n2ri wrote:

so is there a paste to use in hole where heater cartridge goes to help conduct heat transfer better to aluminum block? and where do I get it if so?

A good thought. You can probably use 'heatsink compound' a.k.a. 'thermal grease' - it's not some magic bullet of course, but it's definitely better at conducting than air gaps at least. I spread some in the hole and around the heater before installing originally, seemed like good practice at the time.

Glad the new heater works, good luck. Sounds like a case of bathtub curve.

yes I have a tube of that laying around someplace, Thanks. interesting link on the failure rates. never heard that version before. always got life estemates on appliances when I was doing sales and service of them. most made the last 3-4 decades have been shortened to under 5 years to make sure consumers have to buy replacements enough to keep manufacturers in business due to some as late as the 1960s failing waiting for repeat customers when the products lasted as long as 40 plus years hehe. e.g. Siegler gas space heater company

so is there a paste to use in hole where heater cartridge goes to help conduct heat transfer better to aluminum block? and where do I get it if so?

A good thought. You can probably use 'heatsink compound' a.k.a. 'thermal grease' - it's not some magic bullet of course, but it's definitely better at conducting than air gaps at least. I spread some in the hole and around the heater before installing originally, seemed like good practice at the time.

Glad the new heater works, good luck. Sounds like a case of bathtub curve.

do I need some kind of ceramic paste around heater where it slips into aluminum block for heat transfer or anything? seems like they just use it for insulation etc. anyone know?

least I got 5 heaters for the money but hope they all are not so lame. I get 12.5 volts to heater when on. and it Ohmed good and worked great first few times tried, til I wanted to do a 20min print after loading filament again. then no heat, and check connections and tested. it was dead already.

I also ordered 10 of the tiny glass thermistors for later.

thanks much for the link! I bookmarked main page and subscribed since I will be needing it lots as I mod my ol SD2 to a duel extruder single nozzle unit. I think that can be done including all parts for less than the $500 China clone of makerbots duel wide bed model but it has standard hotends, wood frame etc. so I like how easy the old SD is to repair and mod and lots of upgrades for them. I dont need any bigger print bed so I decided this last week. if I need a part printed to get mine going some time later I know others nearby that can do it so no need for spare printers taking up space.

PID auto tune, instructions on the WIKI.

how do I find that? whats 'the wiki"

I turned heaters on for like 20 secs and felt extruder heating but no temp movements so turned off heaters back off  in command console, checked all connections on wires again, nothing so clicked disconnect then reconnect with temp screen still up. got scale of temps on both and last temps in the boxes by settings in command mod

turned heaters on bit over 10 secs again with same results. what am I missing? must be a reset or something keeping it from communicating live. like b4

n2ri wrote:

that heater is 140w 12v and even after ignoring the wrong dimensions on 1 drawing the hole spacing is a couple mm off from SD2 bed. is this the one you used? and did you mount it under aluminum bed or on top with glass over it? I already done glass on mine so that would be nice if possible then warnings lettering would show through

yes the mounting hole spacing is a little off, i reamed out the hole with a larger drill bit so the bolts would go through. i have mine installed under the aluminum because the thermistor has to go underneath the pcb heater and it would make the bed uneven.

mount it above the aluminum with spacers on the four corners to allow room for the thermistor & wiring, then put a glass plate on top of it.
A thin sheet of cork between the heat plate & the aluminum will help too (with a notch cut for wiring clearance), sending the heat upward instead of letting the aluminum absorb any of it.

that heater is 140w 12v and even after ignoring the wrong dimensions on 1 drawing the hole spacing is a couple mm off from SD2 bed. is this the one you used? and did you mount it under aluminum bed or on top with glass over it? I already done glass on mine so that would be nice if possible then warnings lettering would show through

yes the mounting hole spacing is a little off, i reamed out the hole with a larger drill bit so the bolts would go through. i have mine installed under the aluminum because the thermistor has to go underneath the pcb heater and it would make the bed uneven.