pic: 3D Print Limit Switch CFiber

Details, man. You need to attach details to a picture like this:

  • What filament?
  • What printer?
  • How does it compare mechanically to unfilled PLA/PET/ABS?
  • How easy is it to print compared to other filaments?


*]What am I looking at, exactly?

Basically this.

Sorry guys. Uploaded to reply to a PM from another poster. Didn’t realize this would create some discussion.

What is it? We needed to mount a limit switch on a robot and so we designed this bracket. The limit switch mounted at the top of the bracket (can’t really see it in the photos) and the wiring ran down the channel to the outlet at the bottom.

  • Filament - Carbon Fiber reinforced ABS
  • Printer - Makerbot Replicator 2x
  • Mechanical Comparison - Seems to be stronger and slightly lighter weight than the ABS. My printer doesn’t like PLA and we have not tried the PET so can’t compare to those. Trade off is that it is a more brittle in thinner prints, just doesn’t have the flex that ABS has. We are planning to do some real stress testing with the machine shop instructor. He has some nifty tools we are going use to test the tensile strength compared to ABS. Will post those when we have them.
  • Print temp - I run it at about 210c.
  • Ease of print - AMAZING. Don’t know about you guys that have 3D printers but about 1/2 the time it seems the room temp and humidity (thank you East Texas weather) warp my ABS jobs or they have trouble sticking to the bed. Not so with CF/ABS. Out of 20+ print jobs with it only one failed to adhere and that was a user error (ID-10-T for the techie friends out there and it was all on me :smiley: ).
    Appearance of print - We like it MUCH better than ABS. It is a true matte black finish and significantly smoother to the touch even with the exact same print settings.
  • Cost - Our supplier sells it for $39.95/lb.

I think I got all the questions answered. If there are more post them and I will answer the best I can.

Edit Kevin - If you guys are going to TRI so is our team. I can send one of these with our engineer for you to look/see/feel what I am talking about regarding quality of the print.

Not sure about TRI, have to talk to the Dictator-for-Life-Until-Next-Year (Lucia) about it.

What about delamination? We got a Makergear M2 in the printer raffle, and I used it last year to print string pots for the team out of ABS, but in addition to warpage, I had issues with layers just not sticking together, no matter how hot I ran things. I gave up on ABS and printed stuff from PLA this year, and recently discovered PETG. PET doesn’t absorb moisture (I know!), doesn’t warp, and isn’t as brittle as PLA, though not quite as strong as ABS. It can be a bit messy to print since it’s super gooey and stringy at temperature, but since I can’t get ABS working for me…

I looked around and 3DXTech does a carbon fiber or glass fiber filled PETG that I might try if I need more strength from a part.

Thanks for posting. This pcture just helped me solve a problem

I have stayed away from carbon fiber materials on my Lulzbot Mini due to a statement on their website and this article that says carbon fiber may ruin nozzles. I’m curious if anyone here has 1st hand knowledge of these issues.

Also, how does the carbon fiber ABS part respond to an acetone vapor bath? I’m a big fan of doing this for the better layer adhesion.

WHAT?? Please tell me there is not a hidden message here :ahh: :ahh:

No delamination. I get it *some *on ABS but not a tremendous amount. When I do I re-level my bed and that - so far - has taken care of that problem.

That might just be where we ordered ours :smiley:


I read the same warnings. It is hard on the nozzles due to the coarser nature of CF. Makes sense if you think about it too.
If I had to guess I would say we have run about 40+ hours of CF/ABS printing and so far my nozzles have held up. They are still printing cleanly and don’t appear to be having issues. I make sure to lubricate them often when I am running CF/ABS though and that may help some.

Regarding the acetone bath we haven’t tried that as we have not had any delamination issues with the CF/ABS and the finish is already really nice.

Looks like someone has already done some tensile testing http://goo.gl/lZKCkK

Lucia’s stepping back from Team 57 and handing it over to school management so she can focus on Champs, Lonestar, her two grandsons, and keeping her retired husband busy around the house.

I’ve printed quite a bit with carbon fiber on my rep2 with a PLA based one. Its a bit different than the ABS but I can still give you some insights.

I agree with you, printing is beautiful. I’ve never ever had issues printing it. Almost seems to work better than PLA. Be warned though, buy a second nozzle. It destroys your nozzle quite quickly. We kill a nozzle per .75kg roll of filament which isnt too fun to change out. The nozzle issue isnt the end of the world, but you do need to account for having a new one otherwise your future prints will be terrible. We own four rep2s, so I only let one printer ever use that filament.

It seems stronger than the base material, but we did some stress testing on it and it actually proved to be a bit weaker. We did both compression testing and bend testing and it was a little bit weaker in both. It is considerably lighter though which is where we use it when we have a long arm and need the smallest moment possible.

Hate that for your team but I understand completely. She is going to be one busy hopping lady!

And grandbabies are SO much more fun!! :smiley:

Have you built or put together a box for your Makergear M2? In my experience, using Lexan shielding or some other similar clear plastic to make a semi-insulating box really helps keep the layers together.

You are quite right. The Rep 2x is enclosed and comes with a cover as well. In my room it likes the sides and front closed with the top off. If it is exceptionally cold I put the top on to keep cold drafts from getting in and messing up the job.

I wonder how much of a difference there is between the CF/PLA and CF/ABS?

How quickly are your nozzles deteriorating and are you lubricating them between and during prints? I have run almost 2 spools and not had a problem with my nozzles yet. I know it is a matter of time but am wondering what the contributing factors might be.

Thats a good question on the differences between the two. Sadly I cant test that as I’m not set up for ABS.

I replace my nozzle after every roll. It may be a bit excessive, but I start to notice a bit of a drop in quality after a roll when switching back to PLA. I could get another half roll or so of CF out of it, but rather be safe when it comes to quality of print, and its easy to say “after a roll, replace”.

By the way, your quote in your signature was said by Muhammad Ali. Awesome quote. Have it in big letters on my wall in my classroom

I use an Adinia H800 that gave me fits until I built an enclosure that just slides over the top of the whole printer. I know the Makergear M2 does not come with an enclosure, so I’d say that Kevin Sevcik could eliminate a lot of this delamination issues by building one.

I read that somewhere but could never find solid proof that he was the one that originally said it. Would love to find original sourcing.

Also, I understand the replacing nozzle. I too have extras for when mine does wear out.

Very cool part. Cothran should be familiar with this. He works in our lab.

A little bit more information. We’ve printed with carbon fiber reinforced ABS for about 5 years. It’s a game changer.

First, the carbon fiber (if done right) increases strength, stiffness, thermal conductivity and (most importantly) reduces the coefficient of thermal expansion. We’ve printed complex parts on a Solidoodle with 20% CF ABS, printed the exact same thing out of ABS on our Fortus 900 and compared geometrically with our laser scanner. CF ABS on a Solidoodle is more accurate than ABS on a Fortus. In a nutshell, good material in a crappy machine beats crappy material in a good machine. You don’t need an oven to control residual stress, warp and curl. We’ve done this on big machines (google Big Area Additive Manufacturing). Carbon fiber reinforced thermoplastics is secret sauce in the BAAM machines. We’ve printed parts 20 feet long with no distortion.

Second, the fact that someone’s strength went down tells me the fiber isn’t wetting out well with the base material. All carbon fibers have sizing (or chemistry) on their outer surface that impacts their ability to fuse with a secondary material. If you are using carbon fiber that is sized to interface with resins (typical for aerospace), it won’t wet out well and you’ll get poor adhesion between the fiber and thermoplastic. I’d suggest making your own filament and get pellets from someone like Techmer. You can get the loading anywhere from 5% up to 50%. 20% to 30% seems to be the sweet spot. We get 2 to 3X increase in strength and 8X increase in stiffness. Cost wise, 20% CF ABS is about $5/lb. PolyOne sells good material as well. Another material that is very interesting is PLA with Bamboo. We printed some large parts with 10% bamboo that turned out beautiful. Getting ready to try 20% bamboo.

In terms of properties, realize that they will be anisotropic. All the fibers line up with the bead (the nozzle acts like a funnel). So you’re strength goes up in the bead direction but the best you’ll get is about 80% to 90% of the base thermoplastic properties in the bead to bead and z-strength.

All in all, if you get the fiber with about 20% CF, you’ll overcome a lot of the warp and curl problems.

Thanks for sharing.

So. Did you get the part printed and can you post a pic? May be purchasing a new printer and before I jump all off into PLA I’d like to see how your PLA bamboo came out.