The motor seem to be OK. The question is the encoder. From the picture, it looks like it has 36 strips, so the quadrature encoder should be able to read 36*4 impulses per revolution. That is 144 impulses. The diameter of the belt-running wheel seems to be ~7mm, so 1 revolution will result in 22mm movement. 22mm divided by 144 impulses makes resolution of 0.152mm per impulse. I guess it can be sufby rklauco - General
QuoteLoboCNCI know in production quantities motors like these are about $2.50. Well, if one can get the motor with encoder for, let's say, $4, then add the price of ATtiny85 ($1) and H-bridge (I'm using TB6612FNG capable of driving 2 motors) for $1.4, you have the whole axis done for less then $7. However, I like the system with linear encoder strip a bit more - with this motor/encoder you postedby rklauco - General
Quotecozmicray What is your micro-controller? What code are you using? For now I worked with ATtiny85 from China for less than $2 - that's cheap enough for me However, I tune the PID parameters using arduino pro mini, the code works there too. Misan also ported the code to ESP8266 and additional microcontrollers - check his github. QuotecozmicrayOne can not say an inkjet printer will never runby rklauco - General
QuotebobcI like the idea, but it's hard to find motors from old inkjet printers if you don't have them. Finding a cheap enough motor and encoder with the right specs was always the sticking point for me. You are right. What I'm doing is I am buying reasonably old (4 years max.) printers second hand for price between $0 to $10 (vast majority of them for $0). When you then disassemble the printer,by rklauco - General
Quoteo_lampe What resolution does the encoder strip provide? You can really read an absolute position with these or do you have to home the axis before you turn off the printer? ( to start at a known position next time ) My current resolution (calculated and tested) is approximately 0.047mm per reading. No, I don't know absolute position in the beginning. That's why I have the start-up sequence,by rklauco - General
QuoteLoboCNC rklauko: Great to see someone else working on servo control, but interleaving progress on your controller with the Servolulu development in the same thread is getting a little confusing. Perhaps you could start your own topic. Sorry for spamming your thread. I started a new one and I'll refrain from further posts here. Good luck with your project.by rklauco - General
Thanks to the work of Miguel Sanchez I started to experiment with DC drive for 3D printer. My original goal was to experiment, but it starts to be usefull now. I build a ToyRep printer and it was failure - motors overheated, it was painfully slow and useless. But thanks to Miguel's github repo I am now using the toyrep as a platform to create closed-loop feedback for 3D printers. For now, I feelby rklauco - General
Well, I had a little time tonight, so I played with the closed loop. And I have to say it's fantastic. I created a simple code that does "homing" in the beginning. I verify if the encoder direction is consistent with motor direction - if it's not, I'll adjust the motor direction. This was a frequent problem for me as I undid and put together the printer and by accident connected the motor cable tby rklauco - General
Quoteo_lampeDumb question: What makes a DC motor a DC Servo motor? Is it just the encoder or number of poles or??? Basicaly normal motor with some sort of feedback control (even potenciometer and comparator works OK in RC servos...).by rklauco - General
QuotedrmaestroExciting development. I hope we can use it soon on our printers. Soon This is my work from more than a month ago with a different DC motor with on-shaft encoder (very weak, used purely for verification of ATtiny85 code at that time):by rklauco - General
I'm working on something similar. Currently I have working code for ATtiny85 (see ). I got Miguel's code for PID tuning, tuned 3 motors from old inkjets, used their encoders and encoder strips and I am re-purposing the ToyRep with closed loop now The encoding strip is mounted similarly to standard inkjet, the positioninig accuracy (reading) is 0.044mm, but the motor driver can overshoot by as muby rklauco - General
Hi, all. Did anybody tried to use DRV8880 with RAMPS? I like its autotune feature (based on youtube videos only) and would like to know if somebody has hands-on experience with NEMA17 + RAMPS combination.by rklauco - RAMPS Electronics
QuoteFrans@FranceWhat do you mean with "draw a line on the belt"? Well, I simply took a permanent marker and marked a line on the place the belt was entering the jig above. QuoteFrans@FranceCould it be because of the acceleration profile at higher printer speeds that it's missing "steps"? Most probably. Unfortunately, it seems that it's a "feature" of the encoder - to provide somehow better feeby rklauco - Let's design something! (I've got an idea ...)
Preliminary results: Mouse obtained - I've got a cheap PS2/USB mouse from Aliexpress: PS/2 mouse Mouse contains the MX8733 sensor - capable of 800CPI (datasheet PDF) Connected to arduino - Report mode not working, so I had to switch to stream mode Printed enclosure jig for the PCB+optical sensor - current version works for X and Y, the one I printed only works for Y axis Thingiverse model Have gby rklauco - Let's design something! (I've got an idea ...)
Well, to answer the questions: 1. Yes, I want to measure the belt - I am affraid of the slips and skips that can occure due to questionable PID control implementation - so to measure the target medium can be much more reliable than the source (motor shaft). 2. I am not sure what ips rating the mouses will have - I ordered 2 pcs from Aliexpress the same day I wrote this, they got shipped today, soby rklauco - Let's design something! (I've got an idea ...)
First of all, I have to state I'm not exactly a fan of stepper motors. They consume a lot of power, are noisy and expansive. My idea is to modify a printer to use a "simple" geared DC motor plus position feedback. However, I found the linear encoder stripes to cost FORTUNE. So does the linear encoder and encoder chip. So, my idea: - drive the belt for the printer using DC motor with no encoder -by rklauco - Let's design something! (I've got an idea ...)
This is stupid. I added a single line of comment to the end of start gcode - and now it's outputed OK...by rklauco - Slic3r
I have a stupid question. I've been using Slic3r for quite some time and I like it. Lately, I changed my printer's configuration and added Z probe. Everything works fine with one problem. I modified the custom Gcode for start (to adjust for the probe). And now, when the Gcode from slic3r is generated, it outputs the multiple lines of my custom Gcode into the comments. However, as there is more thby rklauco - Slic3r
For newbies like me: reading the EEPROM is done using the same simple command, but with the last parameter -U eeprom:r:backup.eep Thanks again for the info.by rklauco - Controllers
Thanks a lot! This is what I wass looking for. Now I have the insuranceby rklauco - Controllers
I have Melzi 2.0 board with Repetier firmware version 0.91 (probably). I want to install induction sensor for bed leveling. However, all the comments from the configuration.h and all the other files are removed. Therefore I'd like to install either newer version of Repetier firmware or some other firmware (like Marlin) and configure it. To stay safe, I'd like to backup the current firmware somehoby rklauco - Controllers
Well, I did a bit of soldering. I used the Bluetooth-how-to, but instead of BT module, I used the wires and plugged them to Banana. I disassembled an old laser printer and salvaged some ferite core and wired few rounds of the serial wire around it. And, finally, I connected it to Banana's ttyS3 (UART7). Of course, I only used 3 wires (RX, TX, GND) and also used the 3v3 conversion as for the BT. Nby rklauco - RAMPS Electronics
Wow! I only found this by accident! This is a great idea!!! Too bad I found it after soldering the pins Should be on the wiki, too...by rklauco - General
Just regarding the prices... From China one can get MUCH cheaper overall solution - with all the downsides of the China production, of course. Like: - Mega 2560 R3 for 5.64EUR - RAMPS 1.4 board for 4.04 EUR - 5 stepper drivers including heatsinks for 5.47 EUR Overall cost of 15.15 EUR. Just take care about the fuses and the power sourceby rklauco - RAMPS Electronics
Hmm, this is a bit more than I can understand Yes, the Banana and the printer share the same wall plug as I have it in the cellar with single connection only (and, honestly, the whole house seems only to use 1 phase for all wallplugs). The power brick (meaning the AC to DC adapter) for Banana uses the 2-wire connection to mains (line and neutral), not the protective ground. I do not understand tby rklauco - RAMPS Electronics
Oh, and one more thing - my idea was to connect the Melzi serial directly to Banana's serial port (with voltage converter, of course) - to avoid the USB bus at all. But as Melzi does not provide serial header and I am not keen to break the warranty, I am a bit hesitating to solder on it...by rklauco - RAMPS Electronics
Thanks a lot for the power warning! I totally missed that as I for now only tried to find difference between Melzi and RAMPS To be honest, I don't care about the display at all - I have it for Melzi, but I rarely use it - only in case of serial failure in the middle of the print. I can overcome the power issue by supplying the 5V to Arduino directly using the pin and providing it from a voltageby rklauco - RAMPS Electronics
Sure I know - the $16 was for a pack of RAMPS+Mega+5 pololu modules My problem with the FT is that it is connected to the ATmega directly without resistors, so I kinda hesitate - if the FT for whatever reason reports logical 0 on TX pin, I'll not be able to send anything. But, perhaps, this is not a big deal as there is a how-to on reprap wiki to connect BT module without disconnecting the FT...by rklauco - RAMPS Electronics
Sorry for newbie question. I have a Chineese i3 copy. My melzi board, delivered with the printer, works OK from SD card, but often disconnects the serial connection - and by often I mean every ~25-60 minutes. I want to use OctoPrint, but due to the disconnecting serial port, it's unusable. And, as Melzi does not have serial port pins, I am stuck to SD card printing for now. However, I bought RAMPby rklauco - RAMPS Electronics
Maybe I'm just too stupid, but... There is Arduino IDE working with ESP. The ESP does have the pin limitation, I agree, but you can use shift registers - with 10 times the clock speed, one should be able to simply recompile the firmware with something like digitalWrite to digitalPush... Maybe I'm just too optimistic. But whatever I did with ESP-12 was WAY faster than Arduino, including GPIO operaby rklauco - Developers