Snapmaker U1 feeder brackets for filament dryer.

Please read everything before proceeding as there are parts you may
wish to order first.

The best way to do this is ...

PLEASE MAKE SURE THE DEVICE IS DISCONNECTED FROM THE MAINS POWER SUPPLY
BEFORE MAKING ANY CHANGES. THANKYOU.

1. Disassemble the SpacePi (4 screws under the rubber feet). it becomes the dark plastic innards and the light plastic shell. (we are only concerned with the shell).

2. Prepare to drill 4 holes per side. 2 for the bracket and 2 to insert the PTFE tubes (or you may not be using PTFE tube). Have a marking utensil (pen or pencil) with a long nose and place the bracket on the back of the out SpacePi case where you would like it to sit. Positioning it so that the feeder holes are at the same height as the existing holes (grey) and are positioned perfectly in the middle.

At this point adhere to the British saying 'Measure twice, cut once'. Mark the holes in the bracket base,
and where the feeders would line up with the SpacePi casing.
At this point I would triple check everything, ensure the holes marked for the bracket are the same
distance as each other from the top of the plastic base, just ensure everything is straight. Then do the same for the other side.

3. You have to drill the holes now. In reference to the outer case only, drill 4mm holes for the lower holes where the brackets will be secured. You have very little space inside the SpacePi so you will have to cut the bolts down to as short as you can (with the nut on (you get the picture)).

4. I have added PTFE outer guides stl's to the files section. These are the black guides that are in the SpacePi outer case that the PTFE tubes go into. 
At this point it's important to say, the PTFE tubes that go from inside the SpacePi to the feeders is important to have as it reduces friction and thus aids in the easy feeding of the filament.
Please note though, that the PTFE tube that Snapmaker use (quite cleverly) has a wider internal diameter than the standard. It has an inner diameter (ID) of 3mm and an outer diameter (OD) of 4mm.
You can either cut appr 80mm off each of your existing tubes or order additional tubing. I'd order the additional. This is the stuff I ordered. 

https://www.aliexpress.com/item/1005008386148070.html?spm=a2g0o.order_list.order_list_main.64.6acd1802vVbvX5

back to the PTFE outer guides. You will need to drill 6mm holes for these and glue them in. The PTFE tubes will then thread from the inside of the SpacePI through these and into the feeder.

From the above picture you can see I have drilled straight through to the inside of the SpacePi.
It does work, but it's not ideal. I'm going to redrill those holes say 10mm++ away from the centre
from where they are now. I would prefer them not so far to the side of the spool.

5 Once you have your feeders relocated to the back of the SpacePi and you have extended the
signal wires (look at these I found on aliexpress 
https://www.aliexpress.com/item/1005011978215116.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.1.42a4iiTwiiTwkE&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.354490.0&scm_id=1007.40050.354490.0&scm-url=1007.40050.354490.0&pvid=0d6eff84-5279-4c24-b600-bdfb54cc949f&_t=gps-id%3ApcDetailTopMoreOtherSeller%2Cscm-url%3A1007.40050.354490.0%2Cpvid%3A0d6eff84-5279-4c24-b600-bdfb54cc949f%2Ctpp_buckets%3A668%232846%238110%231995&pdp_ext_f=%7B%22order%22%3A%22443%22%2C%22eval%22%3A%221%22%2C%22sceneId%22%3A%2230050%22%2C%22fromPage%22%3A%22recommend%22%7D&pdp_npi=6%40dis%21GBP%212.04%212.04%21%21%212.69%212.69%21%40211b813b17782612143186842e8a29%2112000057201518734%21rec%21UK%211627483069%21XZ%211%210%21n_tag%3A-29919%3Bd%3Ac3b655fe%3Bm03_new_user%3A-29895&utparam-url=scene%3ApcDetailTopMoreOtherSeller%7Cquery_from%3A%7Cx_object_id%3A1005011978215116%7C_p_origin_prod%3A&tblci=GiCvYPHe7M-bmilK1qoe6xaqXwZr0GkXMBIc5kloyLxBJyDA9m4o0I_siZna7_TJATD6y1Y

Great Price and 1 metre long !!!
Anyway, once everything is done you'll find that feeder 1 and feeder 2 are switched.
So for your two feeders looking at them from left to right you'll actually have 2 1 3 4
In order to correct this we need to make some changes to printer.cfg

Scroll to the end of printer.cfg then scroll up and change this line to the following

variable_channel_sequence: 0,1,0,1

then continue to scroll up search for the following lines and change them to what is here

[filament_feed left]
# extruder
filament_ch_1: 0
filament_ch_2: 1

save printer.cfg and reboot your printer.

Enjoy!.