Extruder Skipping steps 1 hr after print starts

[adamfilip]

Running into issues with my extruder skipping steps an hour into a print

Printing PetG 3mm on .4mm nozzle E3Dv6
.2 layers
speeds are 60mm/sec
Usiing a Bondtech v2 extruder with Geared Nema 17 Stepper
Digipot set to 135 on Rambo
Direct connection on Hotend
Stepper is almost hot to touch. but i can keep my finger on it
50% humidity in room
235 hotend, 110 bed

[misquamacus]

Just to be clear, the printer starts the print fine, then the extruder begins skipping over time without changes to any other settings, correct? More than likely that is caused by overheating of the motor or stepper driver. The motor's safe temp range might be difficult to determine, but the Rambo's a4982 stepper drivers only operate reliably up to about 70C; that temperature needs to be measured on the underside of the board, not on the chip or heat sink topside.

[adamfilip]

i cant get behind the board to read the temp.. perhaps if i just add a fan blowing onto the rambo

[misquamacus]

Something along these lines is helpful for measuring temps. Probes are far more accurate than the infra red guns. Adding a fan to your Rambo will almost certainly solve your problem, just be sure to send the airflow across the board.