I first became interested in classic pattern planes when Rainedave posted his 1/2a versions on the 1/2a site. I found the eyeball article at the Trenton Flyers site. It had a foam wing, and my few attempts to cut foam wings were dismal. I decided to build it with a wood wing, and to learn a little more about CAD. I used the plans from the article and traced the parts and shapes in CAD. I am sure it is not built true to the plans, as the parts did not appear symmetrical once in CAD. I corrected this, but I do not know if I corrected the right way. ANYWAY, It took me a little over a year to get to this point. It will likely take another year to get it sanded and covered, and likely another year to join a club and get to fly it. But its still cool to look at.

FP,

nice job on your Eyeball. Rainedave and his quick work on plans certainly is an inspiration for anyone with classic pattern tendencies...

As a relative newbie with CAD myself, I found that one easy way to obtain symmetry where required is to work on half the part. Wing and stabs would be an example as would be fuse top views and formers. These are then obtained in full symmetrical draft by duplicating the part and reflecting it on it's common axis (e.g., the fuse or former centerline). Of course it's important to match the axes carefully or else one does end up with assymetry.

In 3D CAD much of this is not an issue as the parts are made symmetric about a specified axis and drafted to precision via software intersection techniques.

What are the specs on your Eyeball? Is that an MVVS 40 engine?

David.

flying poodle, you username made me want to post a couple of pics of my little one to go with the little one in your pics The box picture is just after the Fedex man had dropped off a plane that I bought from RCU classifieds.

OK, I got to show a picture of Winston admiring my electric Phoenix 5 from the Wing Mfg. kit.

I made the parts in CAD much as you explain. However, when one side of the stab is 12" long and the other is 11" long, which side do you duplicate? The measurements are not correct but the idea is the same. This happened on the formers also. The engine is a NIB HP 61 with a flow through muffler. The little girl weighs in a 12lbs, 14lbs wet.

My two 80lb labs were not allowed near the airplanes during the photo shoot. "Tail-o-death" has taken its toll too many times.

Whatever techniques you used look like they worked out - your eyeball does not look skewed.

Many originally hand drafted plans are not "CAD symmetric". In other words they have eye and ruler precision but not 3 or 4 decimal place computer precision. But that's OK. When we build with balsa, we rarely are working to more than 2 decimal places of precision even when working with imperial units (i.e., inches). We might typically work with 1.25" or 3.125 ~ 3.13" dimensions as an example. With that in mind, when transferring hand drafted plans to CAD, it is just important that they be symmetric about a chosen dimension. If you choose a stab panel and one is 11" and the other 12", well you can choose which one to go with but once chosen, the other will be identical. This is not a CAD issue but a design issue.

Having a good feel for the proportions of model or a specific design goes a way when it comes to re-drafting or re-designing a model in CAD. In the absence of that, a relatively safe approach is that if stab panels really differ by as much as 1", then the correct dimension is probably the mean of the two - 11.5".

Eventually the little one will no longer leak fuel so you'll only need dry AUW's

I'm familiar with them "tail-o-death" strikes, especially when they are working in resonance!

David.

I know about the 80 lb. "Tail-O-Death" too!