Why is Onyx so popular?

I often hear Onyx as soon as someone mentions printing a key structure item.

Is it because it’s more resilient against impacts than PC? Easier to print? Both like to suck up moisture. Is it easier to print?
What am I missing here?

Just looking at the data sheets

  • Tensile strength and modulus

    • Onyx ------------ 40 MPa / 2400 MPa
    • PC ---------------- 59 MPA / 2048 MPA
    • CarbonX PC — 70 MPa / 6200 MPa
  • Flexural strength and modulus

    • Onyx ------------ 71 MPa / 3000 Mpa
    • PC ---------------- 94 MPa / 2044 MPa
    • CarbonX PC — 90 MPa / 5890 MPa
  • Cost

    • Onyx ------------ $190
    • PC ---------------- $46
    • CarbonX PC — $88

Super easy to print with in the Markforged. Prints like a dream 99% of the time and the Markforged is a champ at cranking out parts with little to no fuss.

Nothing like coming back to a bedplate full of spaghetti during build season when you needed that part. Don’t have to worry about that with the Markforged.

That being said, don’t skip maintaining your Markforged printer. It can and will fail if you don’t and those repairs are costly. Level your dang bed too people.


Everyone be careful what you say here or else the Markforged Mafia might come after you.


We really need to start selling hats.


It’s a consistency thing. It comes pre-dried, in a container that keeps it dry, and is consistently the same. That comes at a premium.

I have a theory you can get similar results from the nylonX and other similar CF filled nylons by putting in work on the drying and storage front. For hobbyists this maybe makes sense, for businesses (the core market for them) the $100 premium is likely worth it.


The markforged printers just work. I feel like I spend more time playing games with my office’s paper printer than I do our Markforged. Yeah, you can really only print one material and don’t have a lot of control over the print settings. But at the end of the day, the premium for reliability is worth it for businesses. I imagine a lot of teams get access to Markforged printer’s through their sponsors


I think if somebody came out with a polycarb-only printer with the crazily good reliability & ease of use of Markforged, and at a lower (or even the same) price, teams might adopt it based on the material tests I’ve seen that demonstrate PC’s general superiority. Business opportunity, entrepreneurs?

From what I’ve read, even printers that include PC on their list of supported materials don’t support the needed high bed temp and high ambient air temp (via heated enclosure) to print medium-to-large PC parts really well (i.e. without significant warping). A friend with a nice Lulzbot printer tried printing PC & had very mixed results.

A neat project would be to figure out how to upgrade a large-build-area printer like the Anycubic Chiron to print PC well, including the heated enclosure & everything, and then share that out. The upgrades required would not be trivial though.


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Eh… My team got a bit of a lemon, but MF support has been responsive while we work on it.

Note all of our prints are usable, just not saleable. More than I can say for my Makerbot experiences prior to the MF. No morning spaghetti!

If I was a business-class user, I would have gotten it sorted within two weeks, but checking in every few evenings during build and working entirely over email was a slower process and I’m still not really happy with where we are. I think I want to add an active drying system…


Sometimes I feel that Markforged falls in the same paradigm as Harley Davidson and John Deere.

Oh no, I think I now have 3 different mafias knocking on my door.


Yeah, they’re not perfect. Support is usually pretty solid but it also helps to stay on them to get results.

My fear is a lot of FRC teams will pick them up, their roll of Onyx will sit in the printer absorbing moisture for 6+ months, their bowden tubes are a year old, the nozzles have never been swapped, nobody on the team knows how to properly level the bed, the same glue stick layers have been on it for a whole build season, etc.

It’s an expensive machine that operates well when taken care of but it’s not bulletproof.


At first I thought “Man these Markforged are kinda persnickety”. Then we got some Prusas. After the newness worn off, it turns out that the Prusas started to get some attitude. Just got through a spat with a Prusa Mini and our relationship is back to normal and healthy. Seems like printers want a monogamous relationship with humans. I feel its a matter learning what is important to the printer and stay on top of those concerns. With the Markforged its bed level, dry nylon, Bowdens and feed tubes, purge line health.

I haven’t got my head wrapped around the prusas yet…


We built a heated enclosure around a Prusa MK3S. Moved the power supply and front panel module outside the hot zone. Added a fan to the control electronics. Max 50degC enclosure temp which is okay for PC printing. Vision Miner Nano Polymer Adhesive on a standard Prusa PEI bed. Filament storage in an active humidity controlled cabinet feeding the printer through PTFE tube. eSun PC filament worked really well.

It’s a decent amount of effort but our goal was PC printing rather than CF Nylon. Next on the bucket list is completion of a proper high temperature printer, a project that has spiraled out of control but should be operational within a month or so.


If your Markforged printer is clicking a lot during that purge line, something isn’t right. That’s not good. I’ve heard of people just ignoring it but you shouldn’t. Less clicks, better prints. The under extrusion utility is nice for troubleshooting this issue, you’ll need a small pocket scale that can measure in grams in order to do it well though.


We’re up to 24 Onyx Ones at work (Auris Health/JnJ), from the initial one I bought ~3 years ago
(the group of engineers has went from ~10 to a few hundred in that time)

Business wise makes total sense at the price point for a printer that’s super easy to run directly by Engineers rather than Printer Technicians running (SLAs, Objets, Formlabs, Carbon3d etc) that we also have. And most of the time they just work, the reduced friction towards making fixtures/prototypes pays for a printer really quick with what we’re doing.

We have had issues on occasion, but overall happy enough to keep the fleet running



Our team has also printed many parts out of Nylon CF and yes it does take allot of dialing in to get good strong prints. Many of our Nylon CF parts are larger than the print bed of the MF. The larger the more the warping issues. The key to eliminating warping issues was the addition of a passive heated chamber. At 100C bed our chamber stabilizes at around 60C. Bing go good consistent prints. For the last couple of months we have been working on a CoreXY build for a heated chamber that can do 100C chamber. 310 x 310 mm plate. Hopefully this will allow us to take robot printing to the next level. The big plus other than successful prints in a chamber is than by keeping the part at a high elevated temp until done and and cooling slowly yield considerable less built in stress. I keep looking at the PA12 CF filaments. They should be better than the PA 6 Pa66 filaments but I have never seen a PA12 CF print or know anybody that has had success. Has anyone tried PA12 CF out there?


Its on my list for one of those days. Right now the Chirons are busy chugging away without hardly a break but we are printing currently mostly ABS and Taulman 910 on them with great results also some HIPS and occasional PETG. The 910 is great for gears what we mostly use it for and we got 10 kg at a sale for 350 (35/kg) a while ago. Yes you got to dry it and we are running it from the DIY printdry. The ABS was donated and usually costs around $10-12 at Zyltech about on par with the HIPs. As a “chamber” for now we drape a 5mil plastic sheet over the print dry and printer - gives us around 50C ambient in there and we also got a Hepa filter circulating the air in there - I know its low budget - but its works and yeah every 20-60kg or so the Chiron needs some TLC. And yes its not completley original we replaced the V5 clone hotend that comes stock with a volcano clone.

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Yeah, I think the Anycubic Chiron at $370 (holiday sale price) with a 400x400x450mm build area is a great option. You can print some good-performing materials with it out-of-the-box, and more materials including some CF blends (example) with some fairly inexpensive mods. It’s higher maintenance than Markforged for sure, but 3D-printer maintenance can be good experience that accrues to other things in robotics.

@mpirringer, did you need to fiddle with the firmware to print at >260C nozzle temps for some of those materials? And how often does the bowden tube degrade & need to be replaced? Thanks

Initially the only change we made was replace the stock bowden tube with a capricorn one. IDK how long the stock tube would have lasted but after printing about 50 kg of HIPS and ABS at 255C / 105 C bed we had a nozzle jam - due to the capricorn degrading. So then we put a Volcano clone on - its a direct fit replacement cost us about $35 from gulfcoast robotics. The only thing that required was to up the maxtemp in the firmware from 260 to 300 and change the thermistor type from 5 to 1. And as we went from no sock to sock (self rolled) we did a PID tune. My chiron now has well over 100kg of filament under the belt and yes there were some problems.

1,) The X and Y carriage wires are steel and so they broke after a while so we replaced them with High flex silicon copper wires

2.) The Hotend as cited above (we are now in the process to go all metal clone on all printers

3.) The bearing on the x axis gt2 pulley disintegrated.

4.) 1 of the wheels that carry the bed on the 2020 extrusion acted up (I think bearing) so we replaced it

5.) Just about a week ago a print took a piece of the ultrabase with it. I ordered a new buildplate but am still printing while I wait for a new one to come from China. I just slice it in a way to avoid the imperfection on the plate.

Beyond that - it is wise to check your nuts and bolts. The grub screw on the x pulley on the motor came loose once and some of the excentric bearings on the rollers need occasional adjusting.

The 2nd Chiron has had no problems but all shortcomings detected on mine (I print about 2x as much) were changed there too when I had the problem so for example we just replaced the gt2 pulley at the time mine failed as a preventative thing.

And yeah we drape a plastic sheet over it as a chamber and we changed from Cura to Prusa slicer as its much better especially if you print with a nozzle >= .6 We print on the Chirons exclusively with a .8

Last year I fired my Chiron up at kickoff and hat this Monday at 2pm when we met at the school (pre covid)

Which by tuesday turned into this

Well we already had the frame designed off season then things slowed down a bit - not printing wise but building wise as there were designing necessary but here are some pics from the build season

Now are experimenting (all remotely) with wrapping the plastic in fiberglass cloth And working on some gears and stuff like this

Well its all Chiron printed with a .8. The hub/ring, planets and sun is taulman 910 the bevels will be taulman 910 too (as soon as we have a mount that does not give you gray hair putting it together) the tire is TPU the blue case/holder is abs that will be covered at the bottom in 17oz woven roving and then everything else in 2 layers or so of 8 or 10 oz cloth (whatever we still have) . But the point is its all Chiron printed. The gears mesh fine
Here is a pic of the planets straight off the printer

Now I probably could get a hardened volcano nozzle and print CF Nylon but I don’t see the point to use chopped CF. So yeah its not a markforged but it gets us parts too that are good enough. IDK how much better the Markforged would be - maybe the one that embeds the continuous CF. But we know the 910 gears are pretty tough you can hit them with a sledge hammer and they still fit. Everything is printed solid so there is no air inside any of the parts displayed except the black bevel gear which was just printed for fit and is ABS everything gets printed in ABS or HIPS (<10/kg) filament first until it all fits. Then we go to the destination material. And we can average 5-7kg/week per printer if we run them 24/7 which we did for for about 3 month earlier this year printing PPE (prusa shields etc) I bought My Chiron for 400 and I spent less than $200 in 18 month of constant printing for replacement/upgrade parts. IDK how that compares to the Markforged. As for filament we get HIPS from toner plastics for $10/kg ABS/TPU/PETG from Zyltech of Hobbyking and Nylon from whoever has a sale - most of the time from Taulman direct.

As for ease of use… IDK I would have to know the Markforged to make a comparison. Assembly took about 20 min. and you are up and printing there are no maintenance contracts or a place where you can send it for repair. Warranty means if something breaks they send you that part like when I complained about the wire breaking - they sent me a new harness - I opted to not use it as it was again steel wire - made my own) and yeah so you are on your own in that. And judging from the FB group for some of them its a problem like someone brought me his hotend that he “tightened the nozzle” to the point that it snapped off. And we had some spaghetti too when someone forgets to turn supports on or does not watch for the first layer to go down welletc. So IDK if the markforged has a feature that saves users from those kinda errors. So its not like a paper 2D printer when it comes to ease of use


It does. It’s remarkably hard to get spaghetti out of it.

The MF printers are about as close as I’ve seen for the price, though it’s gone up considerably.


I just looked and for the price difference they better - lol. This would totally bust the budget. Plus the build volume is relatively small we feel the Chiron is small when you are trying to print a whole robot.