overfeeding issues

Hello everybody,

I have finally finished my first Reprap i2! I decided to get all the pieces myself instead of buying a kit. everything works very smoothly, but for some reason my extruder motor keeps overfeeding the PLA filament so it jams. The printer gets about 3 layers before it jams. I am using wade's extruder with a J-head (.3mm)as well as sprinter with the following settings:

float axis_steps_per_unit[] = {79.87, 80.34, 2737.38,573.7705}

//// MOVEMENT SETTINGS
const int NUM_AXIS = 4;
float max_feedrate[] = {400, 400, 240, 45};
float homing_feedrate[] = {1500,1500,120};
bool axis_relative_modes[] = {false, false, false, false};

float max_start_speed_units_per_second[] = {20.0,20.0,0.2,10.0};
long max_acceleration_units_per_sq_second[] = {100,100,50,10000};
long max_travel_acceleration_units_per_sq_second[] = {500,500,50,500}

Finally, here is a pic of how my printing attempts look like:

Thank you,

Luis

PS: This is my very first post, please let me know if you need any more info or if there are other posts about this issue (did not find them)

Looks like you have a e3d V5, it also looks like it's a clone.
You will have issues with PLA if the above sentence is correct.
You need to use active cooling of your hotend at all times and seasoning or polishing of the ss tube is needed.

Thank you ggherbaz,

so, basically, the cool end is getting too hot, is that it?

Get cooling on that heatsink NOW!
All metal hot ends need active cooling on the fins!

Yes, that is correct. Your PLA get heated too far up the hot end and cools there creating the jam.

The second problem that you have is that you are extruding too hot. Assuming that you were increasing temperature to overcome the jamming problems ?

no, I never increased the temperature. I did noticed the PLA getting too soft pretty high up in the filament, but I thought it was an issue of timing between the motor and the actual extrusion speed. Now that you mentioned the cooling being necessary i am getting my fan ASAP.

Thanks a bunch for such a quick response guys! :-)

Hey guys!

I have corrected the problem! The fan is about 3-4 mm away from the extruder and is working great! here is a pic of how it turned out. Now I have another issue tho, the first layer starts too high off the printing bed. The Z home is at about 0.3mm from the printing bed, but as soon as the extruder starts moving it goes up to about 2-3mm. I am using sprinter and slic3r and I have no idea of where to start. Please let me know if you need any more details.

Cheers,

Luis

Create an offset in either marlin or your slicer, allow in marling to go pass you Z0.

You most likely have already an offset, because printing should start at Z0

Edited 1 time(s). Last edit at 11/11/2014 05:41PM by ggherbaz.

Thank you ggherbaz,

I started playing with the advance settings in slic3r and noticed that the height of the first layer was set up at 200%. I set it back to 0 and I am printing my first try. It seems to be working! :-)

You should print a proper V5 fan duct, sitting that far away is better then no fan but not as good as it can be, it also looks like 30-40mm not 3-4.