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Re: this is what happens when mechatronics goes bad - 6 years ago
I would like to hear more details about the instructions for best cooling. Cross-flow is likely to be laminar and it's standard knowledge that: (copying from Wikipedia) "When fluid is pumped through these channels, it can develop two basic characteristics: laminar or turbulent flow. Characterized by turbulence, where fluid does not flow in smooth layers but is agitated. Turbulent flow, due to thby shadowphile - Duet
Re: this is what happens when mechatronics goes bad - 6 years ago
At first I didn't trust magnetic ball-joints because of their inherent 'brittleness' so I went with the Trick Laser ball-cap rod ends. They work as well as the magball joints but probably not as popular because harder to print your own accurately and not as 'clean', and more parts. I didn't like the offset springs, which interfered with my particular effector, and the spring loops can break offby shadowphile - Duet
Re: this is what happens when mechatronics goes bad - 6 years ago
crap. that puts me back in head-scratching territory. i want to add a 'misbehaving' safety mechanism in but its not easy defining what is expected or notby shadowphile - Duet
Re: this is what happens when mechatronics goes bad - 6 years ago
I have some small copper heat sinks just right for the driver chips and I figured I might as well put them to use since I will be improving the cooling. Should I put them on top of the chip or underneath? I can think of arguments for either one. I like underneath because easier place to mount the fan and heatsinks. Same question about fan placement. I just got my new board today so unless somebby shadowphile - Duet
Re: this is what happens when mechatronics goes bad - 6 years ago
all good suggestions. Im pretty sure its all collateral damage though, to whatever caused the motor going chaotic. No sign of a peel up to snag on. Motor went crazy but job dont know that and beats things around until something dies (usually messily). It must have shorted a 12V line that feeds some LEDS. Still havent looked closely at the Duet but it probably didnt like its power rail violently sby shadowphile - Duet
Re: this is what happens when mechatronics goes bad - 6 years ago
Thanks for the reply PDBeal. Unfortunately I don't have some of that info. I can't verify the drivers were getting hot and at a glance nothing looked like it lost its smoke. I thought the drive chips had thermal protections. I haven't messed with the drive current limits, so maybe 1 or 1.5 amps? The motors are NEMA 17s but my delta effector is rather heavy (unfortunately, for now). I was relyinby shadowphile - Duet
this is what happens when mechatronics goes bad - 6 years ago
After watching a long print job that started well, I went to bed. This is what I found in the morning: Not shown is a burnt out 12V wire, no fan sounds, no comm with webcontrol, and the hot-end assembly ripped out of the effector platform. Oh my. The last day or two I was getting random going-crazy-jumping-and-jamming-into-the-bed at some point while doing auto-calibration patterns. (its a dby shadowphile - Duet
Re: ball-cap rod-end concept pros and cons - 6 years ago
agreed, the magnets would be best with some retention springs. except....why bother with magnets? I found the Trick Laser arms really trivial to pop off and they are as tight and smooth as the magnets. The only thing I would try to change is the springs. I dont like the way they load the rods; hard on the ball-cap-to-rod joint and the little plastic loops break off too easy. I would like to see tby shadowphile - Delta Machines
Re: ball-cap rod-end concept pros and cons - 6 years ago
nice to see a technically accurate depiction of the magball design but what is the issue that motivates a closer analysis? -Delrin, like most plastics, has little response to magnetic fields, plus or minus. The hole in the middle is perhaps THE critical part of the design that results in zero play because it provides a stable load configuration. A full cup would need to be absolutely perfect andby shadowphile - Delta Machines
Re: correcting bed temp offset due to thermistor placement - 6 years ago
I actually thought about bolting power resistors to the underside of the bed in an uneven distribution for that very reason but that comes with its own issues. (coupling to the plate is not as good; hotspots; resistors are thick and need extra insulation, for starters)by shadowphile - Duet
Re: correcting bed temp offset due to thermistor placement - 6 years ago
well I cant argue with those pics! one of the problems I had with the metal plate is it gets much hotter in the middle than the setting before the heat evens out but I had the sensor at the edge cause I thought the thick plate would conduct well enough. Wrong! So recently slotted a thin plate from the edge to the middle to lay down the sensor in the middle, sandwiched between the heater and mainby shadowphile - Duet
Re: correcting bed temp offset due to thermistor placement - 6 years ago
thanks for the inputs. Cool down speed isnt a big concern for me either and I dont do ABS (yet) but Im used to a 500w silicone pad directly laminated to a glass plate so temps were dead on and cooled almost immediately. I love printing on glass but I broke two and decided a heavy tooling plate was the way to go.by shadowphile - Duet
Re: correcting bed temp offset due to thermistor placement - 6 years ago
thanks, I hadnt thought of redefining the thermistor. btw, anybody here that uses a heavy tooling plate: how do u deal with the extremely slow cooling rate?by shadowphile - Duet
Re: correcting bed temp offset due to thermistor placement - 6 years ago
Boy, which *I* had a FLIR! I'm aware of all this. I have a 6mm MIC-6 plate myself. I would prefer the numbers be accurate, then play with *those* rather than just trying to see what works. Why have two uncertainties when one of them could be removed? In an ideal future everything is calibrated and we won't have to dial in every freakin parameter.by shadowphile - Duet
correcting bed temp offset due to thermistor placement - 6 years ago
The math is in my head but no place to execute. My bed surface and the thermistor reading are about 5 deg different after I allow them some time. This is due to the thermistor not being directly on the surface. 1) i would prefer to command the actual desired surface temp than have to manually (eyes roll) add 5 degrees to my commanded temp. 2) Its not actually 5 degrees except at one specific tempby shadowphile - Duet
Re: algorithm to speed up prints? - 6 years ago
I wish they gave some specs. They talk about improved material and printing properties but with no numbers, grrrr! Carbodeon actually makes the nano-diamond stuff; the filament is just one application. They are also looking at finishes, paints, lubricants, etc. If the improved properties are true, even marginally, and the price drops, it could attract a following. Everybody wants to be your goby shadowphile - Firmware - mainstream and related support
Re: algorithm to speed up prints? - 6 years ago
'Fake news' is such a catch-all abused term and doesn't seem to me to apply here. Anyway, my only point was as a follow up to my previous posts about the inherent limits of print speed caused by the thermal conductivity of the filament. Diamond is an excellent conductor of heat and so their invention is entirely reasonable as a (technical) solution to faster print speeds. And the product is forby shadowphile - Firmware - mainstream and related support
Re: algorithm to speed up prints? - 6 years ago
case in point! super-fast printing PLAby shadowphile - Firmware - mainstream and related support
Re: reaction time for z-probe triggers? - 6 years ago
This is great, thanks for your help guys. Sounds like I just need to change a resistor on my 555 timer to drop the pulse time and it should work! (maybe needs some gcode adjustments). I had no use for the disable pin, it was just available on one of the ICs I used. But I should add an LED because you can never have too many blinky lights! I really wish I hadn't blown the serial port on my Duby shadowphile - Duet
Re: reaction time for z-probe triggers? - 6 years ago
Ok, built a new circuit from scratch and now get a 1 second pulse when the zprobe triggers. It is super sensitive but that means false triggers during the bed probe sequence. Is the trigger monitored all the time during the G30 moves? I would like to only enable the probe right before the G30 command and disable right after to prevent false triggers. I have a disable pin on the probe but beforeby shadowphile - Duet
Re: reaction time for z-probe triggers? - 6 years ago
I was in P1 but changed to P8 because of the speed but not enough to help. When you say step pulse you mean whatever is driving the motors? So basically I figure out what that is for the probing speed as a minimum (plus some I'm sure). I was thinking that I would need to add some kind of pulse stretching. thanksby shadowphile - Duet
reaction time for z-probe triggers? - 6 years ago
I'm installing a home-made piezo zprobe under one corner of my hot-end mount so it is preloaded under the clamping forces. When I tap the nozzle I get a ringing signal that dies to zero quickly. This also makes sense cause the hot-end mount has some compliance with an o-ring I added. Anyway, the result is (after transistors and such) pulses on the order of 1 ms to the Duet. Right now I am usingby shadowphile - Duet
Re: autoleveling plus mesh-bed compensation - 6 years ago
oh, so you are actually flexing that plate to make it flat. Yes iVe learned also as an engineer at work how much even thick stuff can flex once you start thinking in microns, especially bridging-type clamps. Wow, you are definitely going well beyond the norm for accuracy. How are you handling the zprobing?by shadowphile - Delta Machines
Re: autoleveling plus mesh-bed compensation - 6 years ago
QuoteRMS, but as you can imagine the peak is very low Ummm, isn't RMS always lower than the peak values? Quoteadmittedly the 8mm thick 400mm round tooling plate with 7 manual height adjustment points and a 4mm borosilicate plate on top goes a long way to achieving this How do you use more than 3 points to adjust a stiff plate? My bed is a 1/4" MIC-6 cut with a waterjet (so residual stresses shoby shadowphile - Delta Machines
Re: talk to duet from a 2nd micro-controller? - 6 years ago
DC42's reply addressed the non-USB port. I did not assume the same settings for the USB since it is used in different contexts. Now that I think about it the M575 can address the USB as well so...pick my own speed I suppose.by shadowphile - Duet
Re: autoleveling plus mesh-bed compensation - 6 years ago
is that peak or RMS? in the past I have gotten as low 11 um wasnt sure I trusted that number though. My typical used to be 50um but this new version of machine taps out around 20um. But that result still has a peak to peak range of .3 (+/- .15) mm so there must be a few high spots swamped out by a lot of accurate spots. Not that it matters. In my opinion these errors should always be reported inby shadowphile - Delta Machines
Re: talk to duet from a 2nd micro-controller? - 6 years ago
Now that is an obscure command! thanks. (although I can't think of why my dummy command running in loop would not immediately reset a different setting for that command sent from web control console.) I don't normally use the USB port except in the early days when that was the only way to update the firmware. Can I just use a simple terminal program like Hyperterminal to test out the debug, assby shadowphile - Duet
Re: talk to duet from a 2nd micro-controller? - 6 years ago
thanks for the feedback. I've been talking and getting replies for a while now and trying to decode the messages. At some point recently I Iost the ability to send messages. -I set checksum option to off (which is why it started working) -The PanelDue serial port is receiving signals fine right at the pin. But the messages are not getting through. I set the code to send continuous 'allow cold'by shadowphile - Duet
autoleveling plus mesh-bed compensation - 6 years ago
What's the general consensus here? I've been doing just the auto-leveling but it's really just best-fit of a plane and can't fix peaks and valleys. (dc42, am I right?) My print area is 350mm across and I want flat to at least 0.1mm. I read that it shouldn't be necessary with an accurate build but my current machine was built with lots of care (all CNC or extrusion parts assembled as square as cby shadowphile - Delta Machines