brazen eagle
I remember talking with someone in this server recently who needed something like this, but I can't remember who it was...
Anyway, I have just posted my designs for servo arms to sit above and below the gantry of my VzBot 235 to push my toolhead cutter lever, direct purge waste off the bed, and wipe the nozzle.
https://www.printables.com/model/1624683-servo-driven-purge-chutebrush-and-filament-cutter
STLs are up now and CAD files will be added in a few days after I clean them up a bit.
rancid copper
Oh I like this. Going to print it!
brazen eagle
Oh I like this. Going to print it!
Let me know how it works out and if you have any feedback! Once I have a stable final-ish macro I'll add it to the Printables page...for now all I can say for sure is I recommend full blasting your cooling fan during purge so the plastic doesn't drip on the chute at melty temps.
rancid copper
I need to dig through my servos but I think I need to order a bigger one than what I have
brazen eagle
honestly the 20kg is overkill for the poop chute/brush arm, but I liked the idea of it sharing most of the parts with the cutter depressor arm, which did need to be strong af
brazen eagle
about halfway back on the left side, attached to the beam where the gantry rails are
probably clearer in the photo of the top one
the chute/brush arm is just directly under this
brazen eagle
yeah it's attached upside down on the bottom of the 2020
rancid copper
This is my thing for cutting with
brazen eagle
I thought about something like that. actually I just tried pushing on the motor itself first lol (my motor mounts are upside down to make room for the triple z mod I designed)
but it didn't quite push far enough, and I had one of the 20kg servos laying around from my previous disastrous experiment with a hub cutter
rancid copper
looks like i'll need to think about where i'm going to mount the chute. maybe on the rear
brazen eagle
is there not space between the front and back Z-mounts?
rancid copper
not with the side cooling fans
brazen eagle
ahh, right, I've never used those. it would probably work on the back
runic blade
will try this soon with a trident
brazen eagle
I'm working on a new version that will use a spring-loaded "drawer" on the arm to catch waste. a bit more complicated mechanically but should make for smaller poops that are easier to catch. the current version works fine for me but the poops end up being long strings that are a pain to clean up.
the concept is you would have an arm that hangs down from the beam to push this out when the arm retracts. I'll update once I've tested it. probably I will leave both published as I expect they suit different situations
brazen eagle
this version still needs some tuning and there are tradeoffs (takes up more space between the build plate and enclosure), but so far it's promising. producing more manageable waste without much added mechanical complexity
runic blade
what macro did you use?
ohh i am stupid, sorry for the question.
do you need a alpha tester for your macro and the spring loaded drawer?
would try that on my wip trident
brazen eagle
ohh i am stupid, sorry for the question.
do you need a alpha tester for your ma...
no worries! I did have to write a custom macro, this is what it looks like right now
runic blade
hmm i see hardcoded positions
all good, i will cook something as soon as printed it 😄
brazen eagle
I abandoned the spring idea and went with magnets instead. basically the drawer has magnets that are attracted to the back/repelled from the front, so it snaps back into place unless it's being actively pushed
runic blade
if that works even better why not
brazen eagle
runic blade
macro should work with the normal and magnet version?
brazen eagle
the z hop variable needs to be bigger with the chute version, it's like 15mm taller
runic blade
also this might sound odd, but this thing could even work with a ender 3
runic blade
the z hop variable needs to be bigger with the chute version, it's like 15mm tal...
alright 😄
one last thing, its kinda not clear what to print. i dont need the cutter stuff, i have my own cutting servo arm thingi. do i just need chute arm, servo mount, arm support and the shim?
brazen eagle
yeah, basically one of the two arms and one of each of everything else.
runic blade
alright
brazen eagle
if you want to test the magnet version this is the current CAD, but it's definitely a work in progress
also to make the surface the plastic drops on a bit more resilient I ended up cutting a piece out of an old damaged PEI build plate and gluing it on
apart from that the v2 needs six 6x2mm magnets and three M3x4mm threaded inserts
runic blade
also to make the surface the plastic drops on a bit more resilient I ended up cu...
will use alu foil, maybe you should stick your head together with @vapid terrace because he created #1413552213695008869 and its more ore less the same idea 😄
brazen eagle
yeah, I've been following that thread too
runic blade
ordered the magnets (cant find my 6x2), will 6x3 also work with some modifications?
brazen eagle
you might have trouble getting the drawer to open far enough
I would say shrinking the diameter would be better than increasing the thickness
so if you can find 5x2s go with that
brazen eagle
main issue for reliability at the moment is poops getting caught in the mechanism. I think thickening the back of the drawer and getting rid of the "bar" over the front of it will be part of the answer. seems more reliable with these quick and dirty modifications done with side cutters and a bit of acrylic offcut.
would very much welcome feedback on this element specifically. photos of where and how any stringy bits get stuck etc.
runic blade
main issue for reliability at the moment is poops getting caught in the mechanis...
printed the cad file that you gave me, where goes the brush? 😄
seems like that part is not in the cad file
brazen eagle
right here in this indent
it's sized for the brush that comes with the Cartographer probe
brazen eagle
very weird, all I can think is maybe Fusion doesn't include a componen in a step file export if it's hidden in the current view...I've re-exported it, there are some differences since this is my latest version but I think the top plate should still fit what you've printed
runic blade
thanks, will print and assemble it tomorrow 😄
runic blade
main issue for reliability at the moment is poops getting caught in the mechanis...
i implemented that fix in the cad file
Removed the front bar and added a small extrusion at the rear of the drawer
i also got an idea how i could implement this onto a ender 3
runic blade
@brazen eaglei dont unserstand how this part is mounted
are there any heated inserts involved and when yes which side?
also how is the servo arm mounted to the servo?
brazen eagle
<@784880700679651358>i dont unserstand how this part is mounted
are there any h...
heat sets in the front then countersunk screws from the back
brazen eagle
also how is the servo arm mounted to the servo?
servo should have come with a bunch of mounting thingies, use the round one with the four screw holes aligned with the ones in the arm
runic blade
yeah i have the round one but bearing will not fit with the small screws
its on hold for now till some components for my servo expansion board arrives
the 5V rail of the leviathan is too weak for that xd
hopefully 5v 5a is ernough xd
brazen eagle
yeah i have the round one but bearing will not fit with the small screws
tbh I lost the screws the servo came with so I used some M2s I had laying around, I think they're 5mm long
brazen eagle
Yeah that'll definitely be too long and hit the bearing
brazen eagle
As for the 5v power thing, I powered my servo off the 5v psu I'm using for my pi
runic blade
you screwed the little screws from below?
runic blade
As for the 5v power thing, I powered my servo off the 5v psu I'm using for my pi
my rpi is connected to the ldo leviathan
brazen eagle
ahh, yeah, that's gonna overload it :\
runic blade
but a solution is in works
ordered the missing header and then lets go
that thing has 5v5a just for the servos and some other small crap :3
also levelshifter from 3.3V to 5V
runic blade
you screwed the little screws from below?
back to this
and how long are your screws?
brazen eagle
you screwed the little screws from below?
I should probably take assembly photos at some point...but that would mean tearing it apart again lol. the screws go in from the servo plate side.
runic blade
I should probably take assembly photos at some point...but that would mean teari...
that would be helpful
can do that for you
so small screws from the servo side?
runic blade
alright from below, thanks 😄
brazen eagle
you can also put an M3 in from the other direction, through the hole in the middle into the threaded hole in the servo. it's probably overkill but I did design it so a cap head M3 will sit under the bearing
the screws I used were M2 x 5mm self tappers I think. possibly 4mm.
runic blade
btw pluggin in the servo was hella scary
i dont why but everything worked except the canbus connection to the toolhead. mcu itself was fine, i thought first the toolhead board died :DDD
brazen eagle
I got a cheap 20kg servo that melted its own wires on like day 2
runic blade
i wonder why 20kg servo
brazen eagle
then I bought the Miuzei ones and everything was fine
it's a holdover. I used a 20kg one for my servo-actuated cutter pusher arm thing, where I wanted it to be super strong when the toolhead was actively pushing on it. and then I just used the same mount for this.
runic blade
it's a holdover. I used a 20kg one for my servo-actuated cutter pusher arm thing...
yeah even there its overkill
i have a servo cut thingi with a small servo, its designed that the toolhead presses agains the plastic frame and not the servo
brazen eagle
it's also just that the two I had laying around in the workshop were either that or a truly tiny one
runic blade
runic blade
it's also just that the two I had laying around in the workshop were either that...
ahh yeah okay that makes sense
runic blade
the screws I used were M2 x 5mm self tappers I think. possibly 4mm.
currently measuing it in cad
brazen eagle
then it melted and I had to buy another one anyway 🙄
runic blade
classic
4mm sounds about right
plastic thingi is 1mm thick, your arm is 3mm thick
time to order 280 screws to only use 2 screws at the end xd
brazen eagle
and then in six months realise you had the damn things laying around somewhere from an old Pi 2 case or some shit
brazen eagle
I got mine out of a whole set that I think was called "laptop fixing screws" or something, it's got multiple lengths of everything from M1.7 to M3.5. So I'll never need to buy a small self tap screw again in my life
runic blade
nice
i also got some plans to adapt this to a ender 3
that will get a kinda overengineered mod but hey, maybe thats also something for here.
i will use the servo to move the arm in position. the toolhead will do the drawer motion
brazen eagle
oh interesting
runic blade
so i tried to run the servo... that thing is a beast, it shredded its own abs base
brazen eagle
that's impressive. went the wrong direction and pushed the arm through the bracket?
runic blade
went to far
well i tried to assamble it
guess what, i ordered the wrong magnets -.-
brazen eagle
the good news is, the latest version I installed has done 500+ filament changes without a failure
runic blade
nice!
brazen eagle
Drawer isn't moving very well. I used alu foil
Probably needs a very smooth surface to glide on. That was why I used a cut up PEI sheet. Maybe reducing the width of the side walls would help, so there's not as much surface area in contact?
brazen eagle
You could use a chamfer so they narrow at the bottom even more
But if you've got anything smoother you can put in the bottom instead of the foil I would try that - maybe cut out and flatten a piece of a soda can?
runic blade
brazen eagle
Definitely looks like there's some friction happening but hard to tell where. Maybe try re-printing the drawer scaled down a few percent? Also, how freely does it move if you unscrew the top piece?
runic blade
close, i will add some material that glides on the alu foil
runic blade
i also think that the turdherder macro will work with the servo arm thingi
but yeah for now i want to fix the drawer.. did you have any issues with springs? thinking about replacing the magnets with springs
brazen eagle
I gave up on springs in the design phase because they took up more space and I couldn't figure out how to get the drawer to come out as far. Never actually tried them.
runic blade
hmm maybe i will try it, for now i am fine adjusting the drawer
if i cant get it t to work i will try it with springs. have some spare
runic blade
yeah i will make a spring version
the drawer is as good as it can get, the problem is i got very very weak magnets i guess... that servo is strong ernough for springs so why not?
runic blade
well lets see if this version works better. i changed alot.
brazen eagle
the drawer is as good as it can get, the problem is i got very very weak magnets...
silly question maybe, but you definitely have all six magnets in the right orientations, so they push away from the front and pull toward the back?
runic blade
yep
brazen eagle
can you tell where the friction is happening? also, how does it move if you unscrew the top piece of the arm? I wonder if it's getting squished a bit
runic blade
at the in position
brazen eagle
no I mean like, which part of the drawer is getting caught on something
runic blade
i think its the rails
brazen eagle
I'd try loosening the top plate. if that helps then maybe reprint the drawer at 95% Z size.
runic blade
fixed it
the rounded corner solved it
also lowered the magnet position a bit (0.5mm), increased the magnet hole diameter to 5.3 and add some other neat stuff. for example low friction surface
brazen eagle
nice, will def integrate some of this when I get around to a final-ish version for posting. let me know how it goes over the next few big prints.
