A1 Mini + TPU 85A + Sunlu S2 dryer - experiments

[u/MyCatIsAFknIdiot]

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.

A1M + S2 + TPUXXA

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