[cs900]

Ok, so I've decided to try a project idea I've had for a while, and since I've pretty much been doing research and practicing for it for my senior project at school, I figured I'd give it a shot over winter break.

So the idea is the make a body, and eventually frame, that is completely free of metals. The main structural material will be carbon fiber with a layer of Kevlar in the breach area for wear resistance, and a layer of carbon and colored fiberglass on the exterior to make it look pretty.

The body will be based on shocker internals since I have tons of spares kicking around and it's a prety simple shape to work around. The plan is to make a multi-piece delrin "male" plug of the main chamber for the internals, breach, and barrel threads; as well as one for the air passage chambers. The Kevlar and carbon will then be molded around these plugs and vacuum infused. All the parts will be held in the correct locations during infusion with delrin machined pieces. The delrin pieces will be permanently become part of the body and will have carbon infused around them. Threaded areas will have several extra layers of carbon in case the threads strip out and I need to make a custom helicoil to put in.

To my knowledge, this is the first time someone has tried this. At least here on PBN. I have all the carbon on order and hopefully it will be here by the end of next week. I'd love to hear comments, suggestions, or concerns people have.

Updates:
So in order to keep everyone up to date without reading thru dozens of pages i'll recap highlights here.
currently working on body 4!



Body 1.0:
Infused plenty stong but had poor surface finish on the inside where the orings are suppose to seal.

sorry picture link broke


Body 2.0
Fixed the oring surface finish by infusing delrin rings inside the body where the orings sit. Also added delring inserts for the barrel threads and bolt guide threads.

turns out the barrel thread and bolt guide inserts had a tendency to break free so I had to install pins to keep them from rotating when installing the barrel or bolt guide. next step was to make the air passages. This was done with smaller carbon tubes:

Next was preparing the exterior shape. Used expanding foam for the main structure support


exterior carbon added:


Finally got the manifold installed and pressure applied. bolt cycles, but I think one of the air passages isn't quite sealed correctly so it's allowing air to backflow thru the noid.

Looks like it's time to start:
body 3.0
started out very similar to body 2.0 with delrin inserts

but switched to a 2x2 twin instead of a sleeve material

Major difference is I tried a new method of securing the air transfer tubes to the body. Assembled and tested. had leaks around where the delrin mounts mated to the carbon body


Body 4.0 here we come!

[paintballa8224]

I've always thought it would be cool to make a carbon fiber marker and just use metal for the parts that need threads. Can't wait to see how it looks.

[cs900]

yeah, i'm attempting to do metal-less threads as well. but like I said before I'm added extra carbon in those areas in case I need to go back and add metal ones later.
this is the mold, and of course it's round

[natezink]

might be able to use a composite(plastics) for the parts that need threads and wrap that in the carbon fiber if you really don't want to use any metal. Just need to make sure the composites can handle the pressure.

[cs900]

well i'm not too worried about the hoop stress, it's the axial stress on the rear bolt guide threads I'm weary about. I guess I could redesign the bolt guide so that it doesn't use threads.

[new ion?]

Held in mini sytle with the rear frame screw or similar? That would be a good idea.

I'll be following this thread almost as close as mine.

[cs900]

yes, i've seen yours. and i have a CAD model all drawn up for an aedes project as well. just never got around to making it. let me know if you need any parts made for it!

[new ion?]

Hahaha, I just may with stuff that I just don't wanna do. Its all REALLY easy stuff.... hell I think I'll shoot you a PM about it.

[anomoly40]

I know turtle cocker guy made a delrin cocker. Keep us updated.

[cs900]

will do. I'm still waiting on the carbon and kevlar to get here.

I might have the plug machined this weekend.speaking of, i'm now considering actualy molding the threads right into the carbon instead of post machining them. I figure the threads should be stronger with uncut fibers. however, thes means adding more complexity to the plug, and I may have issues removing the threaded sections of the plug once the resin has cured. Maybe a test piece is in order....

[y0da900]

If the resin curing doesn't create too much heat in the process, you could always try to make a threaded mold with machinable wax and melt it out afterwards.

[cs900]

yeah, i've thought of that as well, but i'd prefer trying a delring mold piece first. the mold I have been using during the semster, I made from Acetal Delrin, and the epoxy pops right off, but I'm unsure if i can just unscrew the threaded section of the mold easily.

and all the cloth shipped today! I got my resin and bagging material back from school today, and i'm ready to make a test piece with the threads I think.

[cs900]

got the mold started today....

main body turned to within .0015 of the needed diameter. the rest will be sanded by hand to ensure a perfect surface finish.

[Spitlebug]

Updates?

[cs900]

sure....I've decided it's just a better all around idea to make aluminum inserts for the threads. So yesterday I made an insert for the rear threads, and today I'll be finishing up the front of the mold, as well as the barrel threads (autococker of course).

Here you can see the basic shape of the mold, as well as the rear threaded insert already in place. I've secured it with rubber cement. I figure that will hold it in place nicely and keep any resin out of the threads, while being easy to remove after wards. I'll be doing the same fro the barrel thread insert.



and here you can see the joining of the front and rear sections of the mold. This is necessary as once the resin is cured it would be impossible to remove otherwise, and would need to be machined out. You can also see the drastic different between the extruded surface finish and the polished (although my finger marks are all over it).


Also, my Carbon should be here monday, and hopefully i'll be ready to start infusion by then.

[63VDub]

that is quite possibly the cleanest lathe I have ever seen. Will continue watching intently.

[warbeak2099]

Awesome, I'm definitely watching this thread.

[cs900]

Originally Posted by 63VDub

that is quite possibly the cleanest lathe I have ever seen. Will continue watching intently.

lol. Yeah, I'm a little anal about that. If you looked at any of my tools you'd never know that I actually use them.

Thanks guys. Hopefully monday i'll have another update.My carbon is a "stone's throw" away, so it should be here.

[asngt007]

didnt some custom shop a coupe of years back try to do a cocker like this? i cant quite remember it, but dunno?

well IMO you might want to try with a metal insert, wherever the internals go, due to the fact that internal pressures might be a slight issue. great Idea though

correct me if im wrong

[asngt007]

Originally Posted by anomoly40

I know turtle cocker guy made a delrin cocker. Keep us updated.

yes, he did, but I think that these cockers had several pressure issues

[cs900]

the internal pressure shouldn't be a huge issue as long as I have enough layers of carbon, and I can get the carbon to resin ratio correct.

someone made a cocker using carbon tubes slid over a machined body, but i'm unaware of anyone making it mainly from carbon fiber.