Again, as explained above, Table 8 will be the most accurate at printing temperatures. It will be very inaccurate at ambient temperatures. If you want to use table 5 that's fine, but your temperatures are even more incorrect at printing temps.

Ah, thanks for your explanation.   It just shocked me when it said at ambient, i was in the negatives.  I'll try table 8 at printing temps.

Either way, opening the doors seem to keep the fins much cooler.

Again, as explained above, Table 5 will be the most accurate at printing temperatures. It will be very inaccurate at ambient temperatures. If you want to use table 5 that's fine, but your temperatures are even more incorrect at printing temps.

Uhm I like to read all the post for pointers and such. i am actually having some temp problems as well after changing to a Ramps so this thread interested me. But You confused me on that last statement or I am just reading it wrong. You seem to contradict yourself in it.

I did finally have success by using table 5 at 200degf with doors open.  There was a noticeable different in temp of the fins with the door open.

PLA requires cool air through the fins. PLA does not require a heated enclosure to avoid warp.
ABS is less sensitive to cool air through the fins, but does require a heated enclosure.

Print with the door open and possibly a gentle fan to bring the enclosure temperature down, see if that solves it. If it does, you'll need to either print with an ambient temperature enclosure, or seriously step up the fan power.

I also already did the above to make sure airflow is better.  I looked at the e3d wiki.  Even with the cut out above and 12v power, my fins aren't cool to touch.  I suspect that might be the issue but don't know how I could make it cooler as I'm using the fan and fan clip that came with it.

I wonder if its better to print with the front door open?

I removed the carriage and dremmeled out a section so the entire fan is exposed.

I also found that i have to up my temp from the filaments recommended 230 to 235 to prevent any jams. This is better than the 250 I was printing at.

carl_m1968 wrote:

Or run PID auto tune which I am not sure Repetier supports.

Incorrect, PID autotune will not help in this case. PID autotune cannot correct for thermistor tables.

carl_m1968 wrote:

Just an fyi, with that resistor on the motherboard it makes your thermistor measure at 300k instead of 100 or 200k.

Also incorrect. According to:

http://voltivo.com/forum/davinci-firmwa … ruder#3631

R1 is in parallel with the thermistor, and has a value of 1k according to that link. The resistance of a 104GT-2 at say, 200C is 48ohms.

But with R1 in parallel, that's 45ohms total. 45 ohms is a hotter temperature than 48 ohms (about 207C), so the DaVinci will read hotter than actual.

Thermistor table 8 in Repetier will get you close - as noted above you'll be off by around 7 degrees in the range of temperatures 3D printers operate at. Thermistor table 5 is likely way off.

"Measure at 300k" is incorrect. That would require a resistor in series with the thermistor, which is not the case. Please avoid spreading incorrect information.

Sorry, I'm just a noob requoting what I have seen in other places through google searches.  My bad.

Or run PID auto tune which I am not sure Repetier supports.

Incorrect, PID autotune will not help in this case. PID autotune cannot correct for thermistor tables.

Also incorrect. According to:

http://voltivo.com/forum/davinci-firmwa … ruder#3631

R1 is in parallel with the thermistor, and has a value of 1k according to that link. The resistance of a 104GT-2 at say, 200C is 48ohms.

But with R1 in parallel, that's 45ohms total. 45 ohms is a hotter temperature than 48 ohms (about 207C), so the DaVinci will read hotter than actual.

Thermistor table 8 in Repetier will get you close - as noted above you'll be off by around 7 degrees in the range of temperatures 3D printers operate at. Thermistor table 5 is likely way off.

"Measure at 300k" is incorrect. That would require a resistor in series with the thermistor, which is not the case. Please avoid spreading incorrect information.

I'm near same settings as above.  tried temps 190, 200, 210.
Printing at 50mm
Bed temp of 75
Using table 5 (no small pcb board)
Fan is on dedicated 12v
tried retract at 2mm and 1mm
Using Simplify3d

Rather you use the small pcb or not, does not matter. It is simply a pass through for the fan and thermistor. There is a resistor on the mainboard that is the source of every ones woes. As long as you use the Da Vinci stock board there is no premade table for your setup. You have to make your own. Or run PID auto tune which I am not sure Repetier supports.

Just an fyi, with that resistor on the motherboard it makes your thermistor measure at 300k instead of 100 or 200k. So as you see there is no preset table for that value. The best you can do is set it for a known temp, measure yhe actual temp and then changr the set value to compensate.

The issue seems to be the thermistor table being incorrect for the E3D. Looks like I will be dialing in the temp for any filaments I use, but at least I know it needs to be higher.