Hi,

I amplanning to build some carbon rails for a bike saddle. This consists of a rodcontaining multiple curves. I do have a CNC machine to create the molds forthis, but need some help on the best production method.

As materialthe braided sleeve seems to be a good option. These are available in carbon ora carbon/Kevlar combination which should be fine

I plan tomake the rails solid to obtain enough strength, but don’t know how to realize thisin combination with a proper epoxy-carbon ratio in the final product. Whatwould be the best production method for this? How to get everything in themold? I am familiar with hand-layup combined with a mechanical press and/or vacuum,prepregs, resin infusion but.

 

Hope anyonehas some expertise on this.

 

Thanks alot in advance,

Buuk

To ensure sufficient strength in an application like this, the only real option is to CNC mill a metal mould that can be heated and put under high pressure..
You can then use prepreg or hand lay up and expell the excess resin with the high pressure .  Your mould will have to be made with precision milled "channels" small enough to let the resin escape, but not allow fibres to block them.

I have tried to build this sort of thing for various parts for motorbikes and for firearms-stocks ..   It is extremely difficult to get a consistent, strong enough product ..

IMHO it is not worth the effort for "one-offs" -

Also in this particular place you do not want the part to break/crack splinter, so you need at least some Kevlar/twaron/zytel in there ..

A friend of mine simply took the complete saddle - pin assembly off the bike when correctly adjusted, and built a fixed position "carbon copy" of that ..
That way you can build it using the immense strength to weight ratio of a compound curved hollow carbon fibre part --  
This thing is less than a third of the combined weight of the original!!!  But also hard as a rock to sit on ..

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

carbon seat has to be made for your specific weight. because it has to have flex.
like Dravis said otherwise its rock solid. and that means useless for riding. only if its for show and for weighing machine, to show lightness.

but still worth to try it. especially if its for your own joy.

The seat he built using the above method  (Involving nylon stockings, masking tape and other strange "tools" )  was adjusted in some areas to fit to his weight, but since he is much heavier than me, the seat was like a rock to me ..  .. even with the gel/foam on top ..

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)