Replaced X and Y motors with JK42HS34-1334A and 16 tooth pulleys. At 20mm/s, compared to the old motor/pulley combination, the fine pattern is more spaced out and the surface is smoother. At 15mm/s the frequency of the pattern is 2x of that at 20mm/s. Printing faster using opaque filament the fine pattern is not as noticeably as in the transparent filament. Ringing is more evident. My coby kasom - General
With the new board, the coarse pattern that aligned to the e-stepper's full step has gone. The fine pattern is still there, but it's much smoother than the old one when running my finger on it. Wall thickness is now spot on, it was 0.42 because of the rough texture on the surface. At first I thought the fine pattern is due to microstepping so I expected (number of full step on each side) * (miby kasom - General
Quotejamesdanielv thanks for that information, what happens if you lower the driver current to 60%, and then lower it as far as it can go and still print at correct speeds? its just a thing to try. I will try that when the tl-smoothers arrive. My SKR Mini E3 has arrived so now I'm experimenting with it.by kasom - General
415 steps/mm slightly thicker wall.by kasom - General
Quotedc42 It's hard to advise you without knowing what the relationship between Vref on your driver is and the motor current. Maybe someone else knows what it is for the Ender 3 with the stock controller? The rated motor current of the Hemera is 1.33A. Depending on what chip your stepper driver uses, diodes in series with the motor (aka TL Smoothers) may help. They typically help a lot when usinby kasom - General
The stepper of Hemera is not a standard one. Now I'm stuck.by kasom - General
E-stepper microstepping quality Background story: I bought E3D Hemera and wrongly set vref to 0.5v on the stock Ender 3 board. Skipped step severely. Increased vref to 0.7v, calibrated e-steps, etc. Got a rough surface on all sides. Slowing down didn’t help. I printed a cube in vase mode and got salmon skin on all sides. Try varying the print speed. The salmon skin pattern stays the same, butby kasom - General
Quotenumber40fan If yours is dumb, then mine has to be....refrain from using the wrong word here....so how about dumber? No, yours can't be dumber than mine Quotelhartmann @kasom: Hello "this guy." Hello!by kasom - Delta Machines
Quotelhartmann ... Also found this guy on thingiverse that used PCBs as carts/effector mounting plates. Neat idea, PCBs are rigid and have a low profile, which is useful given the diameter limitation. He did not take full advantage of his concept, though. LED lighting would have been a really nice feature. I got inspired by dc42's smart PCB effector. My version is dumb.by kasom - Delta Machines
Quoteclearlynotstefan THe thing is, with a flying extruder, you're already adding that weight to the carrier anyway. and worse, you're suspending it from elastic which is going to bounce it around and exacerbate the effect it has, How much weight can you be adding by adding arms so it gets pushed where it needs to be instead of dangling in the air? It's not about the weight added. It's about momby kasom - Delta Machines
The idea is to move the extruder as slow and less frequent as possible while keeping the Bowden tube sort. With proper look ahead and calculation, the extruder can move the same time, before or after the effector to minimize the acceleration of the extruder. PS: My plan is for the Diamond Hotend. The 3 x extruders are heavy!by kasom - Delta Machines
I've reply to another therad in Delta subforum, as it's more appropriate.by kasom - Duet
I'm replying to this thread instead of the former thread in the Duet subforum because I think it's more appropriate here. Quotefrankvdh Your "double delta" idea would allow the same kind of thing in software, doing on-the-fly digital filtering of the motion commands so that the extruder stays within some specified distance of the hot-end position. Or software could pre-calculate the motion of thby kasom - Delta Machines
Let me rephrase. The main idea is similar to your design, the extruder's movement is controlled. The differences are: 1. I don't want the extruder to follow the effector 100% on the X-Y plane. I want it to move somewhat lazy. Imagine you're walking a dog with a leash. You (the extruder) hold the leash (the Bowden tube). The dog (the effector) may run around you freely, as long as it don't go toby kasom - Duet
Oh... They're not hooked into the second set of carriages. There will be a spool controlled by a motor for each fishing line. Better write a diagram. My English is bad.by kasom - Duet
Driven by 3 motors. I'm not good in expressing in English. I think I'll need time to draw some diagrams. Quotekasom By the way, I'll just hang the extruder using 3 fishing line, controlled by 3 motors. They don't need high accuracy.by kasom - Duet
I forgot another point. 4. Due to the lazy follower algorithm, my extruder will hover over the effector. Not exactly match on X-Y, but close. The normal flying extruder tends to stay in the center, which in turn pulls the effector side way.by kasom - Duet
0. I do know about the flying extruders. 1. I don't want to put more mass on the main carriages. More mass = more torque needed 2. The current flying extruders' movement follows the main carriages, so when doing the infills they are forced to follow the carriage's movements. Mine didn't. 3. Yes, movement from the effector affects the extruder due to the stiffness of the Bowden tube. That's why Iby kasom - Duet
By the way, I'll just hang the extruder using 3 fishing line, controlled by 3 motors. They don't need high accuracy.by kasom - Duet
I think it will be more useful if the extruder moves independently from the effector. Actually, I'm in the middle of designing & implementing this for my Diamond Hotend's extruder. The main idea is that in order to have shorter Bowden tubes, we need to move the extruder closer to the effector. The problem is that the extruder's mass is massive we can't move it as fast as the effector. If weby kasom - Duet
I finally found the culprit that caused the false triggers! A missing capacitor (C6) in one of my HX711 board cause random spikes in the readouts. Replaced the board, problem solved. The 20 Kgs load cells were replaced with 5 Kgs ones too. It is more sensitive but sadly it didn't improve the deviation. Anyway, I think it's usable and I'll move on to integrate Diamond Hotend to my delta. I hby kasom - Delta Machines
QuoteDjDemonD Good work. There are a good number of methodologies for sensing nozzle contact. Thank you! Quotedc42 If you are not already doing it, you may find that adding a Z probe recovery time (R parameter in the M558 command) reduces the false triggering. We use 0.4sec for the strain gauge effector. I haven't tried it yet. Thank you for your suggestion!by kasom - Delta Machines
A little progress. Test run. Delta auto calibration with Duet Ethernet/dc42 fork of RepRapFirmware. There are some fault triggers. Calibrated 6 factors using 17 points, deviation 0.072. Not sure if it is my build or the Z-probe that is inaccurate. Just ordered 3x5 Kgs load cell, hope to improve the S/N ratio. YouTubeby kasom - Delta Machines
I’m experimenting with a load cell based Z-probe. It’s somewhat a mixture of JohnSL's and palmer23's. What’s needed: - STM32F103C8T6 board. I’m using a “black pill” (Any Arduino board could be used, but those * pills board are really cheap.) - STLink v2 or USB to TTL (3.3v) adapter to program the board. - Arduino IDE + STM32duino - HX711-multi library - 3 load cells. I’m using 3 x 20 Kgs becaby kasom - Delta Machines
Quotedougal1957 QuoteQdeathstar ah. I'm curious about it, where is it on the pcb? Could you take a pic Picture of what exactly? if you mean the strain gauges then they are actually designed into the PCB Traces so not much to be seen on a photo (They can be seen as very fine traces in the copper by eye but they don't show up well on photos) From the original photo, zoom in at 1:1 pixel:by kasom - Delta Machines
I've uploaded all related files to Thingiverse.by kasom - Delta Machines
I'm using RobotDigg's carbon tube. 450mm/5mm/8mm. Magnetics + balls from 3D_HOME/AliExpress. They have M4 hole, so you'll need 12 x M4 screws (I forgot the length, will check tomorrow) + 12 x M4 nyloc nut nuts. The magnetic mount: The PCBs were made by EasyEDA by importing the DXF files to their PCB edtior to define the border outline. Texts and graphics were added using the editor. Hope thby kasom - Delta Machines
Quotedc42 Do the heatsinks foul the rods in certain effector positions? If so, would it be better or worse if you rotate the Diamond through 60 degrees by re-drilling the 3 mounting holes? It's close to. I think you're right, I should have rotated the mounting holes, or at least put 3 more holes as an alternative.by kasom - Delta Machines
To mount the E3D v6 or clone's groove mount, use 3 PCBs stacking in the different angles. It's a tight fit.by kasom - Delta Machines
To mount the 3 color diamond hot-end, I use a modified Kharar's cooler's shield from Thingiverse. I'll put the modified version to Thingiverse later.by kasom - Delta Machines