Flexible filament in the Mini?  

RE: Flexible filament in the Mini?

@3dprintedgr

I will try these.  I did have some stringing.  

RE: Flexible filament in the Mini?

I have some stringing too but not something extreme. This part is from yesterday and it was not cleaned after printing, most stringing happened inside the small arches. My worst problem is those seams. Because of the fact that the TPU is really durable, they cannot be cleaned later and they really stick out.

Like with other filaments I believe temperature is critical. Even though the manufacturers have the temperature specifications on the roll, most of the times I found that a lower temperature works best. Usually in the -10C to -15C range. But that's all trial and error and it varies widely.

RE: Flexible filament in the Mini?

@accounts-1

Can you share your printer and filament settings for ngen flex?
thanks

RE: Flexible filament in the Mini?

i used transparent Flexfill98 with the standard slicer settings on my mini. The result is a strange porous dpad.

I can change speed and temperature directly in the mini. Should I set speed to e.g. 30% and reduce the temperature ?
Best regards

Ralf

RE: Flexible filament in the Mini?

@ralf-4

This is similar to my settings.  

RE: Flexible filament in the Mini?

To be honest, since I tried other filaments than Prusament it gets frustrating.  With the flexfill I only achieved very inconsistent porous prints. I tried to increase and decrease the temperature but t does not help. Perhaps I have a problem with the first layer. Due to the gluestick the surface is probably not flat enough. If the print nose is too low I get problems with peeling at uneven areas. But additionally I think that the filament is extruded not very constantly. Anyone here with an unmodified mini succeeding to print flexfill98 ?
best regards ralf

RE: Flexible filament in the Mini?

I found the error. I exchanged the PTFE tube in the hotend and now everything works best !

RE: Flexible filament in the Mini?

I tried several flexible filaments with Mini.
PM Filament TPE32 (hardness 81A) - flexbile but not as elastic
Recreus Filaflex 70A - flexible and quite elastic
Recreus Filaflex 82A - flexbile and little bit more elastic than TPE32
Recreus Filaflex 95A - flexible and similar elasticity to TPE32. Even though more hard

In few weeks I was able to do test prints of simple objects (e.g. gaskets), handlebar mouting strap for bicycle light, fairly comlex mounting strap/cover of connectors for bicycle rear light (print time 2 hours).

Few rules for printing of flexible filament with the Mini:
- Loosen the extruder idler tension screw,
- Make sure you do not have Live Z distance too low. It makes too much pressure in the filament delivery sytem at first layer and can make extruder to clog up right at start of a print (imagine how hard it is to press a syringe plunger while you are holding finger on the syringe tip),
- You can increase your success rate when printing on the far left side of the bed. Having the print head on the left side the bowden tube does not have as sharp bend. It makes extrusion much easier. I had several failed flexible filament prints when the print head crossed middle of the bed getting closer to the extruder and bending the bowden tube in a sharp curve,
- Help the extruder and unroll filament from the roll little bit. It can fail to extrude when there is even moderate force needed to unroll the filament. Maybe this one is not as an issue as I think it can be 🙂
- Slower print speeds

All tests I did were on the stock extruder. The 70A filament is quite rubbery but it worked. Few fails but I was able to get results. I can share video where elasticity of the light mount strap is demonstrated.
Now I have Tianglelab dual drive extruder. Now sure how much it helped. I haven't tried to increase print speeds yet. I follow same rules I did with the stock extruder. I will try if it is able to extrude when printing flexible on the right side of the bed.

Hope it helped for those who want to try flexible filaments.

Rado

RE: Flexible filament in the Mini?

I just printed with Amazon Basics TPU with Generic flexible settings.  A little stringy but good results overall.  

RE: Flexible filament in the Mini?

I’m trying Ninjaflex Cheetah. It seems to extrude okay, I’m having problems with adhesion however, on a long narrow (in y-dir) piece. I’m using the textured sheet at 50C with a nozzle temp of 235C. Relatively low speeds as well. Should I put glue stick on the textured sheet? Painters tape? Something completely different?

RE: Flexible filament in the Mini?

My small test of various filaments including Recreus Filaflex 70A. The object is simple cylinder printed in spiral vase mode. Not as challenging for printing even though cooling should be set properly to avoid collapse of the print in case of flexible filament.
The other filaments are Prusament Galaxy Black and Polymaker Polymax PC (polycarbonate) and Polymaker PolyMide CoPA (Nylon)

RE: Flexible filament in the Mini?

Posted by: @captadhoc

I’m trying Ninjaflex Cheetah. It seems to extrude okay, I’m having problems with adhesion however, on a long narrow (in y-dir) piece. I’m using the textured sheet at 50C with a nozzle temp of 235C. Relatively low speeds as well. Should I put glue stick on the textured sheet? Painters tape? Something completely different?

Did you try use a brim?

RE: Flexible filament in the Mini?

On the smooth PEI bed, instead of using tape or glue stick, simply squirt isopropyl alcohol around the print when you are done, and the print scrapes up easily with a sharp metal spatula.  It's a little easier if the bed is still warm.  I spotted this trick online and it works great.

RE: Flexible filament in the Mini?

Posted by: @rat_patrol

Posted by: @shawn-blakeman

@rat_patrol

Do you mind sharing your settings overall? I have the Bondtech upgrades and have yet to try TPU but would like a good starting point to tweak for the filament that I have. Thanks in advance.

Retraction Setting:

Length: 4.5

Lift: 0

Retract speed: 40

Detract speed: 15

Extra length on restart: -0.5

Wipe while retracting: enable

Retract amount before wipe: 100%

Max volumetric speed: 2

Cooling: 100%, disabled first 4 layers

Nozzle temp: 240

Bed: 60

Extrusion multiplier: 1

 

The volumetric value and nozzle temp are what I primarily tweak on, as it will dictate the printing speed. Make sure you tune in your temps so you are not hotter than needed, but not too cold as to increase pressure on the filament during extrusion. If you have random clogs where it strips out the filament, try increasing nozzle temp 5 degrees.

Different flexibles need different speed/volumetric/temp settings, they are not all the same, but this should give you somewhere to start.

 

This post is quite old now, but I just wanna say thank you for posting these settings. These worked great on my Prusa Mini+ with the Bondtech Extruder upgrade; took a bit of fiddling and trial and error with my printer settings, but with my tuned print settings + your suggested filament settings. The only parts that I did change were extrusion multiplier (set it to 1.15 instead of 1) and bed temperature (55 instead of 60). The filament I used was Flexfill 98A.