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mpatti
01-30-2008, 05:41 AM
I recently purchased the Grizzly 4003G. I noticed that barrels that are around 20 inches are too short to make it through the headstock to the spider gear. On this site, I have read that some people chamber in the steady rest between centers. I am curious how you chamber between centers because I feel limited that my lathe can only work on longer barrels ,24 inches or so, through the headstock.
Can anyone describe this or recommend a good book on this??

Jackson~in~GA
01-30-2008, 07:48 AM
I do all of my barrel work between centers and thru the steady rest. Mainly because the lathe I have setup for barrel work doesn't have a spindle bore large enough to accept a barrel thru it. I start by setting the barrel up between centers. (a live center in the the tailstock, and a face plate and lathe dog on the headstock.) then I turn my shoulder and thread for the action. I usualy leave my barrels a touch longer than finished length, and turn down the muzzle end to make it concentric with the bore. Then I take it down, and install a 4 jaw chuck and grab the muzzle end that I trued up, and place the steady rest just behind the tenon. then I indicate the bore until I get it where I want it and then you are setup to start chambering. I'm sure some of the benchrest smiths will shudder when reading that, but I build hunting rifles, and it's worked for me so far. John Hinnant has a book out that gives in detail various ways to chamber.

JerrySharrett
01-30-2008, 08:24 AM
I recently purchased the Grizzly 4003G. I noticed that barrels that are around 20 inches are too short to make it through the headstock to the spider gear. On this site, I have read that some people chamber in the steady rest between centers. I am curious how you chamber between centers because I feel limited that my lathe can only work on longer barrels ,24 inches or so, through the headstock.
Can anyone describe this or recommend a good book on this??
Many long headstock lathe users start by putting the barrel between centers and turning a portion of the muzzle OD to where it is concentric with the muzzle bore.

Then they make a bushing that is a snug but still running fit with the spindle bore on the bushings OD. Then on that bushings ID they make it to fit the spot they just turned on the barrel muzzle.

Then slip that assembly into a cleaned spindle bore to where you can use a 4-jaw chuck or a tru-adjust 3/6-jaw chuck to indicate and machine the breech (tenon, cone and chamber.

There are variants of this process but that is the basic method to chamber through the spindle on a long headstock lathe.

Dave Tooley
01-30-2008, 09:25 AM
mpatti

Are you using the 4 jaw chuck? If so make yourself another spider to use on the inboard side. I was probably the first to do it years ago simply to shorten up the distance through the headstock.

Dave

Hal
01-30-2008, 10:35 AM
Dave

The internal "spider", is it just a cylinder that will just slide inside your spindle bore and it has 4 alignment screws at 90 degrees to one another?

How tight of fit to the spindle bore. Any pictures. What did you make the spider out of?

Hal

Butch Lambert
01-30-2008, 10:54 AM
I believe that the 4003G lathe has D1-5 tooling. Get a D1-5 backing plate and bolt a piece of aluminum to it and turn. Put it in your mill and drill and tap 4 holes for your spider. I had to do this on my Clausing. Dave has posted photos of his setup and I can email photos of mine.
Butch

Chisolm
01-30-2008, 10:57 AM
I believe that the 4003G lathe has D1-5 tooling. Get a D1-5 backing plate and bolt a piece of aluminum to it and turn. Put it in your mill and drill and tap 4 holes for your spider. I had to do this on my Clausing. Dave has posted photos of his setup and I can email photos of mine.
Butch

Butch
I had thought I had seen photos of Daves setup and did a search but couldn't find it.
Could you post a link to them.
You are correct that it has D1-5 tooling, it also comes with a backing plate.
Thanks
James

JerrySharrett
01-30-2008, 11:00 AM
mpatti, even with the front end spider that Dave and Butch use to replace the 4-jaw chuck you may still come up "short" so to speak. eg Depending on your lathe design and barrel length you may still have to run an internal bushing on the muzzle end while you are chambering the other end.

Dave Tooley
01-30-2008, 11:05 AM
Here we go again

Take a backing plate for a chuck, Turn it down as much as possible, then add 4 screws. Photo attached
No need to add an attachment to it. That's a D1-5 in the picture.
There is also a block added to drive lathe dogs

Dave

Joe
01-30-2008, 11:08 AM
I did almost the exact sam ething as Dave Tooley did. The difference betweenhis and mine is that I used a face plate that was laying around. It works just the same. I can do barrels down to 18 1/2" long

mpatti
01-30-2008, 12:02 PM
I am glad to hear there are some solutions. I will be starting on some longer barrels at first but I will keep all these ideas in mind. Eventually I will want to work on some shorter stuff as well. Thanks.

msalm
01-30-2008, 02:00 PM
For those of you who use that spider arrangement on both ends of the spindle, I'm curious if you ever have any problems with the barrel slipping?

Butch Lambert
01-30-2008, 02:39 PM
Not yet.
Butch

Dave Tooley
01-30-2008, 03:51 PM
I can't say it's never happened but only when I was turning down the tenon at 1250 rpm's and taking .050" off on a pass. Then it was just a few thousandths. Checked it internally with an indicator and it might have moved the bore a couple of tenths.
I face off the end of the stub, set my travel indicator on the saddle to my shank length, turn to the diameter I want stopping .001" short until the last pass, feed in about .020" to relieve the corner of the tenon and shoulder, pull it out which faces off the shoulder, then go back to my shank length number and face the end of the barrel again. I always end up taking a few thousandths off there because of expansion from the heat. If the barrel slipped I would catch it then.

Dave

adamsgt
01-30-2008, 10:23 PM
Here we go again

Take a backing plate for a chuck, Turn it down as much as possible, then add 4 screws. Photo attached
No need to add an attachment to it. That's a D1-5 in the picture.
There is also a block added to drive lathe dogs

Dave

When I went to gunsmithing school 25 years ago, we used 9" swing SB and turned between centers using a drive plate and lathe dogs. After buying a used 12X36 a few months ago I've been looking for a lathe drive plate in D1-4 configuration and been unsuccessful. This looks to be a viable alternative with additional capability. :)

Shiraz Balolia
01-30-2008, 10:24 PM
Here we go again

Take a backing plate for a chuck, Turn it down as much as possible, then add 4 screws. Photo attached
No need to add an attachment to it. That's a D1-5 in the picture.
There is also a block added to drive lathe dogs

Dave

Dave - really liked your idea, so today I went ahead and did the drawings for a "stepped" back plate that fits directly into the D1-5 spindle. It will be one piece cast iron with brass tipped screws for the spider and the normal studs on the back to fit into the spindle. Also did one for the larger lathe that has D1-6. Should be commercially available from us in about four or five months.
Thanks.

Chisolm
01-30-2008, 10:42 PM
Shiraz
Please let us know when it's available.
But then of course part of the enjoyment of having a lathe is making some of your own tooling.:D
Also it sure is nice having someone who is responsive to the customers needs. Thank you Shiraz
James

Dave Tooley
01-31-2008, 08:05 AM
Shiraz

I was going to talk to you about that and a couple of other things at the Shot Show. See you and Gordy at the show.

Dave

Wayne Shaw
01-31-2008, 09:30 AM
"when I was turning down the tenon at 1250 rpm's and taking .050" off on a pass."

Wow, that's getting the job done! :)

Dave Tooley
01-31-2008, 10:13 AM
Wayne

Time is money. I've slowed down to 800 RPM's now. Seems reasonable now. I don't have the eyes I used to have so I've had to slow down some.

Dave

Shiraz Balolia
01-31-2008, 11:42 AM
Shiraz

I was going to talk to you about that and a couple of other things at the Shot Show. See you and Gordy at the show.

Dave

Dave - Look forward to seeing you there. If I am out and about shopping for "toys", have them call me and I will return to the booth.

boucher
01-31-2008, 12:17 PM
Don't mean to hijack this thread but there is another use for this tooling arrangement for those that are limited by a short bed. Just turn the barrell around to work on the Crown. I also install a dead center in the headstock and use this adapter to drive a lathe dog for working between centers. Using this in reverse could shorten things up even more. Can't wait to try it. I would have never thought of just using the screws to drive the work without a dog.

Crow99
01-31-2008, 02:51 PM
Shiraz: Thank you again for being so supportive of the gunsmithing community. Excellent machinery, excellent video, and now specialized attachment. I hope to be one of the first to buy the spider backplate in D-1-5 for the G4003G. When can we order / get on the "list?"

Shiraz Balolia
01-31-2008, 03:05 PM
Shiraz: Thank you again for being so supportive of the gunsmithing community. Excellent machinery, excellent video, and now specialized attachment. I hope to be one of the first to buy the spider backplate in D-1-5 for the G4003G. When can we order / get on the "list?"

It will be about 4 months, I would say, before they are available. Next two weeks are shot because most of ASIA is "closed for business" due to Chinese New Year. Then they will start working on it. After I approve the prototype, a model/item number will be assigned and an order placed. Thanks.

Gordy Gritters
01-31-2008, 03:12 PM
Hey, Tooley

Glad you're coming to the SHOT show - looking forward to seeing you again!

We'll have to get together and tell some more lies about Lee Fischer!!!!!!!

See you soon!
Gordy

mpatti
01-31-2008, 09:17 PM
I have a face plate that came with the lathe that I can turn down and make a fine spider gear from and save some inches. Dave, thanks for the picture!!!

I will also make a bushing for the outboard end but probably will wait to see what barrel I will be working on that needs it first. Thanks Jerry for the idea.

Dave Tooley
02-01-2008, 08:02 AM
Gordy

Lies, We don't need no stinking lies. We can tell the truth about him.

Dave

Dave Tooley
02-01-2008, 08:20 AM
mpatti

Concerning chambering shorter barrels. I want some of the guys here to way in on this. If your barrel is going to be to short to reach all the way through the headstock why not cut it long enough to get out where you can get an indicator on it? The ID of the spindle is just a reamed hole. I've never check mine for concentricity. I would think an inch or so of barrel would have less runout than the ID of the spindle.

Also Joel Pendergraft came up with an insert to go in his spindle that the adjustment screws were facing out and put pressure on a pad or something that held the barrel in place. I've got all kinds of ideas running through my head right now about how to do that. Just depends on how large the spindle hole is compared to your barrel. It could be as simple as pointed tip set screws pushing against ball bearings that are riding on the barrel.

On second thought If I was going to do it that way I would have standard size to slip over the barrel that I had turned down and have the ball bearings go out and touch the spindle. It would involve turning down about 3/4" of barrel then when your done chambering cut that part off. It doesn't take much work holding pressure on that end.

Dave

JerrySharrett
02-01-2008, 10:22 AM
mpatti

Concerning chambering shorter barrels. I want some of the guys here to way in on this. If your barrel is going to be to short to reach all the way through the headstock why not cut it long enough to get out where you can get an indicator on it? The ID of the spindle is just a reamed hole. I've never check mine for eccentricity. I would think an inch or so of barrel would have less runout than the ID of the spindle.


Dave
Dave, IMO it would be a pi$$ poor made lathe spindle that had more than 0.005" TIR in the spindle bore. I know some folks have reamed the spindle bore with something like a shell reamer.

They may have bored the first couple of inches then reamed from there. Problem is, if the hole run-out is very much the shell reamer would eventually start to follow that hole. And, that part of the spindle bore would be where a bushing would actually run. Other than bringing the bore to a particular diameter there would be no reason to ream unless I am missing something.

When you leaving for the SHOT show? Jim left this AM. Look him up and boo him. They are supposed to give him some big award this year!!

J. Pendergraft
02-01-2008, 07:51 PM
Dave referred to the tool I made for doing short barrels thru the headstock. The spindle bore on the Clausing is 2.125" so this type device may not be practical for smaller spindle bores. Also to us this device you have to use an alignment rod like Greg Tannel sells and do all the alignment on the end of the barrel you are setting up to machine. Dave, I like the ball bearing idea, it would work the same as mine but less time to make the tool. Heavy grease would probably hold the bearings in place. I use grease on my pins and they stay in place fine. I don't take credit for this device. I told a tool and die maker what I wanted to do and it took him about 2 minutes to sketch this up.
I have attached a picture of the device and a picture of the angle cut pin and adjustment bolt arrangement.

Jan
02-01-2008, 09:04 PM
...please email me at nevrhad2(REMOVETHIS)@nvbell.net
thanks........... Jan Sarras

Rob Carnell
02-02-2008, 08:08 PM
www.benchrestbulletin.com.au/personalprojects/spindlebushing.jpg

This is the bushing that I made. It has a rubber 0-ring in a groove, and is a press fit inside my spindle. The end is turned down to take a standard pilot, then drilled and tapped for the screw. It works like a dream. The only drawback with this method is that you cannot blow air down the barrel from the outboard end to clear chips. However, I find I can do this just fine from the chamber end.

I just put the bushing into the muzzle end, open the jaws wide, then push the barrel down the spindle with the tailstock until it is in the right position.

Hope the pic comes out ok, maybe I should have cleaned off the oil!

Rob Carnell
Sydney, Australia

PPP MMM
02-08-2008, 03:48 AM
Dave referred to the tool I made for doing short barrels thru the headstock. The spindle bore on the Clausing is 2.125" so this type device may not be practical for smaller spindle bores. Also to us this device you have to use an alignment rod like Greg Tannel sells and do all the alignment on the end of the barrel you are setting up to machine. Dave, I like the ball bearing idea, it would work the same as mine but less time to make the tool. Heavy grease would probably hold the bearings in place. I use grease on my pins and they stay in place fine. I don't take credit for this device. I told a tool and die maker what I wanted to do and it took him about 2 minutes to sketch this up.
I have attached a picture of the device and a picture of the angle cut pin and adjustment bolt arrangement.,,,,,,,,,,,,,,,,,,

A spindle touching closely fitted O ring or two sitting in the groove(s) along the body would improve the effectiveness of this great device by minimising most of the vibrations.

Shoot well
Peter

Dave Tooley
02-08-2008, 08:17 AM
Joel

I knew you had done this using pins. I thought about a Remington 40X trigger with trigger pull screw coming out the bottom. Screw, ballbearing against the spring. It would real easy to drill and ream the holes for the ball bearings. Then just stake them in, so they don't fall out. 3/16" or 1/8" bearings would provide all the travel you would need. Get some long set screws. Ream the ID. You could turn down a sacrificial section of the muzzle to fit or epoxy a bushing on the barrel and turn it down between centers. Snug fit with one nylon tipped set screw should hold it in place Most guys are just a couple of inches short and could reach in with a long stem indicator, maybe even with their standard short stem indicator. Several ways to skin this cat and go a good job of it.

Dave

PPP MMM
02-08-2008, 02:29 PM
,,,,,,,,,,,,,,,,,,

A spindle touching closely fitted O ring or two sitting in the groove(s) along the body would improve the effectiveness of this great device by minimising most of the vibrations.

Shoot well
Peter,,,,,,,,,,,,,,,,,,

As the pins can have a much greater face radius than, 3/16-1/8" thus providing for more spindle contact area, giving more stability and support. As a matter of fact the face radius of the pins can be made to equal the radius of the spindle. Giving a full line of contact, rather than just pinpoint contact.

Shoot well
Peter

J. Pendergraft
02-08-2008, 04:01 PM
,,,,,,,,,,,,,,,,,,

As the pins can have a much greater face radius than, 3/16-1/8" thus providing for more spindle contact area, giving more stability and support. As a matter of fact the face radius of the pins can be made to equal the radius of the spindle. Giving a full line of contact, rather than just pinpoint contact.

Shoot well
Peter

I have my pins radiused a little smaller so when the alignment of the device is not quite concentric with the spindle bore the center part of the radius on the pin will still be the contact point. Some will make the point that you do not require much to hold this end of the barrel, which is likely true. I have a tendency to tighten and hold things more than is necessary.

PPP MMM
02-08-2008, 08:32 PM
I have my pins radiused a little smaller so when the alignment of the device is not quite concentric with the spindle bore the center part of the radius on the pin will still be the contact point. Some will make the point that you do not require much to hold this end of the barrel, which is likely true. I have a tendency to tighten and hold things more than is necessary.,,,,,,,,,,,,,,,,,,,

Concentic or not, if the radius of the individual pins is the same as is the radius of the hole in the spindle it will always act as if it was a sectioned ball of one diameter. If the ball would be the same size as the bore in the spindle it would have a full contact line around its entire circumference. The ball could be tilted and there will always be a full contact line with the spindle. Any two opposite points on the contact line of the ball will always be in contact with the bore of the spindle, regardless whichever way the ball will be tilted. The contact line on the four pins will be always square with bore of the spindle if the pins will have the same radius as the bore. Exactly as if it was a big ball.
The pins with the same face diameter as is the diameter of the spindle are representing the full contact line of two opposite points on the ball. In this case the diameter of the pins is that full contact line. One can say, that the four pins is actually what has left from the imaginary big ball. The larger the diameter of the pins is, the longer is the contact line in full contact with the spindle. If the "big ball" or the radius on the pins is made smaller and it will always have only a pinpoint of contact. THE BIG BALL ONLY SERVES AS AN EXPLANATION, just in case someone limited can't get the picture otherwise.
Have I ever wanted to hold something less while machining? Never. It's a good tool. Making the radius on the pins the same as is the radius of the spindle and one or two grooves along the body to sit O rings into will transform a good tool into an excelent tool. The use of 3/16 - 1/8" ball bearings would compromise the purpose of the tool, much more then the pins with a smaller radius than the bore of the spindle would.

Shoot well
Peter