Matthew, there is no need for the nylon bearing at the rear (though it
won't hurt to have it there) as the rear end is fixed and the torque is
measured by the twisting of the wire. Again my only caution is to make
sure the joints (if any) are mechanically sound. It won't matter too
much for the ministick size motors but if you get to winding larger
material and a joint comes loose it could really smart when the whole
assembly comes out and slaps your hand. I observed this happening to one
of my flying buddies.
A caution for your Brisbane site (particularly if you're plane is
scrubbing the ceiling as we do at most of our sites) - You might think
that you should wind much more than at your local site but when I first
went down to the University of Illinois Armory with a 100 foot ceiling I
was told that I should start by winding the same as for our 40 foot site
and they were right, the plane got right up to the top right away - then
later, by winding too much, I managed to leave my newer MiniStick in the
steel rafters - oh well, it happens.
Where are you located in Australia ? I've got a Sister-in-Law in
Toowoomba.
LeRoy Cordes
AMA 16974
Chicago, IL
In God We Trust
On Sat, 20 Dec 2008 14:21:34 -0800 (PST) matthew taudevin
<mattnsim_at_yahoo.com.au> writes:
thanks leroy, I like the simpler one with the metal bracket as the base.
Could I use a nylon thrust bearing at the back as well as the front of
the bracket? My brain goes into overload when i read stuff that I do not
fully understand.
I have access to lots of music wire (I am a guitar teacher) so most of
the construction should be easy enough. I just do not have a soldering
iron.
Can I just say that all your help so far has been fantastic. Furthermore,
If i can acheive 5 minutes flying with my ministick I will win this years
ministick comp, hands down. As far as I know none of the guys get 5
minutes flying time. If I could get 5 minutes in the hall accross the
road (which is tiny) The gym that we fly in at brisbane is 3 times as
high and I should be able to do over and above 5 minutes!!! that would be
so satisfying. I will do some testing today. stay tuned.
regards
Matthew
From: LeRoy C Cordes <lcordes_at_juno.com>
To: Indoor_Construction_at_yahoogroups.com
Sent: Sunday, 21 December, 2008 4:15:56 AM
Subject: Re: [Indoor_Construction] Re: Optimizing a ministick
?
Matthew there are plans around but here's a copy of a simple one and one
more complex. I like the more complex one (by Cezar Banks) but the
specified wire is too heavy for ministick (I need to make another with a
thinner torque wire). Make sure that any wire joints don't rely on just
solder but use a positive connection.
LeRoy Cordes
AMA 16974
Chicago, IL
In God We Trust
On Sat, 20 Dec 2008 02:53:22 -0800 (PST) matthew taudevin
<mattnsim_at_yahoo.com.au> writes:
there's a cheetah in the tank?? what does that mean? I never even
considered winding to 90% capacity and then backing off to the torque
required for a no touch ceiling run.
should i glue the front wing post to the fuse and leave the rear post for
trim adjustments?
When you say WASH what does that mean? How do I get rid of it?
and .027 rubber that is .68mm YIKES!! I have some .8mm that I might try
first to see what happens.
How do i get a torque meter? Can I make one?
From: Bruce McCrory <hbm55_at_comcast.net>
To: Indoor_Construction_at_yahoogroups.com
Sent: Saturday, 20 December, 2008 4:48:07 PM
Subject: [Indoor_Construction] Re: Optimizing a ministick
I don't see images, but the Utube video was enlightening. Prop looked
good, and your comments mean there's a cheetah in the tank.
Definitely wound to "no touch" torque. You want a torque meter, to
record the no-touch force; then wind to 90% turns and back off to
the "no touch" power. It will extend the flight time, giving you more
turns, longer cruise torque.
.039" (1mm) is going to be too powerful for the weight adjusted
model. It's a good size for A6, however.
Others on the list might see more than me. My thoughts:
The wash can be reduced. I don't use any, relying on the MS to twist
it in during launch torque and climb. Fixed wash equals cruise
hassles and drag. This is a good opportunity to shave down the mass
of the motor stick. Remove smidges of incidence - the bobbing can be
that, or the high wash angles.
MS should be about .08 - .10 grams. Mine are .07(-) and hard wood,
7# - 8#. Thinner sections twist better. Put about 5-7 degrees tilt in
the stab - drop right side. Straighten the wing spars - no wash. Get
some .023"-.027" rubber, same 11" length and wind it to 90% of break
turns to test full model duration (and endurance). .027" is
competition size for your lower ceiling. Start grinding down the MS.
When the weight gets down close and the wound rubber doesn't break
the stick, but the stab levels out with the wing spar line, you are
close. The MS will automatically twist wash-in into the left wing
panel. It's ready for fine tuning in the field house.
If you can beat on the ceiling, test at full torque. A half, or third
motor might help at this stage. The idea is to file down more wood
section on the sides near the front wing post and increase the launch
wash slightly. I've never done anything with the stick behind the
posts but to reduce weight. MHO, the short moments counteract any
advantage to moving the thrust line, like in EZB. Mini-stick seems to
like steady, straight booms.
This is fun homework.
Bruce in Seattle
--- In Indoor_Construction_at_yahoogroups.com, matthew taudevin
<mattnsim_at_...> wrote:
>
> thanks bruce for the info.
>
> My props have helical twist.
>
> rubber is 11" loop of 1mm square and weighs .5grams
>
> The model weighs .6grams without rubber so all up weight with
existing motor is 1.1grams. A little heavy but it is my first
ministick. i may be able to take some weight off with some light
sanding of the fuselage.
>
> ceiling is normal pointed variety and is about 20 feet high. here
is video you will see the obstructions that I mean.
> http://www.youtube.com/watch?v=-wzy7v0funk
>
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LeRoy Cordes
AMA 16974
Chicago, IL
In God We Trust
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LeRoy Cordes
AMA 16974
Chicago, IL
In God We Trust
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