So far, so good. I dried the fresh filament from Bambulab for two days at 120C in a blast oven. It’s great that the heated bed heats so fast, but boy, it takes comparatively forever for the chamber heater to heat the chamber up to 65C. On top of that it does 2 or 3 rounds of bed leveling, far more than when it’s doing PLA or PETG. Apparently truly high temperature filaments are a different ballgame altogether.
Nonetheless, despite all the lead-up, it seems to be printing just fine. I limited max print speed to 50mm/sec just to be sure.
I started to get concerned that the top of the H2D might be cooking the filaments in the AMS 2 Pro, so I put a layer of insulation between the two.
Also, the Bambulab instructions call for using gluestick, but I applied a layer of magigoo instead, just because it was close at hand. Magigoo does make a high temperature version which is apparently preferred for PPS. As it turns out the one I used was Magigoo Flex, so who knows how that might affect the result. I’ll be happy as long as the PPS-CF isn’t welded to the build plate. I can’t even seem to find Magigoo “high temperature” on amazon.
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I had no problems printing PPS directly on the textured PEI, good grip without adhesive. I did not do any large items yet, so it might be required for them.
Also PPS absorbs a lot less moisture than PPA for example, so I had good luck printing it straight from the packaging without drying. PPA was the opposite and needed multi-day drying at 70c.
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Disappointingly, even though it has carbon fiber in it, my first attempt failed: it warped and curled away from the build plate:
I had used the default bambu PPS-CF settings, which set the heated bed to just 110C. Time to roll out the big guns! I’ll try it again at 120C, with no bed adhesive, as per
@maximit above. We know from the temperature uniformity thread that setting the heated bed temperature to 120C gets it up to only 105C actual measured temperature. If that fails too, then I’ll look to use a stronger bed adhesive.
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Yes I would bump the bed to 120c and the chamber to 65c the max. I was also printing at slightly higher temp 330-340c for best layer adhesion and part strength.
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I think I’ll raise first layer nozzle temperature to 330C and subsequent layers to 320C. The Bambu default for all layers had been 320C. Also, I’m increasing print speed to 75mm/sec, since it had no problems with 50mm/sec.
I’m also using a brand new build plate this time, so no chance of build plate surface contamination other than what may have come from the Bambulab factory.
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Off to a good start. At least so far there’s no peeling up from the bed:
Also, I’m able to maintain the filament’s drybox at 3.4%RH while printing, so that probably helps as well.
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imagine my disappointment of blindly buying AMS HT and then realize you can’t dry PPS with it fast
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Yeah, the AMS HT only goes to 85C. If using it in stock configuration, I doubt it will ever effectively dry PPS-CF. It’s below the drying range. I dried mine at 120C, and probably could have gone to 130C.
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Goodnews. This time it looks as though it will be finishing without the warping and curling that beset the earlier attempt:
I think next time I’ll raise print speed all the way to 100mm/sec, which is the maximum Bambulab recommends.
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higher overall bed temp is always better 
eveness doesn’t matter that much though it’s good to have
Yeah, I hope Bambulab fixes their firmware so that we can get a true 120C bed temperature instead of the 105C we’re currently getting (even though it’s set to 120C). On the other hand, maybe we are getting it when the chamber temperature is 65C. AFAIK, no one has measured it with the chamber heater turned on to 65C before. However, I wager it’s still 105C.
I’m letting it cool down slowly, at whatever natural pace it finds, and so far the print is continuing to hold without any lifting or detachment.
In retrospect using the Magigoo Flex on the earlier print was probably a terrible idea.
Anyhow, I’ll soon have my first shrinkage compensation number. After a few more test runs, I should have that number pretty well determined and can then finally get on to some useful printing. First application will be an adapter for 2" non-metalic smurf tube for connecting to electrical outlet boxes. The high heat deflection and natural flame resistance of PPS-CF should make it a good fit for that application. I haven’t been able to find appropriate Carlon adapters for 2" smurf tube. All the commercial adapters seem to top out at 1" diameter.
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oh i think what you’re seeing of “105C bed” is just what the steel sheet does. it’s normal to have a 10C ish drop on top of that bed plate & magnets. my thermal camera says the same thing on both my x1c and the h2d. 55C bed → 45C on top of textured PEI, 100C bed → 90C on top of plate… etc. And that temp recommendation actually has already compensated for this drop.
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So, using the model I just printed, the first pass on shrinkage compensation number is 99.6253%
Definitely more shrinkage than either PLA or PETG. For this reason, I can see why CF is recommended for PPS.
Now printing the second iteration at the higher speed 100mm/sec.
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It will dry PPA and PPS at 85c it will just need a few days. My PPA would not print well out of the package, stuck it in my 70c dryer and after 24 hours same result. After another 48 hours it printed cleanly, so longer drying time can compensate for lower temp.
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I measured a loss of only about 2g of moisture after drying my freshly opened Bambulab PPS-CF at 120C for two days. Considering it has a cardboard spool, that means it arrived fairly dry right out of the package.
For comparison, for a PLA or PETG that arrives on a cardboard spool, I can usually count on removing around 12g of moisture. However, they don’t generally arrive in a mylar bag, so there’s that also. And they cost about 10% as much, so I suppose they aren’t processed as carefully in the first place.
My Polymaker/Fiberon PPS was dry as well, its water saturation is only 0.05% so very low compared to Nylon and other filaments.
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@maximit At what speed are you printing your PPS-CF at? Faster than 100mm/sec?
I think i slowed down the outer wall and top surface to 60mm/s, but left all other speeds unchanged as they are limited by the flow rate anyways.
I miscalculated. First pass shrinkage factor is actually 99.8614%, or about half as bad as what I had initially thought.
This has been fun. Makes me want to try PPA-CF just for the heck of it.
Are you sure the success isn’t simply due to not using the flex magigloo? In the name of science you should try your initial print settings with nothing on the build plate 
