Sikorsky S43 a learning project for Fusion 360 - RC Groups
Thread Tools
Nov 22, 2016, 08:14 AM
Square-rigger
meatbomber's Avatar
Build Log

Sikorsky S43 a learning project for Fusion 360


Well there we have it, after a more than 20 years absence to technical drawing and drafting i think it`s time to come back to it. DIY CNC and actually Plug and play CNCs are staring to get into the realm of the attainable for the hobbyist without mortaging hous, spouse and soul and so making ones own CNCed parts is getting quite posible. And if one doesnt want to do that one can always go to cutting service providers whew !

I learned on paper, working on drafting tables, then on to Autocad which in the mid 1990s was probably in the single digit version numbers. So my remembered skills are spotty at best.

First task at hand was to select WHICH software package, and boy what a selection there is ! I settled down on AUtodesk Fusion 360 mainly drawn by the promise of a free license for hobbyists and so far the software seems to be extremely powerfull and "relatively easy" to use.

To learn the ropes i settled on creating a Sikorsky S43 from an existing Plan by Peter Wank for an electric freeflight model of 46in wingspan.
I`m hoping to create a 3D model of it, and include modifications to make it fully RC.

So far i`ve started about 4 times until seeing the light about creating objects the way they are supposed to be created, and making the sketch for them at the place / plane where we actually want them etc.

so what i have done so far:

1)Created the Fuselage center line and inserted and scaled the plan and placed to have the fuelage top down view centered on the centerline. Tip of the fuselage to be the origin.

2)Created construction lines at each former location
broken the centerline at the former locations to create snap points to allign the former centerlines

3) Inserted the main former outlines

next up will be the 2 half formers in the cockpit area and then the outline of the top, bottom and side keels

after those i`m hoping to 3D spline the chine lines on the fuselage and then start "skinning" by lofting, i`d appreciate comments about that proposed workflow
Sign up now
to remove ads between posts
Dec 10, 2016, 06:26 PM
Square-rigger
meatbomber's Avatar
Well 2 steps forward 1 step back.

i`ve probably 3 times started over from scratch so far already
The Main issue being training my brain to accept that Fusion does want certain things done certain ways OR ELSE!
After posting a thread in the AUtodesk forums i got help by an Australian modeller who in a couple of evenings whipped up the Fuselage for the S43. The Cool thing now is that with the timeline you can actually go back to the start and then step by step look what he did (sort of)
I think i have a much clearer understanding of teh workflow now and so i`ve restated yet again and this time using teh best 3view and a lot of detail pics to get to the result i want to have, which will be the initial 3D Fuselage model.

So far the forward lower fuse is done
Dec 12, 2016, 08:44 AM
Registered User
portablevcb's Avatar
So, what was the proper sequence?

charlie
Dec 12, 2016, 01:53 PM
Square-rigger
meatbomber's Avatar
To RTFM first

No the biggest issue I had was that I didn't understand what happened to sketches and geometry when editing things. With the timeline when you edit something that's been in the drawing from early then everything else disappears so if you wanted to make a change based on a later sketch it was gone in with it your reference.
BUT you can rearrange the items in the timeline. Also FUSION seems to be mainly made for top down construction which In out case means create the outer shell first and then create components according to that outer shell. The outer shell Itself is also a component of the drawing but it's mainly a tool or jig to get what one wants I.e former outlines, rails for extruding stringers and keels etc.
so if one keeps all the sketches for the shell in the shell component things make much more sense and it's easier to keep an overview.

As to the "right" workflow well I guess there is many ways to Rome, but Basically get in side outline, top outline to have something your formers can snap to. Make the chines that are visible as 3D sketches, make any rails for the curved parts where you can identify them and then put the formers in. Then loft the skin. At least that's what I'm doing now
Dec 12, 2016, 04:58 PM
Square-rigger
meatbomber's Avatar
Thats the Fuselage my Fusion "daddy" Dave made up from the Original plans.
Dec 12, 2016, 05:26 PM
Registered User
portablevcb's Avatar
Thanks, I wondered about that. I had always learned to do 3D stuff by making the outer surface first. Just didn't know why.

charlie
Dec 15, 2016, 05:59 PM
Square-rigger
meatbomber's Avatar
ARRGGHhhhh and here i start again fro scratch..

i was wondering why some of my formers didn`t want to show up as profiles. And trying to fix that found that some of the splines on top where not in line with the rest of teh work plane, i had 3D sketch selected all the time and now its been biting me in the but, somehow manipulating with the splines i had moved a point or 2 of the plane and that prevents it from making a Profile in 2D.. Well easy you might say just move them back onto the plane, well and now here i`m stuck because i can only move "relative" distances but not to an "absolute" distance.. i`m sure its in there somewere but in my click trial and error approach i`ve not found it yet.. som more RTFM again
Oct 18, 2017, 06:10 PM
Square-rigger
meatbomber's Avatar
every now and then i`m going back to this project. I need to nerve myself to start doing the struts
Oct 18, 2017, 09:39 PM
The "pro" in procrastination
Steve85's Avatar
Don't lose your nerve MB, good projects are like fine wine, they need some time before we can appreciate their finer qualities. I have a workshop full of works-in-progress that are mellowing nicely...

Steve


Thread Tools