A friend of mines girl friend is really into Science fiction / Fantasy, especially the Hellboy franchise.
She has a Samaritan replica revolver in caliber Break your wrist even if youre Arnold S.
http://www.mwctoys.com/REVIEW_111008a.htm
but the ammo is not very well made, in fact two of the plastic rounds had separated at the base.
So my friend asked me if I could remake a couple of them with real brass casings, thread the internal parts, etc.
The originals are plastic with a base insert. The base is a semi tight insert with a firing pin
that actuates a flashing LED. The bullet is clear plastic, probably an acrylic of some sort, that magnifies the flashing LED.
Anyway I wanted to thread the base to the casing with some fine threading. Ive had so-so results
with internal threading with my home made threading tools so I decided to try a commercial threading
insert tool and holder. Ive had good experiences with Shars both in terms of price and quality so after
some research I ordered the Internal Threading Toolholder 3/8" Shank for 1/4" Insert.
http://www.shars.com/products/view/7807/Internal_Threading_Toolholder_38quot_Shank_for_14quot_Insert
Im planning on doing the final rounds in brass and given the sizes (.600 internal and a bit over .8 O.D) I decided to try it first in some aluminum.
I drilled out then bored some ally to .600 +-.0002 and left the O.D. at 1 accept for a skim to make it concentric.
I then loaded up the tool and set my lathe for 32 T.P.I.
As can be seen from the catalog link http://www.shars.com/files/products/cata...page79.pdf
the toolholder holds the insert at a downward angle providing, if I have terminology correct, rake.
In other words the cutting point itself is somewhat pointing downward when mounted upright in a tool holder.
After confirming my T.P.I. I made the first cut pass at .010 with the provided PC TIN coated insert. The chip came off clean
and full length ( about 5/16 total length). A second spring cut pass produced a very small whisker of a cut. A third pass produced nothing.
I had very similar results with subsequent cuts all the way to .028 where I made 2 spring cuts just to make sure the threading was fully clear.
I was impressed with quality of the cut, even though this was just in aluminum.
After parting off the body of the casing I turned my attention to the base. Since the focus of this post is on the internal
threading tool Ill dispense with a description of setting up and executing the external threading. Suffice to say it went normally.
So how did the tool work? Really well I think. While examining the cut there was obviously less tear out then with my other internal threading tools.
Spring cuts produced less chip at least implying better initial cutting action. The fit of mating parts feels very smooth with very little to no slop.
I Like it and would recommend it. Especially if you work mostly in soft metals like ally or brass/bronze. I dont know how long the supplied insert
would last with softer metals but I wouldnt be surprised if its months or a lifetime depending on usage.
She has a Samaritan replica revolver in caliber Break your wrist even if youre Arnold S.
http://www.mwctoys.com/REVIEW_111008a.htm
but the ammo is not very well made, in fact two of the plastic rounds had separated at the base.
So my friend asked me if I could remake a couple of them with real brass casings, thread the internal parts, etc.
The originals are plastic with a base insert. The base is a semi tight insert with a firing pin
that actuates a flashing LED. The bullet is clear plastic, probably an acrylic of some sort, that magnifies the flashing LED.
Anyway I wanted to thread the base to the casing with some fine threading. Ive had so-so results
with internal threading with my home made threading tools so I decided to try a commercial threading
insert tool and holder. Ive had good experiences with Shars both in terms of price and quality so after
some research I ordered the Internal Threading Toolholder 3/8" Shank for 1/4" Insert.
http://www.shars.com/products/view/7807/Internal_Threading_Toolholder_38quot_Shank_for_14quot_Insert
Im planning on doing the final rounds in brass and given the sizes (.600 internal and a bit over .8 O.D) I decided to try it first in some aluminum.
I drilled out then bored some ally to .600 +-.0002 and left the O.D. at 1 accept for a skim to make it concentric.
I then loaded up the tool and set my lathe for 32 T.P.I.
As can be seen from the catalog link http://www.shars.com/files/products/cata...page79.pdf
the toolholder holds the insert at a downward angle providing, if I have terminology correct, rake.
In other words the cutting point itself is somewhat pointing downward when mounted upright in a tool holder.
After confirming my T.P.I. I made the first cut pass at .010 with the provided PC TIN coated insert. The chip came off clean
and full length ( about 5/16 total length). A second spring cut pass produced a very small whisker of a cut. A third pass produced nothing.
I had very similar results with subsequent cuts all the way to .028 where I made 2 spring cuts just to make sure the threading was fully clear.
I was impressed with quality of the cut, even though this was just in aluminum.
After parting off the body of the casing I turned my attention to the base. Since the focus of this post is on the internal
threading tool Ill dispense with a description of setting up and executing the external threading. Suffice to say it went normally.
So how did the tool work? Really well I think. While examining the cut there was obviously less tear out then with my other internal threading tools.
Spring cuts produced less chip at least implying better initial cutting action. The fit of mating parts feels very smooth with very little to no slop.
I Like it and would recommend it. Especially if you work mostly in soft metals like ally or brass/bronze. I dont know how long the supplied insert
would last with softer metals but I wouldnt be surprised if its months or a lifetime depending on usage.
If it's crazy but it works, it's not crazy.