Can't compare to stepper as this platform never had one Repeatability is 100%, no problem there. The speed is determined by the usage of 8mm rod - therefore I can do 90mm in 12 seconds currently at 12V, but the motor is 30V capableby rklauco - General
Major achievement here. Changing one word in the source file and all of a sudden, everything works!!! I had to define the target1 in source code as LONG, not INT - as the Zaxis has mental resolution. I am now able (while still having multiple of 10 steps) to do movement on Z axis with precision of 0.0025mm. I call it quite good - that's 2.5 microns Not really usable, but it's amazing this is achby rklauco - General
That was my initial idea - just instead of Zero (due to virtually no availability) I plan to use Orange Pi One.by rklauco - General
OK. I put little aluminium heat sink on top of the chip - the same one I am using on my stepper drivers. That seems to help - now the temperature stabilizes around 40 degrees, I can touch the heat sink no problem. I have to change my wiring a bit - I have the 100uF replaced with 470uF - that seems to improve the reliability of motor start, but I cannot find 100nF around - have to do a little shopby rklauco - General
Well, I simulated 2 8-hour long prints with X and Y axis on a single TB6612 and it was as cool as it started. The motor got worm to touch, but the TB did not. I did not put any sort of heat sink on the A4953, I can try it tomorrow and report back the results. I would still like to make the A4953 work - I have a board in mind with ATtiny85, A4953, 2 capacitors and form factor that would make it aby rklauco - General
Well, I found one unexpected issue with the Z axis. Due to VERY high resolution of the movement (4096 steps per mm) I run to the limit of ATtiny85. While driving it using serial port, the ATtiny is OK and can drive the movement quite fast. However, when connecting it to RAMPS, it has to cope with interrupts for both the optical encoder inputs AND the step input. And this is too much - as for eachby rklauco - General
LoboCNC: Do you have experience with A4953? Mine is quite disappointing - I got it yesterday and tested it today and it is quite hot during position hold. Is it due to my board design? (No heat pads or anything similar, but driving only 3.6W 12V motor...)by rklauco - General
Well, I am disappointed. I tested the A4953 and while it works, it gets extremely hot even during position hold. And while doing back and forth 120mm movements it got so hot I could not put finger on it. I had to remove it and put back my TB6612, which works flawlessly. I had to admit, though, that my temporary board is WAY off the reference design - so probably the missing heat-distribution is aby rklauco - General
QuotenebbianNot sure if you guys have come across this driver, but I've ordered one to try out. Reading the specs, it seems like it's only good for 12V, but I have some trouble with understanding the datasheet - it looks like "Output HIGH" will only get 7.7V, not 12V...by rklauco - General
QuoteipcalitAny experience with TI DRV8838 or DRV8835 (dual) from Pololu or did you just use the classic L293N/L298N? The DRV8838 and 8835 are both only for 11V and 1.2A. That's not really enough for majority of stronger DC motors - usual 2D printer motors work with 24-36V and although they are able to work with 12V or less, the torque is lost quickly.by rklauco - General
I tested L293, but it wasn't able to withstand the ~30kHz I am using to drive the motor. The L298 is much better although a bit too big for me. However, it's a bit too big, so I worked with TB6612FNG and that was fantastic. I did have some bad experience with 1 batch from China that had all the capacitors badly rated for 10V and they blew up as soon as I connected 12V. However, the TB6612FNG canby rklauco - General
Quoteipcalit I my design the driving gear is stable and just the bearing moves slightly to accommodate the filament. This should not create variations in the magnetic flux. How did you achieve the flexibility in the bearing? I'm interested in the technical solution as mine is rock solid...by rklauco - General
I don't have the recommended one, that's for sure. I am using the capacitors after the fiasco with the 3.3V rail But I think I found the reason. When there is no filament in the extruder, the shaft is a tiny tiny bit up. That's by design - I achieve a bit better grip by creating the pressure by this slight dislocation. So, when filament is loaded, the measurement is rock steady. When it is out,by rklauco - General
QuoteipcalitDo you have a schematic / pic of the board that you used? Well, I tried to do the schematics - don't kill me, this is my first Fritzing attempt However, I run into a problem. When I start up the whole thing, it measures the angle - and it jumps a LOT. E.g., no motor movement (completely disconnected from all sorts of power), I have this reading: Position=-116.00 PID_output=80.00 Tarby rklauco - General
Well, I would say it may work I didn't want to wait for a magnet - so I just took 5 magnets with 8mm diameter and 1mm width. I glued them onto the gear wheel using 2-3 drips of hot glue. Then I burned one AS5600 by accidentally putting 12V onto its output pin. But later I grabbed another one, spend few hours just to finally read the manual and realize I need 1uF capacitor and as soon as I connecby rklauco - General
Wow, I have to browse how did they made extruder with Mabuchi 130 - have 5 fakes and 2 originals on my messy desk...by rklauco - General
My the suggestion of Misan I tried the EU offices - the package came from Austria. The problem with the magnet of yours is the orientation - check the desired orientation on the documentation from ASM. Even putting the magnets on the washer will not modify the magnetic field orientation My idea was to put 3-4 together and glue them using some hot glue or acrylic side-ways. First I have to test iby rklauco - General
Quoteipcalit 1) if the motors burn (at some point) you have to replace it along with the encoder as the long shaft motor is more expensive from Pololu than the bundle from Aliexpress. If we could get the encoder off the motor, then you can get plenty of N20 geared down to 30rpm for $3 each. The problem here is that the $3 motors do not have the extended shaft. So you have no place to put the encoby rklauco - General
Quoteasbo In the end I exported it as an .stl as I couldn't find all the dimensions. However I'm not sure the dimensions I got from the .stl are quite right, before I go any further do they look right?yep, they are ok.by rklauco - General
Yep, I found it ~week ago, it's already on its way from Chinaby rklauco - General
QuoteasboUnfortunately I could never wrap my head around OpenSCAD, I am quite good with SolidWorks though. Could the STL export help you? I can make one no problem - even using OpenJSCAD.org I can do it online... Quoteasbo Out of curiosity I typed motor encoder into aliexpress and there are some cheap motors with encoders already attached. I've no idea if they're any good for this purpose, and yoby rklauco - General
Wow, the chip is impressive and the $0.40 price from China even more, it has some problems: - SPI - while a lot faster then i2c, it requires all the pins of ATtiny, so no step input or pwm output. I'd have to switch to different tiny version with more pins - that adds space requirements - SPI is slower then analog read and more CPU intensive - I see no PWM output, but even if we had some, we stilby rklauco - General
QuoteasboThis is rather exciting! Assuming it's possible, I think you should aim for being able to use these with pre-existing hardware, I'd love to run these but I wouldn't want to replace my Duet boards. My goal is to make it technically possible NOT to replace anything - you will just pull out your stepper, or redirect the step/direction outputs to free pin and that's it. The driving of the DCby rklauco - General
And this is how it looks like with Chinese cheap e3d v6.by rklauco - General
Well, I tried to design a holder for the extruder, but I came to a problem. The whole extruder is so small, that in order to reliably hold it in place, I'd have to have more material for the holder then for the actual extruder. Therefore I made a modification. I made the whole e3d holder WITH the extruder integrated - therefore it prints as one piece and is as stiff as possible. And still, the inby rklauco - General
Quoteipcalit 4) my plan B based on the AS5600 specs - it has analog and I2C output that could be interfaced directly with the controller without any extra hardware (ATtiny). In this case you would need to poll regularly to get the position of the filament. This is already done for filament detection purposes in most firmware. The only question is whether this gives enough control precision to getby rklauco - General
How precise measurement do you think we need from the idler? How many impulses per revolution would be OK?by rklauco - General
So. My findings from this night: It does work. The motor is quite strong. Actually too strong - when trying to push filament through 0.2mm nozzle the whole extruder assembly torn appart the ABS bond. Next step - print the extruder including the e3d-v5 holder together to avoid splitting under heavy loads. Also, another negative finding - my gear is mounted a bit wrong - it has a tiny bit more griby rklauco - General
This is AMAZING. Not only it has a great grip on filament, it is also unexpectedly fast. It works great and on 12V it runs through the filament like a knife through a butter. Tomorrow I'll test direct connection to my fake e3d-v5 to see how it performs in real life situation. The current version is 25grams only. I decided I won't install the encoder for the motor - it's too expansive. Instead, I'by rklauco - General
Well, this starts to look like something useful. So - I started to re-design the thing based on the original shape. I was thinking about using 4-screw bearing hold with springs to provide sufficient grip for the gear. So I printed the file attached. And then I found I do hot have screws long enough to hold the bearing holder AND the spring. Just out of curiosity I tested it without spring - and Iby rklauco - General