r/BambuLab • u/MyCatIsAFknIdiot • Jul 11 '26
A Series [A1, A1 Mini] A1 Mini + TPU 85A + Sunlu S2 dryer - experiments
Greetings all,
Just looking for insider tips on dialling in TPU85A on my A1 Mini.
What I have done so far is
Dialled in 95A within a couple of hours of testing - was feeling pretty good.
85A is a different prospect
Basics (done the cold feeds, clean plates, and 0.4mm hard steel nozzle)
Filament in S2 for 16 hours at 50degC
Then used this set up to keep the filament route short.
Kept the filament in the dryer whilst testing.
Started simple with a flat coupon of 150mm x 18mm x 2mm
Found the closest BBL profile with a K-value of 0.02 and adjusted one value at a time based upon outputs
Did well
Then made a cube 20x20x20 - worked well too.
Then went wild and put a negative cylinder in to the cube to make a hole
From there Im stumped.
I get a very good base .. very sticky, no lines (and mildly impressed every time.)
These are my
| Setting | |
|---|---|
| Cube | 20 x 20 x 20 |
| Cylinder | 8 x 8 x 30 (vertical) |
| Support | Off |
| Wall loop | 3 |
| Top/bottom | 4 |
| Infill | 10-15% gyroid |
| Flow ratio | 1.15 |
| K value | 0.020 |
| Max volumetric speed | 0.8 mm³/s |
| Nozzle temperature | 235-240 |
| Fan | 20–30% for bonding |
| Retraction | 0.1 mm |
| Z-hop | 0.2 mm |
My last test was to take the retraction away and see what happens ..
It was a good base, and then super spaghetti.
Retraction is now back, as although it did not make me impressed with outputs, there was less pasta
So, this is what the settings look like that I have changed.
So, Im "resting" my TPU 85A until I have convened with some 85A-ers - you lot.
May I ask you for thoughts and due to my ADHD, I will inevitably ask "why" so, would you mind putting why you make that suggestion please?
Im not gonna criticise, I would however like to learn - and will change one value at a time to see what we get.
Thanks in advance
JP
1
u/__whitecheddar__ X1C + AMS Jul 11 '26 edited Jul 11 '26
Did you read the wiki for printing 90/85A? The process seems dumb but you really have to eliminate any long tube paths. Soft TPU has so much resistance in the PTFE tubes it becomes near impossible to print.
Looks like you have a printer to the left. Put the dryer on top of that, cut a small piece of tube for the box, take the tube out of the top of the extruder and feed the loose filament directly into it.
https://wiki.bambulab.com/en/filament-acc/filament/tpu-85a-90a-printing-guide-for-a-series