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General discussion => Gun Building => Topic started by: correntinos on May 17, 2019, 02:18:54 AM

Title: help whith octogonal shaping
Post by: correntinos on May 17, 2019, 02:18:54 AM
good morning I m from Argentina ,which is the best way to filling an octogonal barrel for a flintlock pisto , I have lathe and file only not a milling machine , thanks again if someone can help to me

jose javier calatayud
Title: Re: help whith octogonal shaping
Post by: rich pierce on May 17, 2019, 02:53:11 AM
I did this on a pistol barrel but went from round to octagon the round. Only filed about 4” to octagonal.

I filed the top flat, then using a square to check everything,  filed the 2 side flats. Then the bottom flat. The squareness of the side flats to the top flat is most critical. After that I filed the 2 top angled flats. Got that looking good then roughed in the 2 angled flats on the bottom.

Use a new coarse file to rough it in.
Title: Re: help whith octogonal shaping
Post by: Daryl on May 17, 2019, 03:07:42 AM
I filed a rifle barrel, tapered octagonal to round - back in the last 70's- all I remember was lining up and drawing out the flats for the length of my wife's Seneca stock, then tapered round to the muzzle.  It was a lot of work- I remember laying out the centre lines of the flats, then fling - for days and days.  The barrel was a Bauska 15/16" round in .36cal.
I tapered it from 13/16" across the flats, to 7/8" at the wedding band and tapered round down to 1/2" at the muzzle.  I never used it, but should still have that around here, maybe. I left the bottom 3 flats rounded.  Looked kinda weird.  I figured it might warp as it heated up with firing, so never used it. I was tired of filing at that point. I put a 36" 13/16" .45 GM barrel on her rifle. Shots great. I have a 36" or 38" .40 for it, but might not put that on.
Title: Re: help whith octogonal shaping
Post by: Daryl on May 17, 2019, 03:09:00 AM
good morning I m from Argentina ,which is the best way to filling an octogonal barrel for a flintlock pisto , I have lathe and file only not a milling machine , thanks again if someone can help to me

jose javier calatayud

Draw-filing. Lay out your center lines and side of the flats and get at it.
best wishes Jose
Title: Re: help whith octogonal shaping
Post by: Rolf on May 17, 2019, 10:28:11 AM
good morning I m from Argentina ,which is the best way to filling an octogonal barrel for a flintlock pisto , I have lathe and file only not a milling machine , thanks again if someone can help to me

jose javier calatayud

You migth find some tips in this tutorial. http://americanlongrifles.org/forum/index.php?topic=26376.0

Best regards
Rolf
Title: Re: help whith octogonal shaping
Post by: Pukka Bundook on May 17, 2019, 04:29:53 PM
For putting flats on by hand, I found a "draw-knife" works.

the tool I made from a file. Please see photos. It works much faster than a normal file.
It cuts best if held on an angle to the direction of cut.

All the best,
Richard.
(https://i.ibb.co/bvGrS69/DSCN2858.jpg) (https://ibb.co/WzRcbHJ)

(https://i.ibb.co/brL9pLg/DSCN2861.jpg) (https://ibb.co/qR9Qb9M)


(https://i.ibb.co/pzFnNrn/DSCN2860.jpg) (https://ibb.co/Hz8XRpX)

I sort of "invented" the draw-knife, when I had flats to put on a 43" Longrifle barrel.  (swamped) but this was before digital cameras.


(https://i.ibb.co/qRxHQQ3/DSCN2410.jpg) (https://ibb.co/RC7Xwwk)
Title: Re: help whith octogonal shaping
Post by: JBJ on May 17, 2019, 06:11:51 PM
Richard,
Would appreciate more pics of the "draw knife" file. I'll bet I am not alone in this request! Thanks a bunch.
J.B.
Title: Re: help whith octogonal shaping
Post by: Daryl on May 17, 2019, 07:45:01 PM
A file that works 10 times faster than a normal lathe file, is a body mechanic's file, with the 1/2 moon rounded side to side teeth. It actually cuts curls of steel like lathe turnings, each push or pull, used on an angle like in Richard's picture. Incredibly fast, but takes a bit of muscle to control.

looks like this, but is flat, not rounded: suggestion, wrap each end in duct-tape for hand protection.

(https://ae01.alicdn.com/kf/HTB1L6yczf5TBuNjSspmq6yDRVXa7/14-350mm-Curved-Teeth-Double-Hole-Aluminum-Sheet-Car-Body-File-Car-Panel-Polishing-File-accessory.jpg)
Title: Re: help whith octogonal shaping
Post by: Metalshaper on May 18, 2019, 01:45:38 AM
That style of file  is known by the name Vixen ..
Aircraft industry  uses them and they work really well !

Respect  Always 
Metalshaper  /  Jonathan 
Title: Re: help whith octogonal shaping
Post by: Goo on May 18, 2019, 02:28:44 AM
You only need to file the top 5 flats you can leave the bottom of the barrel round.
Title: Re: help whith octogonal shaping
Post by: Scota4570 on May 18, 2019, 03:35:11 AM
Anyone ever try using the lathe as a shaper?  One could offset the tailstock , leave it in back gear and turned off.  Move the tool with the hand wheel.   
Title: Re: help whith octogonal shaping
Post by: TommyG on May 18, 2019, 03:48:40 AM
One could also make a table set up on the cross slide of the carriage to hold the barrel and chuck up an end mill.  Might work for a pistol barrel with limited travel of the cross slide.
Title: Re: help whith octogonal shaping
Post by: correntinos on May 18, 2019, 04:34:14 AM
thanks a lot dear friends for your helps in this topic , other question someone has a mill atachement for the lathe , for mill the octogonal barrel on lathe ????
Title: Re: help whith octogonal shaping
Post by: Daryl on May 18, 2019, 06:28:47 AM
Taylor called  his body file, "JAWS".
Title: Re: help whith octogonal shaping
Post by: Pukka Bundook on May 18, 2019, 08:07:57 AM
JB,

I will take some more photos of the 'draw Knife'  and Pm them to you .
In middle of field work so won't be Very soon.  been 6 AM  -10 PM days at least just lately. 

Daryl,

That file you show,  I have one as well, come to think of it, but found it about as much work as a fresh broke mule, to keep it going straight! LOL.
Really cuts, and wouldn't want to run over my knuckles with it!

Goo,
Though only 5 flats show, I couldn't bring muyelf to leave a barrel rounded on the under-side!  Make a fiercely heavy barrel as well.
I settled for leaving the long barrel rough on the underside, showing the 'draw-knife' chatter marks.
Title: Re: help whith octogonal shaping
Post by: Buffaload on May 18, 2019, 05:37:36 PM
Scota
I have seen this done to taper a 74 Sharps barrel.
I can’t tell you how uniform the taper was but it was accomplished.
Short barrels would be easier like pistol barrels. You would have less deflection to worry about.
Ed
Title: Re: help whith octogonal shaping
Post by: Daryl on May 18, 2019, 06:43:11 PM
You are right, Richard - it does take SOME "work" and arm/shoulder and back muscles to make it do the job.
Title: Re: help whith octogonal shaping
Post by: Hudnut on May 18, 2019, 10:11:16 PM
One could also make a table set up on the cross slide of the carriage to hold the barrel and chuck up an end mill.  Might work for a pistol barrel with limited travel of the cross slide.

I have done quite a number of barrels this way.
Used a piece of steel channel for the table.  V-blocks to take the barrel.  Took a piece of octagon barrel, turned down a portion to fit in the barrel.  Slit this part, and used a screw with a tapered end to expand it to lock it to the bore of the barrel.  Clamp the barrel with octagon jig to the V blocks.  This indexed the barrel for the 8 cuts.  Use a dial indicator to set the table up so that the octagon will be parallel sided or tapered, as desired.
Title: Re: help whith octogonal shaping
Post by: T*O*F on May 18, 2019, 11:02:01 PM
Quote
Though only 5 flats show, I couldn't bring muyelf to leave a barrel rounded on the under-side!
Some of the UK's finest gunmakers did this on their rifles, including Rigby, Alex Henry, and many others.  Rigby flats are actually cut into the barrel with chisels and files.  The side flats blend in to the round underside.  It was common practice during the percussion era.
Title: Re: help whith octogonal shaping
Post by: bob in the woods on May 19, 2019, 12:25:10 AM
What material are you using for the barrel ?   I've often used a heavy scraper on Colerain, and Getz barrels and you can clean up a barrel pretty fast ....it really speeds up the process rather than just draw filing.
Title: Re: help whith octogonal shaping
Post by: correntinos on May 19, 2019, 05:16:19 PM
thanks again to all new gunsmithing friend for share knolegemments
Title: Re: help whith octogonal shaping
Post by: Pukka Bundook on May 19, 2019, 06:17:05 PM
T.O.F.

Thanks you for that, I have had very few highest end rifles through my hands, and have not seen this, where the underside is left round.
The only Alex Henry I ever owned was a double (.450 /.400 /3 1/4"   ) and the barrels were round of course.
Thanks for the education.
On lesser rifles, the only English ones I have seen were all octagonal.  (all sides that is!)  or round.

Best,
Richard.
Title: Re: help whith octogonal shaping
Post by: Daryl on May 21, 2019, 03:49:54 AM

(https://i.ibb.co/VNc0dGv/Jaws-at-work-by-Runar.jpg) (https://ibb.co/X4rf9Pz)

(https://i.ibb.co/QnH3TJH/Jaws-at-work-by-Runar3.jpg) (https://ibb.co/gwWLfrW)

(https://i.ibb.co/51fJkMv/Jaws-at-work-by-Runar2.jpg) (https://ibb.co/b68GFWL)
Title: Re: help whith octogonal shaping
Post by: correntinos on May 21, 2019, 04:32:16 AM
thanks Daryl great photos
Title: Re: help whith octogonal shaping
Post by: Daryl on May 21, 2019, 06:01:05 AM
These are Runar's photos, from this thread.

http://americanlongrifles.org/forum/index.php?topic=41795.0
Title: Re: help whith octogonal shaping
Post by: correntinos on May 21, 2019, 04:56:19 PM
Thanks Daryl
Title: Re: help whith octogonal shaping
Post by: dogcatcher on May 25, 2019, 11:19:17 PM
Go to this link http://americanlongrifles.org/forum/index.php?topic=26376.0

It provides a detailed method of getting it done.