riffler files for chambering cams?

taiwanluthiers · Feb 3, 2017

One thing I hate about chambering cams is that they are really hard to reach, no normal files will reach it.

I cut mine with a dremel tool and a very long carbide end mill, in a more or less free hand fashion. The ramp is very rough and as a result it can be really hard to chamber a round at times...

I found out there are riffler files, something like this:

Smooth Cut Riffler File Set - File Handles - Amazon.com

They seem like they can reach those places easily. I know some of you make this contraption with a piece of a file at an angle mounted to a mandrel, but I don't have a lathe to produce something like that... but I just need to smooth out some tool marks so I can chamber smoothly instead having to really hammer on the bolt handle to chamber a round.

RWO · Feb 3, 2017

Some things just cannot be done by hand. Yes, those files could allow you to smooth the cam surfaces. But, how do you ensure that they have the same angle, height and surface finish? If you are an absolute file wizard with infinite patience you might be able to get close. If not, one cam is probably going to do all the work. I suggest you save your money for a lathe if action building is to be an ongoing hobby.

RWO

taiwanluthiers · Feb 3, 2017

It's a lot less to do with money, than it is weight. I can't have anything heavy in my room, and since the floor in my room is very bouncy I am afraid if I add a lathe, even a light weight one, it's going to cause a collapse.

What's so bad about one cam doing all the work?

apoc_101 · Feb 3, 2017

taiwanluthiers said:
It's a lot less to do with money, than it is weight. I can't have anything heavy in my room, and since the floor in my room is very bouncy I am afraid if I add a lathe, even a light weight one, it's going to cause a collapse.

What's so bad about one cam doing all the work?

get a garage? and learn some basic mechanical physics before building rifle actions...

taiwanluthiers · Feb 3, 2017

No I don't have a garage at all. I live in an apartment on the 3rd floor.

wesg · Feb 3, 2017

taiwanluthiers said:
What's so bad about one cam doing all the work?

Nothing, really. Plenty of rifles out there with only one bolt lug, or even just the bolt handle being used as one.

paramedico987 · Feb 8, 2017

I made a file just for that job.
It's just a rod turned to the same diameter as the bolt, then I cut a slot on the angle I wanted [helical sort of] in the rod and put a piece of a file into the slot with a long screw.
You can link to my build http://www.homegunsmith.com/cgi-bin/ib3/ikonboard.cgi?;act=ST;f=3;t=26790;st=30
Wasn't my idea, but it worked like a charm!

Incidentally I spoke to a machinist at Kimber Arms about it and he said that even in the industry it's a conundrum. Ram EDM would be the ideal way, but when you say those three letters around the bean counters it doesn't go over well.

taiwanluthiers · Feb 8, 2017

I know about that one. I don't have a lathe so I can't produce something like it. I was hoping for something off the shelf.

taiwanluthiers · Feb 8, 2017

So I ordered some Riffler's file from China but I do not know when they will arrive.

In the meantime I took a standard file, and heated it until red and bent it into the right shape. The steel probably softened a bit but I was able to use this to smooth out the cam surfaces (in conjunction with some sandpaper) enough that the action is much smoother...

Since I don't know anything about recutting a file or anything I think I can use this tool in conjunction with abrasive paste to smooth out hard to reach spots.

gorrilla · Feb 9, 2017

taiwanluthiers said:
I know about that one. I don't have a lathe so I can't produce something like it. I was hoping for something off the shelf.

I used to build molds. So I still have a lot of the tools from a mold making standpoint. In among all that is a set of diamond riflers. These might work better for what you are trying to do. Look for them in any decent machine tool supply catalog. They're not even expensive.
The advantage of having all the cams engaging equally is that the load being spread out evenly. Theoretically, it could be accomplished with a file. But it would be a very painstaking, laborious effort. Depending on the quality of fit and finish you want. Years ago, the apprenticeship programs would give a student a steel block, which had to be filed to size,square, parrallel, and symetrical, all to a specified tolerance. Easily detected with a micrometer and a surface plate. So it CAN be done, and has been done. But don't expect to just jump in there and do the first one. Plus those cams fit a very specific profile, all worked out in the geometry to be the right strength and ease of operation. Again, not impossible, but it will take a VERY educated, patient application of considerabl eye/hand coordination, deft touch, and persistence to produce a good fit.
Your "taiwanluthier" handle intrigues me. Luthier being one that works on or makes stringed musical instruments. Taiwan is of course the island off the coast of China. Those two mixed into a gunsmithing forum is interesting.

taiwanluthiers · Feb 9, 2017

I used to build guitars in Taiwan.

Ideally I would like to make something that looks like a bolt, out of a soft metal such as aluminum or mild steel. Instead of a bolt lug the lug would be cut at an angle that matches the inside angle of the cocking cam. So I could use a riffler to smooth out the jagged edges from using a dremel and end mill to make the cam, then use this tool in conjunction with lapping paste to lap the cam to a smooth ramp. Problem is I don't have a lathe right now so I can't really make it, although I could chuck a 1" bar stock onto my mill and turn it that way.

apoc_101 · Feb 9, 2017

using a mill as a lathe? not the craziest idea at all.

... the craziest idea is turning a power drill bolted to a bench vise into a lathe... my first technique as a young teenager

(nowadays I use my personal lathe as a mill often enough when the others are full up... I call it "the finest horizontal mill in the entire facility".. cuts much nicer than aggregate CNC heads!)

rbrandes · Mar 8, 2017

taiwanluthiers said:
No I don't have a garage at all. I live in an apartment on the 3rd floor.

See if you have a technical school with night classes you can get to. I have found when taking night classes the instructors will let you use the machines to do mostly whatever you want.
Regards, Ray

glbreil · Mar 8, 2017

You can always put the cams on the bolt instead of in the action.

It has been done that way even on some commercially available actions.

Gary

taiwanluthiers · Mar 8, 2017

Wouldn't that reduce the contact area? I don't want to blow the thing up...

glbreil · Mar 8, 2017

Pick up a copy of Stuart Ottsen's Benchrest actions and triggers. Several of the early custom actions had the cams on the bolt. The original Stolle Panda's, Wichita, etc.

It is less surface but not unsafe.

Gary

taiwanluthiers · Mar 8, 2017

glbreil said:
Pick up a copy of Stuart Ottsen's Benchrest actions and triggers. Several of the early custom actions had the cams on the bolt. The original Stolle Panda's, Wichita, etc.

It is less surface but not unsafe.

Gary

Thanks, that's good to know... it's 1000 times easier to cam the bolt than it is to cam the inside surface. Perhaps I can do both... Cam the inside abutments a little bit, then cam the bolt lugs a little bit. I just cammed the abutments with a Dremel tool. It's a mess but I think I got the job done...

climb-101 · Mar 8, 2017

what size of gun are you trying to make? .22 or more like a .338LM

taiwanluthiers · Mar 8, 2017

300 win mag

climb-101 · Mar 9, 2017

got any pics of what your building

riffler files for chambering cams?

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