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Re: Lathe Chucks

Posted: Sun Mar 21, 2010 7:32 pm
by kkendall
KurtHuhn wrote:I think I understand what you mean - but no, I've never had that problem. There's two types of Tower jaws, smooth face and serrated. I imagine that the smooth face would present that problem, based on the pictures of them that I've seen. The Serrated face jaws actually have a more square inside face, allowing you grip some pretty oddball shapes.
I've never seen the smooth jaws. The #2 Profiled Tower jaws:
Image

Re: Lathe Chucks

Posted: Mon Mar 22, 2010 12:45 am
by m.c.
My lathe came with a chuck like this:
Image
I detached two jaws and used the rest, but they were too short to hold tight. I ground the second and third "steps" (not knowing the proper word) down, so the first "step" is now long enough to grip the blocks. Another problem was the tendency to bite off wood chips (and the block droppping as a result ) due to the small contact surface. I solved this by inserting a coin between the jaw and the block. The coin should be a large and thick one. It's a good idea to modify the jaws by welding on an extention steel pad, but since I plan to have a screw bolt chuck, which has been shown somewhere on this site and is usually used for irregular or shaped stummels (but is also good for a regular block), my insert-coin solution is acceptable to me now.

Re: Lathe Chucks

Posted: Mon Mar 22, 2010 1:09 am
by m.c.
By the way, I have noticed an advantage of this kind of chuck. Unlike a tower jaw where there are actually four contact points, which is a benefit if the block is perfectly squared but quite a headache if it's more or less irregular, the chuck shown above offers two contact points. As a result, whether you are drilling the chamber or the airhole, the center of contact is always at the bottom of the chamber, which is also approximately the end of airhole. And that point falls on the lathe axis too. You only need to make sure that part of the block is squared.

And, deeply serrated jaws tend to chip off some wood. I find the texture and pattern on the surface of a coin to offer pretty good grip without hurting the block, provided I exercise some real hard tightening ritual before turning on the motor.

Re: Lathe Chucks

Posted: Mon Mar 22, 2010 1:12 am
by pennsyscot
Kim, I like the looks of those jaws, who distributes them? The jaws that I have are serrated but have are larger inner radius. The ones you have pictured appear nearly flat.
http://www.pennstateind.com/popup_large ... WS&count=1

Re: Lathe Chucks

Posted: Mon Mar 22, 2010 2:12 am
by Mike Messer
m.c. wrote:My lathe came with a chuck like this:
Image
I detached two jaws and used the rest, but they were too short to hold tight. I ground the second and third "steps" (not knowing the proper word) down, so the first "step" is now long enough to grip the blocks. Another problem was the tendency to bite off wood chips (and the block droppping as a result ) due to the small contact surface. I solved this by inserting a coin between the jaw and the block. The coin should be a large and thick one. It's a good idea to modify the jaws by welding on an extention steel pad, but since I plan to have a screw bolt chuck, which has been shown somewhere on this site and is usually used for irregular or shaped stummels (but is also good for a regular block), my insert-coin solution is acceptable to me now.
I haven't read this really good, so if I am completely off, excuse, but, you can turn the jaws around so that the long vertical end of the jaws is pointing in (currently shown pointing out).
Wouldn't that help? ...and maybe grind that face flat if you wanted more surface area?

Re: Lathe Chucks

Posted: Mon Mar 22, 2010 8:17 am
by m.c.
Mike Messer wrote:I haven't read this really good, so if I am completely off, excuse, but, you can turn the jaws around so that the long vertical end of the jaws is pointing in (currently shown pointing out).
Wouldn't that help? ...and maybe grind that face flat if you wanted more surface area?
Good idea, Mike. But my chuck is 80mm, and turning the jaws around would't give me enough space to hold most blocks. So I went the harder way and ground the inside. That saves money faster than you earn it by making a pipe :)

Re: Lathe Chucks

Posted: Mon Mar 22, 2010 10:05 am
by KurtHuhn
pennsyscot wrote:Kim, I like the looks of those jaws, who distributes them? The jaws that I have are serrated but have are larger inner radius. The ones you have pictured appear nearly flat.
http://www.pennstateind.com/popup_large ... WS&count=1
Those are Oneway brand #2 Profiled Tower jaws that Kim posted.

And I've been corrected - One way DOES have two models of tower jaws, but they are known as "serrated" and "profiled". The serrated jaws are ill suited to holding briar blocks in my opinion. The profiled jaws are what I use.

Re: Lathe Chucks

Posted: Tue Mar 23, 2010 9:51 am
by Philthy
I have not seen that type of jaw for the Nova G3 that I have. There is a spigot jaw set that is taller and has aggressive grooves cut in it, but the jaws have a round radius shape. Anyone have experience with these jaws and can say how they work before I buy a set or know where I could find something similar to the profiled tower jaws for my Nova?

Chaps my butt to have to buy four jaws when all I need is two!

Re: Lathe Chucks

Posted: Tue Mar 23, 2010 11:28 am
by Leus
Mike Messer wrote: I haven't read this really good, so if I am completely off, excuse, but, you can turn the jaws around so that the long vertical end of the jaws is pointing in (currently shown pointing out).
Wouldn't that help? ...and maybe grind that face flat if you wanted more surface area?
You cannot turn the jaws around. Some chucks come with two sets of jaws, thought.

Re: Lathe Chucks

Posted: Tue Mar 23, 2010 12:21 pm
by e Markle
Philthy wrote:
Chaps my butt to have to buy four jaws when all I need is two!
I'd be willing to bet someone in the forum would be willing to buy 2 from you.

Re: Lathe Chucks

Posted: Tue Mar 23, 2010 2:16 pm
by pennsyscot
Are the jaws interchangable between chucks of different manufacture? I have a cheapo PSI chuck. Am I stuck with the jaws offered by PSI?

Re: Lathe Chucks

Posted: Tue Mar 23, 2010 8:04 pm
by ToddJohnson
Leus wrote:
Mike Messer wrote: I haven't read this really good, so if I am completely off, excuse, but, you can turn the jaws around so that the long vertical end of the jaws is pointing in (currently shown pointing out).
Wouldn't that help? ...and maybe grind that face flat if you wanted more surface area?
You cannot turn the jaws around. Some chucks come with two sets of jaws, thought.
On most chucks, the jaws can be turned around to accommodate larger stock. I don't know anything about this specific chuck, though.

TJ

Re: Lathe Chucks

Posted: Tue Mar 23, 2010 8:29 pm
by KurtHuhn
There are chucks made for metal lathes (as above) that have reversible jaws.

If it's an independent jaw chuck (each jaw moves via a separate adjusting screw) then the jaws are almost always reversible. Since the screw has matching threads on the bottom of the jaw, it's fairly easy to turn them around.

If the chuck is a scroll chuck (aka self-centering) then sometimes they can be. If the jaws actually screw down onto a carrier that does the moving in and out when you turn a key, these can sometimes be reversed depending on the keyway on the jaw and carrier. If the jaws DO NOT screw down onto a carrier, then the jaws typically can NOT be reversed, since the scroll interface on the bottom of the jaw will be reversed when you turn it around. Most chucks designed for wood lathes are setup like this.

Wood lathe chucks typically cannot be reversed. The are usually intended to operate in a given fashion, with very little deviation from intent (the use of two versus four jaws aside). The jaws on my Oneway chuck are keyed with an arced key, that prevents reversing the jaw on the carrier. I've seen other chucks with similar setup that prevent reversing. This obviously doesn't mean they're all like that, but it is typical.

I have no idea if the PSI chuck can accept jaws from other manufacturers. It might, but that would be atypical. Manufacturers would prefer that you buy all the chuck accessories from them.

Re: Lathe Chucks

Posted: Wed Mar 24, 2010 12:14 am
by m.c.
Examine the threads on the bottom of each jaw. If the threads are short and straight, they are reversible. If the threads come in a curve or arc, they are not reversible. In the latter case, the manufacturer will usually give you another set of jaws which are equivalent to the turn-around ones. Mine is irreversible. By saying "turning around", I just meant using the other set. You guys have real precise cogwheels in your heads :D

Re: Lathe Chucks

Posted: Wed May 12, 2010 9:37 am
by smokindawg
Hasn't been a post here in a while, so I thought that I'd update on my own chucks I use.

I started out with a Delta Midi Lathe (Which I still have and use) and set it up with a Nova chuck (Bought on Ebay). It's the type that takes the two bars for tightening, so is a bit hard to do one handed. It works well and I got it at a good price so is worth the extra trouble. After getting the chuck, I was offered a pair of tower jaws from someone that had the set of four and didn't need them. When I got the jaws, he had actually sent two different sets. The tower jaws and a custom set of aluminum jaws for holding blocks. The aluminum ones are like Kim posted farther up in the post. (The jaws on the right.)
Image

I and a buddy that makes pipes used this set up for quite some time. But I recently picked up a decent Jet 9x20n with stand and some tooling. I then wanted a chuck to use my custom jaws on that would fit the Jet. I took a chance and ordered this one from Grizzly tools. It looked like the jaws I have would fit, and I figured if they didn't, I could just make, or have a set made for the chuck.
Image

I got the chuck and found that the jaws would fit perfectly, except that the screws that hold the jaws on the new chuck are smaller, so I drilled the holes on the chuck out and re-tapped to match the threads on the Nova and then the jaws fit perfectly. I also worried about run-out when mounting this chuck on my metal lathe. Once mounted, I checked run-out and found it to be only .001, so am good to go. The chuck from Grizzly seems well made, tightens and loosens effortlessly and only needing one hand to tighten is much better than my Nova chuck. I haven't used the new set up on the Jet yet, but my buddy has and it works great.

I'm pretty much set up now for lathes and chucks. I have the Delta with the Nova and a 4 jaw independant. I have a Craftsman 6x18 with a 4 jaw independant and 3 jaw self centering, and now the Jet with a 4 jaw independant, 3 jaw self centering, 4 jaw self centering and the Nova-type. (Glad the wife doesn't understand machine tools.)

Re: Lathe Chucks

Posted: Wed May 12, 2010 11:58 am
by e Markle
smokindawg wrote: I took a chance and ordered this one from Grizzly tools.
What's the model number on that chuck?

Re: Lathe Chucks

Posted: Wed May 12, 2010 2:57 pm
by smokindawg
It's part number H7820 on their site. This one has the 1 1/2 x 8 threads but they have others that have different threads. As I said, this is actually a wood chuck, but works fine on my Jet.

Here is the page with them all listed.
http://grizzlyindustrial.com/products/s ... od%20Chuck

Re: Lathe Chucks

Posted: Sun Apr 10, 2011 2:12 am
by JHowell
http://public.jwh.fastmail.fm/images/Chuck1.jpg
http://public.jwh.fastmail.fm/images/Bison1.jpg

The first is a set I made for the Oneway. The second is a set I designed and my friend Mark Yingling made for me. He's made them for a couple of other makers too. Sure, you can get by with less, but it's pretty awesome.

Re: Lathe Chucks

Posted: Sun Apr 10, 2011 2:35 am
by e Markle
JHowell wrote:http://public.jwh.fastmail.fm/images/Chuck1.jpg
http://public.jwh.fastmail.fm/images/Bison1.jpg

The first is a set I made for the Oneway. The second is a set I designed and my friend Mark Yingling made for me. He's made them for a couple of other makers too. Sure, you can get by with less, but it's pretty awesome.
Hey Jack,
Brad Pohlmann recommended Mark to me. How much did that second set run you? Thanks.

Re: Lathe Chucks

Posted: Sun Apr 10, 2011 10:34 pm
by JHowell
e Markle wrote:
JHowell wrote:http://public.jwh.fastmail.fm/images/Chuck1.jpg
http://public.jwh.fastmail.fm/images/Bison1.jpg

The first is a set I made for the Oneway. The second is a set I designed and my friend Mark Yingling made for me. He's made them for a couple of other makers too. Sure, you can get by with less, but it's pretty awesome.
Hey Jack,
Brad Pohlmann recommended Mark to me. How much did that second set run you? Thanks.
Don't remember. I think the chuck was $400-ish, and the jaws were less than that. But Mark is reasonable, whatever he charges, and never mind me, you've got Brad Pohlmann's recommendation. If you want to save money and are going to make a few dozen pipes, just use a Delta midi and a Oneway with tower jaws. Works fine; I made a number of pipes on that rig before I was able to go to a bigger lathe and chuck. But if you're going to make a few hundred or a few thousand pipes, I'd go with Mark's jaws. But that's just me.