SEN 97-34 - 5 Dec 1997

News and Reports - 1997 Issue 97-34

SCAT Electronic News December 5 1997

On Electronic Timers from Martin Gregorie

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Subject : Voltz Kolibri servos

Hi Roger,

If you can post or e-mail the specs of this servo I'd be grateful.
Sounds as if it would be fine for disk release systems like yours, but
it may not be man enough for direct F1A stab control.

Allard van Wallene was saying that he thinks the aerodynamic loads are
sufficient to affect the bunt by slowing the motion of low powered
servos. He thinks you need a minimum of 1.9 Kg/cm torque - this
translates to 26 oz/in. We were discussing the small Czech servo at the
time. On this basis the S80 would be too weak for direct stab F1A
systems (Gewain/ MKS/ Danish) but the S90 or any standard micro-servo
would do it. Any comments?


VOLZ Details

11 of torque, 7.5 grs (weight) Price $39.95
1.3 H x 0.45 W x 1.14 L inches

20 & 11 grs $35.95
1.18 X 1.57 in [they did not give the thickness. ]
This servo has fancy lug permitting either horizontal or vertical mounting
these could be removed for our application.

The Volz height measurements are from the base to the servo arm.

Note that Volz say the torque is increased by 20% for a 6 volt
power supply.

I weighed my Volz and found it to be a little heavier than the 7.5 grams.
The FMA/Cirrus servos have had some critisism from the R/C community
for DOA. FMA clains that they test all and all work. This may be the case
now, it was not when they were first released. The Kolibri is light
because it has a vacumn molded case and the design is such that the case is
not required to keep the gearbox lined up as with a classic servo.

Looking at the FMA catalog the S80 gives 11.1 oz-in and the s90 [same
size and weight but $3 more ] gives 19.0 oz-in. Dallas Parker's 'simpler
bunter' that Jim and I are working on [mainly Jim] has an s90, I will let
you know what happens.

Icarex from Robert Lane
I have recently returned to modeling after a long absence. One of the
first things I did is try all the new materials. Along the way I
experimented with anything that looked promising. Among those was
Icarex. I saw a reference to Icarex in Model Aviation WC report and
thought it was time to share what I have found out so far. Material is
a ripstop microweave polyester. Latest version of it has a
polycarbonate sealed surface. It is essentially waterproof (water beads
on it). Most importantly it requires no sealing or finish of any kind.
It can be bonded with a variety of contact cements. Heat shrinks well
at about 2 oclock on my iron. Too hot and it will develop permanent
wrinkles. Lots of beautiful colors available, not just neons. Some
tissue like colors as well. Has some surface roughness which is nice.
Very easy to cover with. Quite stiff as it is a woven fabric.
Available from serious kite stores. Beware ripstop nylon as it does not
do the things Icarex does. Weight is 30-33 grams/yd2 on certified
scale. (not 1/2 oz or 3/4 as sometimes claimed at kite store) Very
tough and puncture resistant, especially in polycarb finish version. I
have not had any chance to see how it handles high temperatures, but it
has passed cold wet NW environment tests so far. Reputed to be very UV
resistant. We'll see! Price for those who care is about $8-10 yd.
Most stores will sell any quantity you require. I have covered a couple
of wings with it so far. Very happy with it.

My particular focus is in the towline classes, but all the classes have
interesting features. I would really like to get email addresses of A1
and A2 flyers.

Robert Lane
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Roger Morrell