~220mm Heater plates for bed slingers

DocTrucker

Hi All,

What are currently recognised as the heaters (/ heater assemblies) with the most consistent surface temperature?

I've begun to resurrect some old work on setting ups scaling, offsetting, and testing the tolerance of one of my machines and initial results seem to suggest there is a positional related error (within a 100 X 100mm square in the centre of the build area!) that is much greater than the differences in measurements that I was looking at (sub physical step size of the steppers).

I suspect this is temperature related and plan to investigate the difference between two of my machines. Both P3Steel. One with PEI direct on the Mk3 plate, the other using a glass build surface. Unfortunately there are many other differences between the machines such as one is RAMPS with DRV stepsticks, the other Duet v0.6, but should be able to identify positional related patterns.

DocTrucker

I know I also mentioned some testing of the safety shutdowns and a risk assessment a couple for weeks ago. I'm falling behind a little following a minor bug in the household!

dc42

Best I think is a thickish aluminium plate with a silicone heater under it, and your choice of surface on top (PEI, glass etc.). But for a small bed, a lower cost alternative is a 4mm glass plate with a 1.5mm or 2mm aluminium heat spreader plate under it, and a PCB or silicone heater underneath that.

I have never tried the aluminium PCB heaters.

DocTrucker

@dc42 I ditched the PCB heaters after having issues with them shorting out against the aluminium heat spreaders and stinking my workspace out! I'd taken all care in assembling, checked for burs, cleaned etc. but they really needed an electrically insulating layer in there.

I think I'm using the right terminology with the Mk3 - I mean the aluminium PCB heaters. I currently use them tracks down with rears insulated and glass on top most of the time, with the exception of the PEI machine which appears to have a much higher power bed (needed SSR) and I can't find listed elsewhere. I suspect it was a manufacturing error but it heats up real quick!

Can hotend thermistors be used on beds or should you use the larger ones as found in the old RepRapPro kits?

dc42

@DocTrucker said in ~220mm Heater plates for bed slingers:

Can hotend thermistors be used on beds

Yes.

deckingman

@DocTrucker said in ~220mm Heater plates for bed slingers:

Can hotend thermistors be used on beds or should you use the larger ones as found in the old RepRapPro kits?

For info, I'm using an E3D thermistor cartridge on my bed - works fine. ( I drilled a 3mm diameter hole in the edge of the bed, as deep as I can go and as close to the top surface as I can get it).