Re: Reprap Arduino Due Shield project - looking for helping eyes.
Yes PTCs don't limit the current, other than the fact they have some small resistance. They have to heat up and then their resistance gets higher but that takes time. I have also known them to catch...
View ArticleRe: all axis inverted, suddenly
did you unplug the steppers? if so maybe you plugged them in the wrong way round. even if you didnt, try flipping the connector anyway, it should solve the problem.
View ArticleRe: all axis inverted, suddenly
lazzymonk Wrote: ------------------------------------------------------- > did you unplug the steppers? if so maybe you > plugged them in the wrong way round. even if you > didnt, try...
View ArticleRe: all axis inverted, suddenly
Yey, got it working. i reversed the axis in the firmware, but had serious problems uploading to the board. had avrdude error, saying arduino couldnt find the board. got the suggestion of using another...
View ArticleRe: Reprap Arduino Due Shield project - looking for helping eyes.
NoobMan Wrote: ------------------------------------------------------- > Now you see these arent the things fast enough for > this. Only a schottky diode fast reverse time of > 5ns is fast to...
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Re: Reprap Arduino Due Shield project - looking for helping eyes.
Ok, here is a proposed design I am toying with, there may be better component choices. The zener is a fast acting type at 3.6V. The "fuse" is a PTC with trip time 0.2s at 290mA, hold current is 120mA....
View ArticleRe: Reprap Arduino Due Shield project - looking for helping eyes.
A 3.6V Zener will probably leak too much at 3.3V compared to a 100K thermistor so low temp readings will be inaccurate. If the thermistor is shorted to 12V D502 will conduct and put 12V on the 3.3V...
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Re: Reprap Arduino Due Shield project - looking for helping eyes.
This is maybe what I would do. I would look to see if I could increase the series resistor enough to not need the PTC without the ADC input leakage current creating a significant error. Don't have...
View ArticleRe: Reprap Arduino Due Shield project - looking for helping eyes.
Silicon is ("mostly") EM speed on a microscopic waffer. If thats to be protected, somesthing faster would be awesome, but we dont have that yet so we are limited at using something that is at least...
View ArticleRe: Reprap Arduino Due Shield project - looking for helping eyes.
IMHO, my thoughts are zenner alone may be too weak, so i would rather use it in classical fashion in series with 100k resistor to gnd, so reverse biased zener will drive the base of a power transistor...
View ArticleRe: Reprap Arduino Due Shield project - looking for helping eyes.
It doesn't need to be that complicated because a small series resistor limits the current to something that can easily be handled by a zener diode long enough to open a PTC, or maybe indefinitely....
View Articlecant seem to upload electronics correctly
Hi all ... I really need some help before i abandon this electronics setup... It would mean I would have to buy my 3rd setup ! (first was sanguinololu which fried) ... I really cant afford anymore, so...
View ArticleRe: cant seem to upload electronics correctly
I think printrboard has an on chip USB port so the firmware needs to include a driver, unlike other boards that have an FTDI chip or a second ATMega to do the USB. That probably requires a specific...
View ArticleRe: Reprap Arduino Due Shield project - looking for helping eyes.
i am trying to learn what i can from this thread, i am trying to understand how your circuit works nophead, though its late here and i am tired. its just that i think i have seen more than a few...
View ArticleRe: Reprap Arduino Due Shield project - looking for helping eyes.
I see how it works, but if you're comparing it to the circuit from bobc, be aware that it's backwards. In nop's diagram, the Arduino is on the left labelled MPU, and the thermistor is on the right...
View ArticleRe: Reprap Arduino Due Shield project - looking for helping eyes.
The ptc and 22 ohms resistor are part of divider, and thats the problem, like anything else that introduces a voltage drop, it limits the lower point of adc reads, and because thermistor is lower...
View ArticleRe: cant seem to upload electronics correctly
look here for firmware. [printrbot.com] also try enabling communication with device with it unplugged from power, but plugged into usb. also are you using 12v supply. any higher voltage often requires...
View ArticleRe: Extruder heater overpowered to death?
i recently tried silver past. it actually works well. you can also wrap resistor in aluminum foil . just make sure entire surface area of resistor contacts the metal. also key to get resistor to stay...
View ArticleRe: TB6560 with arduino?
I think teacups timings and signals work out of the box, from what i remember the timings and pulse widths were about even, and well within the timings of the board. you will still want to read on the...
View ArticleRe: can I use larger steppers on the RAMPs 1.4?
I also wonder if anyone have tried using bigger drivers. I would like to use my Nema 23 3A steppers with DQ542MA drivers, which can handle 4.2A. Do you need the Pololu drivers or is it possibly just...
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