Fan duct - larger opening?
January 18, 2015 10:37PM
I was wondering - is there a fan duct STL available that has a larger outlet opening than normal - say, about 7-8mm larger interior diameter or so, that still uses the "standard" fan? I am using a J-head type hotend that uses heater cartridges instead of the usual resistor, and while it does a fairly decent job printing ABS, the nozzle block is large enough (due to the need to accommodate a set-screw to hold the heater in place) that it contacts and melts the fan duct opening. I have removed the fan and duct, as I am currently only printing ABS, but I would like to be able to print PLA with the same hotend (I don't have enough money to buy a new hotend for every occasion). I don't know the first thing about using OpenScad so I can't modify the existing STL.

Can anyone help me out or at least point me in the right direction? Please?
Re: Fan duct - larger opening?
January 20, 2015 05:58PM
Nobody? Anybody?
Re: Fan duct - larger opening?
January 20, 2015 07:00PM
get on thingverse.com.. there is one on there... and the duct is a angled fan with low profile... just search mendel90 duct... theres a few to choose from...i have the same j-head and had the same issue...
Re: Fan duct - larger opening?
January 20, 2015 08:17PM
Quote
09zx-6r
get on thingverse.com.. there is one on there... and the duct is a angled fan with low profile... just search mendel90 duct... theres a few to choose from...i have the same j-head and had the same issue...

Which one did you use? And will it fit the "sturdy" Mendel90? The hole spacing is different for the screw holes that mount the fan duct to the X-carriage, between the "dibond" and "sturdy" models, and I have a "sturdy".

Edited 1 time(s). Last edit at 01/20/2015 08:22PM by Rich K..
Re: Fan duct - larger opening?
January 21, 2015 01:46AM
MY mendel is the dibond version made in aluminum...but here's the link to it...
http://www.thingiverse.com/thing:91931

Edited 2 time(s). Last edit at 01/21/2015 01:47AM by 09zx-6r.
Re: Fan duct - larger opening?
January 21, 2015 05:57PM
Is there anybody here who is knowledgeable enough in how to use CAD software, who could tweak the STL for the "Sturdy" fan duct so that it has an opening that is 8mm-9mm larger in diameter? I don't know enough about how to use CAD software to do it myself. Okay, I know NOTHING about how to use CAD software.
Re: Fan duct - larger opening?
January 21, 2015 10:18PM
whats the mounting distance difference ? as far as the opening i can modify it... but the mount, you said is bigger, whats the spec for it? better yet, give me all the specs u want it to be.. ill tweak it..
Re: Fan duct - larger opening?
January 22, 2015 04:53AM
On the Sturdy, the distance between the centers of the mounting bolts is 21mm. The distance between the back of the mounting flange (where it goes up against the front of the X-carriage) and the center of the hole for the hotend is 40mm. If the stock fan duct from the Github files ((fan duct STL for Meldel90 "Sturdy")) is modified, then I would think only the size of the opening would need to be changed.
Re: Fan duct - larger opening?
January 22, 2015 07:28PM
Ok..I'll see what I can do..
Re: Fan duct - larger opening?
January 22, 2015 08:41PM
Thanks! smiling smiley
Re: Fan duct - larger opening?
January 23, 2015 05:14AM
ok..here ya go.. try it out... i cut the original sturdy duct in half, then expanded the nozzle end by 8mm in all directions...
Attachments:
open | download - funky_rottis-curcan.stl (208.2 KB)
Re: Fan duct - larger opening?
January 23, 2015 10:06AM
Thanks! smiling smiley

Have to try it out after I get done printing a set of spool hangers for my smaller spools. The ones I had printed for me by someone else before my printer was operational work great with full PLA spools, but since ABS is less dense, a full spool of ABS doesn't sit on the bearings well, since the filament completely fills the spool and doesn't leave the spool flanges free to rest on the bearings. Found a set on Thingiverse that just hangs from the "stock" brackets!

Edited 1 time(s). Last edit at 01/23/2015 10:09AM by Rich K..
Re: Fan duct - larger opening?
January 24, 2015 02:08AM
What program did you use to modify the STL? I printed it out, but it turned out to be too long overall. Nophead also modded the design, and it was closer to where it needed to be, but the opening needs to be about 4mm closer to the fan. Due to the rectangular shape of the nozzle block, the corners nearest to the fan were still close enough to the sides of the duct that radiated heat caused the duct nearest the block to soften and droop, contacting the block and causing it to melt outright. I tried to use 123D Design, FreeCAD 0.14, and Netfabb Basic, and couldn't get any of them to cut the model so I could try a splice job myself.
Re: Fan duct - larger opening?
January 24, 2015 12:53PM
Goto tinkercad.Com and import the STL to the workplane...you can mod it from there.. if u still have trouble let me know..I'll redo it..
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