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  • Spring meet up in Ontario, April 6/2024. NEW LOCATION See Post #31 Discussion NEW LOCATION

Ontario Meet and Greet May 28th at BrentH's place

thestelster

Ultra Member
Premium Member
Each row of teeth will be offset from the previous row by the thread pitch divided by the number of flutes.

What I want to know is how he stops it from vibrating like crazy as each flute tries to climb its own cut!
No vibration. We have the gullets in the tap that separate the teeth. The length of the teeth is fairly short, so yes there is a small helix angle and there probably is a little binding during the cut, but I didn't have any issues. Look at a thread milling cutter, its like I have 6 of them cutting at the same time.
 

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thestelster

Ultra Member
Premium Member
Tell me more about this Barrel, it appears to have a set of "express" sights incorporated into its design.
The barrel started out as a 2" chrome-moly round blank from Krieger Barrels. .458 caliber. Full octagon, with integral full length sculpted rib, integral recoil shoulder, integral sling swivel projection, integral front sight ramp which accommodates a flip up express night sight. The only parts that are removeable are the rear express sight and front sight.
 

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Susquatch

Ultra Member
Administrator
Moderator
Premium Member
No vibration. We have the gullets in the tap that separate the teeth. The length of the teeth is fairly short, so yes there is a small helix angle and there probably is a little binding during the cut, but I didn't have any issues. Look at a thread milling cutter, its like I have 6 of them cutting at the same time.

I see.

I missed two factors in my assessment.

There are 6 flute, not four. And it's a 1" Tap not a small 3/8 or 1/4.

Because of these two factors, there is very little actual advance along the thread per tooth. So not much to worry about in terms of pulling the tap along the thread Helix. I think a smaller tap would not be as forgiving.

Cool idea!
 

whydontu

I Tried, It Broke
Premium Member
Hi Peter, the tap has not been modified. Its a little difficult for me to explain properly, but here goes. Think of making a thread on the lathe of 16tpi. So in one inch we've cut 16 threads. Now if we attach another tool post directly behind with another threading tool, and advance them at the same time, we're cutting another groove 180° to the first thread. So now in one inch we have 2x16 threads=32 threads, if you had 6 cutters starting to cut a shaft all equally placed around, then you have 6 x 16 threads=96 threads in one inch. Its the same idea as multi start threads. Did I make that more confusing?
This forum is using up a lot of my spare time. I keep running across interesting ideas.

So.

A chunk of 1/2" aluminum plate from my scrap bin, and a truly horrible and dull 4-flute 3/8'-24 UNF tap from a $12 Canadian Tire tap and die set. No coolant. No measuring and the plate isn't set true to the quill. No effort spent in trying to make it pretty, just chucked the tap into my mill (using a drill chuck), and scrubbed it across the plate a couple of times at 500 rpm, 0.010" depth of cut per pass. Lots of tearout, the tap wouldn't cut butter.

My ancient eyeballs and a 32 TPI thread gauge says 96 LPI is about right.

This could be an interesting surface finishing method.

IMG_2226.jpg

IMG_2219.jpg
 

thestelster

Ultra Member
Premium Member
This forum is using up a lot of my spare time. I keep running across interesting ideas.

So.

A chunk of 1/2" aluminum plate from my scrap bin, and a truly horrible and dull 4-flute 3/8'-24 UNF tap from a $12 Canadian Tire tap and die set. No coolant. No measuring and the plate isn't set true to the quill. No effort spent in trying to make it pretty, just chucked the tap into my mill (using a drill chuck), and scrubbed it across the plate a couple of times at 500 rpm, 0.010" depth of cut per pass. Lots of tearout, the tap wouldn't cut butter.

My ancient eyeballs and a 32 TPI thread gauge says 96 LPI is about right.

This could be an interesting surface finishing method.

View attachment 24260

View attachment 24259
Well done. You'll get a better effect in steel or high strength aluminum like 7075. Aluminium is generally gummy and won't work as nice.
 

historicalarms

Ultra Member
The barrel started out as a 2" chrome-moly round blank from Krieger Barrels. .458 caliber. Full octagon, with integral full length sculpted rib, integral recoil shoulder, integral sling swivel projection, integral front sight ramp which accommodates a flip up express night sight. The only parts that are removeable are the rear express sight and front sight.

Wow that is awesome work man. Stand and be acknowledged by a complete amateur that dabbles in the same pool...is that sling anchor inletted into the barrel or free cut in the blank?
Is that threaded for a Highwall or some Sharps action or one of the modern offerings of a single shot action??...Oh ya and Chambering??

Now the "practical" side of me comes out...how come for the huge sight elevation difference between the steel ball and the flip-up Ivory ball. That much difference could be made use of with a Vernier rear sight but with the express sights they will have at least a foot POI change at even a close 100 yrds.
 

thestelster

Ultra Member
Premium Member
Wow that is awesome work man. Stand and be acknowledged by a complete amateur that dabbles in the same pool...is that sling anchor inletted into the barrel or free cut in the blank?
Is that threaded for a Highwall or some Sharps action or one of the modern offerings of a single shot action??...Oh ya and Chambering??

Now the "practical" side of me comes out...how come for the huge sight elevation difference between the steel ball and the flip-up Ivory ball. That much difference could be made use of with a Vernier rear sight but with the express sights they will have at least a foot POI change at even a close 100 yrds.
Thanks for the kind words @historicalarms
The sling swivel stud is integral with the barrel. The barrel is for a custom Magnum Mauser. Caliber is 450Rigby. The ivory flip up bead accurate to minute- of-elephant...if you know what I mean.
 

architect

Super User
Totally jealous I couldn't make it and had to be out of town! I'll just have to swing by Brent's on my own time or wait for the next party :D
 
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