#robotics Logs

Apr 18 2015

01:16 rue_shop3 Jak_o_Shadows, which one?
01:16 rue_shop3 armyofevilrobots, what is the size of it?
01:22 Jak_o_Shadows er, greg's hinged accessible reloaded
01:23 rue_shop3 isnt' the stl enough?
01:23 Jak_o_Shadows I'm wanting to design an interchangeable extruder, redoing the x-axis carriage in the process.
01:24 Jak_o_Shadows But stl's suck to measure from
01:24 rue_shop3 hmm
01:24 Jak_o_Shadows and all the existing interchangeable ones have x-axis bars horizontal, not vertical
01:24 rue_shop3 I thought there was a projector that output pdf
01:24 rue_shop3 ah, funny, I was looking at making my new machine with the x axis the other way around
01:25 rue_shop3 at the same time I want to make the drive idenpendent from the mounting
01:25 rue_shop3 so that the drive system dosn't pull on the bearings
01:25 rue_shop3 (X drive, z bearings)
01:25 rue_shop3 I found...
01:26 rue_shop3 http://www.thingiverse.com/thing:210915
01:26 rue_shop3 that one thats giving me ideas
01:26 rue_shop3 Jak_o_Shadows, ping
01:27 rue_shop3 right now I'm trying to get around a problem mounting my heated bed
01:29 rue_shop3 Z axis motors on the bottom is a bad idea tho
01:29 rue_shop3 as it would cause pressure on the sprung axis of most steppers
01:29 Jak_o_Shadows yup, back.
01:30 Jak_o_Shadows Hey, that carriage looks alriht.
01:30 Jak_o_Shadows Have you got the PCB heated bed?
01:31 rue_shop3 :/ yes
01:31 rue_shop3 my custom one shattered when I tried to dial it up to 1M*c
01:31 Jak_o_Shadows What's your bed? Wood or metal?
01:31 rue_shop3 I went for broke, and it did
01:31 Jak_o_Shadows ha
01:32 rue_shop3 my cold bed is glass on rubber spacers to a aluminum base plate
01:32 rue_shop3 my hot bed is thin mirror with thermal paste to a pcb heater
01:32 rue_shop3 thats all right now, its sitting on the workbench till I work out how to make a leveling mount
01:33 Jak_o_Shadows Why not the 3 screws method?
01:33 rue_shop3 xy rigidity
01:33 Jak_o_Shadows Mmm, I think I get a bit of twist.
01:34 rue_shop3 I'm mulling options
01:34 rue_shop3 I'd like to make a little scisor jack :)
01:35 Jak_o_Shadows haha. Mine is the heated bed PCB, resting on 4 bolts (adjustable), with 2 toothpicks in two adjacent corners of the pcb, and two screws in the other side
01:35 rue_shop3 the self-ratcheting push it down level with the head method is slick
01:40 Jak_o_Shadows I have the issue with greg's is that there's only two tiny bolts attaching it to the carriage
01:43 rue_shop3 but there is no pressure on the bolts
01:43 rue_shop3 ?
01:43 rue_shop3 Imean, if its a teatering argument ok, but there is no pressure on it
01:43 Jak_o_Shadows No axial pressure. It's more the plastic failing when tilting
01:43 rue_shop3 oh wait
01:44 rue_shop3 I think it depends on the nozzel
01:44 rue_shop3 the plate ones I think leave the extruder pressure on those bolts
01:45 Jak_o_Shadows I have a j-head. It's jus that the weight of the stepper motor (in particular) as well as other hanger on things is offset, so the bolts are in bending, which makes the plastic fail at where the bolts rest.
01:50 Jak_o_Shadows https://github.com/buben19/bacon has inventor parts at least
01:59 Jak_o_Shadows He just imported them.
02:16 Jak_o_Shadows bloody imperial units
05:09 SquirrelCZECH_ hmm
05:09 uirrelCZECH_ finally installed z-offset calibra
05:09 SquirrelCZECH_ oh
05:09 SquirrelCZECH_ "z-probe"
05:09 SquirrelCZECH_ problem is... when I run the probing, it doesn't move on y-axis
05:09 SquirrelCZECH_ while normally y axis works :/
22:43 rue_shop3 ok
22:43 rue_shop3 the idea is
22:43 rue_shop3 to take a pwm output, filter the hell out of it, feed it back into an ADC channel
22:43 rue_shop3 close loop control it
22:52 Jak_o_Shadows to achieve?
22:52 rue_shop3 ok whats 2.5 decades back from 6.25Khz?
22:53 rue_shop3 stable analog output
22:53 rue_shop3 compensated
22:53 rue_shop3 I think its about 31Hz
23:17 rue_shop3 hmm
23:17 orlock rue: http://en.crypt.net.au/Prusai3/24.html http://en.crypt.net.au/Prusai3/25.html http://en.crypt.net.au/Prusai3/26.html
23:17 rue_shop3 how does the loop gain go...
23:17 orlock yeah, some under extrusion/infill issues
23:18 rue_shop3 dude, insane resolution
23:18 rue_shop3 nice
23:18 rue_shop3 what did the problem turn out to be?
23:18 orlock still unresolved
23:19 orlock printing fan mounts to see if airflow directed at the nozzle helps
23:19 orlock nozzle/part
23:19 rue_shop3 would you try bumping up the temp by 10c and running at 60% your current speed?
23:19 rue_shop3 just for giggles?
23:19 orlock i have, i have
23:19 rue_shop3 oh
23:19 rue_shop3 no diff?
23:19 orlock nope
23:20 rue_shop3 I wonder if your palstic is wet
23:20 orlock actually, i think the problem went away when i went to something like 40mm/s perimiters, and 15% of that for externals
23:20 orlock or something silly like that
23:20 orlock and it only seems to bea problem with externals first
23:21 rue_shop3 40mm/s
23:21 orlock yeah
23:21 orlock slooow
23:21 rue_shop3 my highest speed is 35, and I usually have to run at 80% or so
23:22 orlock it may even be something like hot end not being 100% perpendicular
23:22 rue_shop3 you may be pushing it too hard
23:22 rue_shop3 I think your plastic cant keep up
23:22 rue_shop3 how many watts on your head?
23:22 rue_shop3 mine is 36
23:22 orlock dunno
23:22 rue_shop3 (12v 3a)
23:23 rue_shop3 FIND OUT!
23:23 orlock is 12v, dunno heater block resistance but it stays within a degree or two
23:23 rue_shop3 if I'm outputting from a 8 bit pwm and inputting with a 10 bit adc, whats my gain...
23:23 rue_shop3 check the current on it
23:23 rue_shop3 easy
23:23 rue_shop3 turn on, break circuit, read, turn off
23:24 orlock the problem only appears when its extruding in a straight line for more than an inch, but not constantly
23:24 rue_shop3 oh, duh, 4
23:24 rue_shop3 yea, the plastic cant keep up
23:25 orlock i still need to insert the nuts
23:25 orlock will heat them up with hot air gun and press them in
23:25 orlock the odd thing is - i can extrude much much faster - with externals last
23:27 rue_shop3 do a test air extrusion for the same amount as that run, see if it always comes out smooth
23:27 rue_shop3 or if its got bubbles