Re: Problem: Cutting prop outlines

From: <mkirda_at_sbcglobal.net>
Date: Tue, 04 Sep 2012 15:09:06 -0000

Interesting thought, Leo. That could explain the issues I have been seeing. Recently cut spars for A6 and they were accurate. Hence the confusion why the thinner stuff would be so weird. You'd expect blade wandering to be worse on thicker wood...

I'll try your suggestion later on this week. Thanks!

Regards.
Mike Kirda

--- In Indoor_Construction_at_yahoogroups.com, "Leo Pilachowski" <leop@...> wrote:
>
> The problem with the A2Z copy of the Harlan stripper is the end of the threaded rod used to position the straightedge. The end on mine is ground down by hand so it is neither perfectly flat nor perfectly symmetrical about the axis. This would usually not matter much if the threaded rod were perpindicular to and centered on the edge of the aluinum straightedge. However, so that various thicknesses of balsa sheets can be cut, the threraded rodded is positioned such that for thin sheets, like you were cutting, the end of the rod sticks up above the edge of the straightedge. Thus, turning the adjustment one half a turn can lead to uneven changes in position. It takes just a 0.005" error in the rod end flatness to make your strips come out with 0.010" differences.
>
> You can fix this by chucking the threaded rod in a drill and carefully grind down the spinning rod to make the edge flat or at least symmetrical. Or, you can raise the straightedge so that the whole rod end contacts the edge.
>
> Or as you did, use the a Jones type stripper like the Tyson's or A2Z sell. For SO kids that need to cut a great many strips of one size, I have them make a dedicated stripper for that size (1/8" for towers, etc.).
>
> LP
>
> --- In Indoor_Construction_at_yahoogroups.com, "mkirda@" <mkirda@> wrote:
> >
> > I tried using the Tyson stripper and it had only one thousandths of an inch variation. Thanks to the person who suggested it off-list.
> >
> > Regards.
> > Mike Kirda
> >
> > --- In Indoor_Construction_at_yahoogroups.com, "mkirda@" <mkirda@> wrote:
> > >
> > > Greetings.
> > >
> > > So I am trying to cut prop outlines today and just having the worst time.
> > >
> > > The balsa sheet is supported full length by blue tape. Using A2Z balsa stripper with broken Candidus blade. Balsa is 0.025". I rotate both micrometer heads half a turn, which equates to 0.025". Cut it and it is 15-18 thousandths. Turn again half turn, and get 30 thousandths. It is almost consistent - too thin, too thick, too thin, too thick. Except once in a while I get one that is what I need.
> > >
> > > Half a sheet is gone, I have two usable outlines. Can it be the Candidus blade is too thin? Wanders maybe? Suggestions?
> > >
> > > Regards.
> > > Mike Kirda
> > >
> >
>
Received on Tue Sep 04 2012 - 08:09:09 CEST