Anyone here know if there are suppliers out there that sell thermocouple that has a smaller than M6 threading? Referencing the same setup that a makerbot replicator 2 has - using the screw with the thermistor inside of it.
Or if you know any suppliers that have the thermistor incorporated into an O ring for an ~M3 screw size? Checked Alibaba and Aliexpress, but that’s unreliable for thermistors mostly.
I’m unclear on what you are looking for. Thermocouple or thermistor?
Here’s a thermistor potted in an M3 stud: http://www.ebay.com/itm/Modular-Screw-on-M3-Stud-Thermistor-for-Reprap-Prusa-3D-Printer-Hot-End-Hotend-/321341736569?pt=LH_DefaultDomain_0&var=&hash=item4ad175c679
@Carlton_Dodd Yes, that is exactly what I’m looking for!
I’m looking for both to compare and see what works/priced best.
AH! That is the replacement we’ve been using for the RigidBot thermistor. It works fine, but (like the original from Invent-A-Part) the leads break easily (very thin).
Thermocouples take different wiring, but can work at higher temps, right?
I think an M4 bolt can easily be packed with a thermocouple DIY, M3 would be harder. Drill a bolt hollow and use “fire” cement to pot a thermocouple in place. Might want to wrap the thermocouple in a thin layer of kapton tape to prevent electrical conduction.
Makerbot uses an electrically insulated thermocouple tip crimped into a brass M3 thermowell bolt. (This mounting technique produces extremely fast & accurate sensing, but is probably not suitable for glass-bead thermistors because of the crushing action in the crimp.) The only easy source I know of for this part is BilbyCNC in Australia.
FlashForge does the exact same thing but with an M4 thermowell. (http://www.flashforge-usa.com/shop/parts-accessories/thermocouple.html)
Wanhao crimps the thermocouple to an eyelet lug that is then bolted to the hot block. (http://wanhaousa.com/collections/hotend-parts/products/thermocouple)