Looking for feedback on my the new design

[steven yampolsky]

So I've been using free 2D CAD tool called DraftSight. It is made by Dessault, makers of SolidWorks. The tool reminds me of AutoCAD 2000LT: all needed features, none of the fluff of later AutoCAD versions. The tool is super fast and easy to use.

I am attaching the DWG of the design so far. I am looking for feedback in several areas in particular:

1) how do I mark differentiate between parts that are inside the fuse vs outside or other parts?
2) I am still not sure how I should organize the drawing in layers.
3) This is the most difficult one: how do I show the openning in the fuse for the sidewinder engine. I am worried the nose will not be strong enough.
4) how do I indicate which what material is used for a part. For example all formers are made out of 1/8 birch plywood except for the molded top half formers which are balsa.
5) How do I create cut views? For example, I want to show what crossection of the fuse looks like near the wing.

The design has several aspects that in combination are not common: all inline, flapless, sidewinder using Brodak 40, molded top and bottom all the way to the front, Russian-style keyhole landing gear mount. The model is inspired by Crayola. The goal is to design an expert level model that can fit inside a small aircraft(I fly a Piper Archer). Yes, I could go the easy way and build a take-apart Trivial ImpactoShark but what would be fun in that?

I posted the file in my SkyDrive public folder for everyone to see: https://skydrive.live.com/redir?resid=9B69DCECFCD2257C!503&authkey=!AN3TJ9cCsfBvQKA. The filename is 2012.dwg

[Bob Kruger]

So I've been using free 2D CAD tool called DraftSight. It is made by Dessault, makers of SolidWorks. The tool reminds me of AutoCAD 2000LT: all needed features, none of the fluff of later AutoCAD versions. The tool is super fast and easy to use.

I am attaching the DWG of the design so far. I am looking for feedback in several areas in particular:

1) how do I mark differentiate between parts that are inside the fuse vs outside or other parts?
2) I am still not sure how I should organize the drawing in layers.
3) This is the most difficult one: how do I show the openning in the fuse for the sidewinder engine. I am worried the nose will not be strong enough.
4) how do I indicate which what material is used for a part. For example all formers are made out of 1/8 birch plywood except for the molded top half formers which are balsa.
5) How do I create cut views? For example, I want to show what crossection of the fuse looks like near the wing.

The design has several aspects that in combination are not common: all inline, flapless, sidewinder using Brodak 40, molded top and bottom all the way to the front, Russian-style keyhole landing gear mount. The model is inspired by Crayola. The goal is to design an expert level model that can fit inside a small aircraft(I fly a Piper Archer). Yes, I could go the easy way and build a take-apart Trivial ImpactoShark but what would be fun in that?

I posted the file in my SkyDrive public folder for everyone to see: https://skydrive.live.com/redir?resid=9B69DCECFCD2257C!503&authkey=!AN3TJ9cCsfBvQKA. The filename is 2012.dwg

Steven

I can't get to it via the link you posted.  Can you file attach the dwg on an email for me?

V/r

Bob

[phil c]

Just some general comments Steve.  Differentiate parts inside by using dotted lines.  The innermost lines should be the thinnest and have smaller dots.  Intermediate stuff should be slightly wider and have longer dots.  The outline should be wider still, for emphasis and more legibility when printed.

Layers still confuse the heck out of me.  I constantly forget which layer I'm on and have to move or re-draw stuff.  So mostly I put it all on one layer.  That way what I see is what I get.  Putting some dimensions and other stuff like construction lines on separate layers is helpful.  Makes it easy to hide them for the final plan.

I've built a few sidewinder full fuselage models.  The biggest hassle in figuring out if you want the tank accessible without removing the engine.  Tie the mounts to top and bottom sheets inside the shell, or else do a firewall mount and add glass inside and reinforcing gussets(perhaps the tank compartment) to stiffen the front end.  Making an outboard hatch to get to the tank simplifies maintainence and is really no different than having a bottom hatch.

Wood and materials are usually indicated by some kind of hatching.  You mostly have to do your own custom ones, since none of the CAD programs have useful ones.  Plywood is usually done with some wavy lines.  Balsa is usually longer and shorter randomly angles lines with some really short ones thrown in(look at a piece of A grain wood).  Foam is a bunch of circles.  Mostly use Text and arrows pointing to a piece to call out what it is or point out important features or items.  Some folks say putting these callouts inside an outline is bad form, but I find it easier to follow than arrows from  a long ways away.

Given it's a 2D program, all cutaway views probably have to be done by hand.  It's not hard to draw a former, add the sheeting(filled with little dots and circles for end grain), holes, pushrods by measuring from the top and side views, etc.

The file doesn't seem to be an Autocad DWG.