Upgrading to PT100

Hi,

It seems that I am unable to resolve my electrical problem, as the fuse keeps blowing. So, I have decided to change to PT100.

I'll buy the daughter board. Where can I buy a 4 wire PT100 sensor? If I can't find it, is it enough for me to buy a PT100 from E3D (just the sensor, not the amplifier board)

Thanks...

When using the E3D PT100 sensor with the Duet, you don't need the amplifier board. If the heater block on your E3D hot end doesn't use the cartridge style thermistor, you will need to replace the heater block with the new type too.

If the fuse keeps blowing, it may mean that you have a short between one of the thermistor wires and the heater block AND a short (possibly only when heated) inside the heater cartridge between the element and the casing. So It's a good idea to replace the heater cartridge.

Edited 1 time(s). Last edit at 04/22/2017 03:18PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Today the fuse has blown when I was trying to remove a print from the bed. The print was paused, so the heaters were on. I use a metal painting knife to remove prints from a metal bed, which uses a MK2 heated bed. I assume the problem is there and not at the hotend. I never really liked the MK2's open connectors and the idea of using a PCB, which has electricity on it, combined with a metal surface. I have ordered a silicone bed heater, which will be better insulated. I hope to correct this problem by changing the bed. Meanwhile, I have ordered a box of 250 mA fuses (100 of them). With the speed that I am burning them, they'll barely last me 15 days

I know this is a risky question but would it be possible to use a fuse with just a little bit higer value witout risking the Duet? I am not talking about 2 amps, but maybe around 400 mA?

Yes increasing the rating to 500mA should be OK. We chose a low value so that it would blow quickly, to protect the VSSA trace on the Duet and its vias to the ground plane against a direct short from VSSA to +24V; but you have bypassed that trace anyway.

But you ought to find and fix the root cause.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].