Check This out. Carbon Fiber Cello build.

petah

petah

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www.youtube.com/watch?v=-uzsAa606u0


You don't need to have a vacuum to take air bubbles out. You can use a heat gun on low and 'paint' the heat over the CF and this exposes the air Bubbles

You could probably make a pretty sweet uke this way. Using a ukulele mould.

... Maple neck....... that would look awesome. Any builder willing to try?

If not I'd be happy to give it a shot.
 
thats an awesome video. I would've thought the top and back'n'sides piece would be cured together but there just glued.
 
you can cure them together!!

what you do is make a inside mold out of Styrofoam to hold/support the sound board. now after everything is cured you can melt the foam with acetone. acetone will not harm CF.


the foam melts like sugar in water when you introduce acetone.

Dang I should start my own company :)
 
I watched the video and thought yes, I'm gonna try that next year. One piece molded body and neck with koa/spruce top and ebony fingerboard/headplate overlay. Slim jim tenor cutaway design with active electrics was my initial thought... Not sure about the baking process though. I am looking into this tentatively.
 
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You mean like this

UA20-BLK_back_sm_.jpg
UA20-BLK_front_sm_.jpg


http://www.ovationguitars.com/index.cfm?fa=detail&mid=2218
1598meii4gb_sm.jpg
 
petah said:
http://www.youtube.com/watch?v=-uzsAa606u0

You don't need to have a vacuum to take air bubbles out. You can use a heat gun on low and 'paint' the heat over the CF and this exposes the air Bubbles

If not I'd be happy to give it a shot.
Click to expand...

Please tell me your not a engineer, the whole point of carbon fiber is strength to weight.

No vacuum autoclave step mean extra resin that means extra weight. Weight in all the wrong places for a instrument

Carbon over foam core that is left to cure is basically just expensive dangerous fiberglass. That you will have to sand and carbon dust is not something you want to be around. Also carbon fiber plus lots of heat if the resin goes dry creates some super nasty byproducts.
 
wearymicrobe said:
Please tell me your not a engineer, the whole point of carbon fiber is strength to weight.

No vacuum autoclave step mean extra resin that means extra weight. Weight in all the wrong places for a instrument

Carbon over foam core that is left to cure is basically just expensive dangerous fiberglass. That you will have to sand and carbon dust is not something you want to be around. Also carbon fiber plus lots of heat if the resin goes dry creates some super nasty byproducts.
Click to expand...


That caught me by surprise too. Vacuum molds are so easy to make.
 
I own the ovation tenor, I'm pretty sure both hese models have molded plastic backs, not carbon fibre. The tenor is plastic.
 
RonS said:
That caught me by surprise too. Vacuum molds are so easy to make.
Click to expand...

They are pretty easy. But normally its not a enclosed body. I could see making tops and the like or backs and sides but not the whole thing.

If it was me. Positive mold for backs and sides out of wood sanded smooth to 400 and covered with release agent. Vacuum bag and a UV and heat light for cure depending on resin. Could be done very cheap. Like ~25$ in materials.

Top's are flat so just buy the top in the thickness that you want from a online source in dry carbon cut it under ventilation and correct dust filtration and then bind. Use the leftovers for a cover plate.

The neck would have to be wood. I cannot think of a way to do it without making the mold on a CNC machine. You could do it in a wood mold provided you took the slope into account and had a mold release point but that is not a trivial project.
 
wearymicrobe said:
They are pretty easy. But normally its not a enclosed body. I could see making tops and the like or backs and sides but not the whole thing.
Click to expand...

Agreed. I played the 12 string Ovation that was all Carbon fiber and it did sound really nice. I guess I'm a traditionalist, I would prefer a wood top.

If it was me. Positive mold for backs and sides out of wood sanded smooth to 400 and covered with release agent. Vacuum bag and a UV and heat light for cure depending on resin. Could be done very cheap. Like ~25$ in materials.
Click to expand...

Ditto.

Top's are flat so just buy the top in the thickness that you want from a online source in dry carbon cut it under ventilation and correct dust filtration and then bind. Use the leftovers for a cover plate.
Click to expand...

Interesting, I didn't know that was available.

The neck would have to be wood. I cannot think of a way to do it without making the mold on a CNC machine. You could do it in a wood mold provided you took the slope into account and had a mold release point but that is not a trivial project.
Click to expand...

Owning a CNC would be nice. I've purchased time on a CNC at a local university and had a engineering student do the work for me on other projects. Really inexpensive.

Why not make a mold using Plaster of Paris or some other similar material. Carve out your neck in wood, float it in Plaster of Paris. You might need to make 2 molds to accommodate the headstock. Since Plaster of Paris would leak you would need to paint it to hold the vacuum. Align the body, neck and headstock into one unit. Apply a release agent and you are ready for the carbon fibers.

BTW, I've used waterbed mattresses for vacuum bags when I needed really big bags to hold a large project.
 
RonS said:
BTW, I've used waterbed mattresses for vacuum bags when I needed really big bags to hold a large project.
Click to expand...

I bought a lot of expired wave bag reactors for the same thing.

As for the neck, It could be done but it would take some really careful CAD work. The shelf of the nut the curve on the heel, and adding material inside to allow for attachment which is a whole big old bag of worms. The frets and slotting on a cutter might be possible but you would have to build the material up pretty heavy for the soundboard which would get expensive really quick.

Though a single piece of carbon flat cnc cut for a fingerboard out of .25 plate carbon would work well.
 
I made a Mould 6 months ago with the intention of producing a carbon fibre lookalike backed concert uke with a spruce top ..I have access to all the equipment and materials needed to do it, CNC Machines and ovens and the rest..in the end I thought whats the point ? Ovation and others had already done it :( I still have the mould tho just in case I change my mind or think of another idea.

USA Spelling (MOLD) UK Spelling (Mould) Who cares???
 
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wearymicrobe said:
I bought a lot of expired wave bag reactors for the same thing.

As for the neck, It could be done but it would take some really careful CAD work. The shelf of the nut the curve on the heel, and adding material inside to allow for attachment which is a whole big old bag of worms. The frets and slotting on a cutter might be possible but you would have to build the material up pretty heavy for the soundboard which would get expensive really quick.

Though a single piece of carbon flat cnc cut for a fingerboard out of .25 plate carbon would work well.
Click to expand...

I guess that is why Ovation started out using a wooden neck and ebony fretboard. K.I.S.

RonS said:
Why not make a mold using Plaster of Paris or some other similar material. Carve out your neck in wood, float it in Plaster of Paris. You might need to make 2 molds to accommodate the headstock. Since Plaster of Paris would leak you would need to paint it to hold the vacuum. Align the body, neck and headstock into one unit. Apply a release agent and you are ready for the carbon fibers.
Click to expand...

Making separate pieces for the mold then joining them would be a lot easier. While CNC is great, sometimes the old fashion way is just simpler.
 
the foam core idea was kinda stupid on my part ( the principle works but you would want the board to vibrate so you wouldn't want it to be a solid piece yadda yadda yadda)

TimBuck Please Please Please Please make CF back concert and add a CF sound board! with maple neck!



That is a dream uke of mine. After playing a CF guitar ( Awesome! )... A uke would be... Golden!
 
I don't undertsand - the sequence in the video showed something familiar to me: laying up like fibreglass. I assume that the resin 'cures' chemically. Why then does it need cooking? Is there an additional process going on here? I can see why you'd use the vacuum...
 
I think I saw west system epoxy there so I would assume it is making the epoxy thinner so that the excess runs off faster, it will also make the chemicals cross bond more rapidly and could possibly make the epoxy harder ie: more brittle and resonant.

Seems to me this could be done reasonably easy in a home shop with an old non kitchen oven, vacuum press and plywood/ polished waxed resin molds.

The trick would be finding the correct balance of materials.

Ok I think I know they use slow cure epoxy for layout time, but it than needs heat to cure.
 
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