DELTA G2S - ABS many problem with extruder : forced feeding !

Hi everybody !

So it was nice to build, setup and print with my new GEEETECH G2S but i print only with ABS (i never test with PLA).

See the video : [youtu.be]

The extruder force (clac-clac-clac, the motor lost steps) despite :
- Correct mounting, firmware and software.
- Cleaning with ejector pin like this topic : [www.geeetech.com]
- Setting screws, 240°C temp and 1,11V at driver like this topic : [www.geeetech.com]
- Modify the plastic extruder like this topic : [www.geeetech.com]
- Replace plastic extruder by metal extruder.

It's not slicing parameter, i slow extruding (100mm at 2mm/s) via repeiter host.

I'm very unhappy about this, please have you this problem and solve it ???

Thank's so much

There many things you can check.

1. the specs or your stepper. You want to set it near 80% of the specs current, Also make sure of your driver current formula

2. Your temp, are they really 240C ? maybe you got a out of specs thermistor, Checking the thermistor with a multimeter with a thermocouple, you put the sensor directly into the nozzle in the heatbreak and record the difference then adjust the thermistor to match. This one was my problem when my extruder give me headache.

3. Are your firmware set to absolute or relative extrusion ? Cura is using absolute so if your firmware are set in relative this will give you LOT more plastics to push then if set relative, must of the other slicer are using relative by default but you can use a M82/83 in the start code to switch between relative/absolute.

Quote
GroupB
There many things you can check.

1. the specs or your stepper. You want to set it near 80% of the specs current, Also make sure of your driver current formula

Extruder motors are 42HSC8402-15B11, and specification appears the same as 42HSC8402-25B : Rated current: DC 1.5A
Stepper driver are A4988, do you find 1,11V is to low or to much ??

Thanks !

The formulamfor a4988 are : vref/(8*rs)
Rs is the sense resistor should be 0.05 unless its a china one and they change it in this case you have to check shematic and figure where is the sense resistor, the value on it.

If you follow the formula 1.1v / 0.4 = 2.75A and a busted pololus!

So your sense must be lower maybe 0.1 ( china usual one)

1.1 / 0.8 = 1.375A in this case its in range but a little on the too much side for your motor, they can probably work the same around 1.2A- 1.3A and generate less heat on the driver and the stepper.

So if you sense is 0.1 ohm ill check the other thing on my list its not you driver/stepper

Quote
GroupB
The formulamfor a4988 are : vref/(8*rs)
Rs is the sense resistor should be 0.05 unless its a china one and they change it in this case you have to check shematic and figure where is the sense resistor, the value on it.

It's writed "203" on sensing resistance of my stepper driver (it's a 20K resistor ?) :



Datasheet of the reseller is : https://www.geeetech.com/Documents/A4988-Datasheet.pdf but comments of the page product is confused : https://www.geeetech.com/stepstick-a4988-stepper-driver-module-p-577.html , sometimes 0.1 sometimes 0.2 ...

Maybe it's a 1A stepper driver and it's normal to not have enough power for motor ?

Thanks so much !

Edited 3 time(s). Last edit at 11/11/2016 05:30AM by josse34.

You can also use another method but its more complicated, but more precise , its the one I used with my previous china driver before my raps128.

[www.youtube.com]

a resistor 203 make no sense but a R203 = 0.203 ohm

Check with a multimeter if its 20k your multimeter will read it , if its 0.203 there a good chance your multimeter dont have the range to read it

Can you push the filament with your finger ( bypassing the extruder) without too much force ?