Why add a Fan at Extruder-nozzles ? (Page 2 of 3)

Yes, our CTC has the 'Mightyboard' and came with Both 'Replicator-G' and 'Makerbot-2.4' software, on a SD.
I Don't think I want to install any other Firmware in printer
until it becomes extremely Necessary .

I don't know, I think I would be very tempted to flash to Sailfish (Saltfish   ) and enjoy the benefits of true open source.

I got the Fan-duct printed and I have fan to go in it,
and now to Mount and connect it to power.

Just remember this printer operates on 24 volts. So you will need a 24 volt fan.

I have never had to control the speed or time when the fan runs. My just comes on at power up and runs through the full print from first layer to last layer. I have never had an issue printing PLA and using a fan in this way. I don't find all the control of it necessary. But then again I also level my bed so that PLA sticks very aggressively to a hot clean glass plate.

Yes, may Not need it to be adjustable, but thought I would experiment with that Also,
to see how much cooling is really required for different filament types.

I've been doing most objects in ABS but I plan to do more in PLA, HIPS, Nylon, etc.

You may want to look at your printer closer if we are talking about the CTC. In order to change nozzles you will have to remove both motor fans so you can get to the set screw that holds the feed tube in the mounting block. The nozzle threads into the heat block and butts up against the feed tube to create a seal. If you don't remove the complete nozzle assembly with heat block and feed tube then you will not get the proper seal when switching the nozzle and plastic will leak from the upper side of the heat block

In order to get a proper seal you have to remove the heat block from the feedtube, then swap out the nozzles, then butt the feed tube against the nozzle inside the heatblock and lock it in place with the set screw on the back of the heat block. Then you have to reinstall the the assembly in the mounting block and adjust the nozzle height and lock in place with the set screw in the mounting block.

Well if by some chance the threaded section of a new nozzle is shorter and does not butt up against the feed tube you have the potential for a leak that could not show up till well into a multi hour print when it starts to drop hot globs of plastic on your model. I am just saying just like with the E3D the feed tube threads into the heat block and then gets locked by a set screw. Not sure if the E3D has a set screw. But the nozzle must butt up to the feed tube inside the heat block or it will leak. Normally you would install the nozzle till it seats fully in the heat block. Then screw in the feed tube till it butts up against the nozzle and then secure the setscrew. Then adjust the rotation and position in the mounting block and set it with that set screw as well. That would be the proper way although there are improper ways that you have just been lucky with.

* I just now noticed this post

I think those people that have layer separation with ABS are not setting the nozzle Temp high enough.
I use 245. C and have had No problems with separation.
I have a fan that cools the X & Y stepper-motors and it also circulates some air thru the printer
and that fan needs a open printer with No enclosure.
Stepper-motors get way too Hot without that fan.

Sorry, but I see No need for an Enclosure.
They hold in the heat Too Much, those motors need to be cooled or they will Fail !
Walls and top will just 'Get in the Way' LOL

I've used filament from many spools of ABS , purchased off eBay,
so I doubt there is anything different about them, but it is possible .

An enclosure reduces the temperature gradient in your prints, making them less likely to warp. If you end up with warping issues on larger prints or prints that have particularly tall sections that act as heatsinks, an enclosure will help. The motors can handle the heat if VREF is properly tuned, but the board should be away from the heat as much as possible. Heat is the enemy of most electronics.

A fan is useful for ABS for two things: short layers and overhangs/bridges. Layers that print too quickly will not cool fast enough and subsequent layers will print on molten plastic. Overhangs are helped by a fan because it keeps them from curling down, in my experience.

Start slow, but never assume you will never not need something.

Your new to printing, but you will learn soon. You really should listen to and not discount the advice of veterans. Some of us like myself have been in this filed since it emerged. Nothing about the technology or media has changed since.

If you have not seen a use for an enclosure or fan yet then I doubt you have made a large print or a print that has taken more than 6 hours.