I have the cheap 100K 3950 Beta thermister as well: Haven't been able to find a data sheet. If the original thermistor was 10 K with a 4.7 K pull-up, then shouldn't the 100K therm pull-up be something like 100K ? I'd like to compare with Heart-Steinheart calc instead. Where can I find the A-B-C coefficients for this calculation? I need a bed heat control to add to an M3D printer I juby KM6VV - General
I bought one of the inexpensive Chinese 2.5W lasers. No TTL (PWM) control. I expected that I wouldn't be able to do grey scale type burning, but that's OK. My question, The 'modules' take 12V, and don't have TTL input. I assume I can't just feed the module with PWM'd 12v from something like the bed heater supply? The constant current circuitry inside the module won't like it? What Laser modby KM6VV - Laser Cutter Working Group
Might want to verify the correct thermistor, must match setting in software. Which do you have?by KM6VV - RAMPS Electronics
I have RAMPS/Mega2650 running for 3D printing. I'd like to run GRBL on a second Mega with RAMPS for CNC. I can compile and load, but nothing runs. I read that GRBL is for Atmega 328. And RAMPS is for the '2650. A new UNO and CNC board is on the way from China... I tried a GRBL_RAMPS 1.4, but I can't get it to compile. It doesn't seem to set up a library, or have an GRBLupload . Thoughts?by KM6VV - RAMPS Electronics
I just ran into that tonight. My Z min works for homing, but the Z max end stop is not seen. I have RAMPS 1.4. I can't find where Z_STOP_PIN is defined. This looks like we only get either Z_MIN_PIN or Z_MAX_PIN. #ifdef Z_STOP_PIN #if Z_HOME_DIR < 0 #define Z_MIN_PIN Z_STOP_PIN #define Z_MAX_PIN -1 #else #define Z_MIN_PIN -1 #define Z_MAX_PIN Z_STOP_PIN #endif #endiby KM6VV - Firmware - Marlin
I'm still looking at the MK8 extruder I bought. The brackets I've seen are indeed too flimsy. As I have to design a mounting bracket for my PCB router anyway, I might as well make a split-ring type of mount. I've also just found heat cartridges advertised as 12/24V, Which is obviously wrong. Probably just more 12v elements. No mention of the resistance of the units. So I continue to getby KM6VV - General
Pure 24v would be good and clean in design. My CNC PCB Router is about 12" x 12" in footprint, and I'm considering building its power supply into a 5" high 16" x 16" rack mount. the router should mount nicely on top. A small enclosure will hold the RAMPS board, processor and LCD. Initially I'd planned to drive the PCB router with a PC. That may not be necessary if Marlin can do the job. Hoby KM6VV - General
Thanks guys for the information! Knowing the hot end is 40w sheds some light on the problem. I read 3.6 ohms on my Fluke, so it wants 12v. Disappointing. I want to avoid a dual (12/24v) power supply, but I can initially use two supplies, and later look for a 24v hot end (I see you have one). Too bad they don't do a dual element hot end). I intended to run 24v for heater bed, extruder, NEby KM6VV - General
I finally received my extruder, and it says its for 12/24V (I didn't notice that before!). I want to operate it on 24v, but I don't see any way to select the voltage. I understand the cautious on running the RAMPS board on 24V.by KM6VV - General
I suggest you use a larger stepper, say NEMA #23 (or a pair in tandem drives), and external stepper drivers for each stepper. Otherwise, make up a drive board with four (4) TB6560 stepper drivers, and drive one stepper with each driver. They can share the step/direction signals.by KM6VV - RAMPS Electronics
I'm looking at the Arduino megapololu shield schematic, and up in the left hand top corner are the pins for Arduino connectors. I am familiar (was?) with the pins of the Arduino boards, and have used the boards several times. This shield schematic has only the 'local' signal names, with no match to the Arduino pin (signal/port) names. The two vertical rows suggest the sockets on the sides of tby KM6VV - RAMPS Electronics
I set my heatbed and extruder to 998, (Merlin 1.1.5), and I show 25C for both on graphics LCD, and I haven't seen a temp error since! Never saw compile errors.by KM6VV - Firmware - mainstream and related support
Yes, I've added G28 to home axis before the G1 move. Not sure if it's needed. Might depend if a power-up was done first. I am getting movement now from MDI, but not from manual jog under Repieter. I haven't been able to find out what Repieter sends the RAMPS board. I suspect it sends G&M codes of it's own for 3D printing, or maybe Marlin automatically does setup for 3D; like turning onby KM6VV - RAMPS Electronics
Hi, Thanks for the tip. It's related to inch/mm mode. I set support for inch mode, // G20/G21 Inch mode support #define INCH_MODE_SUPPORT //alm Maybe doesn't initialize in INCH correctly. G20/G21 Not certain yet, but it looks like I need a mm move first, then change to inch. Still testing. Absolute mode doesn't seem to be a problem, never got the first move. I usually do a block of 'Gby KM6VV - RAMPS Electronics
Hi Obewan, all. The forum thinks I'm a robot! I'll edit a few lines and try again. Only limited success. Still can't issue Gcode move (G1) commands. I can move steppers from prepare/move axis on LCD, however I can't move from issuing G1 X1 command (but got 'ok') from connected Arduino terminal. G28 'home' moves all three axis. Issued M17 first (enable stepper motors). RAMPS14_test runby KM6VV - RAMPS Electronics
Thanks! That did it.by KM6VV - RAMPS Electronics
Thanks, Ran the M119, got: 17:47:51.639 : x_min: TRIGGERED 17:47:51.639 : y_min: TRIGGERED 17:47:51.639 : z_min: TRIGGERED I found and commented out the endstops, but although I can now go negative in xyz (per move screen display), the stepper still only turns positive. // If enabled, axes won't move below MIN_POS in response to movement commands. //alm for testing #define MIN_SOFTWARE_ENDSTby KM6VV - RAMPS Electronics
I posted this under RAMPS hardware, but realized maybe it is a software problem. I have Marlin loaded on my RAMPS board and Arduino. Move axis can only step in the + direction (XYZ) There is a direction signal that changes with direction when I move the shaft encoder + or -. The enable line goes low when I start a move, and goes off after inactivity. Steppers are OK. I've tried different stepperby KM6VV - Firmware - Marlin
I have Marlin loaded on my RAMPS board and Arduino. Move axis can only step in the + direction (XYZ) There is a direction signal that changes with direction when I move the shaft encoder + or -. The enable line goes low when I start a move, and goes off after inactivity. Steppers are OK. I've tried different stepper driver modules. I've tried both with and without the limit sw's plugged iby KM6VV - RAMPS Electronics
I can't find the board now. That's probably where I got it, from somebody wanting to drive unipolar stepper motors. Although I have several old unipolar steppers (from old disk drives), I don't want to use them! So do all these board designs tend to use the same processor pins to drive the stepper modules; control heatbed, extruder and fan, as well as limit switch and temp sensor inputs? Betwby KM6VV - RAMPS Electronics
That's true, but if they SAY unipolar, I'd think they mean to drive it using a center tap. Most of my bipolar steppers have 4-wires. Not so much about the steppers, but I was wondering about the pins used by the boards. I did find a GRBL_RAMPS1.4, so looks possible... Thanks.by KM6VV - RAMPS Electronics
I just got a RAMPS board, and loaded Marlin on the Arduino. I want to do Laser. Can I switch to GRBL code and (LaserGRBL)? I know the RAMPS is bipolar and the GRBL has (drives) UNIPOLAR. but at the Arduino drive level, the pins could be the same, or maybe a header file can be configured on the GRBL build? Thanks, Alanby KM6VV - RAMPS Electronics
Thanks. I have downloaded and tired Inkscape, and I'm studying the video. I haven't tried Ponterface yet, although it was on my list. The SD card is running, although so far, Marlin doesn't like my line numbers. Seems Marlin wants you to start on line 0, an increment by 1 (and only 1) for each line. Not the way I write code. But I can put up with that for now (edit out line numbers). I haby KM6VV - Firmware - Marlin
Sender may be the next program I try. I'm trying Repetier right now, but not sure how well it will work. Sometimes it sends Gcode to Marlin, sometimes not. Between Repetier and Marlin, doesn't like my line numbers (N1000.. ) Doesn't to modal moves (G01 etc.). OK, I can get around that for a while. What I really want to do (first) is to run a laser. Tried LaserGRBL, but it doesn't want to tby KM6VV - Firmware - Marlin