X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=G+5i7Os5 c=1 sm=1 tr=0 a=Io3XLIBld6c7WvdWTVA04w==:117 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=x7bEGLp0ZPQA:10 a=IbIfy7DuNpcA:10 a=J70Eh1EUuV4A:10 a=dItZCVzeAAAA:8 a=o1OHuDzbAAAA:8 a=Ia-xEzejAAAA:8 a=tXwS-ErFAAAA:20 a=7g1VtSJxAAAA:8 a=Fcb_p3pDl9E31v2F4jYA:9 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=547lnJGUwZAo06BpY4kA:9 a=WWyTWhGjYsjuVsMN:21 a=AHA7rJRvoFYIrxRqZpkv:22 a=5YQ6H4ZxyGn-KoBYtt8s:22 a=Urk15JJjZg1Xo0ryW_k8:22 a=grOzbf7U_OpcSX4AJOnl:22 From: "Dustin Lobner dmlobner@gmail.com" Received: from mail-yw1-f44.google.com ([209.85.161.44] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 12972310 for flyrotary@lancaironline.net; Thu, 19 Sep 2019 10:04:16 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.161.44; envelope-from=dmlobner@gmail.com Received: by mail-yw1-f44.google.com with SMTP id r134so1272406ywg.2 for ; Thu, 19 Sep 2019 07:04:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=inZ0/ynDHlCa6OWRTqzIEsi7X2YBqeG+NrTZ7hjjMBg=; b=d7o1AM8C3Q7vYCNCUX4RhZs34nJh/VMdwyr2VYARfQ//lWWOoeKJAkbUa1A+JVM0Gn NuEI7ogTd9p1lSYgOJC5u5+9mUyaWyT8zfuTYDnwBhTO8AHCDuTejCA2x5yufssRo0gB K0mJJZMuyDGBFUmgp6JojC0VXCBVRq5FhhSRLsLgC9ywqu8KMtADuMXvtxYWlW+RCdM/ OQB8Gt5MacU5Yst+T0ZXnXALPuRtRqfZId/jOBEWVy8sX+M9WBS6QMnfGNWwVfwqXAkC EMd/rq2P/WdZPqlZsXP/Y79AqtUQj+OkLAxIe03F4sAr4cy3KhL0y1tzXRE1l17jdleH eicw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=inZ0/ynDHlCa6OWRTqzIEsi7X2YBqeG+NrTZ7hjjMBg=; b=q/fSr0H9U0YMMPoModgOtHJdKdr/7LNQDDySZuijZwVEjjGufLbfG6BJaBvQYwzXMf TpOLrLJDGLACLiraxkQPQgb3M7L8ag23zTDtZyv9EvE6pQYIXVu/EJk6D242SJJvxQ0R 48QJfpFvTwDIjia1w/PCi0al/fBfU88yGcFInwrZj2qAhHmBxMxIKzWavsMVeO+zCxY2 5i5W804G0+I21UGRNx2rKf4jWk/NphaYbDtMhZT4T5UcynHa0ts/aILD/+uCuDPhHQju 2X/h9Ubr7C7cSxpt+k4baWPK9I/UDjP7ErUK9wmpFl3rk4zEnjfBXoEsQwmZqoNtF3Vc X0RA== X-Gm-Message-State: APjAAAX2f2upXsn084/yQgwPYuG4bIWAp8amdwvFPQrYCHmJGd2hSGN1 HX1wvVDIqgfVpKS007YuOxepomd73eROpX2rz5zKzmDx X-Google-Smtp-Source: APXvYqxXHpXFAL0TiFPOOPfOZRTOYR0/Ianq8xlRokLFQAu/mh6dfXVVrLPtUwqekRG+1TtiDTzteYWVbKcyfDmEqc8= X-Received: by 2002:a81:1d05:: with SMTP id d5mr7677268ywd.299.1568901838047; Thu, 19 Sep 2019 07:03:58 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: Date: Thu, 19 Sep 2019 09:03:46 -0500 Message-ID: Subject: Re: [FlyRotary] Bell mouth 3D printed To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="000000000000be8e2e0592e86ca4" --000000000000be8e2e0592e86ca4 Content-Type: text/plain; charset="UTF-8" Finn, I've been doing 3D printing for awhile now, never tried ABS though. I've used 3D printed parts primarily for model rockets, things around the house, etc. The stuff holds up well, moreso than one would think normally. One suggestion I'd have is higher infill - when I'm printing something that needs to hold up, I usually run about 75% infill. I'm not sure if that's possible with ABS or not, so I don't know if that's actually good advice. One thing you can do, and only with ABS, if you take a shop rag and wet it with Acetone (I think, google it) if you wipe the part with the acetone, it dissolves the first layer or so (until the acetone evaporates). This allows you to smooth the ABS with the rag and get a gloss finish on it. You can also do vapor polishing: https://www.matterhackers.com/articles/how-to-vapor-polishing I don't like the hot method, if you look down the comments section someone explains how to do the "cold" method. I'd try that. Good luck! Dustin On Thu, Sep 19, 2019 at 8:36 AM Finn Lassen finn.lassen@verizon.net < flyrotary@lancaironline.net> wrote: > My first experience with 3D printing. > > I had bought a new Ender-3 and a 1Kg spool of ABS for less than $200. > > Article and pictures here: > > https://drive.google.com/open?id=1LbQcJIGnjsfNWfL5qiwz5ev7ze9IWAzm > > I copied the "best" picture from the RET_Bellmouth_Sept.pdf article, > pasted it into Paint and saved as Bellmouth.bmp. > > Imported that into Fusion360 as canvas. Calibrated it so throat was > 19.972mm (1.18") > > Made a spline matching the left curve up to the top. > > Added a tangent arc (radius). > > Added a 2mm rectangle that extended the throat about 1" with an 1.25" > ID. (The bell mouth will slide 1" down on the 1.25" OD pipe.) > > Added a "looks good" spline from part of the arc down to the throat. (I > believe that in our case, where most of the air comes from behind the > bell mouth, air should have a smooth path along the outside of the pipe > and radius of bellmouth.) > > Revolved the whole thing to get the solid bell mouth. > > [The result is actually a bit smaller overall diameter than the > recommended 2.13 * 30 + 2 * (0.08 * 2.13 * 30) = 74mm] > > Exported to a .stl file. > > Downloaded and installed Ultimaker Cura 4.2.1. > > Opened the .stl file with Cura and "sliced" it. 20% infill. This changes > the solid inside to a criss-cross pattern. Looking at it being printed > it appeared?? to produce about 3/32" thick walls by default. > > Saved result to .gcode file. > > Printed with the Ender-3. Took 3 hours and 15 mins. > > Nozzle temp default for ABS is 240*C. Spool says 230-260*C. Seeing how > some of the strands didn't stick and pulled across the mouth, I think > I'll use a higher nozzle temp on the next print. > > I printed it with mouth down. Unfortunately that resulted in a radius > quite different from the design model. I'll try to smooth the lip on my > first attempt with epoxy or JB Weld and sandpaper. If I print it throat > down, it'll probably need support along the outside that'll have to be > cut after printing. > > Will ABS be strong enough? I think so. The airflow should keep temps > well below 85*C. > > Finn > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > --000000000000be8e2e0592e86ca4 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Finn,

I've been doing 3D printing f= or awhile now, never tried ABS though.

I've us= ed 3D printed parts primarily for model rockets, things around the house, e= tc.=C2=A0 The stuff holds up well, moreso than one would think normally.

One suggestion I'd have is higher infill - when = I'm printing something that needs to hold up, I usually=C2=A0run about = 75% infill.=C2=A0 I'm not sure if that's possible with ABS or not, = so I don't know if that's actually good advice.=C2=A0 One thing you= can do, and only with ABS, if you take a shop rag and wet it with Acetone = (I think, google it) if you wipe the part with the acetone, it dissolves th= e first layer or so (until the acetone evaporates).=C2=A0 This allows you t= o smooth the ABS with the rag and get a gloss finish on it.=C2=A0 You can a= lso do vapor polishing:=C2=A0https://www.matterhackers.com/articles/how-to-v= apor-polishing=C2=A0 I don't like the hot method, if you look down = the comments section someone explains how to do the "cold" method= .=C2=A0 I'd try that.

Good luck!
Dustin

On Thu, Sep 19, 2019 at 8:36 AM Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net>= wrote:
My first= experience with 3D printing.

I had bought a new Ender-3 and a 1Kg spool of ABS for less than $200.

Article and pictures here:

https://drive.google.com/open?id= =3D1LbQcJIGnjsfNWfL5qiwz5ev7ze9IWAzm

I copied the "best" picture from the RET_Bellmouth_Sept.pdf artic= le,
pasted it into Paint and saved as Bellmouth.bmp.

Imported that into Fusion360 as canvas. Calibrated it so throat was
19.972mm (1.18")

Made a spline matching the left curve up to the top.

Added a tangent arc (radius).

Added a 2mm rectangle that extended the throat about 1" with an 1.25&q= uot;
ID. (The bell mouth will slide 1" down on the 1.25" OD pipe.)

Added a "looks good" spline from part of the arc down to the thro= at. (I
believe that in our case, where most of the air comes from behind the
bell mouth, air should have a smooth path along the outside of the pipe and radius of bellmouth.)

Revolved the whole thing to get the solid bell mouth.

[The result is actually a bit smaller overall diameter than the
recommended 2.13 * 30 + 2 * (0.08 * 2.13 * 30) =3D 74mm]

Exported to a .stl file.

Downloaded and installed Ultimaker Cura 4.2.1.

Opened the .stl file with Cura and "sliced" it. 20% infill. This = changes
the solid inside to a criss-cross pattern. Looking at it being printed
it appeared?? to produce about 3/32" thick walls by default.

Saved result to .gcode file.

Printed with the Ender-3. Took 3 hours and 15 mins.

Nozzle temp default for ABS is 240*C. Spool says 230-260*C. Seeing how
some of the strands didn't stick and pulled across the mouth, I think <= br> I'll use a higher nozzle temp on the next print.

I printed it with mouth down. Unfortunately that resulted in a radius
quite different from the design model. I'll try to smooth the lip on my=
first attempt with epoxy or JB Weld and sandpaper. If I print it throat down, it'll probably need support along the outside that'll have to= be
cut after printing.

Will ABS be strong enough? I think so. The airflow should keep temps
well below 85*C.

Finn


--
Homepage:=C2=A0 http://www.flyrotary.com/
Archive and UnSub:=C2=A0 =C2=A0http://mail= .lancaironline.net:81/lists/flyrotary/List.html
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