Re: Wing Post Socket Mounting in a Rolled Motor Stick

From: LeRoy C Cordes <lcordes_at_juno.com>
Date: Fri, 20 Jul 2007 09:17:09 -0500

Good description, Cal - a photo would be a great addition to the writeup.
 I can't imagine using a drill to cut through the motor stick with no
damage - WOW !
 
LeRoy Cordes
AMA 16974
Chicago, IL
In God We Trust
 
On Thu, 19 Jul 2007 23:08:51 -0000 "calgoddard" <calgoddard_at_yahoo.com>
writes:
> Thanks all for the advice.
>
> I ended up determining the best estimate for the CG by mounting the
>
> prop, putting on a 2.0 gram rubber motor and taping the wing posts
> to the side of the motor stick (MS) but without flying, just
> balancing the plane on a thread.
>
> I rolled some wing post sockets, then determined the drill size that
>
> would make the right size mounting hole. I tested the drill on some
>
> similar balsa and determined it was sharp enough to cut through
> without splitting.
>
> I then made a drill jig with two inch long diameter brass tubes to
> guide the drill. The tubes were held between two 1/16 inch balsa
> sheets glued to opposite sides of a balsa frame. The tubes were
> spaced apart the proper chord dimension to match up with the wing
> posts. The drill fit snugly in each tube without slop but could be
> easily twisted.
>
> The drill jig had legs to grip opposite sides of the rolled MS
> without damaging the same. I taped the jig to the MS after
> alignment to ensure it would not rotate.
>
> I then hand twirled the drill bit in each tube, and was able to
> neatly cut through the MS. I held a piece of scrap balsa against the
>
> bottom of the MS to ensure a clean lower hole with no break out or
> cracking. When the drill jig was removed I had two aligned,
> diametrically extending holes with no damage to the MS. This was
> nice since it took me a few hours to make my first rolled MS.
>
> It was then easy to glue the sockets in the MS with Duco cut 50%
> with acetone. The wing posts slid into the sockets just fine. I
> then put some wash in on the inboard TE of the wing.
>
> I will see how my guess on the CG location works tomorrow when I fly
>
> the plane for the first time.
>
> This is pretty basic stuff for you F1D guys, but may help anyone
> just making their first indoor plane with a rolled MS.
>
> I did come in .4 grams below my target weight for the plane, and
> this was made possible by use of the rolled MS. This allowed me to
>
> use really hard wing posts. I hate it when those things break.
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
 
 
 
LeRoy Cordes
AMA 16974
Chicago, IL
In God We Trust
Received on Fri Jul 20 2007 - 12:17:15 CEST