Controlling the Extruder Fan

[morerice]

I have questions about controlling the extruder fan for my Orion printer. But first, here are my issues:

1) When I am warming up the extruder to a target temperature, the extruder fan kicks on. This seems counter productive as the fan is cooling as the extruder as it is trying to warm up. I noticed it takes a while for the extruder to warm up. Also, if my target temperature is high, say over 230 degrees, the extruder will simply not be able to get up to temperature and peaks out at about 225 degrees. I found if I put my finger on the extruder fan to stop the fan while the extruder is warming I can cut the warm-up time by half and easily reach my target temperatures. Once the target temperatures are reached, I release my finger and let the extruder fan come back on.

2) I noticed that while printing, my real extruder temperatures are always 10 to 15 degrees lower than my target temperatures. It seems again, the extruder fan is cooling the extruder too much. So again, during the printing, I carefully put my finger on the extruder fan to stop it until I can see on the LCD display that the target temperature is has been reached. As soon as I release my finger and the fan kicks in, the extruder temperatures again drop.

So my question, do you recommend any way to automate the extruder fan on/off or speed to better match the extruder target temperatures with the extruder real temperatures?

Thanks, Mo

[Mac The Knife]

Instead of trying to control the fan, which is there for the heat break, you should try wrapping the aluminum portion below the peek heat break with kapton, or silicone tape to insulate it. Highly recommended is to replace the two resistors with a 12 volt, 40 watt heater cartridge.

[Mac The Knife]

Here's Gene's video on upgrading the hotend.
https://www.youtube.com/watch?v=xvXKt3x ... e=youtu.be

[morerice]

Thanks for the great info. Good video. Yes, I see the advantages of taking some Kapton tape and wrapping the aluminum portion below the PEEK heat break. I can not imagine why SeeMeCNC would not do this as stock on all their hot ends. Cost can not be an excuse as this is 6" of tape and would add 1 minute of time at the factory.

What are the advantages to upgrading to a new screw in thermister or the 40 watt heater cartridge versus all stock?

Thanks, Mo

[Mac The Knife]

The screw in thermistor is more secure,, The heater cartridge heats up faster, which also allows it to maintain a more steady temperature.

[morerice]

Thanks for the super fast reply! Like 3 minutes. Wow.

Looked on eBay for a 40 watt heater cartridge. Found nothing. Any idea where to get a quality one?

Found the threaded thermister: http://www.ebay.com/itm/321341736569

15mm Kapton tape is on order.

Thanks, Mo

[Tincho85]

Use a grub screw to hold the heater cartdrige, like this one:

[img]https://www.doodaddoes.com/wp-content/u ... HotEnd.jpg[/img]

https://www.doodaddoes.com/product/stef ... d-upgrade/

[morerice]

Just wondering, what is the stock heater cartridge wattage? Just wondering what the difference is to the upgraded 40 watt one.

Thanks, Mo

[Mac The Knife]

The stock heater is a pair of resistors, which fail after a time. It could well be that one of yours is fried. If you go with a cartridge, the physical dimensions are 6mm x 20mm.

[morerice]

I very much appreciate you all answering my newbie questions!

Here are a few more... So I'm convinced that I want to do the thermistor and 40 watt heater cartridge update. Just wondering is there anything I need to change in the software or hardware to accommodate the higher wattage heater? I vaguely recall reading about changing PID values somewhere. What are PID values and where I change them?

[morerice]

Found the answers to my own questions. It's right there in the Rostock MAX v2 Assembly/Users Manual pages 232-234:
http://download.seemecnc.com/rostockmax ... dition.pdf