Help - Where should I wire my Hot End Fan?

1) You can splice into the wires for you extruder motor fan.
2) You can splice into your E3D fan.
3) Depending on the board you have, you may have a header for a 2nd/Gcode fan
4) You can buy a few accessories off Amazon to run multiple fans off a separate PSU (like I do)

Get a 100k ohm pot rated at a couple of watts and put it on one side of the fan. Then you can vary its speed somewhat.

Unless the fan is PWM driven you won't have that much degree of speed with any pot regardless of it's resistance. Once you get below 6 or so volts the fan will start stalling.

Thanks for the suggestion guys, but is that going to just cut my speed by a percentage? It doesn't sound like it has much control.

I do have some extra electrical parts laying around and some arduino stuffs. I'm not the most experienced with electric design but do you think there is a way I can wire in a slider type of control and could anyone possibly point me in the right direction to attempt something like that?

Thanks for clearing that up, Ward.

Yes, I do have a printerboard, an E3Dv5, and am running RH. I would like to use the slider in RH to control the fan (the E3D fin cooler) but I am not opposed to making an analog hack if that is necessary. I was having some serious clogging issues without the fan but now I am having some layer separation issues.

I am not running a fan to cool my PLA prints, but maybe I should be. Is there a file out there that allows for both the cold end fan and the print fan?

Yes sir, the cold end fan is what I am talking about here. Sorry about the confusion.

I will flip the fan around so it is sucking the hot air out instead of blowing air in, that should fix any air blowing back onto my print.

Also you are correct about having an underlying issue. I was messing around with different layer heights and was doing my first attempt at printing at a .4 layer height with a .4 nozzle, which was causing my prints to barely bond. I didn't realize this until just now. Bringing the layer height back down should alleviate that issue.

I will test these out and report back once I get my belts in, snapped one last night.

Lastly, I should have clarified this as well. I have your Bulldog XL mount for the SD3. I see that you have a mount for a nozzle fan on Thingiverse. Will that mount work if I don't have Lawsy's carriage? Also, if I were to decide to mod up to the Lawsy Carriage design, is there anything I need to order other than the (8) LMU8 bearings? Can I recycle the rods on my current carriage or do I need to order new ones?

Try .2963 for a layer height that'll fix you bonding and layering issues.
As far as my carriage goes for the bulldog which mount do you have.  The one with bearings and the integrated nozzle fan mount is the preferred mount and all I can say is you can try the stock rods and see or just replace them with known good ones.

That mount works well I just don't have a fan duct integrated into it for the G-code fan.  I actually have a printer running that setup right now and it works fine.  BTW fish line will replace a belt real quick.