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People building or using RepRaps.
Re: Strange Z axis behavior - 12 years ago
I use RAMPS 1.4. Basically the end stop wires cannot be tied (using spiral wrap or whatever) to the motor cables. I found once I separated them out so they just dangled loosely about 2 - 3 inches apart from the motor cables then all of my (endstop related) problems just went away. Of course, that just left the *other* problems. The RepRap is a project consisting of nuts, bolts, and problems.by blob - Reprappers
Re: Strange Z axis behavior - 12 years ago
Solved my problem after talking to the awesome dudes on irc. It was crosstalk causing false triggering on endstops. My suggestion - update the buiild instructions so it doesnt have all the wires being grouped together with spiral wrap.by blob - Reprappers
Re: Strange Z axis behavior - 12 years ago
So, I have just brought 4 new motors and 1 new Pololu from lulzbot and... the exact same problem. Clicking in Pronterface "X -100" will sometimes move it 1mm sometimes the full amount. With a new motor and new Pololu. So logically, it must either be a faulty ramps or a faulty version of Sprinter firmware? I wish there was an easier way to debug this problem - its getting impractical to just throwby blob - Reprappers
Re: Strange Z axis behavior - 12 years ago
I'm not sure what you mean by "backwards". They are connected such that they move in the correct direction. As far as I'm aware, there is no polarity or difference in plugging in coils in either order - in fact the Mendel instructions say to swap the wires around if it moves in the wrong way. Could someone with motor skills confirm this?by blob - Reprappers
Re: Strange Z axis behavior - 12 years ago
I'm a little unsure about how to set the Vref to 0.36V. Is this simply adjusting the trimpot? It sounds like the Pololu is doing the shutdown/restart thing, athough I felt the driver chip and it did not seem hot. Is it possible it is cutting out for some reason other than heat? The X axis motor certainly gets too hot to touch during operation. Does this mean that these motors will be unsuitableby blob - Reprappers
Re: Strange Z axis behavior - 12 years ago
Hi, So, I solved the second half. RAMPs default home is whatever it boots up as. So I needed to set the extruder to the correct home then reboot the RAMPs. I'm having major problems with my motors though. My motor specs are below. If I turn the pololu too far clockwise, it starts jumping and ticking out loud. If its too far counterclockwise, it just doesnt move. Either way, it seems to move inby blob - Reprappers
Strange Z axis behavior - 12 years ago
Hi, Im getting weird stuff going on with my Z axis which might be two (unrelated?) problems. When I use pronterface to go up or down by increments of 10 it will sometimes go down by a lot, other times it goes down by only one or two millimetres. Any idea what may be causing something like this? Secondly, when I go and click print, the extruder head raises up by some strange amount and starts pby blob - Reprappers
Re: Got Sanguinololu 1.3a, now what? - 12 years ago
IIRC, you only need dapa to burn the bootloader & change fuses. You use avrdude to do this. I guess the thing to check a few times if avrdude doesn't work would be the right pins are connected on the DB25. Remember they are numbered kind of funny depending on what way you look at the connector. If hes already put the bootloader on, like he claims, just plug it in via usb. If it doesnt pop upby blob - Sanguino(lolu)
Re: Got Sanguinololu 1.3a, now what? - 12 years ago
I have had dapa working on a 644P in Ubuntu, no problems at all. Is it possible the guy you brought it off installed the wrong bootloader? Do you know what state the fuses are in? Normally they are set when the bootloader is written but maybe he didnt do that? I made a dapa programming board separate from the Sanguinololu, its pretty straightforward. All it takes is a few resistors and a oscilby blob - Sanguino(lolu)
Re: Polarity for 12v input - 12 years ago
Hi, thanks for your tips. So, I had the 12v input around the right way. my pololus were wrong way around, but now they should be ok. My mosfets and pololus are room temp, only my vreg gets super hot when a pololu gets plugged in. Do I need to attach the seperate 12v power for each motor? Can I have just one pololu installed for testing purposes? Does it need a motor attached before the vreg willby blob - Sanguino(lolu)
Re: Polarity for 12v input - 12 years ago
While it doesn't seem to be the issue, one of my problems was the Pololu driver boards where around the wrong way. Thanks to the "helpful" rev1.3 example photo posted as SL1.3a_dual_z.jpg on the main page which has them plugged in around the wrong way... Might be worth deleting that image?by blob - Sanguino(lolu)
Re: Polarity for 12v input - 12 years ago
So I have done some basic debugging and it seems to heat up only if I have a Pololu board plugged in. Doesnt matter which one, they all seem to cause the voltage regulator to overheat. Which end should the screw pot be facing? Any ideas whats going on?by blob - Sanguino(lolu)
Polarity for 12v input - 12 years ago
Hi, for rev 1.3 could someone let me know the correct polarity for the screw terminals? I used ground as the closest to the corner, and my LM7805 became extremely hot within 30 seconds or so. I think either the LM7805 is the wrong way around (the metal part is facing the outside of the board) or the screw terminal polarity is reversed?. Thanks in advanced!by blob - Sanguino(lolu)
Re: Programming error - first mismatch at byte 0xf800 - 12 years ago
Didn't for me, but I think it's more overall computer speed related.by blob - Sanguino(lolu)
Re: Programming error - first mismatch at byte 0xf800 - 12 years ago
Finally worked it out! Thanks for the suggestions but it seems to be unrelated to the lock bit. The problem was that I use Win7 x64, so was programming it from within a VM. Turns out my computer was too slow to run avrdude. When I booted into Ubuntu on a flashdrive it worked perfectly!by blob - Sanguino(lolu)
Re: Programming error - first mismatch at byte 0xf800 - 13 years ago
One idea I have is regarding the crystal. I am using a 16MHz resonator as per the instructions. However, when I plug the recommended fuse settings into an AVR calculator i.e. -U lfuse:w:0xFF:m -U hfuse:w:0xDC:m -U efuse:w:0xFD:m it says that the setting is for a 8mhz external oscillator. Is this an issue, or is perhaps the fuse calculator mistaken? Cheers!by blob - Sanguino(lolu)
Programming error - first mismatch at byte 0xf800 - 13 years ago
Hi! Please someone help me! I'm having big problems programming the Sanguino bootloader. My setup is: atmega664p DAPA programming, through ISP header on the complete Sanuinololu 1.3a board. (as per the instructions on the wiki page ) Programs fuses first - success. Then I try programming the bootloader and I get: C:\arduino-0022\hardware\tools\avr\bin>avrdude -p atmega644p -C c:\arduinoby blob - Sanguino(lolu)
Re: Confused about 644 vs 644p - 13 years ago
Thanks for your response! So I take it from your answer that the 644P is required, and the 644 wont cut it? Maybe its worth updating parts.txt in git so noone else will make this mistake in the future? I'll order a 644P and continue with the Sanguinololu since I've already got most of the parts. I'd still love to know if the fuse command above has hosed the 644 chip, because if not there might bby blob - Sanguino(lolu)
Thick sheet - how thick? - 13 years ago
Hi everyone, I'm currently building a Prusa Mendel at the moment and got to the part where I needed a bottom print plate. Using the recommendations here (http://reprap.org/wiki/Mendel_materials_procurement#Thick_Sheet) I cut MDF 4.7mm thick. I then got to the step where needed to attach the timing belt to the plate and noticed it said: QuoteA 10mm thick print bottom plate is spot on Damn. migby blob - Reprappers
Confused about 644 vs 644p - 13 years ago
Hi all, I am attempting to build a version 1.3a Sanguinololu and am very confused regarding the type of atmega chip that should be used. I pulled the git repo from and used parts.txt to order all my parts from my electronic supply. Parts.txt version 1.3a lists: QuoteIC2 ATMEGA644-20PU ATMEGA644-20PU DIL40 atmel So that is what I brought. Now all the informatby blob - Sanguino(lolu)