hi! I'm not what I can call an expert when it comes to stepper motors, I know how they work, I know about motors drivers and i played (fixed) some 3D printers.... but now I want to build my own and I want the frame to be enougth versatile so that I can use use for wood cnc, (maybe some other materials too...), for 3D printing, and maybe for laser wood cuting.... looking at the comercial frames availables I didn't found ones that fits me.... my "stepper motors requirements are " X axis : 2 steppers + ball screew Y axis : 1 stepper + ball screew Z axis : 2 sterppers + ball screew extruders : 2 extruders (material + support) (optionnal : 2 mores extruders for "color printing") this makes me 7 steppers motors, 9 at most... most 3D printer controller use one driver on X, one on Y and some have dual output for Z, for extruders, they have usually 3 Extruders, which means that one is missing for whole requirements.... at first I was looking at BIGTREETECH SKR Pro V1.1 Carte de contrôle 32 bit ARM CPU 32bit Mainboard Smoothieboard pour les pièces d'imprimante 3D Reprap Imprimante 3D et fournitures from ectronique on banggood.com it has X Y Z0 Z1 E0 E1 E2..... I couldn't find any mother board or "controler" add on, that have enough "driver slots" so I begun to interest me about synchonizing.... so that I can use a single slot (for example X) to drive 2 motors.... what I understood is that a single controller can drive 2 motors, but it's not recommanded since the power is divided by 2... but maybe if the controller has enougth power this can be a solution???? other option was to have a "command" replicator and 2 drivers... say the controller use UART for communication, a board with 1 UART input and 2 outputs (and some software to show the readings of controler states as if there was one controller) but I couldn't find any.... I saw also about H bridge, but if I correctly understood, it's not advised to have a controler driving 2 H bridges... what is advised on the forum is to have one controler per stepper... but there is no board with 9 outputs... with the board of the link I can achieve the minimal requirements... but it would be really nice to have the 2 steppers that miss... thanks in advance for the help!
Hi JLM, you can chain up as many (to a point) of the step and direction wires to multiple drives as you need. you can see in this pic of my drive box how YR and YL have signals in parallel. Cheers Gary
Hi Gary! thanks for the answer! that's look interesting your electric connections! it looks as if you have one USART outgoing of the arduino and connected to many controlers! that's exactly what I'm looking for!!!! do you have any schematics ? how do select one driver from another? I means if you share a bus (SPI/USART), there must be some selection mecanism (chip select GPIO, address mapping....)
Hi JLM, it's not usart, it's GRBL program on the arduino, digital pinout pulses, for step pulses and direction high/low, that's what typical stepper drives understand. The red wire is the +5v shared on all the drive input channels and the other wires are XYZ step and direction low. Lots of info here at GRBL Wiki and any drive manual, GRBL is not setup for printers unfortunately. Cheers Gary
https://www.trinamic.com/fileadmin/...cuments/TMC220x_TMC2224_datasheet_Rev1.09.pdf page 19 show how to have multiple driver using a single USART... too bad they didn't used the @ field in communication protocol (fixed to 0....) it could have saved a switch.... is there any good drivers out there that I should have a look at?
