Making a Full Profile Compensator with an Integral Cone. For a 1911.

[wrmiller]

I could use some suggestions folks, thanks.

I've made a few full profile compensators in the past, but have always put them on a bull barrel. However this time I have a standard diameter barrel and would like to cut a integral cone into the back of the comp.

In my limited/hobby type thinking, I have two ways to approach this: One would be to chuck it up in a four-jaw chuck and very slowly take interrupted cuts out of the piece of 4140. It's 1"x1.5"x3", and the .406" bore is offset towards one end. So I'm going to be whittling off a fair amount of steel using a interrupted cut. FYI I have some HSS bits coming so as not to destroy my carbide inserts.

The other way would be to stand the rectangular piece on end on my little 6" rotary table. The problem with this is that I'm unsure as to how I'm going to secure the piece to the RT. I don't have a small front-mount 4-jaw to put on the RT, and can't afford to buy one right now. And I don't have a little machinist's vise to clamp to the RT. All I have on-hand right now is a hold-down kit. I have already made a mental note to myself to find a front-mount four-jaw chuck when I can afford it.

Any suggestions how I might accomplish this using the RT? Or should I just wait for my HSS bits and have a large mug of coffee for when I have to cut the cone on the lathe?

 

[Silverbullet]

Would a taper reamer do it or chamber reamer . Then it would be just hand work slow n steady. Rent a reamer is an option.

 

[wrmiller]

Would a taper reamer do it or chamber reamer . Then it would be just hand work slow n steady. Rent a reamer is an option.

It's an outside diameter cut, not a inside one.

Kinda looks like this.


I'm trying to set up for the 'cone' at the back.

 

[francist]

If I were doing it (which I’m glad I’m not!) I don’t think I would trust the rotary table setup. I’d go the lathe route but waste away what I could with a saw to get close to the offset required. There would still be interrupted cuts, but not as many.

Looking forward to seeing what you come up with, you always do impressive work.

-frank

 

[wrmiller]

If I were doing it (which I’m glad I’m not!) I don’t think I would trust the rotary table setup. I’d go the lathe route but waste away what I could with a saw to get close to the offset required. There would still be interrupted cuts, but not as many.

Looking forward to seeing what you come up with, you always do impressive work.

-frank

Yea, I was kinda thinking the same thing, but using the mill to cut away some of the excess material. I was hoping someone might come up with something I hadn't thought of, but there may not be a better way.

I'll see what I can do.

 

[MontanaLon]

I'd do it on the lathe after hogging off much of the material on the mill or otherwise. You could remove most of the chips and give yourself an octagon with 1 move of the vise on the mill. Or if you want to get it closer to round do a bolt circle with the DRO with enough holes to really get it close to round before you set it up in the lathe.

 

[38super]

1 1/2 round stock, offset 7/16 in a 4 jaw. Or make an offset jig, slab the round stock. Kinda rough cutting til you get to a full cut.

 

[Tozguy]

Or should I just wait for my HSS bits and have a large mug of coffee for when I have to cut the cone on the lathe?

Good plan, HSS is much better than carbide for interrupted cuts.

 

[wrmiller]

Good plan, HSS is much better than carbide for interrupted cuts.

I'm currently waiting for some cooler weather.

I'll be using the 1.5"x1" rectangular 4140 stock that I normally use for full-profile comps. Once I've milled the comp's chambers, I'll drill/bore/ream the small bore (in this case, .406" for 10mm) in the mill, and while it's there I'll remove as much of the excess stock as I can, then move it to the lathe to do the larger boring, threading, and OD profiling of the cone. It's a lot of work, but it is what it is if I want a custom one-piece cone comp. Besides, it gives me something to do.

 

[38super]

Sure helps to hog off excess material. I tend to avoid spendy alloys, comp baffles burn out soon enough. Besides, I get bored with a design and build another.