Building the Stevens Favorite

[Tom Griffin]

Tonight was breech block night. I sawed out a piece of the O1, squared it up and located the three cross holes. Two of the holes were temporarily threaded to screw the block to a sub-plate for the rotary table work. It was then set on a sine bar at 12º, the slot milled and the firing pin hole added. Next it will be mounted to an aluminum sub-plate containing locating holes for the centers of all the arcs. As with the receiver, that will make the rotary table work a lot easier and faster.



More long slender end mills. This one is 3/16" diameter by 1 1/2" long. The secret to making them long lived is to plunge cut first and side mill to finish. The slot was cut as deep as possible with a standard length end mill before resorting to the long one. This cut was over an inch deep and made in one pass using .02" steps. The same technique applies when milling tool steel like this or when milling aluminum. A lube such as WD-40 is necessary for deep slots in aluminum to keep the cutter from loading up.



Gauge pins are handy for locating features from cross drilled holes. Just place a pin in the hole and touch it off with the end mill or drill using a piece of paper between them. Here, the block is set up to drill the hole for the firing pin. To set the 12º angle, I just put a pin in the chuck and held the bottom of the slot against the side of it as the vise was tightened.

 

[Tony Wells]

Excellent work, Tom. Good documentation as well.

 

[ScrapMetal]

You lost me right here...

Probably more my ignorance rather than your explanation but I'd really appreciate it if you could put this one in "idiot speak" for me.

I want to let you know that you're killing me with this project. Beautiful work AND I'm getting the hankering for a Steven's myself. Almost picked one up at the last gun show due to you, most likely will at the next one (at least you'll get the blame when I explain it to my wife :biggrin won't be nearly as nice though.

-Ron

 

[Tom Griffin]

You lost me right here...



Probably more my ignorance rather than your explanation but I'd really appreciate it if you could put this one in "idiot speak" for me.

I want to let you know that you're killing me with this project. Beautiful work AND I'm getting the hankering for a Steven's myself. Almost picked one up at the last gun show due to you, most likely will at the next one (at least you'll get the blame when I explain it to my wife :biggrin won't be nearly as nice though.

-Ron

Thanks Ron.

I'll take the blame if it will get you a new rifle. Remember though; it is a boys rifle so it's rather short and small, but still a heck of a lot of fun to shoot.

Plunge milling is when you use the end of the mill to do the cutting instead of the side. If you tried to side mill a 1" deep slot in tool steel with a 3/16" end mill it would just bend and break because you wouldn't be able to generate enough force to make it cut. By plunging it to full depth and moving over a few thousandths at a time you can get the job done and with the end mill in one piece (hopefully). Once the slot is roughed to depth, then you can side mill with very light cuts to get it to the proper width with many climb and conventional passes and free passes to get slot to size at the very bottom. An end mill like this is very flexible and moves around an alarming amount. :bitingnails:

Tom

 

[David]

Very nice work Tom!!!! Thank you for sharing with us. I can't wait to see finished classic!

David

 

[bvd1940]

I am still watching and am duly impressed, real nice work and documentation

 

[ScrapMetal]

Thanks Ron.

I'll take the blame if it will get you a new rifle. Remember though; it is a boys rifle so it's rather short and small, but still a heck of a lot of fun to shoot.

Plunge milling is when you use the end of the mill to do the cutting instead of the side. If you tried to side mill a 1" deep slot in tool steel with a 3/16" end mill it would just bend and break because you wouldn't be able to generate enough force to make it cut. By plunging it to full depth and moving over a few thousandths at a time you can get the job done and with the end mill in one piece (hopefully). Once the slot is roughed to depth, then you can side mill with very light cuts to get it to the proper width with many climb and conventional passes and free passes to get slot to size at the very bottom. An end mill like this is very flexible and moves around an alarming amount. :bitingnails:

Tom

Got it. Kind of what I thought but I wanted to make sure. I'm aware of the size of the Steven's, it'll actually be "for my son". :biggrin: It would make a great companion to the Ruger Bearcat.

Thanks much,

-Ron

 

[Tom Griffin]

Thanks David and Bill.

I'm takin' the night off so the shop is dark, but should be able to finish off the breech block tomorrow after work.

Tom

 

[Tom Griffin]

All of these basketball games are getting in the way of progress, but I still managed to finish up the breech block and get it fitted to the receiver. I took a few extras pics to show the method I use to locate a part on the rotary table and generate radii, the same technique used on the receiver. The few extra minutes spent making the subplate can save hours of setup on a part with many radii.

Next in line is the firing pin, then the cocking lever and the link to attach it to the breech block.



First, the table is centered on the spindle with an indicator and the dials or readout set to zero. Then the part is centered on whichever radius needs to cut using s pin in the spindle, and clamped to the table. If the radius being cut ended on the part then the part would also need to be indicated parallel to the table and the dials on the rotary table dilal zeroed as well so the angle could be read.



The table is then offset by the desired radius plus half the diameter of the cutter (tool offset) and the radius machined.





Large radii like this are easy to blend by eye. On smaller radii, it works better to calculate the tangent angle.

 

[knifer-one]

I have been following this build from the start. True craftmanship! One question about centering the workpiece. The s pin you mentioned,is this chucked and then put into the hole? How did you mount the piece to the subplate? (sorry,2 questions).
keep posting. We hope to see a video of the finished product in action.