Stock Taz 6 Thermistors

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doenute
Posts: 69
Joined: Thu Jun 18, 2015 7:33 am

Stock Taz 6 Thermistors

Post by doenute » Tue Mar 06, 2018 12:24 pm

I am completely fed up with the delicate nature of the existing stock thermistors.

Does anyone have a step-by-step method of what is required to move away from these things to something better? Part, source, how to modify printer settings?


Thanks!

kcchen_00
Posts: 1601
Joined: Thu Feb 19, 2015 12:42 am

Re: Stock Taz 6 Thermistors

Post by kcchen_00 » Tue Mar 06, 2018 9:35 pm

Changing thermistors could require re-compilation of the firmware.

Which thermistors are you having problems with?

doenute
Posts: 69
Joined: Thu Jun 18, 2015 7:33 am

Re: Stock Taz 6 Thermistors

Post by doenute » Wed Mar 07, 2018 7:13 am

The 100k Semitech GT2 ones that Lulzbot puts on their stock hotends. Either I am very heavy handed and keep breaking them or they get the wires crossed or they ground out on the hot end. Either way it is a PITA to keep putting everything back together only to find it does not work at all or it stops in the middle of a print.

To me it looks like the ones at E3D are superior from the perspective of mounting and being robust. But I don't know about their electrical properties.

kcchen_00
Posts: 1601
Joined: Thu Feb 19, 2015 12:42 am

Re: Stock Taz 6 Thermistors

Post by kcchen_00 » Wed Mar 07, 2018 9:58 pm

No crimping - that's the nice thing about the new cartridge thermistors. They are precrimped with pins that work with a molex/JST type connector. Not sure if they work with the hexagon single extruders... but I'd bet they could.

doenute
Posts: 69
Joined: Thu Jun 18, 2015 7:33 am

Re: Stock Taz 6 Thermistors

Post by doenute » Thu Mar 08, 2018 11:40 am

Do the E3D ones require any firmware changes or just changing the electrical and mechanical attachments?

Thanks

kcchen_00
Posts: 1601
Joined: Thu Feb 19, 2015 12:42 am

Re: Stock Taz 6 Thermistors

Post by kcchen_00 » Thu Mar 08, 2018 3:36 pm

I'm not a firmware guru, but I believe they are a different type of thermistor and require a change.

ocelot27
Posts: 48
Joined: Sun Jan 29, 2017 4:10 pm

Re: Stock Taz 6 Thermistors

Post by ocelot27 » Sat Mar 10, 2018 12:39 pm

doenute wrote:
Thu Mar 08, 2018 11:40 am
Do the E3D ones require any firmware changes or just changing the electrical and mechanical attachments?

Thanks
I you order the E3D hotted for the Taz 6 will come with the correct thermistor in a potted brass cartridge.

I went to thermocouples on my hot ends (all E3D) - indestructible and you can make them yourself - just need to get the converter board and wire it up to a spare analogue input pin and change a few values in the firmware. I've had several thermistors go wonky for no reason - they are by nature very delicate.

-john

doenute
Posts: 69
Joined: Thu Jun 18, 2015 7:33 am

Re: Stock Taz 6 Thermistors

Post by doenute » Mon Mar 12, 2018 7:40 am

John, thanks for that. Is there a place to begin learning how to make the firmware changes necessary? I'm not really intimidated by it, just don't know where to even start!

Thanks,
Bill

ocelot27
Posts: 48
Joined: Sun Jan 29, 2017 4:10 pm

Re: Stock Taz 6 Thermistors

Post by ocelot27 » Wed Mar 14, 2018 1:43 pm

I was too - you really just have to dive into it - I can help you configure the FW for a thermocouple - it's actually very simple and you always have your back up stock FW to fall back on.

You need to get the E3D amplifier board and wire it to 5v+ and ground on the controller board - this thing here:

https://www.filastruder.com/collections ... board-v1-0

Then in the FW you just change the pin number for the temp 0 (extruder) to the pin you've plugged the analog output from the TC board to and the temp pull-up table for a k-type thermocouple - I'll walk you through it.... literally takes 1 minute to edit the FW for this and you'll never have to worry about a sensor failure - you can beat a thermocouple with a hammer and it will still work.

The other issue with thermistors is that they are dependent on the input voltage being perfectly correct which of course can vary slightly depending on how well the voltage is controlled on the controller board etc etc.

I can make you a k type thermocouple and test it to verify that it's perfect if you don't know how to make them. The problem with buying one is that the leads are often too short and you need to have K type TC alloy wire going all the way to the amplifier board unless you want to get into gold contacts - basically you don't want any TC to non TC crimp or solder connections between the actual TC and the board - it can throw off the temp values although in practice and from my testing it's negligible.

-john

doenute
Posts: 69
Joined: Thu Jun 18, 2015 7:33 am

Re: Stock Taz 6 Thermistors

Post by doenute » Fri Mar 16, 2018 1:28 pm

John,

Thanks again for your generous offer to hold my hand through this. I will go ahead and order the part and at least get that far. Was thinking about PMing you, but I suspect I'm not the only one that can benefit from the rest of this process so I'll update this thread when I get that far.

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