Hotend temperature decreasing but firmware not see that

Hi , im using mks base v1.6 and mks tft v1.0 on my prusa clon.

when im printing sometimes extruder skipping steps and my print is failling. i just did a test on my printer and try to print a vase with %25 scale 0.25 mm layer hight 0.4 mm nozzle and 235 C with abs. (with my PLA test , its worst).My printer stop at %75 of print and didt go again . after then that i restart the printer immeditaly and check the temperature. howend temperature was 100 C and bed somethink lie 50C. print was stop like 20 - 30 sec ago and it cant drop that fast to 100 C from 235 C. i think my hotend temperature is dropping when im printing but firmware dont see that. what can i doo about that , how can i fix this?

I am having the same problem as of late, but the temp is higher, not lower

Quote
furkanbcr
Hi , im using mks base v1.6 and mks tft v1.0 on my prusa clon.

when im printing sometimes extruder skipping steps and my print is failling. i just did a test on my printer and try to print a vase with %25 scale 0.25 mm layer hight 0.4 mm nozzle and 235 C with abs. (with my PLA test , its worst).My printer stop at %75 of print and didt go again . after then that i restart the printer immeditaly and check the temperature. howend temperature was 100 C and bed somethink lie 50C. print was stop like 20 - 30 sec ago and it cant drop that fast to 100 C from 235 C. i think my hotend temperature is dropping when im printing but firmware dont see that. what can i doo about that , how can i fix this?

20191128-022437-HDR-1.jpg

Yes you can drop that fast. The drop from 230 to 100 happens a lot faster than the drop from 100 to 30 does. Same with the bed.
What you are describing is a jam. Skipping happens when you are printing faster than your hotend and spew out plastic. Slow your speed down and/or increase your hotend temperature. Too many retracts can cause skipping and jamming as well. Set your slicer to only retract when crossing open space and see if that helps. These are the two most common causes of what you describe.

DLC

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Kits: Folgertech Kossel 2020 upgraded E3Dv6, Anet A8 upgraded E3Dv6, Tevo Tarantula enhanced parts and dual-head, TronXY X5SA Pro(E3DHemera).
Scratch: Large bed Cartesian, exchangeable heads, Linear slide Delta, Maker-Beam XL Micro Delta, 220x220CoreXY.

For the OP.
Was the print cooling fan running? Could be cooling the nozzle.
Not sure what happens when the printer stops - may still have the cooling fan running which would cool the hot end quickly.

Raiders issue going hot would suggest an electrical issue. Can you give a better description of the issue and sequence of events?

I had to replace the board, went with a BIQU MKS base v1.6. I have been using a daoki M3 (104-gt2) screw in type of thermistor off of amazon. Did ok for a bit. I have bought a K type thermometer (4 Channel ) and have been checking the temps on everthing. Software was set for 190, temp reading 220 or greater. Change to the same type of themorsite, same thing. I did a PID tuning, ran fine, but then when I changed the vaules, but temp is over by about 30 degrees.

Changed to a different type of thermistor(epocs?), same thing. I have been using a
BCZAMD 3D Printer Parts Super Wire Connection for Ceramic Cartridge Heater Heating Tube/Thermistor 100k Ntc 3950 Hotend CR-10 Anet A8 (SPL-2, 10PCS) to make it easier to change the hot end, have the Heater, thermistor and fan connected through them, (one each, not three into one). I have NTC 3950 thermistors to try yet.

I have an identical printer, with differtant issues, going to plug the same hot end into it, see what happens. Should rule out the thermistors and connector, whichs leaves the board as the problem or the marlin file I am using.

Sorry this took so long, I had to bury a friend and haven't been in the trouble shooting mode. Going to correct the issue with Printer number two add a new hot end before I do anything with #1.

My guess is the board right now, and have tinkered with the idea of trying to change E1 to E0, connect the thermistor straight to the board. IF the problem is the board, don't if I will buy from the same maker. Thermo tables gone off. Right now I don't want to buy a new board.

The type of printer is Fabrikator Mini, v1.0 everthing but the screws has been changed, hell #2 I built


Let me know what you think or if l left anything out LOL

Have you checked the thermistor spec against the pull up resistor (on the controller ?) and the config file for the firmware.
Found this link [smoothieware.org]

Regards

I will have to do some homework to understand what you are asking, so I would have to say no. I am not using a MKS base v1.6 with Marlin, so my config file is thermal settings. The old board was a V1.4. I suppose the 1.6 requires a change in marlin, the only changes I have made are the are too the type of thermistor I an using, so far a both 1 and 5, will check it with an 11 soon

Just checked the thermistortables.h against what I found here, I wonder if change my tables to match what I found would do anything, which would make it a software issue

Edited 1 time(s). Last edit at 02/20/2020 06:11PM by Raider.