"Hi Guys,
You
saw the photo of the front end for my Vultee in the May-June 2007 issue
of MAX-FAX. This thrust adjustment technique is a winner for
radial engine models and offers you an easy and simple way to address
the trimming procedure. Since the photo was taken I’ve
retrofitted and retrimmed several of my models using this
technique. The models don’t fly any better but the trimming
process was certainly easier. The Geezers “Gizmo” also does this
job very well and is still the most practical method for inline engine
models.
The
hardware (cup point set screws and the blind nuts /T-nuts) are
available from Micro Fasteners (
http://www.microfasteners.com). See attachment for sizes and prices. Earth magnets are available from Easy Built models and Dave Rees.
I’m
using 4-40 screws but 6-32 screws also work for large models. You
can trim off the flanges from the blind nuts with tin snips if
necessary. Be sure to add enough cowl rings to hide the gap
caused by the trim adjustments. The 4-40 screws use a 0.050 allen
wrench and the 6-32 screws use a 1/16” allen wrench.
The
blind nuts are located at the 2, 6 and 10 o’clock positions.
Drill holes for the blind nuts and install them first (hot
stuff). Put in the screws and leave them proud. You can
press the nose plug assembly against the screws to mark it for the
magnet locations. I use a drill bit (held in my fingers) to
recess the magnets. Brad point works best but any will do.
Hot stuff them in place.
This
trimming setup offers two excellent benefits. (1) Easy and
accurate trim adjustments and (2) the magnets hold the nose plug
assembly snugly against the screws regardless of their settings.
In other words, even if the nose plug loosens (as it usually does) it
will remain in place.
You
may be tempted not to install the 6 o’clock screw. You really
need it! It serves three purposes: (1) It’s available in
the unlikely event you need up thrust (2) It ensures the security to
hold the nose block in position. (3) It provides a field spare in
case you drop one of the others in the grass (you’d never find it)."
Claude Powell
Hi Guys,
Ed Bojanowski has put together a package for this exact setup about 2
years back and I think he still sells it. He had a nice little
screwdriver typ tool included for making the adjustments if there is
any interest. I found putting the magnets in the nose to hold the
block on worked great. I use 1/32" thick magnets to add shims and
change the thrust angle. This too is very easy. Some
pictures showing the magnets mounted in the wood, how the block fits on
and covers everything and then how you can use them for shims.
Neat thing about the shims is you can remove them for judging and then
pop them back in. We have more details on mounting the magnets on
our tips page at the website.
See you soon
Dave.
And check out Dave's web site for more building tips/links and his great model kits --- http://www.easybuiltmodels.com/sitemap.htm
Hi Guys, Take this with a grain of salt! For the just completed
2007 FAC non-nats I lubed all my motors with a silicone spray lubricant
( NOT PROTECTENT ) instead of DC33. Only one rubber loop failed
during the two day contest. I examined the rubber for damage such
as tears, nicks and abrasions of any kind. I didn't find
any. Obviously the lube was doing it's job. It would appear
the rubber simply failed at it's weakest point. I'll use
this approach for the rest of the year to see if these good results
continue. The preparation consisted of washing the rubber in
clear water and drying it before lubing it. I put the rubber
loops in a plastic baggy and sprayed the lube into it. Remove the
rubber loops, shake off the excess lube and let them air dry (it
doesn't take long). I don't think this is any better than DC33
but it does appear to be an acceptable alternative. It's nice to
have choices. The silicone lube doesn't spray the inside of the
fuselage, is easy to use, readily available and inexpensive. I
suspect all brands are about the
same but the one I've been using is called:
"3-in-1 Professional" silicone lubricant. It's made
for the WD-40 company and can be found on the WD-40 website. I
haven't seen any write-ups about this but I believe some of the
modelers are using it and I think Dan Driscoll is doing some
comparative testing. Keep an eye on future Max-Fax issues.
Claude Powell
First one from our friend Claude Powell in West Virginia!
Subject: GLUE DISPENSERS