Thanks for pointing out the modifiers. After checking out this video I think I should be able to create internal structures in the part by modeling another part in the shape of internal structure I want, with infill set to 100%. EDIT: seems to be working (except some infill patterns cannot be 100%)- one thing I'm not sure is how well this new infill will be integrated with part's walls since mby newbob - Printing
So I actually tested it by manually feeding the filament into the hotend... The hotend did not leak, did not clog and heat creep was very low. There was a notable temperature gradient through out the nozzle so the extruder would hardly extrude at 190degC, but it flowed, at about 15mm/s, quite easily at 210degC. Some kind of sleeve over the threaded part of the nozzle would help even out theby newbob - Developers
1) can a slicer print solid horizontal cross-section every x height interval? For example: 100x100 cube with 10% infill with slicer printing a flat horizontal 'wall' every 10mm. 2) can a slicer start printing horizontal walls right from the bottom even when vertical wall feature does appear later in a print? For example: cylinders stacked on top of each other, each slightly smaller than the prby newbob - Printing
It's just a Volcano nozzle mated with a standard heatblock, throat and heatsink. Screws keep it together, I suppose I could add an M6 nut to attach nozzle and throat together. If that works than I'll try using stainless steel capillary tube for the throat. I've noticed that new hotends have much bigger melting zones but not necessarily larger heating blocks hence the idea of using standard pby newbob - Developers
Great addition and definitively adds to boards flexibility. I suppose current limiting and polarity protection would happen outside of the board? One thing I would move is the electrolytic capacitor to be closer to the IC and after onboard power IN. Probably a challenge to route though -maybe put the cap or screw terminal on the bottom layer side?by newbob - Controllers
I stumbled upon an old article describing a simple way to drive a shift register with only one pin. This method utilizes input capacitance combined with the fact that shift register 'shifts' on rising clock edge to drive the Data input of the shift register. Variable duty cycle clock output seems to be a perfect application for ESP32 RMT peripheral. It has up to 80MHz resolution and combby newbob - Controllers
How is the roller shaft supported on the bottom end?by newbob - General
I can imagine two scenarios where sensoreless homing would fail: slop ('play') in the carriage that causes deflection which is not repeatable causing accuracy to decrease. uneven linear motion resistance due to misalignment, bearings, etc which would trigger static threshold or cause to increase threshold to exclude false positives at the cost of accuracy Reading corresponding forums, it seemsby newbob - General
I'm certainly aware of your successful designs. I put together a (cartesian with drill rods as rails so it was a joy to tweak) printer years ago. As I (and my kids with me) learn by doing I want to finish a controller for a printer and have been pondering what to cut out. So far it seems I can leave out all the end-stops except for Z axis and filament sensor when using Trinamic drivers. Substiby newbob - General
I should clarify that I'm asking from the angle of what controller would I need. Multi extruder would require temperature sensor, cooling fan, heater and motor support for each additional extruder. Enclosure would require another mosfet. Mesh leveling would require additional 1,2 or 3 Z motors. Would printer controller control filtration or lighting? I do not think so. I wonder what is bettby newbob - General
When I wrote my question I had cartesian printer in mind, however I do not see how different it would be from a delta. Primarily I wonder if stall detection is reliable for homing for cartesian and delta printers. I misspoke when wrote 'bed leveling' as I also had Z homing in mind. I understand that Z homing will not work with stall detection if bed has springs or soft build surface. Expandinby newbob - General
Extruder heater control Bed heater control Fan for Extruder Sensor for bed leveling (I do not think stall detection works for that) End stops can be replaced by Stall detection X, Y, Z, E DIR and STEP Bed temperature probe Extruder temperature probe Is Trinamic stall detection reliable or does it need a mechanical switch as a backup? Did I miss anything?by newbob - General
Are there any issues using Input only pins (35-39) for SPI's MISO on ESP32 WROOVER or WROOM module? EDIT: I should have googled some more: it is working:by newbob - Developers
Microstep table does not work w/o knowing where you are in the rotation so we would need feedback from a step motor indicating zero position. When sending coil current values, MCU can estimate, with high probability, at which part of full step a motor is in w/o motor angle feedback. Anyway, I think value from SPI control (old 20 bit SPI that TMC2660 uses) comes from knowing microstep count anby newbob - Experimental and Hobby
UHMwPE has a lot of right properties such as high abrasion resistance, high fatigue, water and UV resistant, low stretch to be a belt replacement. Therefore I've been wondering if anyone tried it?by newbob - Mechanics
I think this is what BIGTREETECH S42A closed loop might be doing (knowing bigtreetech, it's probably clone of something else). Anyway, TMC2660 (TMC26x, and generation prior) lets you apply coil current directly via SPI (newer Trinamic stepper drivers, like the one in Duet 3 or TMC2130 do not). SPI overhead is large and I'm not sure how feasible it is to communicate with the drivers quickly andby newbob - Experimental and Hobby
EN LOW will power down driver's MOSFETs, so one could attach clock fail detect circuit to EN pin when clock fails. EDIT: datasheet says to disable MOSFETs with EN before shutting down the clock. Well, if pulling EN low will not work than shutting off VCC_IO will, for sure.by newbob - Experimental and Hobby
Trinamic datasheets do not recommend external clock above 16Mhz (and they lowered max clock from 20 to 18MHz with newer ICs). I always assumed this was due to EMI - could you point out the reasons why external clock does not work well with TMC266x?by newbob - Experimental and Hobby
TMC2660 can be clocked at 20MHz resulting 10MHz SPI clock. 10000000 / (20*4) = 125000 'steps' per second 16 * 200 = 3200 steps per revolution (with 16 microstepping ) 125000/3200 = ~39 revolutions per second 39 * 2mm (GT belt) * 20 (teeth sprocket) = 1560mm / second 780mm/s at 32 microstepping 97.5mm/s at 256 microsteppingby newbob - Experimental and Hobby
Maybe DIMM like clip would work better, although, it would have to rely on plasticity of the printed part and groves instead of holes may add cost to PCB.by newbob - Controllers
Just FYI, for reference, Panucat TMC2660 driver board is $13.50 + shipping. There are, of course, some pluses to your solution, namely opensource project, a configuration that is cheaper to fix or upgrade or expand, and probably supports more stepper motors.by newbob - Controllers
Thanks @dc42 for pointing that out. Interestingly, that partial schematic does not include 10nF caps on SRA and SRB lines. @ghent360 I saw your blog - your controller board is two layer PCB? That is impressive - I would have thought that's impossible with ST32F running at 180MHz EDIT: Having second look, both Trinamic datasheets (for TMC2130 and TMC2660) call for 100nF capacitors. 1uF caps aby newbob - Controllers
Klipper is the right choice IMO. I do however think that the best way of adding GPIO to ESP32 is via I2S interface and shift registers. In any case, I'm looking forward to your progress.by newbob - Next Wave Electronics Working Group
As part of my new year resolution I resumed a long lost project so I've read a thing or two about tmc2660. Trinamic recommends 100uF per Ampere (though IIRC they do not follow their rule with BOB boards). Cap should be low ESR so it has to be mounted as close to the driver as possible. One advantage of going with larger cap is lower ESR. Smaller 100nF cap should be even closer, 1-2mm from VSby newbob - Controllers
TMC2224 has INDEX output that sends a pulse every 4 steps. I wonder if that could that be used for stall detection: if 0 INDEX pulses arrive after sending 5*(micro steps per full step) step pulses then it means movement have stalled.by newbob - General
I am thinking of building a bitcoin rig and use waste heat to warm the printer chamber.by newbob - General
You're right, a shield would be needed on rpi. There are plenty of GPIO shields for rpi and, like you say, standalone MOSFET boards so hardware should not be difficult. Probably software is the only bit that is missing. EDIT: added benefit on doing PWM and ADC on rpi would be, of course, less io between rpi and controller and faster updates. Another would be cost savings when using multipleby newbob - Firmware - experimental, borrowed, and future
Ok, I found another difference: steahlthChop in TMC2130 and steahlthChop2 in TMC2224: quote from TRINAMIC: "steahlthChop™ is using a pure current regulation without any pre-regulation. Depending on the steepness of the acceleration the target current might not be reached during the accereleration phase. We improved this in the version, stealthChop2™. Here we are using a pre-regulation which alloby newbob - General
I've been thinking what would be an optimal klipper controller board. Due to timing requirements, end stops, stepper drivers, MCU controlling Enable, Dir and Step, digitalWrite and comm link (UART) to rpi would have to be on the controller,. Sdcard reader, display, rotary encoder functionality should be on rpi as well as PWM (fan, heat), ADC (temperature) Would you agree? Are there be any aby newbob - Firmware - experimental, borrowed, and future
Which driver is better, TMC2130 or TMC2224? It appears the biggest difference between them is UART and the other over SPI which is 10 times faster and better supported. EDIT: soon after I posted, I found there's an issue with TMC2224 turning off when driven fast: https://github.com/KevinOConnor/klipper/issues/196by newbob - General