Two MK4 kits, different results - General discussion, announcements and releases

RE: Two MK4 kits, different results

JP Guitars — Fri, 01 Dec 2023 19:07:54 +0000

You need to factor in which is correct if you have two, logically you should have three with voting to establish correct reading and a warning for the minority report.

RE:

Brew — Fri, 01 Dec 2023 17:20:24 +0000

Posted by: @trilithon

I have often wondered what the cost would be to add a second thermistor and input on the system to have a double check of sorts to validate the accuracy of the primary thermistor.

That reminded me of the quote from the movie Enemy of the State "But who will monitor the monitors"

Having a second thermistor would definitely be a good idea. However, like any other sensor on the printer it would be an added cost that shouldn't be needed unless it was a common issue. Which in my opinion fixing the bad sensor issue in the first place should be the way to go.

RE: Two MK4 kits, different results

Trilithon — Fri, 01 Dec 2023 16:55:26 +0000

Posted by: @brew
Good to hear. Looking forward to hearing how the new one works. Interesting that the bad one passed the tests. Guess it was only slightly faulty.

My assumption is that the self test just tests to see if the heater heats up and the thermistor detects it. What value the thermistor sends in this case is erroneous. It is reading 30-40c too low. I have often wondered what the cost would be to add a second thermistor and input on the system to have a double check of sorts to validate the accuracy of the primary thermistor. Another layer of safety too, I mean, what if it have been way off and overheated the hotend?

RE: Two MK4 kits, different results

Brew — Fri, 01 Dec 2023 00:58:43 +0000

Good to hear. Looking forward to hearing how the new one works. Interesting that the bad one passed the tests. Guess it was only slightly faulty.

RE: Two MK4 kits, different results

Trilithon — Fri, 01 Dec 2023 00:51:53 +0000

I swapped the thermistors between the printers. The printer that was printing perfect started stringing horribly, and the bad printer printed great! So the problem followed the thermistor.

Dunno why I didn't think to swap them earlier, duh.

Thanks for the help and suggestions!

RE: Two MK4 kits, different results

Hello — Thu, 30 Nov 2023 18:06:25 +0000

Posted by: @trilithon
Chatted with Prusa support, they are sending a new thermistor.

Thats good

RE: Two MK4 kits, different results

Trilithon — Thu, 30 Nov 2023 17:51:02 +0000

Chatted with Prusa support, they are sending a new thermistor.

RE: Two MK4 kits, different results

Brew — Thu, 30 Nov 2023 16:10:26 +0000

They do have some in stock. I have one arriving tomorrow that they just sent. Hopefully it's not one of the faulty ones that they're supposed to have.

RE: Two MK4 kits, different results

Hello — Thu, 30 Nov 2023 06:01:43 +0000

If you contact prusa support they should send you a new one

RE: Two MK4 kits, different results

Cary — Thu, 30 Nov 2023 04:58:35 +0000

I have a MK4 kit and a MK3 ->Mk4. They were shipped about 5 months apart. With Input shaping on, one prints matte and the other one glossy. I reported it and was told that they have a bad bunch of hot end thermistors. They can't send me a new one because they don't have any "good" ones to send. The glossy one with IS is apparently the bad one and the one I prefer.