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DimitriS
January 12, 2006, 07:02 PM
Is this possible ?? :confused:

I've been reading about it but I want your take on what will be needed to do something like that. :)

Dimitri

HSMITH
January 12, 2006, 08:31 PM
Sure, it is possible. The machine isn't even that complicated. You could also buy 'standard' CNC machines that will make a barrel.

Making great barrels? There is as much art as science in making a really good barrel, and lots of pipe in the reject bin.....

DimitriS
January 12, 2006, 08:48 PM
HSMITH,

LOL I dont want a CNC machine to do it. Actually I've been using DesignCAD to draw up a machine that can do it automaticlly. :)

Not really CNC per say. It would run off a microcontroller to control the rate the one motor turns the barstock and control the other motor to "push" the stock at the right speed through to make different rifle twists. :cool:

The machine I "invision" will be 88.5 inches long :eek: and can handle up to 31 inch barrel assuming I'm making a 300RUM or similar length chambering. :D

This is all assuming the machine will work (I think I could get all to work after a few test barrels) and I can get all the parts for it. :)

What do you think ?? :confused:

Dimitri

HSMITH
January 13, 2006, 08:02 AM
I think using a motor to control the stock turning is going to need a gear reduction and/or a transmission to control output speed. It would take a MASSIVE motor to have the power needed at the very low speeds the barrel will need to be turning at without reduction.

If you are looking at single point cut rifling you will need a way to index the barrel or cutter accurately for each cut. If you are looking at button rifling you will need a LOT of power to pull it through the barrel.

I think pushing the stock is the wrong way to do it, the bit size is going to be small and long, like pushing a rope up a hill. I think you need to pull the tool through the stock.

You will also need to gundrill the barrel blanks relatively straight and control the size closely before even going into the rifling process.

Just a few opinions, hope it helps.

DimitriS
January 13, 2006, 01:43 PM
HSMITH,

Thanks for the information so far :D

I'm not sure how this would be done but here is a picture of my "vision" of a working machine attached here. :)

What do you think ?? :confused:

Its Button rifling I think. The cutter makes all of the cuts on the same pass and it does the cutting by having the machine push the metal into the cutter and it has a seperate motor to do the turing. :D

Dimitri

HSMITH
January 13, 2006, 08:59 PM
I still think you are pushing a rope up the hill trying to push the stock over the button. Once the supports drop away the entire rod length that is in the bore will be unsupported in the bore, and it will bend and rub on the barrel bore best case. Worst case, and what I suspect will happen is that the bit will break. Pulling it through greatly simplifies the machine as well as alignment of the stock to the bit.

DimitriS
January 13, 2006, 09:52 PM
HSMITH,

Yah I guess I'm not sure though how you would make a machine that could pull it through :(

I understand what your saying to pulling it through but I'm really unsure how I'd do it. In my mind it somehow seems simplier pushing a large square stock then pulling a thin rod.

Maybe put rubber padding on the rod to make it stable in the barrel ?? :confused:

I'll take any advice you give I can really use it as I dont know much about barrel making execpt from a couple articals I've read. :(

Dimitri

HSMITH
January 14, 2006, 10:08 AM
For simplicity I would make the rod with a ring or flats that a setscrew/s could engage to couple the rod to the traveling part of the machine. The same mechanism you are using to traverse the stock should work to traverse the tooling.

I am a big fan of the KISS method. If I were going to do it I would probably make the machine with hydraulic rams to pull the tooling through. I would rotate the tooling through a stationary blank by using a rack and pinion, the rack would be stationary and the pinion would be on the travelling part. The pinion would drive two more gears between it and the ring gear on the rotating 'chuck' that will hold the tooling. Swapping out the two gears in between would let me change the twist rate easily, and from the little thought I have put in it would be extremely repeatable and accurate.

My experience is all CNC, but with a lot of deep hole work. I wonder what actual barrel making machinery looks like........

jcims
January 14, 2006, 10:24 AM
GunTec TV, sponsored by MidWay USA, has had a few segments on barrel making. They always seem to start off with 12' bar stock in varying diameters and steel types. Seems they rough-cut the bore first with, essentially, a really long drill. Then, as HSMITH said, they pull a reamer through to get the final dimensions... In all of the segments i've seen, the stock rotates and the cutting head is stationary.

In the three factories i've seen, they all use a button to rifle the barrel.

One thing they showed at Schilen is they 'de-stress' the barrels by heating them up to something like 800-1200 degrees and let them sit for a bit. They do this once after the initial cutting, and once after the rifling. In at least the latter case, they pump in nitrogen to displace all of the oxygen to avoid oxidation. I don't think this does anything for the accuracy of a cold barrel, but i think it does help improve the accuracy as the barrel heats up.

I haven't seen anyone cut rifling yet (although i had seen mention of a manufacturer using EDM to cut it...just haven't seen it on TV or anything)

Edit: Just found this...for airguns, but you may get some ideas:
http://www.quackenbushairguns.com/Airgun_barrels.htmhttp://www.quackenbushairguns.com/Airgun_barrels.htm

DimitriS
January 14, 2006, 12:24 PM
Thanks for the replys :)

HSMITH,

How did you do deep hole drilling ?? :confused:

So what your telling me is that I should rework my idea to have the bar stock connected to where the drill bit is and instead of pushing the metal I should pull the metal ?? If so I'll think of a good way to do that :D

jcims,

Yup the cutting head is stationary thats why I was planning on doing it this way but pulling the bit and rotating the stock makes sense after all since everywhere I've read about button rifling which is what I'm planning on doing says they do pull the "button" :)

Dimitri

SamD
January 14, 2006, 12:30 PM
How many thousand barrels are you planning to make?
The reason I ask is that the expense of making a machine to do it all in 1 trick is really steep. Not economical at all unles you are making several thousand and preferable sevral hundred thousand.

On the other hand you can drill a barrel in several ways (or not drill at all sometimes) and you can make a rifling machine at home for next to nothing.
Only 2 pieces of metal required other than fasteners.

Sam

DimitriS
January 14, 2006, 12:35 PM
Sam,

I'm planning on making maybe 10 barrels or so :p

Its for a learning experiance more or less. And who knows if it works out all right I might make it a small bussince for cheap barrels for all of thouse surplus guns when buying and installing a barrel in it for 200$ isnt worth it ;)

My machine that I posted up there could only handle one barrel at a time and it wont cost a million plus .... mayabe up to a thousand dollars assuming I build and rebuild it alot and work out all the bugs 100% in the system to make if I dont count my time because it will be like a hobby thing for me :cool:

Dimitri

SamD
January 14, 2006, 12:45 PM
DmitriS,
For that number I would drill them on a lathe and cut rifle by hand.

I couldn't describe how to make a hand rifling machine but would insted suggest that you purchase a copy of the "Foxfire Book vol 5" which has instructions and some dimensioned drawings to make arifling machine.

If you wanted to go "by the book' you could make a barrel from horsehoe nail scraps.
Rifling a drilled barrel is identical to rifling a forge welded muzzle loader barrel and the book will show you everything you need.

Sam

DimitriS
January 14, 2006, 12:55 PM
Sam,

I understand what your saying about cost verses benifits but this is more of something I want to do as a hobby then anything else :)

And I'll look that book up at the bookstore :) I aready bought 600$ worth of books this month another one wont hurt. :eek: (College books but still :cool: )

Sam I got to ask you do realize if the drillbit is turning when your doing the cutting it will wobble too much ?? Thats why barrel companies have the metal do the turning/moving not the drill bit. And with a large 50+ caliber barrel you can have a pretty thick drill bit allowing you to turn it but with a 300cal barrel its too small to turn the drillbit :)

Dimitri

SamD
January 14, 2006, 04:34 PM
Dmitri,
Thats why I said to drill it in a lathe. The tool remains stationary, the work turns.

Frank Howe Gunsmithing Vol II shows how to mke your bits, braze them to the Shelby tubing, pressure feed for lube, the works.

Sam

Don H
January 14, 2006, 04:36 PM
Dimitri,

You might want to take a look at this 3-hour video on building a rifled barrel machine sold by a fellow Canadian, Guy Lautard:

http://lautard.com/rmv.htm

Unclenick
January 14, 2006, 04:44 PM
I have those videos. A little slow from an entertainment standpoint, but they give a really good idea of what's involved.

Nick

Don H
January 14, 2006, 05:06 PM
Nick,

So, do you think they are a worthwhile investment? Could a rifling machine be built from the information in the videos?

DimitriS
January 14, 2006, 07:41 PM
SamD,

Your right my mistake. :)

Don H and Nick,

I might get thouse vedio's cost is a slight factor now as I've spend alot on college the last couple of weeks. :)

I wont be copying him though just using his machine as a idea to improve apon mine :D

Dimitri

Unclenick
January 15, 2006, 03:26 PM
Don,

If you're at all familiar with machines, yes they contain enough information. Their purpose is to show how to make and use such a machine. They modify an existing lathe.

If you are not familiar with basic machinery, you can do worse than to get the late David Gingery's series on how he built a machine shop from scratch over a 20 year period; starting with the casting foundry. He takes some shortcuts, like using allthread for a master lead screw (not recommended), but you can learn quite a bit about how these things work and go together. Lindsay books had them when I last looked.

As to whether it is worth it? If you like doing things yourself, it can be. Would it be economical? Depends on how well you can scrounge and how many barrels you intend to make? The old lathe to serve as the base machine can set you back the cost of a number of barrels. By the time you buy good quality steel billets for making your own and ammortize the machinery over the number of barrels you intend to make, the savings may not be better than just buying finished barrel blanks from Douglas. Plus, you are still going to need a conventional lathe for chambering. So you are into some space and equipment before you are finished.

I settled for having a conventional lathe and buying rough-contoured blanks.

Nick

Don H
January 15, 2006, 03:48 PM
Thanks, Nick, for the overview. I have a couple of Gingery's books from about 30 years ago (the aluminum foundry and lathe, IIRC).

SamD
January 16, 2006, 11:53 PM
A little discussion on the subject here:

http://www.practicalmachinist.com/ubb/ultimatebb.php?ubb=get_topic;f=16;t=000631

Sam

Unclenick
January 17, 2006, 04:16 PM
SamD,

Excellent thread reference! Worthwhile for the book download link alone. It shows the same situation as the Lautard tapes. You need a lathe to convert or adapt to boring and reaming before monkeying with the rifling itself.

Nick

DimitriS
January 17, 2006, 07:19 PM
Thanks for all the tips so far. :)

Nick what would you think of building a machine that was microcontroller controlled to have presets for drilling and reaming as well as fuctioning the machine for the proper twist during rifling ?? :confused:

Dimitri

Harry Bonar
January 18, 2006, 02:56 PM
Dear Sir:
Your enthusiasm is commendable. I would say that you can go to Douglas barrels in Charleston W.Va and they will give you a tour about the shop and every aspect of barrel making. I realize that is a long way from Canada but you're sure to find a barrel maker there who would help you, in Canada.
In the Modern Gunsmith by J.V. Howe he tells of a man in the canadian wilderness who made a barrel from raw materials and it shot!
The old mountain gunsmiths made barrels for their muzzle-loaders under trees, in the woods, at forges, under every hindrance - and more accurate barrels have NEVER been made!
Harry B.

DimitriS
January 18, 2006, 03:11 PM
Harry,

Thanks for the reply :)

Douglas isnt too far if it means I can get a better understanding and refine my design before I make it. Might make the trip if I got myself some spare time and money just before I get started. :D

I dont belive there are any barrel makers in Canada. As a matter of fact I only know of 2 firearms companies in the whole country (Para-Ord and Demaco now owned by Colt). :)

Its cost verse cost. This is a personal project I dont ever execpt to get my money back from my machine. If visiting Douglas or any other barrel maker will help me spend less pocket money because I'm not just reading/thinking how your supposed to do it then its all the better :D

Dimitri

Unclenick
January 20, 2006, 12:12 PM
Dimitri,

I don't see any problem with your idea in principle. For drilling and reaming, controlling the feeds rates with stepper motors is basic NC machining. I'm not sure you even need a microprocessor if you are dedicating the machine to barrel making? Controllers for stepper motors are available or you can make them, so you just need to generate pulses to the motor drives at the right speeds and ratios. Basic clock and programmable dividers could do that as well as could a micro. The interface could just be mechanical switches in either case.

The rifling is a little different. Unlike the drilling, where it doesn't matter if one of the stepper motors drops a phase from time to time, you need absolute position information to align the cutter for each pass. I built a scanning X-ray densitometer interface in the early 80's that did these basic functions. It used shaft angle encoders, counters, and registers to buffer I/O for a computer bus (PDP 11, if that tells you how old the gear was - 2 mb disk cart the size of a stack of pizzas) and to recieve locating information and move the stepper. A rotating glass drum held the X-ray while a stepper on a lead screw drove a mechanically linked light source and sensor pair along opposite sides of the glass.

So, yes it is all doable. Something to think about. If big steppers are used for both indexting the blank and for running the lead screw, it is not inconceivable one machine would serve both to drill and ream as well as to cut rifling. For the small shop, that would be advantageous. It would also minimize setup and alignment problems. Interesting to consider.

Nick

DimitriS
January 20, 2006, 01:22 PM
Nick,

Thats what I was thinking :D

The Microcontroller is basiclly a 8-bit computer that is all on one chip used for automating things. I have delt with them before and I know how to use them so I basiclly will do what you said execpt I wanted it to be one button control.

Basiclly in a layed out plan it will work like this:

-> Button pressed
-> Microcontroller interprets
-> Microcontroller controls the motor controllers to provid ether proper drilling speeds or rifling speeds
-> Controller controls the motor as derected by the Microcontroller.

It shouldnt be too hard as you said in principle. :)

Whats funny is that the single microcontroller can do everything the whole computer you had in the 80's on one chip and without resortign to using pizza sized disks. :cool:

The rifling is a little different. Unlike the drilling, where it doesn't matter if one of the stepper motors drops a phase from time to time, you need absolute position information to align the cutter for each pass.
Wouldnt I only need to worry about this when dealing with cut rifling ?? :confused: I'm gonna button rifle so all the rifling cuts are made at the same time. It shouldnt matter too much execpt it might mean slight differences in the rifling from barrel to barrel but then agian it shouldnt matter too much :)

Nick What do you think ?? :confused:

Dimitri

Unclenick
January 20, 2006, 02:56 PM
Yeah. I'd forgotten you were going to button rifle. I was thinking of the cut rifling because of the video tapes and machinist site link discussed earlier.

I was trying to work out a way for a single machine to drill and ream and run the rifling cutter all without removing the barrel blank from its chuck. In principle it can be done. In practice there are some awkward elements. Be an interesting challenge, though.

Nick

DimitriS
January 20, 2006, 03:17 PM
Nick,

I've since edited my design. Thanks for all the help guys! You've been great so far and a fountain of knowlage and ideas. :D

I basiclly just modified it slightly and the barrel does stay in the machine the whole time. Doesnt get chambered or chamber reamed in the machine though. I designed a little benchtop unit for that. :cool:

All you need to do is install the gun drill bit, press a button, install the reamer press a button, install the button, press a button. Not too hard I dont think :)

I dont got a machine shop now and I'm still in college for Tool and Die so wont start this project for atleast another 2 years. But 2 years is like nothing for me I have a bad sense of days/weeks/months :p

Tell me Nick, how does this refined version look ?? :confused: ITs not as complicated in the layout. And I edited what part the barrel goes in. Now the barrel supports lock in the barrel and it also turns it.

The metal stock used would be 35inchs long, It should be able to cut up to 27.5 inch barrels (to cover most lenghts) eaisly but if you did 2 cuts I'd imagine you could make a 35inch for a 50BMG or 30ish inch for barrels that are long action rounds.

So you'd drill out the barrel and then make the chamber if you wanted a really long one. Its a option if needed without really adding to the cost/size of the machine. I wouldnt do it though. :p

Dimitri

Harry Bonar
January 25, 2006, 09:54 PM
Hey Guys:
You're ALL beyond this old boy!
Harry B.

DimitriS
January 25, 2006, 10:01 PM
Harry Bonar,

No your not :p Its simple 101 machining. We just made it complicated by trying to make a machine to do it automaticly for us instead of doing it all by hand. :D

PS. Without the "old boys" new guys like me wouldnt know what to do! Everything is built on something that was aready made. :cool: :D

Dimitri

BIGJACK
January 27, 2006, 08:47 PM
Yall interested in a new thread on re-inventing the wheel, for a cannon of course (firearms related).:D

You can do it deimitris, get-r-done!!!

DimitriS
January 27, 2006, 10:11 PM
Thanks BigJack I think so too :)

Need money and time now. College sucks :o

Soon as I can I'm gonna go for this though. :D

Dimitri

BIGJACK
January 29, 2006, 11:41 AM
Dimitirus, if you are in college put this stuff on the back burner and your head in the books. You will nerver regret it. GET-R-DONE and then you can do this stuff, right.

owen
January 29, 2006, 12:39 PM
If you are button broaching, which is a form of swaging, I'm 99% sure the shape of the button controls the twist rate. The button is pulled through the gundrilled blank, and is allowed to spin on its arbor. A large hydraulic cylinder is used to pull the button through the barrel. The hard part is getting the right shape for the button.

For the gundrilling, get the highest pressure oil pump you can afford. It makes all the diference in the world. Don't peck gundrills. It screws up the self-made bushing. 1000 psi - 100 gal/min would not be out of line. Make sure its easy to replace the drill bushing in the machine.

Cut broach rifling is probably not practical for a rifle barrel. The tool has to be as long as the barrel, and will probably cost in excess of $30K. You do have to control the twist rate externally.

Electrochemical machining is pretty slick, and would let you continue to play with your servos, in addition to letting you play with funky power supplies.

owen
January 29, 2006, 12:44 PM
I'd like to add that it is usually easier to spin the part than it is to spin the tool. Especially when you are gun drilling, that high pressure oil can be hard to seal up.

Why are you using square bar?

I think you would be better off trying to rebuild an old engine lathe to do this.

DimitriS
January 29, 2006, 05:31 PM
BIGJACK,

I'm not gonna start this project till after college. Need to learn all I can in college to understand how to do this well :D College and learning what I need to right now is going great I understand it all 100% I bet I could take my exams and pass at this point thanks to reading everything in advance :cool:

owen,

Thanks for all the tips :D And as for using bar stock is just to have a little more metal on the stock when I'm drilling and rifling so I dont bend the barrel or something while drilling, I figured the more metal the better. :) Plus its not like I couldnt simply just cut it to the proper contour on a lathe afterwards :D

Dimitri