Bed heating issues

So, I’ve only had my TAZ about a month now, and the bed is barely able to make it up to 85 C. On the latest print, I’ve waited over an hour and it’s still at 75 C. That includes some down time from the printer getting disconnected somehow multiple times from my computer, which is another annoyance, but a different topic all together. A couple of weeks ago, It heated just fine. I could even get it hotter than 85 C.

Any solutions, diagnosis, etc. would be appreciated.

As an aside, I’ve been so disappointed with how long the bed takes to heat, that I tried to switch to PLA, but of course you all probably know the problems with PLA that plague this printer. I haven’t even had one successful print with PLA so far. The filament will not even come out of the nozzle. I’ve added PFTE tape as suggested, and will try another print tonight. Between the PLA issues and the bed issues, I’m starting to get buyer’s remorse.

The ambient temperature of the space you are printing in has a huge impact on how quickly the bed heats. are you in a heated interior room, or a garage? if the latter, how cold is it in the garage itself?

If you are in an interior room and it is never getting hot enough, I’d turn the printer over and check the thermal sensor. it’s taped on the heated bed most likely, and it is possible it is no longer attached to said heated bed and needs to be re-taped. It could also be going bad, which would be covered under your warranty and if so you would want to contact lulzbot customer service.

If you are in a non heated space, you can either try building an enclosure around the printer, move it indoors, wait and buy a 24 volt bed, or wait until your garage gets warmer.

The printer disconnecting from your computer should not be happening. check your USB power settings inside power management and see if your USB ports are set to go to sleep on screen saver, etc. Also selecting the “high performance” option for the power settings will alleviate that issue under windows 7.

Someone else will have to help you with the PLA issue though, as I’ve actually never printed with it.

You should email Lulzbot support.

They will walk you though a couple of tests to track down the issue and help get it resolved. Several of us have had this happen with our TAZ 1 beds and it looked to be the bed shorting itself out. Here are a couple of forum threads about this:

In my case, the silicone heater in the bed went bad so Lulzbot did a bed swap. I’ve been happily printing ever since and the process to get it replaced was pretty painless.

BTW - if you add a fan, you should be able to print PLA ok. I had terrible luck with it, until I used Scott’s fan design here:

  • Adam

If you don’t mind, if you have access to a multimeter, you can run through some troubleshooting now and email support at with the following information:

With the printer turned off and unplugged you can disconnect the heat bed from the wiring harness and test the bed for the proper resistance. The smaller wires are for the thermistor and should read ~100k at room temperature. The larger connectors are for the heated bed heater coils and should read between ~0.8 Ohm.