If you follow the earlier link to the schematic, you will see the power LED in the lower right corner of that first box. It is *supposed* to be connected between ground and a resistor. The other end of the resistor then connects back to VCC, which is your 5V supply. If that light is some times on and sometimes off despite your PSU *always* being on, then it may mean there is a loose connection orby dazed.dnc - Reprappers
I also use skeinforge with the makerbot. I don't see a (convenient) way to use different replace.csv files for each profile, which leads me to believe this is not the most user-friendly option for my particular setup. Far as I can see, I would have to move the file when I didn't need it. I don't see an option for changing the script like you get with "fill" or "speed", which would make this confiby dazed.dnc - RepRap Host
I had to fiddle with the firmware code a bit in order to get my PID loop responsive enough. My memory is a little fuzzy, but I think the key changes I made were: //in "configuration.h" #define SLOW_CLOCK 750 //default was 1000 or maybe 2000? - didn't seem to check the temperature often enough //my PID settings - I think this is close to or maybe even exactly taken from the makerbot PIDby dazed.dnc - Reprappers
No luck with the new skeinforge either. Even after changing the comments, the reprap just locks up when it gets the first E code. It will print Gcode made by the host software just fine though. Unfortunately, without functional bridging, that Gcode is useless. I'm going to try some of the other tools, but I'm pretty sure this is not a problem with the host software. Something causes my reprap toby dazed.dnc - RepRap Host
I downloaded Skeinforge 35 last night, but I have yet to try it. Before that I think I was using Skeinforge 17 or 18. I saw the "dimensions" tab, which I guess enables the E codes, but my reprap stops responding after it tries to purge the extruder. I see that the G1 command with the E code was sent, but it never starts extruding. I notice that Gcode made by the host software is using ";" for coby dazed.dnc - RepRap Host
I have been using Skeinforge to slice up models for my makerbot and it does a great job of altering the tool path to span gaps where needed. Now that I have a Mendel, I'm trying to print the same part using the host software. The host software just ignores the gap and continues printing the normal infill pattern over open air though. Generally, one end of each line does not land on any support siby dazed.dnc - RepRap Host
I would also recommend the RAMPS shield. If you use an all-in-one solution and you burn up a stepper driver, for example, you have to replace all three of them. With the ramps shield, you just pluck out the bad one and replace it. It'll cost you $15 instead of $50-100. I like the compact size and easy pin access too. If you buy from Ultimachine, you won't have to worry about customer service eithby dazed.dnc - Reprappers
I noticed the same thing with my motors. Apparently if you try to run the motors too fast the stepper driver chip can't keep up. You have to either turn on the next level of micro-stepping or set your feed rates lower to reduce the frequency of switching the step pin. I thought maybe this was related to EMI noise on the logic lines, but I tried several values and pairs of filtering caps and it dby dazed.dnc - Reprappers
If you look at the schematic on their website, you'll see a 100k resistor (R9) between the enable pin and ground. This is a "pull down" resistor that makes the stepper default to the enabled state. You need a 5V (or 3.3V depending on what your logic level voltage is set to) signal at the enable pin to disable it. If I'm not mistaken, this is inverted from the normal gen3 stepper drivers. When yoby dazed.dnc - Reprappers
On its surface, that looks like a great solution. I'm not quite convinced enough to give it a try myself though. It seems to be getting mixed reviews as far as durability goes. At $33 plus shipping per can, I would like to hear from more people before trying it myself. The cost would be more acceptable if I knew I would have another application for it at some point, but nothing else comes to mindby dazed.dnc - Reprappers
Not that I'm a huge stepper motor expert or anything, but I would expect that as long as you stick to models that use bearings on the shaft, the motor will probably outlast other parts on the machine. Also, don't overheat them. If you treat them well, I see no reason that they won't outlast the printer itself. I sometimes scrap printers and pull off common circuits. I have seen some 5+ year old oby dazed.dnc - Reprappers
If you are in the US, you might give a shot. They get a lot of overstocked items then resell them at low prices.by dazed.dnc - Reprappers
I noticed makerbot is selling PTFE coated nozzles. The idea being that the PTFE prevents plastic from sticking to your nozzle then breaking off after it balls up a bit. This sounds like a good way to improve print quality and make the machine less sensitive to bad skeinforge settings. Is there a chemist or someone here who knows of a good no-machining (or minimal machining - read "hand held drilby dazed.dnc - Reprappers
I think my heater is too overpowered or the thermal mass is not enough for bang/bang to stabilize. I'm getting temperature swings just as big as with PID. I have been reading Nophead's blogs and it sounds like 3 degrees can make a surprising difference in the quality of the parts, so I would like to do better than a 10 degree temperature swing. I have been trying to determine how to measure anby dazed.dnc - Firmware - experimental, borrowed, and future
I tried combining bits from Joaz's fork with the original. I wasn't able to print with it, but the temperature control did seem to work. I made some other changes to the way the heated build plate works, so it won't be as simple as copy/paste. I am not using a slave controler, so I did not attempt to edit the slave firmware either. I'm not sure what you will need to change to make it support theby dazed.dnc - Firmware - experimental, borrowed, and future
The "official" hydra-mmm firmware has a slave firmware packaged in the .zip along side the master firmware. http://sourceforge.net/projects/hydra-mmm/files/Software-and-Firmware/Hydra-MMM_v1.4/Hydra-MMM_v1_4.zip/download I have not tried it though. Maybe the slave firmware is different, but I don't think the original master firmware supported a thermistor when using it as an all-in-one firmware.by dazed.dnc - Firmware - experimental, borrowed, and future
Thanks for doing the grunt work and pointing that out. You just saved me a lot of time and guesswork. I'll grab the new files and give it a shot. Edit: Does the following also apply to this firmware? Quotehttp://reprap.org/wiki/Arduino_Mega_Pololu_Shield The FiveD Firmware uses Timer1, which is also used for PWM on pins 11 and 12, so we can not use those pins for the heater in FiveD Firmware. Thby dazed.dnc - Firmware - experimental, borrowed, and future
Given that Pin 47 uses port L and is number 2 on that port, have I got this correct? #define DIO47_PIN PINL2 #define DIO47_RPORT PINL #define DIO47_WPORT PORTL #define DIO47_DDR DDRL Attached is a list of pins and associated ports/functions for an arduino mega. I intend to put them in the firmware myself eventually, but I thought I should post the list here for anyone interested in the meaby dazed.dnc - Firmware - experimental, borrowed, and future
Triffid_Hunter (): Thanks for the detailed explanation. I saw the link about "stringification" but it didn't quite sink in until I saw your example and learned what "##" does. I have a datasheet for my chip and I see where it lists the "ports". I think I have all the information so it is just a matter of translating it all into a usable set of pin definitions. That might take a while consideriby dazed.dnc - Firmware - experimental, borrowed, and future
I have looked in arduino.h and all I see (regarding the arduino mega anyhow) is this: #if defined (__AVR_ATmega1280__) #endif /* __AVR_ATmega1280__) */ #ifndef DIO0_PIN #error pins for this chip not defined in arduino.h! If you write an appropriate pin definition and have this firmware work on your chip, please tell us via the forum thread #endif While I see a bunch of stuff like this: #defby dazed.dnc - Firmware - experimental, borrowed, and future
I haven't found firmware for an arduino mega that I'm happy with yet. I have been reading up a bit about this firmware and it sounds promising, but it doesn't have pin definitions for an arduino mega. I'm not entirely sure of what I'm doing, but I think I'd like to try adding these pin definitions and see if I can make it run on my RAMPS kit. I'm familiar with the adruino style of using some funby dazed.dnc - Firmware - experimental, borrowed, and future
The biggest (only?) downside I have heard of is that the PTFE tube will stretch, which causes some lag between extrusion starts and stops due to the build up and release of that tensile force. I thought maybe some steel braided hose with a PTFE liner might reduce the amount of elongation and make the effect less significant, but I have not had a chance to try it yet. Shorter tubes will have lessby dazed.dnc - Reprappers
I have been thinking about the glass barrel design a bit. I'm thinking of trying something using two shaft set collars, a PTFE washer, and a segment of brass tube with nozzle built in that is just long enough to hold the heater and clamp onto with a shaft set (M6 threads cut into the bore of course). The idea is to use two 6mm bore shaft set collars to clamp the brass bits and glass together witby dazed.dnc - General
rocket_scientist: I assume you have been heating the tips and stretching them to create a nozzle? Is it possible to instead create a kind of mold that you heat up and press the tube into? Or maybe you just need to get the glass red hot and shape it like marble makers do with those spoon looking things, except use a specially shaped tool instead. I saw earlier discussion about trying to wrap theby dazed.dnc - General
Thanks for the advise. I really need to get this machine running since I have a couple of time-sensitive projects going on. I think what I'll do is stick with the current set up just to keep things moving forward. It doesn't sound like there is an immediate threat to the circuits and it looks to be decently efficient energy wise, so I think it is acceptable for now. Even if it does wear out the aby dazed.dnc - Firmware - experimental, borrowed, and future
Thanks for the informative explanations. My understanding of how thermocouples work was way off base. After digging in the firmware code a bit, I also noticed that it uses linear interpolation to fill in the gaps in the temperature table. While it might make the execution loops a little longer, linear interpolation makes it relatively insignificant that our temperature tables have gaps. I shouldby dazed.dnc - Reprappers
I was just going to edit my previous reply, but I see Triffid_Hunter posted, so I'll start a new one. I measure that the heater draws an average of 0.5A to maintain a steady state. At 120V, this means I am drawing about 60W to keep the build plate at a steady 100C. It takes 264W (120V at 2.2A) for about two minutes to get it to 100C. Considering a typical filament bulb is rated at 60W, that doesby dazed.dnc - Firmware - experimental, borrowed, and future
The mosfet does switch all the way on if I write 1023 to the output pin, but if I use the above code, the output seems to settle at a much lower value - which only partially switches the mosfet. It reaches a relatively steady state immediately after the first overshoot, which is how a good PID loop is supposed to look. I just wasn't sure what this would do to the circuits since this intentionallyby dazed.dnc - Firmware - experimental, borrowed, and future
I was getting 10-20 degree temperature swings from my PID controler. I spent all weekend trying to adjust it and wasn't able to do much better than a plain bang-bang control does. I also tried making my own temperature lookup table as well as swapping in the published ultimachine thermistor table. This got my temperature readings a little closer to the actual temperature, but I still had big swinby dazed.dnc - Firmware - experimental, borrowed, and future
I'm assuming the IC on the thermocouple sensor boards is some form of microcontroller or that it could be emulated using the arduino and appropriately written firmware. While I have done some basic electronics and firmware hacking, I'm not an EE and I don't know anything about the complexity of programing firmware to emulate the sensor or what the extra overhead would cause. Has anyone attemptedby dazed.dnc - Reprappers