Form Futura PP Centaur on Core One
Hi all.
I'm trying to print PP (polypropylene) on my Core One +
When I load the filament it works very fine.. it grabs the stuff fine and purging is totally fine. I can purge all I want without any problems.
BUT when i stop purging and the printer will retract the filament, the extruder starts clicking like a beast. If I start a print nothing works, just extruder clicking and no filament coming out the nozzle.
Maybe the filament is too soft for the extruder to handle??? I have no problems at all with TPU.
Anyone out there with a good idea.??
RE: Form Futura PP Centaur on Core One
I've just got to the exact same point as you: same printer, same PP, same purge ok, same clicks and no filament!
When I've got timeI'm going to try adjusting the tension on the Nextruder feed. It's possibly too tight for the PP.
And like you I've recently printed TPU 95A and 85A with only minor problems loading & unloading. Print quality is great.
RE:
I don't have any issues at all print PP filaments. If you can print TPU 95A, then you can easily print PP since it's a harder plastic. My guess is the nozzle temperature is not correct and you are getting a clog. Also, you should be using a 0.6mm nozzle and not a HF 0.4mm.
I use PP a lot to print funnels and tools for resin printing.
I would start with printing a temperature tower.
RE: Form Futura PP Centaur on Core One
I have made a step forward by using this part:
https://www.printables.com/model/596608-nextruder-modified-idler-lever
PP is now printing, sort of ! I'm not sure I agree that PP is a harder plastic: perhaps when extruded and set, yes, but the FormFutura Centaur PP filament itself is as soft if not softer than TPU. I find that simple shapes print ok, but any small details get lost and/or messed up. Like, I'm trying to print a bag clip (flexible hinge) and the hinge is fine but the clip details just fall apart.
(I just realised I can probably attach a photo)
As the print progresses, I have 3 observations: 1) the PP extrudes very soft and 2) I feel that (at least when printing the clip end) the printer was not giving the plastic enough time to cool before a z move, and 3) not sure if something has changed (eg printer firmware) but it seems to me that the printer has become more violent at non-print moves, such that multiple very short moves possibly shake the model excessively, resulting in distortion and - at worst - dislodging the part from the print bed (requring a brim where I did not need one before). This is on other plastics too, not just PP.
RE: Form Futura PP Centaur on Core One
I have made a step forward by using this part:
https://www.printables.com/model/596608-nextruder-modified-idler-lever
PP is now printing, sort of ! I'm not sure I agree that PP is a harder plastic: perhaps when extruded and set, yes, but the FormFutura Centaur PP filament itself is as soft if not softer than TPU. I find that simple shapes print ok, but any small details get lost and/or messed up. Like, I'm trying to print a bag clip (flexible hinge) and the hinge is fine but the clip details just fall apart.
(I just realised I can probably attach a photo)
As the print progresses, I have 3 observations: 1) the PP extrudes very soft and 2) I feel that (at least when printing the clip end) the printer was not giving the plastic enough time to cool before a z move, and 3) not sure if something has changed (eg printer firmware) but it seems to me that the printer has become more violent at non-print moves, such that multiple very short moves possibly shake the model excessively, resulting in distortion and - at worst - dislodging the part from the print bed (requring a brim where I did not need one before). This is on other plastics too, not just PP.
Pure polypropylene has a Shore hardness of 55-90D where as most TPU starts at 95A or 50D and gets softer. It means polypropylene is almost always harder than TPU (at least what I have printed). That aside, when printing something like this you slow down the volumetric flow rate, increase part cooling at this area or better, add a cylinder next to the part which will give the layer enough time to cool.
RE:
According to the spec sheet, FormFutura Centaur PP is 50D which is considerably harder than 95A. However polypropylene is more flexible than TPU.
Anyway, @DMartin could you zip your project file and attach it here? I'll fix it up for you so it prints nicely.
RE: Form Futura PP Centaur on Core One
Appreciate your offer; I'll knock the file(s) into shape in due course and post here.
RE:
Ah, ok here it is.
I've modified your project in 2 ways and attached. The first version *_1.3mf creates a sacrificial cylinder next to the clip. This purposely allows the layers on the clip to have more time to cool. The second version *_2.3mf uses custom g-code to slow the print speed by 50%: M220 S50 where the clip layers start above the base of the body. A 3rd way you can do this is to decrease both "Enable fan if layer print time is below" and "Slow down if layer print time is below". In this case you can set the later one to 5 seconds. Which will do the same as the 2nd example I attached.
Advice is to experiment with all 3. The third one (setting the layer print time) is usually what I adjust. I just wanted to show you alternative methods.
RE: Form Futura PP Centaur on Core One
OK thanks, I'll try and report back here! At the moment I'm about to install and try "MK4S Bogie Idler & Main Plate" to see if that helps with loading PP (and maybe TPU also). I've just printed some PP-CF and that's a totally different (as maybe expected) filament to the Centaur PP. Prints ever so easily and nicely. But no good for plastic hinges!
RE: Form Futura PP Centaur on Core One
OK thanks, I'll try and report back here! At the moment I'm about to install and try "MK4S Bogie Idler & Main Plate" to see if that helps with loading PP (and maybe TPU also). I've just printed some PP-CF and that's a totally different (as maybe expected) filament to the Centaur PP. Prints ever so easily and nicely. But no good for plastic hinges!
CF adds stiffness and makes it less likely to warp. But as far as flexible parts it's not the right choice. I've use the MK4S Bogie Idler & Main Plate mod on my core one. Works well for softer filaments.
RE: Form Futura PP Centaur on Core One
The new "bogie idler and main plate" don't seem to make anything worse, but improvement is minimal, possibly a little help with TPU.
PP I can get to print one time in 3; I can get it to extrude by helping feed the filament, maybe opening the idler to help, but when the extrude finishes and the filament retracts, most times if I ask it repeat the extrude nothing happens (at least I stop it after a few mins). Have had to drag filament out a few times but nothing too tangled luckily.
So, I notice when the PP retracts, unlike (eg) PLA, the filament disappears completely from the feed and sometimes I can just see a tiny end of it at the top of the feed. A manual push usually then gets it to move and appear. It's the disappearing that's the problem, it seems. Clearly there's no filament for the feed to grip and pull down, so nothing extrudes. I don't know why (unlike PLA) the retraction seems to go wrong (too far). Well, I can guess it's due to the different filament properties, but as to how to compensate I have yet to find the answer.
For info I have definitely found that for soft filament the tension in the idler arm needs to be nearly too loose (falling open). And then when reverting to PLA, a full turn of each bolt adds enough tension to allow it to feed successfully.
With TPU (and probably this PP too) I think that the Nextruder filament sensor sometimes does and sometimes does not detect the filament as it passes through. Furthermore (at least in my machine) it does take quite a push sometimes to get past the Nextruder sensor into the feed channel. And the opposite has been a problem eg with TPU: after unloading that filament and then trying to manually pull it out, it jams; I had to open the top Bowden connector and pull the filament from there - still needs a sharp tug but at least it comes out, and in one piece. So something about that filament sensor (or very close to it) seems to be an issue. Has anyone modified that part of the Nextruder?
And finally, I've tried a 0.6 nozzle and 0.4 and can see no difference in how the filament feeds (or doesn't as the case may be).
RE: Form Futura PP Centaur on Core One
The new "bogie idler and main plate" don't seem to make anything worse, but improvement is minimal, possibly a little help with TPU.
PP I can get to print one time in 3; I can get it to extrude by helping feed the filament, maybe opening the idler to help, but when the extrude finishes and the filament retracts, most times if I ask it repeat the extrude nothing happens (at least I stop it after a few mins). Have had to drag filament out a few times but nothing too tangled luckily.
So, I notice when the PP retracts, unlike (eg) PLA, the filament disappears completely from the feed and sometimes I can just see a tiny end of it at the top of the feed. A manual push usually then gets it to move and appear. It's the disappearing that's the problem, it seems. Clearly there's no filament for the feed to grip and pull down, so nothing extrudes. I don't know why (unlike PLA) the retraction seems to go wrong (too far). Well, I can guess it's due to the different filament properties, but as to how to compensate I have yet to find the answer.
For info I have definitely found that for soft filament the tension in the idler arm needs to be nearly too loose (falling open). And then when reverting to PLA, a full turn of each bolt adds enough tension to allow it to feed successfully.
With TPU (and probably this PP too) I think that the Nextruder filament sensor sometimes does and sometimes does not detect the filament as it passes through. Furthermore (at least in my machine) it does take quite a push sometimes to get past the Nextruder sensor into the feed channel. And the opposite has been a problem eg with TPU: after unloading that filament and then trying to manually pull it out, it jams; I had to open the top Bowden connector and pull the filament from there - still needs a sharp tug but at least it comes out, and in one piece. So something about that filament sensor (or very close to it) seems to be an issue. Has anyone modified that part of the Nextruder?
And finally, I've tried a 0.6 nozzle and 0.4 and can see no difference in how the filament feeds (or doesn't as the case may be).
I have not printed Form Futura PP but have printed about 2KG of Sunlu and YouSoo PP to date without much drama. Even before the TPU mods, I didn't have any problems getting the filament loaded into the nozzle. Also, the filament sensor in the Nextruder is a magnetic switch. The filament pushes a ball to the side which moves a small magnet in front of the sensor. One additional mod I would recommend is replacing the spring with an opposing magnet.
You should not have to loosen the idler arm and I would recommend against it.