Building The Steven's Favorite

[TomG]

Today was hammer time. In between spring cleanup, I managed to get most of it completed. I chose to mount it on a sub plate as with the breech block and the receiver only the hammer only had one hole in it so I had to add another in an area that would be cut out. I also decided to forego the screws and just use pins, relying on the clamps to hold everything down. I made a design change on the fly and added some extra material on the top for some cocking serrations and also some additional material on the half cock notch to make it more "safe" since the half cock position is the actual safety.



Here, the blank is mounted to the sub-plate that has all the center holes located just as with the receiver. Since there are a few radii that end on this part, I had to indicate the edge of the sub-plate and zero the degree scale as well as center it on the rotary table.



Since there was only one hole in the hammer, I had to be sure to clamp on the hammer while machining to keep it from moving.



The rough shape is finished. The half cock and full cock notches still need to be cut and the top of the hammer serrated.

Cutting the notches in the hammer turned out to be a royal pain. Not because it was difficult work, but because I neglected to get the machining order straight before starting the part. With all of the different angles, it would have been much easier to machine the notches before milling the outline of the hammer. Then there would have been lots of straight and right angle surfaces to work off. The two angles of the full cock notch were cut and the half cock notch roughed out with and end mill, then the half cock notch was finished with a form ground fly cutter.



This was the setup used to cut all of the angles on the notches. Some of them were set with a sine bar and some with a protractor. This pic shows the form cutter ground to cut the deep half cock notch. The bluing (Magic Marker) serves as a witness to show when the cutter touches.



The finished hammer. Each of the eight different angles around the notches was a separate setup.



This shows how the breech block, lever, connecting link and hammer all interact. In this pic, the lever is being cocked and the link is pushing the hammer to half cock. Once there, the link will pass the hammer allowing the lever to actuate the extractor, which is farther down on the task list. I think it only makes sense to make the trigger next.
I had to use the shop for actual work today and between that and the Wings game, not much got done on the Steven's. I did manage to make the sub-plate for the trigger and get a piece of O1 mounted on it, but nothing photo worthy. As soon as I get the use of the mill back I'll get the rotary table back on and start cutting the trigger, probably tomorrow night. My significant other is up north through next week so I'll have a lot of Steven's time when I'm not holding down the fort.

[TomG]

I got most of the trigger finished tonight. It took longer than expected because I decided to make some changes on the model to make it easier to machine. The sear was the hardest part just because it was so darn small and hard to see. This part was a good application for carbide tooling just because the end mills required were so small and long and the material was tool steel. I don't use carbide much, but it was handy for this application. Next is the backside of the trigger and possibly rounding off the front so it feels better on the finger (another thing I changed on the model).



After mounting the trigger to the sub-plate, the first two cuts were made on the front of the trigger.



Next came the back side of the sear (on the right) and the flat that the trigger return spring pushes on.



The sear tapers 10º to .030" which matches the half cock notch in the hammer.



The newly added curve on the front of the trigger was milled to a 3/8" radius with a form tool mounted in a fly cutter. It was ground on a 5/16" tool bit and mounted in a fly cutter, then the part was spun on the rotary table against the spinning form tool to generate the curve.



The radius on the back side was milled to size with a 3/32" carbide end mill.

The machining is complete and it's ready for hand finishing.

[EdK]

Tom,

As I've said before, I'm not into guns but it is just fascinating following the machining aspects of your gun build.

Ed

[TomG]

(06-26-2012, 05:24 PM)EdAK Wrote: Tom,

As I've said before, I'm not into guns but it is just fascinating following the machining aspects of your gun build.

Ed

Thanks Ed, I'm glad you are enjoying the build.

There aren't many installments left so I'll need to get back to actually making chips instead of just writing about it.

Tom

[DaveH]

Tom,

I am also enjoying it very much

I even know what the sear is now (I googled it )

DaveH

[TomG]

(06-26-2012, 06:01 PM)DaveH Wrote: Tom,

I am also enjoying it very much

I even know what the sear is now (I googled it )

DaveH

Excellent Dave! Before this post, a sear was primarily something done to a steak on the barby.

Tom

[doubleboost]

Great thread Tom
Keep it coming
John

[ETC57]

(06-27-2012, 04:14 PM)doubleboost Wrote: Great thread Tom
Keep it coming
John

Here, Here,

Jerry.

[TomG]

Thanks guys but it's going to have to wait a bit. I'm going on vacation next week where there's no high speed internet.

Tom

[TOM REED]

I have enjoyed your build immensly and really hope you make your plans available as I for one would like to try this build, it would make a nice piece and conversation piece alongside my other firearms especially built from scratch. You have done an excellent job. tom