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Dirt Cheap Automatic Tailstock Feed for Your Metal Lathe
- Thread starter YYCHM
- Start date
Ya...… I don't think a spider would have prevented that.
Dabbler
ersatz engineer
ABOM79 made a steady rest that bolted to his big universal mill that steadied the stock about 36" from the back of the headstock. Your better choice is to use a spider and trim your material so that no more than 6" sticks out from the spider.
Accidents like that are tragic, preventable and unnecessary.
Accidents like that are tragic, preventable and unnecessary.
OK..... I just thought it was clever.
Brent H
Ultra Member
- indeed, but here is my rub with it - your drilling through something - small lathe max 3-4”. You need to seriously set up to do this automatically? Realistically you can only drill 4” deep amd it’s drilling, - other reasons to advance the tailstock?
Maybe a bit of a “rant” but how lazy are we these days that 3” or drill travel cannot be done by hand?
I think if you tried forcing a drill using the lead screw only bad thing would happen unless you got the feed rate perfect for the drill size and material. I'll stick to feeding the drill by hand where I can feel what's happening
Tom Kitta
Ultra Member
There is a safety pin in the lead screw - or should be - in case something is about to break.
People drill from the carriage sometimes but the feed is set not for threading but for RPM - say feed of 0.003 - same as on a drilling machine or mill. I never needed to do so - its mostly for "hard drilling" on sturdy machines with lots of HP - AFAIK - the reason is it takes time to setup right & unless you are doing production or heavy drilling tail-stock is more convenient. Yes some people "mark" things for quick setup. Maybe I am wrong and some drill of carriage on mini lathe & find it quick.
Why the heck don't people turn off that machine instead of standing around watching it self destruction?
historicalarms
Ultra Member
One time I had a 30" rifle barrel that i wanted to drill out to install a new rifled barrel insert, a common gunsmith job. They all use hand drills to do the job ... but, me being a farmer thought hell there has to be a better way. I rigged up a simple catch-hook that would catch the front of the cross slide and clamped to the tailstock, when the powerfeed was engaged the tailstock was just dragged along at the same rate...worked wonderfully for the first 15 inches of drilling.
This barrel (1890's vintage steel) already had a .375 (38-55) hole in it and I had to increase to .625....should be a simple drill operation shouldn't it! Just drill an inch or so, unhook and pull out to clean the flutes and run in, hook up again for another inch...It was until the mid part of the job...that drill bit jammed up and broke off with 2/3rd of the flutes stuck in the barrel. With that damn bit chucked to the tailstock, I couldnt feel the drag increase the way I would have had I been using the tried& true way of using a hand drill.
That little operation in "knowledge gain "cost me several hundred dollars to (and very lucky to do so) find a comparable vintage barrel to replace the buggered one.
This barrel (1890's vintage steel) already had a .375 (38-55) hole in it and I had to increase to .625....should be a simple drill operation shouldn't it! Just drill an inch or so, unhook and pull out to clean the flutes and run in, hook up again for another inch...It was until the mid part of the job...that drill bit jammed up and broke off with 2/3rd of the flutes stuck in the barrel. With that damn bit chucked to the tailstock, I couldnt feel the drag increase the way I would have had I been using the tried& true way of using a hand drill.
That little operation in "knowledge gain "cost me several hundred dollars to (and very lucky to do so) find a comparable vintage barrel to replace the buggered one.
Oh ouch. That sounds like the type of learning I do.
I don't understand what you mean by hand drill. You mean feeding the tail stock quill in by hand? (turning the wheel).
Ya, I'm not quite following this either. Drilling through 30" with a hand drill? What does the bit look like?
Dabbler
ersatz engineer
Gunsmiths that do this for pay tend to use a piloted drill using a typical hand-held drill. I think that way is very unprofessional.
--They should use a piloted gun drill with pressure coolant on a lathe, hand fed by the carriage. A gun drill of this type type of drill will properly follow the bore, and leave a very consitent and accurate result.
--They should use a piloted gun drill with pressure coolant on a lathe, hand fed by the carriage. A gun drill of this type type of drill will properly follow the bore, and leave a very consitent and accurate result.
historicalarms
Ultra Member
Just an ordinary "plug er inta the wall" hand drill.
historicalarms
Ultra Member
There are two methods regularly used. Either an extended length drill long enough to drill half way from either end of a barrel (Brownells supply them) or as in my case, I center drilled the drill bit shank and cut a spud onto the end of a long 1/2" round bar (long enough to drill completely through from one end) and welded them together. The spud is to assure that the bar is centered to the axis of the bit...That part of the equation worked alright...Where I went wrong was that I didn't have the means to properly grind a short pilot to the front of the bit. Without a pilot , the bit flutes probably started to load pressure on one side or another until the bit started to track off-center, eventually breaking.
historicalarms
Ultra Member
First time I have ever had reason to question on of your post's...and with humble respect to your vastly more experience in the trade....
I don't know how a "gun drill" can work on something with an already established bore. The gun drill geometry requires a solid face to drill into for two reasons. The first is that the cutting lip is cut so that a "centering dimple" is constant in front of the drill. The cutting edge rotates around this dimple and in essence is the pilot for the gun drill all the way through the drilling sequence. This geometry also directs the cut filings down the long groove cut into the bit shank (deep hole drills have no spiral flutes, just a long V straight shaped groove).
The second reason that a solid face to the front of the drill is required is that it is required for the massive pressures required to push the filings down that straight channel for the full length of the drill, however long that might be (longest I have seen is 48"). Recommended pressures I have researched from gun drill manuf. are always in the 6-800 psi range. I suppose that 800 psi would also push the filings out through the already established bore if they were allowed to get to the bore but again, the geometry of the cutting lip is designed to direct the cuttings into the groove. Without the pressure buildup needed I think a gun drill would load up with cuttings the same way my spiral bit did. Reaming chips are always pushed out ahead of the reamer by fluid directed down between the reamer shank & bore wall ( 300 psi recommended).
Building a gun drill from scratch was the main reason i got into this hobby in the first place and I did collect most everything I would need to do so but life & family obligations got in the way...
The barrel maker i referenced before in this thread started boring his custom 30" barrels on a 60" bed lathe with an old automotive power steering pump for a cutting fluid delivery system ( they are rated at 1200psi or so) and a hand full of different sized gun drills. His rifling machine was an old lathe bed with the carriage removed and a hand operated "slide" riding on the ways. All this in an old 10 x 14 1940's grainery on his farm. He has since added a "purpose built" front shop to house his store-bought deep hole drill. i have never seen it working but Ron claimed it would drill a 20 ft joint of bar from one end to the other. Like I said, I never seen it working but have seen 20 ft joints of bar laying beside the bed of the thing.
Dabbler
ersatz engineer
You are 100% right about a normal gun drill being not appropriate. I said a piloted gun drill. you make it custom for the bore - we used milling inserts and ran the gun drill at 30PSI for the solulable oil. It is constructed much like a single cutter boring bar, but with a pilot on the front, but of course hollow and meant to be presurized.
It wasn't just prejudice that prompted the remark. I helped Bert fix a job years ago that was badly botched by using a conventional plug-in hand drill, ground to a a built in pilot. I'm sure it was similar to what is sold today by Brownells. The problem was, due to a problem with the drill or operator error, It didn't even follow the bore well, it was out over 10 thou in two spots but I can't remember exactly how much. As in your case we were salvaging a genuine valuable antique. Our case was different than yours as our bore was now crooked, but Bert showed what he deemed the correct way using a similar tool.
- So our fix used different techniques to achieve the same result. He brought to the table stuff he learned while in the Army and in doing deep hole drilling while working for Remmington Arms. I respect his opinion on this and we successfully recovered the botched job by using a similar, but modified technique.
It wasn't just prejudice that prompted the remark. I helped Bert fix a job years ago that was badly botched by using a conventional plug-in hand drill, ground to a a built in pilot. I'm sure it was similar to what is sold today by Brownells. The problem was, due to a problem with the drill or operator error, It didn't even follow the bore well, it was out over 10 thou in two spots but I can't remember exactly how much. As in your case we were salvaging a genuine valuable antique. Our case was different than yours as our bore was now crooked, but Bert showed what he deemed the correct way using a similar tool.
- So our fix used different techniques to achieve the same result. He brought to the table stuff he learned while in the Army and in doing deep hole drilling while working for Remmington Arms. I respect his opinion on this and we successfully recovered the botched job by using a similar, but modified technique.