I’m did a little bit of a happy dance the other day. I managed to get my Qd-bd extruder to poop for the first time.
I got my little wiring breakout board done, and I cut a piece of glass to used double sided tape to get it to stick to the table. Since my rig mounts to a flat marble plate, I’m going to attempt to not use the springs to preload the table… We’ll see how that works.
Ok… In the initial pooping experiments, I used the default values in sprinter for a 100K thermistor and it seems like I couldn’t get anything to work till I was at 220C. Soooo… those values must be in the code somewhere.
In sprinter there is a file called thermistortables.h
I made the following hacks and pasted in the values from http://www.fabric8r.com/forums/showthread.php?728-Thermosistor-delta-values-etc:
Ok.. I confused myself earlier but I think I understand things now.
So basically the Arduino can measure 5V and bust it up into 0 to 1023. Digital.
So what I think we’re looking at in the thermistor tables here: https://github.com/kliment/Sprinter/blob/master/Sprinter/thermistortables.h is the digital value from 0 to 1023 on the left side and the corresponding temperature on the the other.
Here’s something I need to look at. http://learn.adafruit.com/thermistor/using-a-thermistor
Ok.. So I have the table resistance from Qb-db now I need to figure out what the resistance is in the Ramp 1.4 Arduino.
According to this is 4.7Kohm http://thefutureis3d.com/images/800px-RAMPS1_4schematic.png
I played around with my tables… And started playing around with a test cube.. But no joy… It seems like like I’m not getting enough grip with the wheel I hobbed. I used smallest tap that would fit into an R8 collet. I’m thinking that was too large a radius. I tried the qu-db gear as well and no joy as well.
It seemed like I could get plastic to extrude when I press down on the filament, but my wheel just isn’t gripping enough.
I googled a bit and found something of interest…
Sooo… I think I need to put this aside for a while.. I think I need to hob another gear with a smaller tap.. I have a lassy tapper, that could hold the tap and then hold that with an R-8… Holding it with a drill chuck is not and option since the side load would push it out of the holder.