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Sine Bar Rifling Machine

johnoder

Diamond
Joined
Jul 16, 2004
Location
Houston, TX USA
I built one of these about 25 years ago (for a customer) from drawings I made but no longer have. If enough people are interested in building one for themselves I can give a pretty good verbal description of what I did. It was for slow twist ML barrels.

John

Okay - here goes. I'll start this off and add to it as needed, either by editing this post, or replying as needed to following posts.

A sine bar rifling machine is not nearly as exotic as the name implies. Think of it as a rifling machine with a taper attachment akin to an engine lathe's. A way to rotate a rifling head without using traditional rifling guides, which at the very least are a PITA to make.

If you take a wide flange beam about 12 feet long that is a place to start. This should be about a W10X45, which is a nominal 10" deep and 8" wide beam with 5/8" thick flanges. You need to get the edges of those flanges machined on one side of the beam. I.E., two edges facing up, nice and flat their full length and both in the same plane(we have turned the beam on its side so these two edges can be the start of the "ways"). To those two edges, bolt on two 1" X 2" X 12 ft. lengths of 1018 cold drawn bar. This of course requires tapped holes in the edges of the beams, and drilled and counterbored holes (for socket head cap screws) in the 2" faces of the 1018 bars. Put 1/4-20 screws on 4" centers. When this is all lined up nice and parallel (you did clean off all burrs and chips and made sure screws were flush or below flush), with the screws tight, you have the beam with with the 1018 bars on, 2" faces facing up, centered on the flange thickness of the beam. Already it starts to look like a bed. Rig up some legs for this to get it up to your choice of working height. Your bed is is already a 700 lb plus assembly, so take care.

Here is a sketch of the beam with the machined edges highlighted, before drilling and tapping any holes for the 1" X 2" 1018 bars

beam.jpg


(more later)


[This message has been edited by johnoder (edited 08-17-2004).]
 
Maybe I should rethink my approach here. Before I go further in loading up this website with verbiage and "sketches" I will need to know interest level. Anyone out there really interested in investing probably around $2500 of their own money and a bunch of effort to build one of these?

John
 
One thing that never suprises me anymore is the knowledge and ability of the gentlemen that frequent this site. If you layout the plans, you can take it to the bank that someone will build it. I will also wager that someone will do it for way less than you ever thought possible.
 
i have built a sine bar rifler in 1973 using the principal of brockways in the ned roberts book.
was much easier using bill larges h&r grasshopper but for all you rifle nuts just be aware that building a machine to give you a rate of twist doesnt mean that you have won the war, you still need cutters a cutting head(adjustable)one for each caliber high pressure pump for sulphur based cutting oil(bestoil)and do you want to hand cut bbls or do you want a 6'hyd cyl and pump bill large said that his 66" hand rifler killed him. as you can see there is a lot more to cutting a bbl than jumping on to some h-beam but dont take this as discouragement always challenge yourself the bbl you rifle will always shoot better than a production bbl even if only in your mind...by the way is anyone intrested in rifled barrels any caliber any twist up to 72"
 
Thanks Jim:

This one used a Duff Norton "jacuator" with 1" lead ball screw, and includes a 6:1 gear reducer as part of the package. Drive this with a motor to suit cutting speed. This is a bit less than half the $2500 mentioned, but does a nice smooth job of traversing the carriage.

John
 
to answer your question about being willing to spend the time and money to build a sine bar rifling machine I for one will start as soon as the plans are ready.
thanks
Doug
 
Doug Mc:

If you will read first post you will see plans were not intended. Maybe, if more interest than a few, I will continue with verbal description, and perhaps a few more "sketches". Too much effort to expend if substantial interest does not materialize.


John
 
John thanks for the input. I think you will be very surprised how many of us have been gathering parts and info for several years. Please keep the discussion going. Anything you share will be greatly appreciated. Thanks alabamaed36046
 
By popular demand......

Let's say you have the bed as above ready to go.

Next you need a carriage. It has to do several things which will take some noodling.

It has to slide nicely up and down your bed ways. I used eccentric (adjustable) cam followers but today would recommend precision ground UHMW (ultra high molecular weight polyethylene) which is tough plastic that is very slippery. You can buy precision ground blanks for not much from McMaster-Carr and attach them with brass flat head screws. You need the carriage to have minimum play side to side and up and down, which means you will need "gib" or retainer plates to hold it down. (use 1" plate aluminum for main part of carriage).

The carriage does two other real important things. It mounts a pair of pillow blocks that hold the hollow spindle that rotates the rod that the cutter head is attached to, and it has a rear extension of the main carriage plate that extends to rear and forms "ways" for the slide that is moved by the sine bar sliding block. This rear slide has a rack gear bolted on the front of it. This rack gear extends under and engages a pinion gear on the aforementioned hollow spindle. Natuarally, the rack gear has to be at the right elevation to suit the pinion gear, and the hollow spindle has to be at the right elevation to suit the parts holding the barrel to be rifled (which we will get to later).

Another thing the carriage has to have is a mount underneath for the nut of the ball screw.

Now, the foregoing will no doubt generate some questions, which is okay - just rememeber there is only one of me.

In the meantime, get with your favorite Power Transmission vendor and get them to order you a Duff Norton KDM 28031-60. It will cost about $1100. It will have 60" of travel, which is all you need for a 48" barrel machine. If you are thinking longer barrels, well first make the bed longer and then change this number from a 60 to whatever you need. What you will get is a very neat little 6 to 1 worm gear box with a long 1" dia, 1" lead ball screw sticking out of it with a loose flanged ball nut. There is a pilot on the end of the ball screw that you can provide a bearing for later. You weren't actually done with the bed yet, and you will be adding to it as we go along. A plate will be needed on the carriage end of the bed for mounting your big investment.

More later....

John
 
John
I wasnt expecting you to produce "plans" however would be grateful for any information that you provide.
What is a "bill larges h&r grasshopper" as mentiond in one of the other posts?
Thanks
Doug
 
Hi, Doug Mc:

Stay tuned, maybe you'll see something you can use. Alaska! Brother Vic has been there coming up on thirty years, owns a shop in Anchorage.

Maybe toolmakerjim will enlighten us on your question.

John
 
a harrington & richards adjustable pitch rifling machine about 12' long weighs about 6000#.
very verstile could cut right or left hand twist, just be sure to have the correct cutter in the head otherwise the tool would drag if the clearence angle was wrong.
you had to understand the codes that he used to set the pitch (could cut straight to about 1 : 24" or anything in between).
i wish i could find one of these now for hawken or buffalo barrels.
 
Jim's post on M89 threads reminded me to suggest that a less costly substitute for the Duff Norton ball screw job would be a home brew reduction box and a multiple start screw. I see McMaster-Carr will sell you six feet of 1" dia, 1" lead TEN START acme screw for less than $300 - even in heat treated 4140. The idea for the 1" lead of course is to have a reasonable FPM cutting speed of the carriage without the screw zinging around at 1200 RPM or so. 300 RPM on a 1" lead will get you 25 FPM.

John
 
Is it necessary to use a screw type drive? Why not use a hydraulic cylinder or a chain drive. With a sine bar system imparting the rotation all that is necessary is to move the carriage back and forth smoothly and consistently.
Or am I missing something?
Doug
 
Hi Doug: This topic was started by me to relate what I did building one about 25 years ago. By all means, do what works for you if you build one.

John
 








 
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