RE: Printing TPU on the MK4
Sadly, I only had the instructions to work by. Very loose settings seem to work for PETG and TPU so I will leave them loose per my TPU setting. I'm a bit unhappy that this is "common knowledge" but was not conveyed in the assembly instructions (at least at the time of my assembly). I had looked at all the notes and don't recall seeing it there, but may have missed the note. I shall go back to the instructions and post the adjustment myself. This silly adjustment caused me a lot of grief, which only showed up on long prints. Had to print the equivalent of 3.5 prints to get one ok one. I was 1 success out of 9 tries.
Weird, the post (and user) I responded to disappeared... In any case, I did post my comments in the assembly document, as I promised. Might as well save someone else the trouble of stumbling over this.
RE: Printing TPU on the MK4
@ssill2 I received the PrintDry Pro 3. Have a couple silly questions for you. (Couldn't even determine which forum to post this in!). How are the silicone plugs installed? There's only two of them and the instructions don't tell you or show you what to do with them. Are they installed from the inside of the box or the outside? I presume the filament is threaded through it. Do you plug all the rest of the holes in the box? There's 12 holes! I figure some of them could be open, but 12?
RE: Printing TPU on the MK4
I don't feed the filament from the dry box. I just try the filament after I'm done using it. I don't plug any holes. I set it to 65, throw the spools in and the dessicant packs so they get dried at the same time and come back later. I live in CO so the relative humidity doesn't warrant having to actually feed the filament from the dryer while it's running.
@ssill2 I received the PrintDry Pro 3. Have a couple silly questions for you. (Couldn't even determine which forum to post this in!). How are the silicone plugs installed? There's only two of them and the instructions don't tell you or show you what to do with them. Are they installed from the inside of the box or the outside? I presume the filament is threaded through it. Do you plug all the rest of the holes in the box? There's 12 holes! I figure some of them could be open, but 12?
RE: Printing TPU on the MK4
In a fit of insanity, I am trying to print some smaller spool adapters for my PrintDry Pro3 in TPU. The small spool adapter doesn't fit my Prusa spools, it needs to be a little bit smaller. So I modeled it in FreeCAD and am attempting to print it in the Sainsmart TPU with the last settings derived from my last go at TPU. After slicing I find it is nowhere near the MVS limit, unlike the previous design/debacle. So I have reasonable hopes of a successful conclusion. I'm half way through the print now.
There is a bit of stringing at 218C, especially in the interior bore. Of more concern are the globs of TPU in the bore. They are harder to remove than angel hair.
I'll know if it is usable in two more hours.
RE: Printing TPU on the MK4
I don't even use the spool inserts for the printdry. I just hang them on the spindles. Again though, I don't bother with printing them from the printdry itself. I just dry the filament after I'm done using it and then throw it in the bag with desiccant packs to be ready for the next use. Your setting slook spot on with what I print with.
RE: Printing TPU on the MK4
I'm printing TPU out of the dryer at this point. It was raining this morning. Haven't hooked up the PTFE tube, so just filament is coming out of the box.
I printed some little bins yesterday on red Prusament PETG just hanging on the spindles, because that was my only option. I'm hoping these smaller spool adapters will be a little better. Almost ran out of filament on that print. (Maybe 15-20 turns left.) This red filament (direct from Prusa) was really wet when I received it, it snapped and hissed. Since I was a newbie, I didn't understand what that meant. Had some truly terrible prints. Like molten blobs and super adhesion to the satin sheet.
Due to the 65C drying of the PETG I can report that the same red filament printed flawlessly yesterday. The PrintDry unit really helps. Thanks for the tip on this. Back to TPU again.
What can I do to reduce stringing? Or is this something you have to live with? For this print I was at 218C, I can try reducing the temp a little, maybe increase the retraction amount?
RE: Printing TPU on the MK4
for the sainsmart I do 3.5mvs, vs your 3.6. if you lower the mvs, you can generally also lower the temperature since you're effectively trying to feed less filament through. Generally stringing eliminated by lowering the temp, but you also have to lower the mvs(usually) because the filament won't ooze as easily through the nozzle the lower the temperature. generally respect the spool temp with this in mind. retraction is generally meant to help with stringing also, but with the limitations of flexible filament it's generally a very limited length. again this goes back to doing very small test objects to see if you can get the behavior you want. Every new brand/type of tpu is an adventure like this. it's ever so frustrating. it's great when you get it working but as you've discovered, ever so frustrating until it does.
I'm printing TPU out of the dryer at this point. It was raining this morning. Haven't hooked up the PTFE tube, so just filament is coming out of the box.
I printed some little bins yesterday on red Prusament PETG just hanging on the spindles, because that was my only option. I'm hoping these smaller spool adapters will be a little better. Almost ran out of filament on that print. (Maybe 15-20 turns left.) This red filament (direct from Prusa) was really wet when I received it, it snapped and hissed. Since I was a newbie, I didn't understand what that meant. Had some truly terrible prints. Like molten blobs and super adhesion to the satin sheet.
Due to the 65C drying of the PETG I can report that the same red filament printed flawlessly yesterday. The PrintDry unit really helps. Thanks for the tip on this. Back to TPU again.
What can I do to reduce stringing? Or is this something you have to live with? For this print I was at 218C, I can try reducing the temp a little, maybe increase the retraction amount?
RE: Printing TPU on the MK4
You can eliminate the stringing between separate parts if you print them sequentially. Just turn on "sequential printing" and adjust the spacing of the parts on the plate accordingly. No more strings between the parts.
RE: Printing TPU on the MK4
It's functional, so it's good enough, but the exterior stringing is a downer. Not show piece quality, more like hobby grade. The ultra fine stringing goes away with a heat gun, but the coarser stuff doesn't and is difficult to remove. Nonetheless, it is ok for my purpose, it does hold the spools. The TPU printed ones on top in blue, the original small ones that came with the PrintDry.
Slowly getting there!
RE: Printing TPU on the MK4
Yes, I had forgotten about that option, but I was going to mention printing one object at a time.
You can eliminate the stringing between separate parts if you print them sequentially. Just turn on "sequential printing" and adjust the spacing of the parts on the plate accordingly. No more strings between the parts.
RE: Printing TPU on the MK4
Not many things in 3d printing are as rewarding as finally getting a reasonable print with tpu. it's such a pain.
It's functional, so it's good enough, but the exterior stringing is a downer. Not show piece quality, more like hobby grade. The ultra fine stringing goes away with a heat gun, but the coarser stuff doesn't and is difficult to remove. Nonetheless, it is ok for my purpose, it does hold the spools. The TPU printed ones on top in blue, the original small ones that came with the PrintDry.
Slowly getting there!
RE: Printing TPU on the MK4
You can eliminate the stringing between separate parts if you print them sequentially. Just turn on "sequential printing" and adjust the spacing of the parts on the plate accordingly. No more strings between the parts.
Wish I could enable sequential printing, but the slicer is preventing that. It says the part is too tall to prevent collision with the X rods. My part is 30mm high. I tried separating the parts to opposite corners of the sheet and it still says it is illegal data.
RE: Printing TPU on the MK4
Did you check which part will get printed first? Perhaps it will work if the x-rods never will be above the part that was printed first?
RE: Printing TPU on the MK4
I just tried to create a project for this. I set the "Extruder Clearance Height" to 50 mm and then created two objects with a height of 40 mm each, one at the front of the plate and one at the back. I checked in the slicer preview that the one in the front would be printed first so there would be no interference with the print head and the x rods when the part at the back of the plate would be printed. Then I saved the project and I also sent it over to OctoPrint. There was no error message from the slicer. I have not printed it, but I seem to have gotten further than you.
RE: Printing TPU on the MK4
I just tried to create a project for this. I set the "Extruder Clearance Height" to 50 mm and then created two objects with a height of 40 mm each, one at the front of the plate and one at the back. I checked in the slicer preview that the one in the front would be printed first so there would be no interference with the print head and the x rods when the part at the back of the plate would be printed. Then I saved the project and I also sent it over to OctoPrint. There was no error message from the slicer. I have not printed it, but I seem to have gotten further than you.
I did something similar after reading this. Wasn't familiar with using sequential. The height setting wasn't intuitive to me, so thanks for the explanation.
I'm going to try the Sainsmart GT-3 TPU tomorrow. I'm drying the new spool overnight. It is supposed to be faster printing, with an alleged higher MVS. We'll see if I can print anywhere close to 5mm3/s, which by the way is what Prusa says Sainsmart TPU would print at. Fortunately, if it goes awry, I can kill the job and probably only lose one print.
RE: Printing TPU on the MK4
The GT-3 TPU is printing very well. Very low stringing so far. Quite encouraging.
RE: Printing TPU on the MK4
One of the completed GT-3 TPU prints on the sheet. As printed. Way, way less stringing than before. No thick strands. Perfect exterior. This will clean up great. Second print is in progress, on the opposite corner of the sheet.
RE: Printing TPU on the MK4
I'm wondering if some kind person could take a look at the attached prusaslicer file for a keychain I am trying to print in Overture TPU. I've tried several times with multiple changes to the settings and to the idler tension screws and I cannot get it to print. The most it has ever printed is up to the bridging infill at 2.2mm (layer 11) and then the dreaded clicking starts and extrusion stops. This was with the settings saved in the 3mf and the idler tension screws backed out about 2 to 2.5 turns (approximately 1 - 1.25 mm). When I backed the screws off to about 2 mm the situation was worse and the clicking started at layer 2.
I took the default Amazon Basics TPU file and modified it to match the numbers given on the filament (210 - 230 C and 20 - 40 mm/s print speed) and some numbers given in this thread.
I did read through this thread before trying to print with TPU but maybe there's something I am missing.
RE: Printing TPU on the MK4
I looked at your .3mf. and since you've slowed down your retraction speed(a big cause of jams I've seen other than too fast), I'm going to say you're still trying to print too fast. I see you're using an mvs of 3.5 and a d temp of 220. I would either lower the MVS or increase the temp to make it easier to push the filament through the nozzle. I'd try 225 for your temp and maybe 3 for your MVS.
I'm wondering if some kind person could take a look at the attached prusaslicer file for a keychain I am trying to print in Overture TPU. I've tried several times with multiple changes to the settings and to the idler tension screws and I cannot get it to print. The most it has ever printed is up to the bridging infill at 2.2mm (layer 11) and then the dreaded clicking starts and extrusion stops. This was with the settings saved in the 3mf and the idler tension screws backed out about 2 to 2.5 turns (approximately 1 - 1.25 mm). When I backed the screws off to about 2 mm the situation was worse and the clicking started at layer 2.
I took the default Amazon Basics TPU file and modified it to match the numbers given on the filament (210 - 230 C and 20 - 40 mm/s print speed) and some numbers given in this thread.
I did read through this thread before trying to print with TPU but maybe there's something I am missing.