use of carbon fiber filaments

[mgreenATC 0]

I want to use carbon fiber filaments to make some replacements parts for motors and sports vehicles,  We have an S5 bundle.  Will the printer work with carbon fiber?  Any recommendations on the type of filament?  I see that many are made with nylon base or is ABS base better?  Any recommendations on the extruder head?

[gr5 2,172]

S5 is fantastic with GF and CF filaments.  You need a ruby nozzle such as the "CC 0.6" print core.  Regular nozzles will wear down in just a few hours of printing.

 

Avoid ABS if at all possible.  The fumes are nasty and the parts tend to have "grain".  In other words they tend to be quite weak.  I really like xstrand GF30 with glass fibers (fiberglass).  Seems better than carbon to me.  There are many good CF filaments as well.  Realize that the carbon is chopped up into tiny pieces so the strength and stiffness increases are small.  But definitely real.  GF30 is I think 30% glass fibers.  I've been very happy with their PA6 GF30 (pa6 is nylon) but xstrand also has PC (polycaronate) and PP with GF30.

 

Nylon needs to be extremely dry and I recommend spending 8 hours drying the filament first.  Even brand new filament tends to be too wet to print.  Unspool enough for your print and put on the print bed with the spool on top and a towel on top of that.  Heat to around 70C for around 8 hours just before you print.  After 8 hours of printing on the back of the printer it's wet again.  Store with a few cups of desiccant and recharge the desiccant every month.  In other words nylon is tricky but once you get it down it's a great marerial.  I usually print Nylon out of a zip lock with desiccant in the zip lock (for prints longer than an hour).

 

PP is really hard to get to stick to the bed.  Get the special printing kit from ultimaker that includes adhesion sheets.  These really suck as they tend to rip when you remove parts.  They really suck.  But are necessary for PP or alternatively get Magigoo for PP.

 

PC isn't exactly easy either.  There is no easy filament that will get you good results with GF or CF filametns.

 

Another trick is to buy carbon fiber rods and pause your print when there are places to insert the rods, usually towards outside edges of the part.

 

Pay attention to working temperatures as many of the nicest plastics to work with will melt at temps below 100C.  Nylon gets pretty soft at 100C but will not melt so it may be fine even at 100C if it has fibers.

 

PLA gets soft at 52C.  nGen, cpe, petg typically about 10 or 20C hotter than that.  ABS right at 99C.  Nylon gets very rubbery above 110C.

 

It really takes 100 prints to get good at a new material and it can be a painful process.  Especially if you don't ask lots of questions or ignore advice.  Nylon is a very rewarding material once you get good at it.  Both regular and filled.

[mgreenATC 0]

Do I need a 0.4 or a 0.6 print core for 2.85 mm filament?

[Travis7s 25]

Both are designed for 2.85mm filament. 0.4mm will be able to do finer details but the tradeoff is slower prints.

[gr5 2,172]

"CC" is for abrasive filaments.  Abrasive filaments tend to have fibers which can clog a 0.4 nozzle although most are fine.  The manufacturer usually recommends a minimum nozzle size.

 

For most prints 0.4 is a good compromise.  99% of what I print is not much bigger than a deck of cards and even then I often use 0.6 for faster prints.  If you are printing things larger than a shoe then you may want to even go to 0.8mm nozzle.  the quality goes down a bit.  there's also more stringing with larger nozzles due to leaking.  But quality with a 0.8 can still be pretty nice.

 

Actually most prints I do are probably about the size of one finger and those I usually do 0.4mm nozzle.