quote:

Originally posted by kcstott:
http://www.harborfreight.com/c...taf?Itemnumber=66164

Thanks, but that has a 1.5 inch spindle bore.

The one Tapper2 is referring to has a 1.875 spindle bore.

Jim

quote:

Originally posted by kcstott:
Here's one for you Westpac.

Why is the receiver faced off?
Why Is the bolt face faced off?
The lugs don't count as that is for strength But then why all this attention to getting things square and concentric if the chamber doesn't matter?
Seriously I'm not trying to pick a fight or question your ability It's an honest question As I don't smith for a living.

Watch this video and you will see what I am talking about. You will notice that he doesn't concern himself with the alignment between the muzzle and the breech end. His only concern is that area where the chamber will be. He doesn't take you back to the rear of the machine for a look see, but if he did, I will bet you the bore is running out.

http://www.youtube.com/watch?v=aII2tbavKnM

quote:

why all this attention to getting things square and concentric if the chamber doesn't matter?

What I think Westpac is saying is that dialing in the muzzle doesn't necessarily do anything to make the chamber concentric with the bore as the bore wanders. The bore is just a pipe and is usually not perfectly straight.

As long as the muzzle end is supported close to center so that it doesn't wobble around while turning, the reamer pilot is going to lead the reamer down the bore, and as long as your setup, whatever it is, allows the reamer pilot to lead straight down the pipe, the chamber will work.

The video say. "Getting the bore to run as straight and true as possible is one of the most important thing you can do."

Now he is making an adjustment on the muzzle end he's just not indicating the muzzle.

But my problem with the video is he is using the tail stock to with a drill chuck to indicate the barrel. That's a Bozo No No for a machinist. Drill chucks aren't worth a shit for centering off of. He needs to insert a mandrel that is about .0005" undersize of the bore to indicate off of. There's no telling what that drill chuck is doing to his reading.

Edit he was using a live center no problem with that.

PM sent to Westpac

quote:

Originally posted by kcstott:
The video say. "Getting the bore to run as straight and true as possible is one of the most important thing you can do."

Now he is making an adjustment on the muzzle end he's just not indicating the muzzle.

But my problem with the video is he is using the tail stock to with a drill chuck to indicate the barrel. That's a Bozo No No for a machinist. Drill chucks aren't worth a shit for centering off of. He needs to insert a mandrel that is about .0005" undersize of the bore to indicate off of. There's no telling what that drill chuck is doing to his reading.

Edit he was using a live center no problem with that.

If I was going to do the work to rechamber and crown a new barrel, here is the way I would do it. Place the barrel through the headstock and center the chamber end in the chuck using a live center to get close. Then I'd indicate the muzzle end of the barrel as close as I could get it with 2, .0001" indicators, 1 at the muzzle and the other at the end of the rod. Then I'd go to the chamber end and do the same process of indicating in, probably taking extra care to get it as close to .0000" as I could. Move back to the muzzle end, insert rod and find top dead center and mark for reference at both ends of the barrel. Thread and chamber so TDC remains pointing at 12 o'clock. Flip barrel around and dial in both ends, this time starting at the chamber end and then muzzle end...then crown the muzzle. This is the method that makes sense to me given that we know barrels are not straight as we'd like to believe. The only thing we can do is work around this fact and possibly use it to our advantage(gaining elevation by clocking TDC upwards). Depending on the level of accuracy you go to in dialing in a barrel, I doubt that you'd be able to indicate the chamber and muzzle to run true at two points on a rod, at the same time, without inducing stress in the barrel to do so. If you can it would probably be either coincidence that the muzzle and chamber sections being indicated on are in perfect alignment with eachother or an exceptionally straight barrel. But, don't take my words as gospel, I'm just speaking in theory!

And I thought I was going over board.

I' would not indicate with tenth's indicators ie .0001" resolution.
The lathe spindle is not that accurate. Unless you are using a hardinge lathe or Like someone that shall remain nameless that has a friggin Monarch BUTCH

Your typical lathe spindle will run out at least .0005" and more likely on older used machine it's closer to .001" so using a tenths indicator is way over kill and leaning on the machine the wrong way will through off the reading. Ask me how I know.

Either way I guess we are talking about a piloted reamer and so long as the area you're working in is dialed in it should be fine.
The more I think about it the more I see I'm being way more precise then i need to be.
And It would save a bunch of time too.

quote:

Originally posted by kcstott:
And I thought I was going over board.

I' would not indicate with tenth's indicators ie .0001" resolution.
The lathe spindle is not that accurate. Unless you are using a hardinge lathe or Like someone that shall remain nameless that has a friggin Monarch BUTCH

Your typical lathe spindle will run out at least .0005" and more likely on older used machine it's closer to .001" so using a tenths indicator is way over kill and leaning on the machine the wrong way will through off the reading. Ask me how I know.

Either way I guess we are talking about a piloted reamer and so long as the area you're working in is dialed in it should be fine.
The more I think about it the more I see I'm being way more precise then i need to be.
And It would save a bunch of time too.

Well.....I did have a Monarch 16CY up until this past summer when I sold it, but that's not why I'd dial in with a tenths indicator. Assuming you want it as close to perfect as you can get within the boundarie of your equipment, you have to indicate to the next degree of resolution on the indicator. Spindle runout doesn't rear it's ugly head when you are dialing in because there's no load on the bearings and for the types of loads chamber work would exert I doubt that even a wore out spindle would produce as bad as it indicates. I'm anal retentive enough that I'd dial in to the tenth or find out why I can't, I've run several lathes in the past few years ranging from junk to finely tuned machine and I feel pretty confident that any one of them could dial in a barrel to satisfy me. My point being that with whatever you are dialing in, if the indicator you are using doesn't have enough resolution to account for your baseline of runout, then you can't achieve the level of accuracy you are aiming for. Diailing in a barrel to half a thousandth should be fairly easy, but you aren't going to do that with a .001 or even a .0005 indicator, imo. If you want to dial in to within a TRUE 1 thousandth, you aren't going to do that with a .001 indicator, nor are you going to get anything diald in to a TRUE tenth on a tenth indicator, but you can easily dial in a thousandth or a half on a tenth indicator.

On another note and since I am a big fan of the 10EE, I'd like to give it my vote for a gunsmithing lathe despite obvious challange of having the long headstock. I never would have considered it as a gunsmithing lathe until I saw another thread on another sight that the poster explained how he worked around having too much headstock(or not enough barrel as was the case). It was a pretty neat idea I hadn't thought of but seams obvious once you see the set up. I'd like to post the link to it if it's not against the rules of this board, I'm new here so not too familiar with the rules yet. My dream lathe would be a 30" 10EE inch/metric with a retrofit servo drive, but I like to be able to eat food other than ramen noodles too, sooooooo.

quote:

Originally posted by kcstott:
The video say. "Getting the bore to run as straight and true as possible is one of the most important thing you can do."

Now he is making an adjustment on the muzzle end he's just not indicating the muzzle.

But my problem with the video is he is using the tail stock to with a drill chuck to indicate the barrel. That's a Bozo No No for a machinist. Drill chucks aren't worth a shit for centering off of. He needs to insert a mandrel that is about .0005" undersize of the bore to indicate off of. There's no telling what that drill chuck is doing to his reading.

Edit he was using a live center no problem with that.

The only thing he is using the drill chuck for is to hold the "grizzly rod". The rod has a close fitting bushing and when he inserts it into the bore, in actuality what he is indicating in is the runout in that portion of the bore where the bushing is riding.

Thanks for all of the suggstions so far.
Just to give a little more information about what I am looking for.
I will be needing a Lathe with single phase power requirements. The types of projects I would like to use it for would be the typical rebarreling of bolt action rifles & all that entails. Truing an action, threading, chambering, & crowning of barrels. As I am sure any number of other projects that come along.
So far I see that a 10x40 with the biggest hole through the headstock that I can find, or afford. Please let me know if I have misunderstood.

I would definitely go for a 3 phase machine and use a VFD to get your 3 phase and it will also give you variable speed control.
You might look for a Rockwell lathe. They are very good gunsmith lathes. !.400 spindle bore, short headstock, and variable speed.
Butch

hvy barrel,

Grab your phone book and call every Machine Shop or related business in your area. With the change over to CNC over the years you might just call up someone with exactly what you want setting in the back warehouse. When I was looking to move up from my 10x24” Atlas I did just that (call around) and ended up finding a nearly new Summit lathe for less $$ than the Grizzle Gunsmith model, about 20 miles away. I got to run it before I bought it,and the shop owner delivered it to my shop. Don't shy away from a 220V 3 phase machine. Hooking up a static phase converter or (better yet) a VFD is a piece of cake for a decent electrician.