Hello Danny
I have a Becker 4201 and TRT250. Also using a PS Engineering PMA-4000-IRS
audio panel.
Sorry but can't help out with using 4201, havn't yet fired it up.
I used a flycutter to cut holes, think I purchased it from Aircraft
Spruce.Be prepared to get dirty, I used a cutting fluid that was Lard, but
whatever you do keep it plenty wet.
You need a piece of alloy to practice on to get hole sized proper.
Anticipate which way loads will be on tool, and load the tool before
tightening. This will put in your favor chance of size change is minimal.
Cut it out on a piece of nice flat plywood, and clamp, have pilot hole
already drilled.
If you are having a problem getting proper size, I used a caliper to
measure from other side of guide drill to cutting tip. Go slow as you can
with cutter speed and keep the bit cutting, keep the cutter sharp, I used
stone and lard every half dozen cuts to keep razor sharp, this will limit
chatter.
A few other ideas, I installed a UMA light wedge to match the
electroluminescent on the rest of panel.
I also used countersunk hardware, gives a nice finish. I used either Torx
Safety, torx or allen stainless hardware purchased from www.mcmaster.com.
I fooled with sandblasting hardware heads and it looks nice, if i hate it,
could easily paint.
Another issue I had with my Instrument module is the polyester layup was
not very well bonded to the wood. When trying to cut out the wood for
insert clearance, the stuff easily delaminated. I found by installing
nutplates which use aluminium flush pop rivets, and adding flush rivets
between the nutplates it held things much more better in place!
Hope this helps.
Ron Parigoris
|