.5mm or larger nozzle - the easy way

[eldrick 65]

This is my second .5mm UM2 nozzle, and this time I did it the easier and more precise way.

In order to print stronger structural parts, and to print them faster, you need a larger nozzle. The larger thread of plastic is stronger, and the back-pressure to the extruder motor is less, so you can print faster.

In trying to enlarge a UM2 .4mm nozzle the first time, I took a new .4mm nozzle from Ultimaker, and used a drill press to drill out the hole, and then sanded the tip very lightly by mounting it in the machine and then moving it around very lightly on 2000-grit sandpaper on the build plate.

This gave me a slightly oversize (probably .53mm or so) nozzle and with a wider flat on the nozzle than necessary, and which had a habit of accumulating overheated plastic around the flat, and then letting it go while printing, leaving brown/black spots.

This time I rethought the process, after realizing that I was only trying to remove .1mm (.004") from the inside of a very short tip. It doesn't need a motor to drill that little brass, and a drill-press or lathe is prone to drilling a slightly oval hole due to misalignment with the center of the .4mm hole.

So this time I simply took the drill bit, which is a near-perfect fit inside the 1/8" upper part of the nozzle, let it self-center in the original hole, and spun it with my fingers for about 20 seconds. It drilled right through, leaving a perfect hole, and no enlargement of the flat, so it prints without building up melted plastic chunks that release into the print. This nozzle works much better as a result.

The drill bit I used is this one: http://www.mcmaster.com/#catalog/121/2447/=vm0pxl

It's a #76 wire-gauge size, with a 1/8" shank. About US$5.00.

If I wanted an even larger nozzle, I'd drill it to .5mm first and then enlarge that to .6mm with a larger bit, using the same technique.

 

[ultiarjan 1,223]

interesting technique .... however at some point, maybe not at 0.5 but for sure at 0.8 you do want the "shoulder" (the flat around the hole) to become a bit bigger to be able to print wider. When I drilled (dremel from the inside) a nozzle to 0.8 I just used some sandpaper wrapped around a little block of wood to sand the shoulder a bit while holding the nozzle in a vise. Worked out fine.

anyhow I'm hoping never to use any of these techniques anymore as I'm about to receive the block with exchangable nozzle from Anders Olsson....

http://umforum.ultimaker.com/index.php?/topic/7689-custom-heater-block-to-fit-e3d-nozzle-on-ultimaker-2/

 

[eldrick 65]

Agreed re. the larger flat for larger nozzle, but a more precise method would be to mount the nozzle in the printer, put some very fine sandpaper on the bed and move the head around a bit, to ensure that it stays level to the bed.