Extruder Voltage Problem  

Re: Extruder Voltage Problem

Hi Dave

I don't know who makes a 12" i3v printer; certainly not Prusa Research - the largest made by this company is 250 x 210 x200 mm.

Can I suggest that you contact the manufacturer of your printer as this forum is for users of the PR "original" i3 and i3 Mk2.

Peter

Re: Extruder Voltage Problem

Ignoring the first part of my message (it's an open source chassis but the guts are Prusa)

The problem is as follows:

All set up, calibrated, axis all homing and working.

Trying my first print and the extruder won't fully heat up.

12 volts at source input.

5 ohms on extruder heater.

Only 5 volts on Extruder mosfet output.

What is configured wrong ?

RAMBo board with Marlin software.

Re: Extruder Voltage Problem

Dave

What firmware version are you running?

Peter

Re: Extruder Voltage Problem

Dave

Thinking about your problem, it seems as though you have only 5V on the 12V rail (or the output is being PWM regulated to 5V which is highly unlikely, unless the firmware is wrong).

As the extruder heater is run from the same fuse as the electronics, the fuse and power feed should be OK, so back to the firmware. could be using a wrong pinout?

The only other possibility that I can think of right now is that the RAMBo has a problem.

So, which firmware version are you running?

Peter

Re: Extruder Voltage Problem

Just had a look at the RAMBo schematic. It would appear that the two 12V inputs are isolated, so although the steppers and controller will run when powered via a 5V supply, the extruder will display exactly what you are seeing. Can you therefore check to ensure that both 12V rails from the PSU are supplying 12 V and not 12 V + 5 V.

Peter

Re: Extruder Voltage Problem

I confirmed that all 3 input rails are at 12volts.

I used Arduino 1.6.5 to install Marlin_RAMBo_1-1b_GLCD

I have tried other combinations of Marlin with RAMBo-master but none of them seem to install anything that displays on the LCD.

Re: Extruder Voltage Problem

The firmware that you have mentioned is for the Lulzbot TAZ2. If this is an Original Prusa it will be using the Rambo Mini.

Re: Extruder Voltage Problem

but the guts are Prusa
...
I confirmed that all 3 input rails are at 12volts.

This is a full RAMBo board (or a clone); not the RAMBo mini as supplied by Prusa Research.

Dave what you have is nothing to do with a Prusa "original" i3 printer not Prusa Research as a company, therefore can I suggest that you go to your parts supplier and ask them for help.

Peter