There are a lot of filament holder and buffer design, enraged rabbit ERCF has its own buffer design as well. but this one, is for IKEA Samla 22L box, to hold 3 filaments with buffer.
( box top cover size measure 39CM X 29CM X 27CM, ikea code name 801.029.76 , cover code 904.550.86 , 22L ).
The 22L samla box is a “small” size box, it's just right size for 3 filaments, and it's cheap.
So we can keep filament dry.
So that our filament won't be left outside of open air, they are kept inside the Samla box, they are dry, since we have built in buffer for each filament, we can use them to print while they are in the box, and use them with multi material system , like ERCF.
The buffer system is inspired by ERCF 's buffer system, but designed from scratch.
About buffered filament length:
I use 3 rounds in buffer wheel, with 3 rounds, it can hold about 950CM length of filament.
I believe 4 rounds could be too tight, the friction is too large for ERCF and extruder to pull.
but YMMV.
The buffer cage/base size is optimized for samla 22L box, it's a very tight fit for 3 filament holder in the box.
If I make the filament base larger/wider, then we can't fit 3 filament holder system in one 22L samla box.
I have tried quite a lot of brand of filament , they all fit, amaz*, polym*, overt*, sunl*, crea*, filame*, . The only one brand (pril* ) of my old filament roll is too thick/tall/high to fit, and that brand stopped selling in my country, so who cares.
thickest filament roll to fit is 68mm.
Please take a look at the pictures how my samla box/buffer/ERCF look:
I have two Samla Box (22L) on top of my Voron, so I can hold 6 filaments.
my Voron is 250mm size.
My ERCF is 6 colors so two boxes is just right.
My ERCF is mounted on the top/back of my voron printer using my ERCF mount design
https://www.printables.com/model/572132-ercf-enraged-rabbit-carrot-feeder-voron-24-mount
It's not a 10minutes small project, quite a few components need to print and some hardware is needed.
there are 3 main parts to print and assemble:
1 filament roller base
2 filament buffer
3 box fitting for Pneumatic Connectors ( PC4-M6 straight )
Design consideration about bearing or nail+ptfe:
I saw a lot of filament roller base design use bearings, I tried that too, it turned out bearing is indeed not a good choice for the job.
I also made and tested bearing roller and nail roller, obviously nail roller has much smaller friction than bearing design. Check the compare video.
In this design, I use nail ( finish nail, dia 1.8mm , they have smooth surface), . They are cheap, 3-4-5$ for a box about one/two hundred pieces. And PTFE (2mm inner 4mm OD diameter)
The nail diameter is not highly precise necessary, it's not rocket surgery, about 2mm and can easily insert and rotate in the 2mm ID PTFE tube is good enough.
some finish nails, standard PTFE tube (ID 2mm, OD 4mm), M3 hex nut, 4pcs, M3 Hex socket head screw 8mm long 4pcs.
check picture for roller base.
We need the bearing adapter tight fit, but currently our printer cannot be that precise.
The bearing adapter need a OD be 6mm, and and ID 3mm.
while OD is 6mm and be tight fit, we can print , but at the same time, ID cannot be printed as about 3mm, the easiest way is to use M3 tapping drill to make it 3mm to tight fit the M3 screw.
buffer and base is now fully assembled, for one filament.
optional, print base_link.stl part to link 3 filament roller base together.
If you so happen want to use other size of bearing, then you can design your own bearing adapter and wheel, since it's easy. the wheel should be 11.6mm thick.
Put it inside the samla box left most or right most position, plan the space for another two filament base/buffer.
at this time we can print and assemble the box fitting, so we can start using filament and printing while it's inside the box….to make other two filament buffer/base.
because we need the filament gets out of the Samla box, a box fitting is necessary, I use Pneumatic Connectors PC4-M6 straight for the job, check picture for detail.
Too bad we must drill holes on the box wall, without a hole, filament cannot get out.
to install filament fitting parts, we also need two more screw holes.
so 3 holes for one filament.
Measure and plan twice before drilling, Samla 22L box is not expensive but it's not very cheap.
the main filament hole should align and face the tube_holder_base.stl's outside hole.
use M3 screw 10mm X 2pcs for one fitting
M3 nuts X 2 pcs
PC4-M6 connector
PTFE tube ( ID 2.5mm and OD 4mm) as ERCF suggests. We use 2.5mm ID tube (instead of 2mm ID tube ) to reduce friction.
When a filament base/buffer/box fitting is not used, we can use the box fit block to block it to keep the air out.
Samla Box top mount holder.
A box of filament could be 3kg + 1 kg (base, buffer, Samla box etc) = 4kg, so two boxes could be 8kg, it's heavy, the poor Voron acrylic top panel may not be strong enough to hold two boxes for long time.
We don't want to put it on the thin acrylic panel.
For Voron 250mm, we can use this box top mount holder, just print, easy, lost cost.
( For larger size voron, may need other solution, ie 2X 2020 extrusion with the right size. )
print 4X box_top_mount_vert.stl, install using M3 10mm X2 and hammer nut X2 for each on VORON top rail left/right. ( 8 M3 10mm screws and 8 hammer nuts)
Tip: install and tighten the vertical M3 screw first, the top screw later to make it stand straight.
print 2X spacer_block and 2X spacer_block_B for.
Use M2.6 8mm to install the spacer_block.stl or spacer_block_B.stl.
It only works for Voron 250mm. for Voron 300mm it's too small too weak.
now we can put the samla box on it, and the two heavy samla box not touching the acrylic panel at all.
Use 40% or more for the top mount holder since it need to carry 8KG of weight.
Check picture
1 When using buffer wheel, the friction is something must be deal with.
with everything we do, the friction is still large when using wheel.
so we must let ERCF to help to pull the filament out, it's better we use extruder stepper motor sync feature
https://github.com/ntchris/ERCF-Software-V3 (my fork of the happy hare ERCF software, has a few of enhanced features like always enable motor sync and different filament temperature handling etc from the original https://github.com/moggieuk/ERCF-Software-V3, from the original ERCF software…)
Also use Springy mod to help to let the ERCF gear to engage hard enough.
https://github.com/moggieuk/ERCF-Springy
2 can also use foam tap to help to seal the box cover better. put 1mm thick 8mm or 10mm width on the Samla cover.
3 samla box clip to help to close the cover tight.
search for Ikea_Samla_Clip_5-11-22L_by_Wookbert_Rev._G2.stl or other type you like.
no support needed.
any material should work, I use PETG.
20% or more.
3 or 4 parameters/wall
sorry it's a bit too large for MK3 print bed.
The author marked this model as their own original creation.