September - October - The Recreational Aircraft Association

Product Reviews
VR3 ENGINEERING PREFITTED
FUSELAGE TUBING SETS
When Bill Weir told me that there is a new company
in Stratford putting together packages of
chrome moly tubing for homebuilders, I was only
mildly interested. However when Don VanRaay of
VR3 Engineering addressed the London chapter, it
became apparent that this company has broken new
ground and could revolutionize the fabrication of
fuselages, motor mounts, and any industrial fabrications
from tubing, whether round or square.
In the racing car industry there are already a
number of companies selling machines that purport
to profile the end of a tube so that it will make a
reasonable saddle joint with another tube. Some of
these machines use a holesaw for cutting; heavier
duty machines use a milling cutter and have some
sort of adjustable angle vise. Some have a punch
and die set and nibble the end of a tube to make the
fit. For light tubes my personal preference is a good
pair of snips to rough the shape, and a bench grinder
with a wheel dressed to the diameter of the tube to
be fitted. All have their limitations, and all require a
good bit of eyeballing to ensure that the angle of the
joint and the clocking of the ends is correct. None of
these methods provide a perfect fit and the result is
usually some wasted tube and a lot of filler rod when
welding. Loose gaps mean that a lot of hot metal has
been poured in, so when the joint cools there will
necessarily be warpage. Sometimes this can pull the
Menno Peters (l) and Don Vanraay
(r) with one of their machines
fuselage out of shape, and the builder must “correct”
with a dead blow hammer and a strong arm.
Enter VR3 Engineering. The genius of their product
is the CNC machine that Don VanRaay P.Eng
designed and built. Using this machine, all tubes are
rotationally milled to a tolerance of .001” no matter
how many tubes are fitted into a cluster. The gaps
between tubes will never be more than .010”, something
impossible to achieve by traditional methods.
Up to now 1/16” has been considered pretty good,
and I have seen many homebuilt fuselages that obviously
had gaps of 1/8” filled with welding rod. To
achieve their close tolerance requires that VR3 first
model the entire fuselage drawing in their CAD program,
a task that can take as much as two weeks at
the keyboard, depending on how well the designer
has drawn his plans. Once the model is complete,
the program calculates the end profiles and lengths
for every tube of the fuselage. From here on it is the
work of their in-house built special purpose CNC
milling machine to cut and label each tube, ready for
packaging and shipping.
There has to be a cost for all of this, but it is reasonable.
The typical set of tubes for a fuselage is
$34-3600 CDN including shipping. As soon as the
builder receives his package he can lay it out and
begin tack welding. Because of the accuracy of cuts,
there is very little jigging required. Contrast this with
the typical 2 place high wing fuselage that requires
nearly $2000 worth of raw material. To this must be
added the cost of packaging, brokerage, and ship-
32 Recreational Flyer September - October 2006