Jump to content
Ultimaker Community of 3D Printing Experts
Sign in to follow this  
pmeyer

Heated bed kit debug help

Recommended Posts

 

Just added a heated bed kit to a UM1. Unfortunately, I get no heat.

Everything else works (x/y/z, extrusion, nozzle heat and temp sensor). With bed temp set to zero, I get fine prints (on blue tape).

With bed temp set to 70, set point shows as 70, but measured temp stays 0. Bed stays cool.

The fact that bed reads 0, not ambient of ~20, makes me think more than one thing is wrong. If it was just the heater driver, I'd at least see ambient. If it was just a bad or disconnected temp sensor, the heater would go on (but possibly overheat).

Thermistor resistance is about 109 ohms at ambient. Heater resistance is about 3.7 ohms.

Help?

Paul

Share this post


Link to post
Share on other sites

Thermistor resistance is about 109 ohms at ambient.

 

Perfect. But where did you measure the resistance? Try measuring underneath the printer. Often you get an open where you screw down the wires on the bed or in the solder joints where the terminal block solders to the heated bed.

Have you ever inserted a 4.7K resistor in the circuit board? If so you need to remove it. This detail is not mentioned I believe in the instructions.

 

Share this post


Link to post
Share on other sites

Perfect. But where did you measure the resistance? Try measuring underneath the printer. Often you get an open where you screw down the wires on the bed or in the solder joints where the terminal block solders to the heated bed.

Have you ever inserted a 4.7K resistor in the circuit board? If so you need to remove it. This detail is not mentioned I believe in the instructions.

 

Thanks for the help. I never modified the main board. Could the resistor have come with the printer?

I'm measuring on the exposed 90 pins that go to the thermistor connector on the PCB (see below). I'm getting 108.9 now.

By the way, how do you disconnect the power supply from the heated-bed PCB? Once I connected it I can't seem to get it off. I see there is a slider on the end, but pushing it or pulling it still doesn't seem to release the connector. No big deal for now, but eventually it would be nice to be able to remove it.

FullSizeRender.jpg

I get 108.9 right now.

 

Share this post


Link to post
Share on other sites

Perfect. But where did you measure the resistance? Try measuring underneath the printer. Often you get an open where you screw down the wires on the bed or in the solder joints where the terminal block solders to the heated bed.

Have you ever inserted a 4.7K resistor in the circuit board? If so you need to remove it. This detail is not mentioned I believe in the instructions.

 

Solved!

The three wire jumper from the heated-bed kit PCB to the main board (temp3) is defective. 5v and Signal both have a good connection, but the middle (ground) is open (infinite resistance measured from the exposed pcb pin to the mainboard pin).

Replaced that cable with three loose jumpers and I read 19C on the bed, and it heats up!

I'll start a test print while I see if I can repair the jumper.

Paul

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Our picks

    • Taking Advantage of DfAM
      This is a statement that’s often made about AM/3DP. I'll focus on the way DfAM can take advantage of some of the unique capabilities that AM and 3DP have to offer. I personally think that the use of AM/3DP for light-weighting is one of it’s most exciting possibilities and one that could play a key part in the sustainability of design and manufacturing in the future.
        • Like
      • 3 replies
×

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!