Paul could you please post the drawing for the oil pan and
include the
materials and dimensions?

I'll be using a mount almost identical to the CH-801 you
previously
designed. Also same for the S-beam? When fabricating the
S-beam what radius
is desired for the bend please? Does one use a hole saw for
the lightening
holes or a fly cutter? Thanks a bunch. I have an autocad
viewer, so should
be able to view a .dwg or .dxf file.

C. Smith

Here are some old designs but they may need to be adjusted
your type of airplane.


Paul Lamar


What is the material & thickness for the oil pan?I'm assuming 6061-T6,
but not sure on thickness.

I did make note of 0.063" 4130 -- so will place that on the next Aircraft
Spruce Order.

C. Smith -- as to hole saw or fly cutter:  I'd recommend the hole saw, as
you are cutting through a weld bead on the 4130 box.  I guess you could
clamp the two pieces side by side and cut the
holes before bending the 4130.Make sure Paul has everything
designed for your 801 before you start cutting.  On the photos is look like
the tubes are welded in place into the beam, so I suspect a milling machine
with a fly cutter will come in handy to "surface to top" to keep everything
equal when tightened down.

Tom

How good are you at welding aluminum. Some people can weld beer can :)

Anything from .049 up to .1875 will work with some weight trade off. I
suggest a little tig practice to see what you can do. Check the oil pan bolt
pattern as the RX8 engine differs from the 13B. Use the bolt center finders
and tap the aluminum down on top to center punch the holes. A carbon fiber
oil pan will work with high temp epoxy and with the upper center hard point
type mount found on the 801 and the BearHawk.

If it is a Zenair 801 I have an improved  mount for that using the upper
center hard point. I'll redo the old dwgs.

Don't get me wrong. If you have a 801 mount this new one will not be worth
retrofitting. The only way to get the airplane done is freeze the design at
some point and build it. Both mounts will work.

Paul Lamar

I'm building a CH-640, not an 801. They do share the firewall with the
exception of the upper center mount point. 640 is a low wing, whereas the
801 is a high wing, and the upper point is there to help transmit the loads
to the spar, as I've been told by Zenair. I only said that it is very close
to the 801 mount. Don't need the upper point, so no need to re-do.
I'll be using light weight center and end housings, so I'm just starting
with the S-beam to use in a test stand/mock-up until all the fuel injection,
MSCD ignition is finalized. Once a final installed weight is determined,
then we would go ahead with finalizing mount design for the 640.
So the s-bean is fabricated in 2 C-channels? I don't see the cross-section
dimensions, just the long  view. What is the bend radius please?
I've done a bit of tig welding, will be purchasing my own welder soon, but
have access to some nice equipment at work.
Thanks for the tips Jerry, Tom, Paul.
C. Smith

OK that will require a rear motor mount of a different design.
Are the firewall angle back and hard point dimensions the same as the
801? If not I will need a sketch and the the distance from
the firewall to the prop flanges as well as the position
of the thrust line.

The S-beam length is going to be a function of the cooling system
chosen. Side rad or bottom rad? One must find out if everything
is going to fit in the cowl :)

Paul Lamar



I'll get the numbers and drawings organized for you in as soon as I can.
C. Smith