Prusa_i3 Heating and Fan

Hello All,

New to this game.
I recently finished building my unit and ran the test software to dial in the limits and settings.

I noticed while the tutorial asked to heat the unit up with the fan going 100% that I would never achieve the target temp of 230c the fan simply cooled it down. Without the fan I was able to achieve a hot enough unit to extrude filiment but that took a rather long time. I checked the wiring and everything seems solid enough. Are there wiring upgrades needed for a better current? Some of these wires are very thin.

My standard fan duct seemed to blow the air to much on the extruder and not on the print, this was one of my first printed models a redesigned fan duct to direct air flow to print.

I generally run the fans about 50% speed unless I have to do Bridging then I speed it up to 75%.

My 3D Printers came with Power supply wires so small that if i would have tried to use them it would have melted the wires.
Ended up Using 12AWG 20AMP solid core house wiring, as i had it on hand.

Have also upgraded another 3D Printer to 12AWG 20AMP stranded wire Business Radio Power cable.

I Also replaced both 110 volt power wires as they too were under rated, with Computer Power Cords.

Edited 1 time(s). Last edit at 07/29/2017 09:33AM by Roberts_Clif.

Thank you for this initial response. I will go ahead and upgrade the main power, I agree they are vastly under rated.

My fan has no ducts. Simple fane mounted to the face of the extruder motor. No direct fan on the actual heater. Im hoping by upping the main power line the overall heating will increase.

I am sure it will.

My Fan Duct looks like this

Quote
Knedberg09
My fan has no ducts. Simple fane mounted to the face of the extruder motor.

That therefore sounds like it's your extruder cooling fan and not a part cooling fan, which Roberts_Clif was discussing above. That fan is important and not optional; without it you'll get problems including frequent blocking of the extruder.

I'm assuming from your description that you've got a MK8 style extruder but a photo would help - there are many, many prusa style printers.

However, if you can barely make temperature with the fan off, and not achieve it with the fan on, then something is wrong. Do you possibly have a heater element intended for 24V operation on a 12V power supply? Can you measure the resistance of the heater element?

Quote
Knedberg09
Hello All,

New to this game.
I recently finished building my unit and ran the test software to dial in the limits and settings.

I noticed while the tutorial asked to heat the unit up with the fan going 100% that I would never achieve the target temp of 230c the fan simply cooled it down. Without the fan I was able to achieve a hot enough unit to extrude filiment but that took a rather long time. I checked the wiring and everything seems solid enough. Are there wiring upgrades needed for a better current? Some of these wires are very thin.

I Made an assumption he had a Part duct fan, because of his statement "with the fan going 100% that I would never achieve the target temp of 230c the fan simply cooled it down"

Edited 1 time(s). Last edit at 07/30/2017 06:22PM by Roberts_Clif.

Quote
slippyr4

Quote
Knedberg09
My fan has no ducts. Simple fane mounted to the face of the extruder motor.

That therefore sounds like it's your extruder cooling fan and not a part cooling fan, which Roberts_Clif was discussing above. That fan is important and not optional; without it you'll get problems including frequent blocking of the extruder.

I'm assuming from your description that you've got a MK8 style extruder but a photo would help - there are many, many prusa style printers.

However, if you can barely make temperature with the fan off, and not achieve it with the fan on, then something is wrong. Do you possibly have a heater element intended for 24V operation on a 12V power supply? Can you measure the resistance of the heater element?

Sorry its been awhile hoping everyone is still around to help out. I have since checked all the wiring. Everything is good cuts and installed nicely.

Still a very slow heat up. especially if fan is on and target is not achievable. How do I measure the resistance? I have the tool but again, new to this. No idea what prusa I have,

Still here!

It does take a while to heat up either The Hot end or the Bed
1 minute 15 sec for Hotend to 200 C
1 minute 37 sec for Hotbed to 60 C

Disconnect from the Controller and measure using a multi-meter on the Ohms scale.

Edited 1 time(s). Last edit at 10/22/2017 10:20PM by Roberts_Clif.

Oh yeah we are for sure out of that range, with fan at full as instructed I hit 110C in about 3 minutes and it levels off. setting is for 230c

the heat bed I havent even tried to play with just yet.

I was trying to get the ohms read on the heat end. where specifically should I place my red and black probes to get the read out.

Edited 1 time(s). Last edit at 10/22/2017 10:17PM by Knedberg09.

Pictures would really help, as would knowing the type of extruder, hot-end etc

What is the wire size connecting power supply to the Controller. A lot of 3D Printers come with way to small power supply wiring.

Reprapguru DIY RepRap Prusa I3 V2 Black 3D Printer Kit
The RepRap Guru Prusa I3 V2 has an Impressive 8"x8" heated build area topped with a genuine piece of borosilicate glass. The V2 also includes the 2004 LCD w/ SD card reader allowing the user to print from a SD card with out a computer connected. The V2 uses a 1.75mm direct feed extruder that is fitted with a .04 nozzle allowing a print resolution of 100 microns. The V2 frame is constructed of 1/4" premium cast acrylic accompanied with plastic injected molded parts for precision fitting and a sleek professional look. The V2 is fitted with our custom spool holder allowing a free hanging reel or classic desktop reel.

This is the product I bought I will get Pictures soon.