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View Full Version : [I hate wires] Heating Element Question And Heater Circut Education Requested



Left Handed Spud Wrench
10-24-2015, 08:17 PM
Ok so one of my 3D printers blew a heater this morning. Not entirely unexpected, it is the original heater and it has seen a lot of cycles as of late.

This is not a HUGE deal as XYZ is sending me a replacement... they won't send me a spare however. If I need additional heaters I have to request them.

Going forward I plan to buy two more extrusion heads from them so I have spares, and when the warranty runs out I'm chopping and modding this one to run a real extruder head... not this sad but adequate entry level offering.

http://i61.tinypic.com/2qk4g3k.jpg

Got looking I see that you can buy a heating element similar but not the same -- of course XYZ went there. You have to get their version or bite the big one. Well being of an Engineering mind and not accepting "can't be done" as an option... I bring the following question to the Team here:

Heater is 12 volts. 35 watts. 6mm around by 25mm long, Plugs into a board in back.

http://i62.tinypic.com/2n1f8k2.jpg

http://i57.tinypic.com/16c9ljq.jpg

My two choices on Amazon for "get it in a reasonable time frame" are... 20mm long by 12 volt by 30 watts or 20mm long by 40 watts.

The 5mm makes little difference as that 5mm simply sticks out of the nozzle and does nothing but accumulate carbon crapola.

My concern is that five watts. If I get a smaller one will the power supply unit be affected in any way? I don't see how five watts less will do anything other than increase my heatup time. Five watts more might blow the Chinailicon chips that control the heater system or cause the PSU to go into magic-smoke mode.

Figured I best get a cross-section of opinions and hopefully more information so I don't wreck my machine.

http://i60.tinypic.com/hs19mq.jpg

Left Handed Spud Wrench
10-24-2015, 08:19 PM
Oh and the nozzle is all black from the amount of buildup it accumulates during runtime. That's not from the heater failing.

Mike Amick
10-24-2015, 09:42 PM
Is this a closed loop system with feedback of temperature, or just time based ? Thats a huge determination.

Left Handed Spud Wrench
10-24-2015, 10:33 PM
Closed loop. A thermistor reads the temp and the computer adjusts it.

I do have access to the PID tuning, to anticipate the next question. :)

Paul Alciatore
10-24-2015, 11:36 PM
If it is a closed loop heating system, chances are either of those elements will work just fine. Assuming that both of them are 12 Volts, the 30 Watt element will draw a little less current and, as you said, take a little longer to come up to temperature. The lower current will be less strain on the power supply and the control circuit.

If you use the 40 Watt one, it will draw a little more current (35 W draws about 3 Amps and 40 W about 3.33 Amps). And it would warm up a bit faster, not a lot. 3.33 Amps is only around 11% more than 3 Amps. There is little chance that the extra 1/3 Amp will do any harm. Most circuitry is generously over rated. Even Chinese designs would have somewhat of a safety factor.