 12" thick. I couldn't do separate slabs as I didn't know the layout at the time.


Jeff- that is an awesome machine you scored. My uncle bought one I found for him last year and it is mine when he gets to where he can't use it anymore(he is 85). My Nardini, meanwhile, does pretty good work.

Yes it's true. And how many thousands of machine shops are just rented out warehouses with machinery on the floor??

Yes all machines should be on a isolated concrete foundation as per OEM specs. I'd be willing to bet that less the half the machines in the US are on correct foundations.

Thing will shift but if goo attention is paid matters can be caught early.
As for a home shop doing basic work I would not even sweat it.
Now if it was a large CNC or a Jig bore. You bet I'd pay big bucks for an 8000 Psi foundation how ever thick required.

My jig borer sits on a thickened slab too but not an isolated one. It is heavier than my Nardini too!

I put massive amounts of concrete and reinforcing bar into this floor but that doesn't make it perfect.

The I was getting at is yes you should do something to support the machine but most don't. Not saying it's a good idea for precision work but it's not like the lathe is going to fall through the floor either.
It all comes down to you use and your intended results of your parts. Want good part? Do your best to eliminate outside influences on the machine tool.
LAst shop I worked in the jib borer and jig grinder where in a separate room on huge foundations with climate control to keep everything stabilized.

My machines in the garage go through some wild temp swings in the winter but not to bad. at most it's a 30 degree swing.

I poured a 7" thick slab in my shop with lots of rebar. I'm already wishing I'd gone 10"-12".

Dennis, the more I use it, the more I appreciate how good it is! In general, if something isn't pretty much perfect, it's because the bozo who had it in the past repaired or adjusted something all wrong. The compound worked fine but felt funny; I rebuilt the gib tighteners and replaced a stripped bolt and it's smooth as silk now. The crosslide was smooth as glass in the middle part of it's travel but tightened up at each end. I suspected worn nuts, but no! It was Bozo again. He'd completely misunderstood the backlash adjustment setup, and in the process (this still floors me), lost the bearing off the far end of the leadscrew! I tore into it last week and found the bearing in the oil sludge under the slide. After fixing the backlash adjuster ass'y and adjusting the preload on the front bearing, and of course reassembling it with the rear bearing actually bearing the aft end of the leadscrew, I've got under .005" backlash and glassy smooth end to end.

Anyway, my point being that a high-quality used machine starts out "right" and can usually be returned to that state. Then you've really got something. I do worry that the Grizzly that Spotshooter wants might not start out right. Then again, he won't have to de-Bozo the thing when he gets it, or run the risk of buying a used machine that's truly worn out in an unfixable way. I see the conundrum.

I kinda have a fetish developing with my Webb. They made a 17x60 version of my lathe, as well as a 20x80. Both Mori Seiki copies. I truly hope one doesn't show up cheap locally, or I'm in trouble.

Dennis, I think you'd [bleep] over the Dutch lathe I saw over Xmas. Roughly a 18x60, 6000 lbs. A Hembrug A1. It's as beefy as the Webb, and reputed to be of similar high quality, but talk about obscure! It's in the family and may be mine someday.