REFLECTOR: TruTrak Automatic Trim

[Bob Jackson (Jax Tech)]

Ours worked well for more than a year, but it's been 'down' now for several
months for unknown, at least as yet, reasons.  We haven't had time yet to do
all the troubleshooting TruTrack has asked for to isolate the problem...

When it was working correctly, the only problem we used to have was in
trimming fast enough during the big transition while slowing from high speed
cruise (~180 KIAS) to approach/landing speed, which requires a very large
trim change from full nose down to full nose up, often in less than a
minute's time.  You can help it out by just holding down the nose up trim
button, but if you don't help enough, the elevator servo clutch will slip
and 'dump' the nose, which can be a very disconcerting event and feeling
when you're shooting a an actual approach IMC and low to the ground.  

The Velocity has very high pitch stick forces when slow because the canard
doesn't have all that much surface area, which necessitates (in my opinion)
very high elevator deflections in the landing configuration.

All in all, though, I think the TruTrack Auto Trim module is a very
worthwhile addition to autopilot operation.  Works very well if you don't
make rapid speed changes.

I'm curious if GRT has something similar out now, or how (and how well) they
handle rapid and large pitch trim changes.  If we were configuring over
again now, I think we would be looking very closely at the GRT autopilot
system and it's components.  We are very happy with the GRT EFIS, even if
it's human interface is not very 'sophisticated' or easy to use.

Bob Jackson
Turbo Cross Country XL/RG
N2XF

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of William Walker
Sent: Sunday, January 01, 2012 11:38 AM
To: reflector at tvbf.org
Subject: REFLECTOR: TruTrak Automatic Trim

Anyone flying with TruTrak's Automatic Trim module? If so, how would you
rate it's function and service so far?

 I see it has come down from $1100 to $350 and was considering adding it to
my Velocity's pitch trim servo. 

Bill Walker
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