Re: Tools

Paul Butler (pgb@kau1.kodak.com)
Wed, 17 Jan 1996 09:27:37 +1100

Further to the topic of a overhead routing tool for cutting fuselage formers,
spars and other difficult shapes.

Yesterday I purchased a Hitachi Laminate Trimmer which is a small router. It
is more powerful than a Dremel (and probably makes much more noise (30,000 RPM))

This unit has one advantage over the Makita I looked at in that the adjustable
base also allows the body to be set at a angle to the base 0 to 45 degrees)
and a probable disadvantage in that it is less stiff. I hope to overcome any
potential stiffness problem by adding a second mounting bracket on the opposite
side of the body where the edge guide is normally attached.

The next step is to build a suitable base where router is mounted vertically,
cutter down. The frame to which the router is mounted will be hinged so that
it can be lifted up away from the work. This will allow blind holes to be
cut, eg. inside plywood fuselage formers.

The base will provide for a number of attachments:
A guide pin that align with the cutter (and is the same diameter as the
cutter) so that a template can be offered up to the pin and the work which
is attached to the top of the template is profiled by the cutter as an
exact match to the template. ( Near enough anyway.) A spacer will be between
the work and the template to prevent the cutter striking the template.

Guides for running straight sections such as spar booms past the cutter.
By suitable design, scooped out sections like I beams and plain sections
like T and trapesiums can be cut.

As aid to getting guides correctly aligned with the cutter, I intend to use
a mandrel that fits into the cutter holding collet. At the end of the mandrel
will be fixed a disk of a diameter and thickness that represents the enclosed
rectangle of the section to be cut.

More latter as I progress with this adventure.

Paul Butler