What's new
What's new

Carbon fiber frame

Monday

Plastic
Joined
Oct 29, 2016
Can a revolver (.45 colt) frame be made out of carbon fiber instead of steel? If so, how thick does the carbon fiber need to be? Can the frame be cut out from ordinary carbon fiber plates?
 
Is this an academic question or do you intend to build one? Have you handled a bare Ruger single action frame? The frame on my Ruger seems pretty light, I think most of the weight is in the cylinder, barrel, and other hardware.
Since the Ruger frame can handle extra heavy loads you could probably grind off some excess metal and use only factory level loads and save a couple ounces.
 
OK, just guessing speculating here but why not. I believe the majority of a carbon fiber composite is related to the orientation of the fibers so figuring out which direction the stress is at any given pint on the frame would be critical so the the fibers could be arranged properly. So along the top of the frame the fibers would run predominantly parallel to the barrel. Seems good to me. Now what about where the barrel is threaded into the frame? Fibers are now ninety degrees to the direction of what I am guessing is the major stressor which would be the bullet entering the forcing cone. Also you have either threads in the carbon fiber which seems weak to me or a threaded insert which would need to be well embedded also not ideal. I reckon you would need some really good stress modelling to see if this would work. Then there is the issue of if you dropped the pistol and it struck a hard surface would the composite survive the shock? One point to not is that any failure of a fiber structureis likely to be catastrophic.

I am curious to see others thoughts on the matters.
 
Carbon fibers only have "strength" in tension. The resin matrix is the only thing providing strength in other directions.

Say you took a piece of rope and soaked it in glue. After it dried you could still pick up a pretty substantial weight with it.

If you stood that piece of rope up and placed a substantial weight on the end of it you would crush it when you overcame the compressive strength of the glue.

If you stuck the rope straight out and hung a substantial weight on the end it would snap when you overcame the bending strength of the glue.

If you put substantial torque on it with a wrench it would snap when you overcame the torsion strength of the glue.

You could overcome some of this varying thickness, resin matrix, oversize bushings but it wouldn't look much like a normal revolver.
 
Ruger does make some poly frame revolvers, same class as the j frame S&W
only a few oz lighter then Al frame models.

you wouldn't want a 45 colt to be very light felt recoil gets nasty
notice no one even bothers making 44mag or 45 colt in anything but steel
for a reason.
S&W had enough trouble with the frame not being stout enough on the early model 29s.
 
I thought .45 long colt was a good round for this project, since it’s a lowpressure round, very low pressure compared to for example .454 casull.

My idea wasn’t to make the carbon fiber myself, but buying plates of carbon fiber instead of steel and cut it out to a frame. It doesn’t seem to be that easy afterall, in any case my goal with this project is to keep the weight down, I want to make a really leightweight gun, either a revolver or a deringer, and carbon fiber is the most leight weight strong material that came to my mind..
 
I thought .45 long colt was a good round for this project, since it’s a lowpressure round, very low pressure compared to for example .454 casull.

My idea wasn’t to make the carbon fiber myself, but buying plates of carbon fiber instead of steel and cut it out to a frame. It doesn’t seem to be that easy afterall, in any case my goal with this project is to keep the weight down, I want to make a really leightweight gun, either a revolver or a deringer, and carbon fiber is the most leight weight strong material that came to my mind..


IMO, a person might be best off with a injection molded part with uni-directional carbon fiber and some kind of poly base. I was looking in to making AR lowers in that manner.

As far a the .45 ACP being a "low pressure" cartridge (at least compared to a .454 Casul) yes, but that is not where the issues really lie. The barrel, breach, bolt, etc. are the parts taking the punishment from the pressure. The frame is dealing with recoil, mechanical friction and possibly hot escaping gases and crud. If you are thinking of starting with a 1911 how do you secure the points on the cut out CF frame (should be steel) that track in the slide? Just glue them on? I've have more thoughts on the details but don't have the time to write about all that comes to mind at the moment.

If anything, try starting with a simple .22 LR type of pistol. with a simpler configuration than the 1911.

JMHO

-Ron
 
I wouldn’t try with plate.
My choice would be filament wound, fabric and scrim with prepreg and post cure.
It can be done but you have to model the stresses and meet them with fiber orientation in the layup.
Think of the frame as wanting to explode from being inflated from INSIDE the material.
The filament needs to contain that stress as well as meeting longitudinal, torsion and inside corner stresses.
Any case where you miss judge the stress vector will happily and quickly separate the laminate.

Get a striped frame in hand.
Draw all views out on a large piece of paper and start drawing in stress vectors.
Look for stress concentrations and determine if fiber orientation can be arranged to counter those forces.

Fiber reinforced plastic as in “glass filled nylon” and similar materials were conceived to meet some load cases by a homogenous cast product with short fiber in random orientation.
It MIGHT be possible to use one of these types to cast or machine from solid this project but one can easily exceed the strength of this type and shatter parts in service.
Steel frames routinely crack when overloaded.
Expect yours to crack as well if you are not specifically meeting loads with the material you use.
Remember- steel is good in compression, CF is not.

Look at it this way- the resin will have a strength of about 5000 psi.
That’s not enough to meet loads- all the resin does is maintain the fiber orientation so that those filaments carry that load.

Parts like this are made by placing filament fabric and scrim into molds which are compressed externally and or internally.
If you don’t feel like making molds I would forget about CF pistol frames.
 
OP is talking a revolver here, not a pistol or bolt action.

The cylinder is where the pressure is. As long as you have a steel cylinder and barrel, the main issue would be erosion of the topstrap, which could cause a failure of the frame.

.45LC is originally a black powder round, and generates nothing like what a .44 Mag does in terms of pressure- 14000 CUP vs. 36000. Modern .45LC ammo is restricted to these low pressures because the manufacturers expect this ammo to be used in old SAA colts.

The only issue with the N Frames in .45 LC was that the cylinder walls were pretty thin due to the case diameter- this is why Smith did not recommend +P loads for the M25. Even so, the revolver was plenty strong enough to handle them.
 
There is still a lot of pressure trying to push the barrel cylinder apart when fired. The cylinder also is rotating on a pin that is not in line with the recoil force. Those are just a few problems that I saw immediately.

I don't think milling a revolver frame out of carbon fiber panels instead of steel would be successful.
 
“ OP is talking a revolver here, not a pistol or bolt action. ”

He can try- worse that will happen is the part will break in use.

He should get his head around the material strength requirements and how he is going to meet them.
CF plate is a funny material.
Start by reading this:

Anisotropic vs. Isotropic: Why It Matters in Composites / Rock West Composites

Et al...

CF is a brittle material.
It will break if used incorrectly.
 
There is still a lot of pressure trying to push the barrel cylinder apart when fired. The cylinder also is rotating on a pin that is not in line with the recoil force. Those are just a few problems that I saw immediately.
All revolvers share those same issues.

Like I said, imo the key is the topstrap. If that's done right, the rest is pretty straightforward. Done wrong, it would be dangerous, since a failure of the topstrap would be pretty catastrophic.

The amazing thing to me about revolvers is that they are as accurate as they are- with all the moving parts, and the alignment and timing that has to be there for it all to work.
 
OK so lets play this game a bit longer. How about a design similar to the original colts where the cylinder pin took the stress and was embedded in a beefy matrix in the frame? Just freewheeling here. No top strap but also no swing-out cylinder for reloading.
 
OK so lets play this game a bit longer. How about a design similar to the original colts where the cylinder pin took the stress and was embedded in a beefy matrix in the frame? Just freewheeling here. No top strap but also no swing-out cylinder for reloading.


those start to stretch.
the Walker colt and the dragoon were both prone to blowing up due to
metal used, and probably a tiny bit of accidental over charging.

better yet look at the S&W Schofield and the colt SAA both the same bore
you couldn't use 45 colt in the Schofield because it used shorter cases
think 38 special and 357 mag.
or in this particular case 45 Schofield and 45 colt
the break top Schofield wasn't strong enough to handle the 45 colt
now that is for the originals, not modern reproductions.
but is why the swing out calendar became the standard.

top strap really strengthens the frame
an other example the 1858 Remington as compared to the 1860 colt army.

after almost 200 years of evolution one would look back and wonder
what ever possessed Sam Colt to come up with that open top design in the first place.
 
All revolvers share those same issues.

Like I said, imo the key is the topstrap. If that's done right, the rest is pretty straightforward. Done wrong, it would be dangerous, since a failure of the topstrap would be pretty catastrophic.

The amazing thing to me about revolvers is that they are as accurate as they are- with all the moving parts, and the alignment and timing that has to be there for it all to work.

My concerns were, what is retaining the barrel (threads in CF? some manner of insert?) and what is holding the cylinder pin parallel to the barrel.
 
About any threaded/pivoting/rotating feature would require some kind of insert if you expected any longevity. Also anything taking direct forces like the recoil plate.
 
this is a really bad idea for multitude of reasons, here are some:

composites do not take point loads well, failure (in case of carbon fibers especially) will be sudden and catastrophic

carbon fiber is very stiff and has high tensile strength, but it also fractures easily, aramid (kevlar) fiber would make much more sense for such a project

forget about ready made sheets, strand orientation is what provides the strength, and the shape of the frame combined with fibers being orientated in the sheets (90 degrees) will mean that in the most likely place of fracture (top corners above the cylinder) you will at best have half the fibers orientated in somewhat useful direction, for show piece - fine, but definitely not for a functional firearm

what has a chance of working would be to use unidirectional material (all strands in one direction), strips of it, and lay that over a mandrel to be cured, that way you would end up with a part where the fibers are orientated in a useful way and not being cut my machining action, but the overall shape of the part will make this almost impossible to do, and you will not have control over the outer shape of the part much, meaning - it might have the strength, but not the looks, if you start to think about machining it from the outside - again, you will chop up the fibers and will lose structural strength - this method is used in carbon fiber bike frame manufacturing, they reinforce the tube joints this way, they do some sanding later though to smooth things out, but they have the luxury of of space around the joint, they are not really constricted by other elements on the bike, just weight, revolver on the other hand has barrel, pin, striking mechanism in a tightly packaged space

the other common problem with using unidirectional fiber material is that it has a typical mode of failure where it splits along the fibers, that is the reason why woven fabrics and stitching and angled layer layup is used to try to prevent this, top of the frame of that revolver - ideally you'd have all fibers going in one direction there, but you need to tie them together somehow so it would split, and the shock from firing a shot definitely has a chance of doing just that

but the real question is - why you would want to do this in the first place?! it is not like a lighter gun will always be better, the whole idea seems pointless, unless you're ok with absorbing all the recoil with the joints in your hand
 








 
Back
Top