Tips on printing super stiff filaments
I've been printing a lot of Siraya Tech PPA-CF which is at the limits of the Core One (290C nozzle temp) with a Diamondback 0.6 nozzle. It is the stiffest filament I own and I can't get it to feed into the nozzle via the Bowden bend without it snapping and if I do manage to get it past the filament sensor it snaps before entering the nozzle.
The only way I've been able to print it is by taking the top off and feeding it into the Nextruder directly like I've done for super-soft TPU. After that, it's very easy to print. I use it for my model rocket structural component and it is ridiculously strong. If I hit it, it has a metallic ring to it.
I would prefer printing from a dry box attached to the Bowden tube but haven't managed to get it to work yet. Perhaps I need a Bowden bend with a less steep angle? Any tips appreciated.
Anyway, it's interesting that for my stiffest and softest filaments I have to take my top off...
RE: Tips on printing super stiff filaments
Is it equally stiff when warm? I have not tried this material but I usually print directly from a dryer, after sitting in the dryer for an hour or so any filament warms up and at least the first few layers seem to dry up, maybe this could be enough to allow the filament to follow the original path if fed directly before the print?
/Anders
RE: Tips on printing super stiff filaments
Is it equally stiff when warm? I have not tried this material but I usually print directly from a dryer, after sitting in the dryer for an hour or so any filament warms up and at least the first few layers seem to dry up, maybe this could be enough to allow the filament to follow the original path if fed directly before the print?
Unfortunately nylons get even stiffer and more brittle when they are dried. I contacted Siraya Tech and even though I told them I have a Prusa Core One they replied (I'm paraphrasing) "Not compatible with AMS systems, direct drive only" So I take that to means that Bowden tube setups don't work with this filament. I can still print it if I bypass the Bowden tube and have a setup to feed it in through the top and still keep the chamber closed so it's not a show-stopper.
RE:
I have experienced something similar with Bambu Lab PPA-CF and Creality PPA-CF. The filament is new all is fine.As soon as the roll is only 30% full, the radius of the filament is so small that it breaks, even during printing. However, if I heat it up to 100 degrees in the dryer and run it through a straight piece of brake line, it gets better. Maybe that will help.
RE:
I have experienced something similar with Bambu Lab PPA-CF and Creality PPA-CF. The filament is new all is fine.As soon as the roll is only 30% full, the radius of the filament is so small that it breaks, even during printing. However, if I heat it up to 100 degrees in the dryer and run it through a straight piece of brake line, it gets better. Maybe that will help.
Good tip. My dryer only goes up to 85 but I might give that a try. I print enough of it that it's worth my time for a dedicated setup. I might have to get the SUNLU E2 but really don't like the design (nor the price).
RE: Tips on printing super stiff filaments
I know. The E2 isn't the prettiest, but it's powerful. In the TDS for your Fulament, it says to dry at 100°C for 4-6 hours. I can highly recommend it!
RE: Tips on printing super stiff filaments
Is it equally stiff when warm? I have not tried this material but I usually print directly from a dryer, after sitting in the dryer for an hour or so any filament warms up and at least the first few layers seem to dry up, maybe this could be enough to allow the filament to follow the original path if fed directly before the print?
However, if I heat it up to 100 degrees in the dryer and run it through a straight piece of brake line, it gets better. Maybe that will help.
Siraya Tech got back to me again and said basically the same. That is, print it from a 100C+ dryer. Looks like I'll be getting the E2 after all...
RE: Tips on printing super stiff filaments
The price of the E2 is not exactly inviting. But consider this: I don't know of any other dryer in this price range that can reach 110 degrees. Just for fun, I rewound half of a PPA-CF roll and wrapped a temperature sensor between the layers. After a certain amount of time heating up, the filament actually reached 110 degrees. I was very surprised and, of course, delighted.
RE: Tips on printing super stiff filaments
So I did dry it at a higher temperature (100C for 6 hrs) and it made no difference. I have a toaster oven that had been modified as a reflow oven and is PID controlled. So I chucked the spool in there. I think the problem is I have the "cheaper" PPA-CF filament that has chopped fiber mixed in with the plastic and not just at the core. I may try the later and see if I better luck getting it to the nozzle via the Bowden tube.
RE: Tips on printing super stiff filaments
If you take the filament in your fingers and try to bend it straight, does it break?
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If you take the filament in your fingers and try to bend it straight, does it break?
Yes, it's quite brittle. I can snap it by straightening it.
I have had multiple successes bypassing the Bowden and feeding it directly into nextruder with the top off, but then I lose the chamber heat. This stuff doesn't seem to warp and I have my printer next to an external ventilation fan. So far I've gotten successful prints. It's just annoying I can't get the idler bogie to lock on to it if it comes in through the Bowden bend. If I try to force it, it snaps. The Bogie has been modified to be more TPU friendly so maybe if I switch back to the stock Bogie I'll have better luck.
I'm going to try modifying the bogie arm or maybe remixing the Bowden bend to try to straighten it more before it enters the nextruder. Or just stick with a softer filament. This is the only one I have problems with.
RE: Tips on printing super stiff filaments
Either reroute the bowden tube, or change the idler arm to a single wheel version, available on printables. Have never snapped siraya Ppa-cf ever since i swapped. Layer adhesion actually seems quiet strong even at 290, at least in structural settings.
RE: Tips on printing super stiff filaments
or change the idler arm to a single wheel version
Do you have a link for us?
RE: Tips on printing super stiff filaments
or change the idler arm to a single wheel version
Do you have a link for us?
https://www.printables.com/model/1236396-single-wheel-nextruder-idler-lever-for-brittle-fil/comments
Theres one easier to swap in and out nowdays, will see if i can find it. I used the one above, slightly annoying to swap, but now it works. Havent tried if its impossible to print tpu with this though. Other materials are ok.
RE: Tips on printing super stiff filaments
Thank you very much!I will test this with my PPA-CF from Creality, which only breaks when printing with the remaining filament on the spool.
RE: Tips on printing super stiff filaments
The swap out versions are here: Quick Swap Dual and Single Idler
Anyway, will give this a go. I've also been working on a Bowden bend redesign that has a straighter entry into the Nextruder.
RE: Tips on printing super stiff filaments
The swap out versions are here: Quick Swap Dual and Single Idler
Anyway, will give this a go. I've also been working on a Bowden bend redesign that has a straighter entry into the Nextruder.
With the standard idler I could get it to work by rotating the Bowden entry bend 180degree, and loosening the idler tension alot. The issue is that the material bends first in one direction and then the opposite in the extruder, hence why it snaps.