Hi everybody, I’m new here, but have some experience with composites under my belt.
Does anybody know if it is possible to seat bearings directly in carbon fiber?
My application is a full suspension mountain bike frame.
I have made a foam core, will do wet lay-up, vacuum bagging, and post curing.
I was wondering if it would be possible to seat the ball bearings directly in the fiber, if I add 5% by weight carbon multi-wall nanotubes?
Cheers
Not sure. I would think so, or at least a thin bearing housing. That way, if you have issues with the bearing (or it isn’t aligned when you make the part), you can redo the bearing. I have not kept up on the MWNT additives with strength. Most of the time it’s added for other reasons, but I would think it helps in strength.
Thanks, I’ll give it a shot then.
Aligning the bearings should be no big deal, if machining the mold part of the bearing seat,
I’ll report back how it turns out.
Thanks
You just need a bearing race be positioned, pressed into the carbon fiber frame.
What do you mean by that?
I’m not sure I understand what you’re saying?
I intend to glue ball bearings directly into the carbon, if possible?
It is possible but I wouldn’t recommend it. If you bond them in, you will not be able to change them, later. Best would be to bond in an aluminum or titanium sleeve that allows the bearing to be press fit into it.
yes its possible you may get some better ideas by looking at high speed composite rollers for the printing industry the bearings (ceramic)are often directly mounted into carbon tubes
another technique which would allow you to do this is what we in F1 call cotton reeling (though i dont think our affectionate name will show up in any searches) we use this for harpoints where bearings and engine mountings will be used
pretty sure one of the largest companies in the bicycle world do this but give it the name of net moulding
Trek writes some blah-blah on their sire about Net molding benefits, but I couldn’t find anything technical.
A search for net molding on Google did not do much for me either.
Could you describe the general idea behind net molding, or point me to more information?
Cheers!
The bicycle industry loves its buzz words
net molding in Treks case is nothing more than ensuring the part as it gets demoulded requires no machining this is slightly different to a net preform which is then charged with resin in a tool though this can be used in conjunction whilst allowing for the expansion and contraction or the mould tool.
for example a bearing housing is within spec for a bearing straight out the tool with no post machining to get it concentric or to bore tolerance…
the easy thing is to look up trek patents they love to patent things which are common knowledge if you work in the right industry
A simpler approach would be to imagine a tube which is interwoven with a skin
i can think of at least 3 structurally excellent ways of doing this without the hype and expensive tooling might see if i can find a picture it tells a thousand words
Mr magura i replied earlier explaining this but it seems my post needs to be moderated
I have sent you a PM.
Thanks for the explanation. A picture would sure be nice.