HDTenEightyP/NetNews huggingface dataset:
From: svoboda@rtsg.mot.com (David Svoboda)
Subject: Re: Another Fiberglassing Question....
Organization: Motorola Inc., Cellular Infrastructure Group
Date: Thu, 19 Nov 1992 16:45:06 GMT

In article <BxvpC8.CAs@ra.nrl.navy.mil> tse@ra.nrl.navy.mil (Anthony Tse) writes:
|In article <1992Nov17.152802.26427@rtsg.mot.com> svoboda@rtsg.mot.com (David Svoboda) writes:
|>In article <1992Nov16.162843.26528@informix.com> robertw@informix.com (Robert Weinberg) writes:
|>|
|>|How do you make the fiberglass lay down nice and tight while the epoxy sets up?
|>
|>Use polyester resin instead?
|
|   Is that really better?  I've done some fiberglassing with polyester
|resin, you have about 10 minutes before the stuff become so cured that
|you can't work it anymore.  I always thought epoxy (the kind for
|fiberglassing, not the kind for glueing) is better, lighter (and more
|expensive).  I knew a guy who built and sold model racing boat hull,
|I think he put his glassed hull under heat lamp.

You used too much catalyst.  See, it's not like epoxy, where the ratios
between resin and hardener are fixed.  Polyester can be made to set in
anything from three minutes to five hours, depending on how many drops
of catalyst you use.

Epoxy is NOT lighter than polyester.  You use exactly the same techniques
(toilet paper) for application, except that it is really cheap, so you
don't mourn throwing all that away in the paper.  But it sets up to a
VERY hard, crisp surface that sands and feathers very nicely.  And it
can be mixed with talcum powder or micro-balloons for a very light,
sandable filler to go over the first application.

And while polyester smells bad, it does not induce a damaging sensitization
(allergy) like epoxy does over time.  Yes, the catalyst is dangerous to your
eyes, but no more than Drano, and you're no splashing it into a sink, you're
only carefully dripping it into a cup, and besides, you DO wear safety glasses 
while using modelling chemicals, don't you?

Oh, and as to the original question, I feel that straight polyester resin
is just the right consistancy to make glass cloth stick around compound curves 
nicely.  You *can* get epoxy to do that, but you have to thin it very carefully
to the right consistancy, and that only comes with experience.

I mostly suggested polyester resin as a joke, as I am fully aware that it is
out of favor at the moment among most modellers, for one reason or another.  I
do strongly suggest that everyone try it sometime in their modelling carreer,
though, just to try and make an informed decision.

		Dave Svoboda, Palatine, IL
From: tod@cco.caltech.edu (Tod Edward Kurt)
Newsgroups: rec.models.rc
Subject: Re: Question About Speed Controls.
Date: 20 Nov 1992 21:57:00 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: sandman.caltech.edu

<IO10046@MAINE.MAINE.EDU> writes:

>    I have a question about the operation of speed controllers.
>What is ment by high frequency speed controls?  I known that they
>are supossed to be better for the motor and its brushes but why?
>Does it reduce brush arching?  What does the output of a controller
>look like?  Maybe:

>    ----  ----  ----    7.2V
>    |  |  |  |  |  |
>    |  |  |  |  |  |
> ----  ----  ----  ---  0.0V

>    What is the frequency?  In the KHz?


>Aaron Brasslett
>University of Maine

I can't think of why exactly it's better for the motor (execpt maybe
that it's always being driven at the same voltage, but that's pretty
much exactly what it looks like.  Typical ESCs run around 2500Hz and
pulse the motors with a varying duty-cyle square wave.  The advantages
of this are higher torque over entire speed range (since instantaneous
current and voltage are constant) and cheaper power transistors can be
used.  It's also much easier to control.  From talking to various
manufacturers of these things, it sounds like most of them just take
the brains out of your typical $11.99 servo, fix the feedback
resistor, and add power mosfets to drive the motors differentially.
I'm working on an ESC of my own right now, but I'm having a hard time
finding chips that are still in production (@$&!! old spec books!)
The ESC makers also add goodies like regeneration (recharges your
battery and brakes at the same time!) and a torque control.  These I'm
still working on.  You trying to design your own?

					-Tod

Newsgroups: rec.models.rc
From: colangel@carla.JSC.NASA.GOV (Michael Colangelo/MDSSC)
Subject: Electric Warbirds
Organization: IGOAL
Date: Mon, 16 Nov 1992 03:44:05 GMT

Does anybody know of plans or kits available for electric powered WWII
airplanes?  

Thanks,
        Mike
From: bm511@cleveland.Freenet.Edu (Ronald G. Martin)
Newsgroups: rec.models.rc
Subject: ModelCAD
Date: 23 Nov 1992 14:44:50 GMT
Organization: Case Western Reserve University, Cleveland, Ohio (USA)
NNTP-Posting-Host: hela.ins.cwru.edu


Does anyone have experience with or comments concerning this software package?
Saw the ad in the November issue of RC Modeler, pg. 93.
	Thanks,
	  Ron
From: patch@sequent.com (Pat Chewning)
Newsgroups: rec.models.rc
Subject: Slope sites in Denver/Boulder Colorado wanted
Date: 16 Nov 92 22:52:55 GMT
Distribution: usa
Organization: Sequent Computer Systems, Inc.


I will be vacationing in the Denver/Boulder around Christmas and plan on
bringing my portable slope glider.  I would appreciate any pointers to slope
sites in the area, particularly around Morrison Colorado (near Red-Rocks
Park).

Thanks in advance,

Pat Chewning
Newsgroups: rec.models.rc
From: mhanafi@magnus.acs.ohio-state.edu (Mahmoud Hanafi)
Subject: Engine Data for .61 K&[CB
Organization: The Ohio State University
Date: Thu, 19 Nov 1992 22:04:37 GMT

I need some data on the K&B .61. I'll  take any kind of data.
Please Send email to mhanafi@magnus.acs.ohio-state.edu
thanks
Newsgroups: rec.models.rc
From: ch@eiaut2.tuwien.ac.at (Christian Kral)
Subject: problems with airbrakes, need a tip
Organization: University of Technology Vienna, AUSTRIA
Date: Mon, 23 Nov 1992 13:09:22 GMT

Hello out there,

who knows a good working thing with which I can get a large linear move
out of a normal servo?

My intentions are to change the way of powering the airbrakes, because
now it is necessary to adjust them before every launch. I want to remove
the old system wich works out of the fuselage with one servo and to
build in servos into both wings. Therefore I need the longitudinal move.
The real problem is that the wings are very thin and the mechanism has
to work proper without any need to be serviced.
The plane is of F3B kind and the airbrakes need 14mm from full-in to
full-out position. The longest servo lever I could use is 12mm (1 inch
is 25.4mm, => 14mm = 0.55", 12mm = 0.47")

Here is an up-down cut through one wing:


                                         -------------------
         This is the break in action ------>   |////////////
                                               |////////////        
     =======================================================  \
          +---|---------+          =========================  |
          |   |         |                   |                 |
          |   |         |                   |                 |
          |---o---      |                   |                  > wing
          |             |                   |                 |
          |             |                ===|                 |
          +-------------+                 ^ +---------------  | 
     ==========^==========================|=============^===  /
               |                          |             |
               |                          |             |
               |                          |          airbrake
  This is the (micro) servo               |
 with shown end- and middle-        This is the air brake lever
 position of the servo arm.         which has to be moved in and out
   The length of this arm           longitudinal.
 is limited by the thickness        The full move is more than the servo 
   of the wing.                     can do due to its too short arm.


Now think the end of the servo arm and the brake lever being connected
and you see the problem. The whole servo move is less than the brake
needs. On the other hand there isn't plenty of space to build something
complicated into the wing, also it has to be shock resistant!
The point I don't understand is that I cannot be the only guy with this
problem! Who has an appropriate solution for this?

Thanks in advance,

Christian.


-- 
Christian Kral . Dept. of Automation . University of Technology Vienna . 
Treitlstr. 3, 1040 Vienna . AUSTRIA . phone: ++43 1 58801 8188 . 
fax: ++43 1 563260 . email: ch@eiaut2.tuwien.ac.at                 
Newsgroups: rec.models.rc
From: griffith@acuson.com (Paul Griffiths)
Subject: Rocket Powered Gliders 
Organization: Acuson; Mountain View, California
Date: Mon, 16 Nov 1992 20:05:18 GMT


	Has anyone seen/heard/tried anything with regards to
the rocket powered gliders?!  The boxes seem to suggest rocket
assist takeoff to 1000 ft or so and hours of gliding enjoyment...
I have quite a few hours of thermal soaring and am sorta tempted
to give one a try, but something tells me I'd be getting way over
my head..(no pun intended) Any comments?!
			-Paul

Newsgroups: rec.models.rc
From: jpp@StarConn.com (John Pettitt)
Subject: Soaring Edge Software
Organization: Starnet-Public Access UNIX--Los Altos, CA  415-949-3133
Date: Sun, 22 Nov 1992 22:33:01 GMT


Well it's that time of year again and my father waould like some
software called `Soaring Edge' for Christmas.   It's available in the UK
(where he is) for UKL 45 (about $70).   I would like to know if anybody
has a US source for this software and a price. 

Also any other suggestions for software products that I should buy him
(He is into sailplanes and has a PC running Windows/DOS).

Please reply by mail as I am normally found on rec.aviation rather than
models.rc :-)
-- 
John Pettitt					jpp@starconn.com
Archer N81034					apple!starnet!jpp
Me, say that, never: It's a forged posting!	Fax:   +1 415 967 8682
						Voice: +1 415 967 UNIX
Xref: sparky rec.models.rc:4694 ne.forsale:5136
From: brs@cs.brown.edu (Brian Stormont)
Subject: Re: Gentle Lady building ???
Organization: Dept. of Computer Science, Brown University
Date: Sat, 21 Nov 1992 05:42:46 GMT


My first plane was the Gentle LAdy. I put in the suggested extra strength
in the wings. Being my first plane, it took tremendous abuse, and the wings 
were never an item to fail. (Even after smashing in a baseball field 
backstop) The one weak item I found was rudder - it tended to lack a good
connection to the plane, and needed to often be re-glued.

Over-all, I thought the plane was very durable, and a lot of fun.


-Brian
Organization: Penn State University
Date: Wed, 18 Nov 1992 23:36:06 EST
From: <N42@psuvm.psu.edu>
Newsgroups: rec.models.rc
Subject: Re: Another Fiberglassing Question....

Again, use wax paper on the outer surface. It will not only produce a smooth
surface but will help in holding down the cloth and give you the opportunity(sp
) to squish any excess epoxy out of the glass.  I define excess epoxy as any
amount of liquid that you can displace with a finger or roller>
Regards Scott Gregory
Newsgroups: rec.models.rc
From: mkfeil@bcrki9.bnr.ca (Max Feil)
Subject: Re: Boston area R/C car racing? (& R/C Flying)
Reply-To: mkfeil@bcrki9.bnr.ca (Max Feil)
Organization: Bell-Northern Research, Ottawa, Canada
Date: Tue, 17 Nov 92 16:59:38 GMT

In article <1992Nov17.013242.16395@europa.asd.contel.com>,
chapin@ssvax.gte.com (Barry Chapin) writes:
> Also, for the flyers out there:  I really enjoyed building the truck.
> Staying up till 3-4am some nights, having to work the next day.
> I would like to get into flying now, am want a real chalenge.  
> Preferably above a starter plane.  In reality, tell me if I'm in
> left field, I would love to build a helicopter, but have heard
> flying these beasts is out of control.  I was told when I bought
> the gas truck that it was advanced for a starter vehicle, but
> had no problems with it.  Is it totally of of reason to look
> into building a helicopter?  I have quite a basement / toolset /
> and mechanical design / physics background.  What are prices
> for heli kits?  I would also be interested in building it, and
> maybe selling it after its built, although I would enjoy a crack
> at flying (crashing?) it, but would not enjoy the expensive loss.

Building a helicopter kit isn't really that hard. The setup, trimming, and
flying aspects are much more challenging. In my opinion, you will get much
more out of flying the thing (with help) than just building it. (With
helicopters, it is usually more assembly than building, unlike non-ARF
airplanes.) I would also highly recommend a simulator. It can speed up
the time it takes to learn to hover dramatically. My friend could hover the
first flight with his heli since he spent a fair bit of time on his
Dave Brown simulator. Having fixed wing experience also helped him. When
I started I wanted to go with helicopters as well, but after seeing how
complicated they are decided to go fixed wing first. I've never looked
back - you can't match a precise 100 MPH low pass 2 feet above the runway
with the gear up.

> Are the majority of the pilots out there also REAL airplane/heli
> pilots? 

A number of R/C pilots have flown full size airplanes (I'd guess around 15-25%)
but they all say that models are just as hard or harder to fly. I haven't met
many full size helicopter pilots, so I'd guess the % is closer to 5%.

> How similar to a real helicopter doe the R/C fly (ie:
> are all the same flight controls present, or are the R/C's 
> greatly simplified. 

The R/C helicopters are suprisingly realistic and have all the same basic
flight controls: fore/aft & left/right cyclic pitch controls on main
rotor for pitch & roll, tail rotor pitch control for yaw, and throttle
mixed with collective main rotor pitch. Many model helicopters also can
perform great autorotation in case of engine failure, and thanks to superior
strength and thrust to weight ratios can also do wild aerobatics such as
inverted flight, and 540 degree stall turns.

Max
--
Max Feil  mkfeil@bnr.ca | Disclaimer:
Bell-Northern Research  |   What do I know? I'm just a Nerd on the Big Ranch.
P.O Box 3511 Station C, |
Ottawa, Ontario, Canada.| "Enrich The Soil, Not EveryBody's Goal" Peter Gabriel
Newsgroups: rec.models.rc
From: svoboda@rtsg.mot.com (David Svoboda)
Subject: Re: K&B Help Wanted! (Was Re: Radio Selection)
Organization: Motorola Inc., Cellular Infrastructure Group
Distribution: usa
Date: Thu, 19 Nov 1992 17:23:59 GMT

In article <10330@tetons.idaho.amdahl.com> rbs@sawtooth.idaho.amdahl.com (Bob Smith) writes:
|In article <Uf2Fp2K00iUyQ2dlcG@andrew.cmu.edu>, mm7q+@andrew.cmu.edu (Michael Oliver Muller) writes:
|> Hello-
|> 
|> (stuff about K&B vs. O.S., stuff about details of engine problems deleted)My 
|> 
|> >question is: How do I set this engine so that it both idles and
|> >                transitions to full throttle without quitting?
|> 
|> I have a Royal 40, and I have the exact same problem. Any suggestions on
|> fixing this problem would be GREATLY appreciated. (Short of buying the
|> seemingly superior O.S. engines :) )
|> Mike Muller
|
|One problem I had with the engine is that if the mixture is way off, it's hard
|to tell if it's too lean or too rich.  (Actually, it's not always easy to tell
|when it's close to the correct setting either!)  In that case, just close it
|way down 'til you're pretty sure it's to lean, then slowly open it 1/8 turn
|at a time until the engine will transition decently.  Once it transitions,
|re-set the high speed needle; then check the low speed again.  You might
|need to iterate a couple times between the two until both are set right.

I think you are talking about idle mixture here, right?

Another way to tell if an idle is too rich or lean is how it acts idling
over time.  That is, you bring it to idle, and wait, carefully listening
to the idle speed.  If the idle speeds up, slowly, until it dies, it's too
lean.  If it slows down and dies, it's rich.  It should come to idle, then
slow down from that point very slightly, and hang there indefinitely.  Then
when you transition to full throttle, you should see a bit of white smoke,
but no sputtering, then a perfect scream at full throttle.  Remember that
adjustments to the idle mixture can affect the high speed mixture, so check
the engine often at full throttle.  And be sure to warm the engine up before
trying to adjust anything.

If the idle is great, the high end is great, but it still bogs or dies in
the midrange, try to figure out if the midrange is just rich or lean (run
the engine at half throttle and momentarily pinch the fuel line--if lean,
the engine will slow down or die, if rich, the engine will speed up), or
the transition is bad.  A rich or lean midrange can be tank position, fuel
tubing routing or size.  If the problem is purely in transition, look for
the wrong plug temperature, or look for a leak or obstruction in the muffler
pressure overflow, or again, tank or fuel tubing problems.

One more thing.  Many people are talking about breaking in the engine on
the ground.  This is fine, but DON"T tie the airplane to the ground and just
run the engine for a long time.  Put the airplane on a picnic table, or on
the roof of your car, or something, to keep it from ingesting dirt.  Dirt
can wear out a new engine before it even gets broken in, especially a
ringed engine.

			Dave Svoboda, Palatine, IL
Newsgroups: rec.models.rc
From: brs@cs.brown.edu (Brian Stormont)
Subject: Re: Gentle Lady building ???
Organization: Dept. of Computer Science, Brown University
	<1992Nov15.201504.20065@bnr.ca>
Date: Sat, 21 Nov 1992 05:50:53 GMT


To echo someone else's response, you have to do something very screwey to
get a non-flying GL.  Having never built a plane before, I probably did
some pretty shoddy work, but it flew quite well, and took tons of abuse
(like trying to do a loop too close to the ground - not that a successful
loop with this kind of plane is graceful - it's more like a stall. Anyhow,
the worst the happened was the nose got buried in the grass, but the plane
remained intact.)

I found the GL a great plane to learn to fly with.

-brian
From: sringrose@galaxy.gov.bc.ca
Newsgroups: rec.models.rc
Subject: Re: Aileron/Elevator mixers?
Date: 17 Nov 92 16:24:12 -0800
Organization: BC Systems Corporation


>> planes, like Klingberg wings, have no elevators (no tail at all). Even fairly  

Boy is my face red! I've been flying a Klinberg (my second) and a Me Komet for
some time now.  I dismissed electronic mixing for wings many years ago
because my FGK mixes rudder/elavator on two sticks instead of one (geee.....
could one stick mixing be elevator/rudder?) and I have always found that
computerizing something makes it computer-unfriendly so have stayed away
from the new radio's (if they are as intuitive as this editor, I'll never
pick one up).  I am using Dubro mixers right now as I just can't do the
Swiss watchmaker trip on a sliding tray - it either slides but doesn't fit
the airplane or fits the airplane and doesn't slide. Anyway, forgive the
stupid question......

Scott Ringrose
Printing and Presentation Services
B.C. Systems Corp.
Internet:SRINGROS@BCSC02.GOV.BC.CA
Newsgroups: rec.models.rc
From: rcnixon@cbnewsb.cb.att.com (russell.nixon)
Subject: Various threads
Keywords: Epoxy, ST, Florida
Organization: AT&T
Date: Fri, 20 Nov 1992 16:43:14 GMT

Re: Thinning epoxy, anhydrous isopropanol can be purchased at the major chain
drug stores.  Being anhydrous, it contains no water! :^)  I just bought a pint
for shrinking the tissue on my first stick 'n tissue gummiband model, but it
is just the thing you want to thin epoxy.  Just don't use too much.  It seems
to me to increase the setting time also.  Dope thinner or lacquer thinner
can also be used.  I got a Sig Cabinaire kit to keep myself out of trouble
while staying here in Florida without the family.  I'm being relocated to
the Orlando area (YAY!!!) and the flying goes on year 'round.  I've never
built this kind of model and it has given me a real appreciation of the
FF folks.  I can't wait to trim and fly it, but I think it will spend most
of its time hanging over my desk.

    Super Tiger engines are great!  I've only got one, but I plan on buying 
more when the need and chance arise.  Mine is an S45 ABC and it is a torque
monster.  I bench ran it on a GP mount bolted to a 5"X5" piece of 1/4" ply.
The ply was held in a BIG bench vise on a really solid workbench and when I
rev'ed it, I swear I could see the ply bending.  The carbs are worth buying
and mounting on other brands of engines.  The carb has a restrictor in the 
throat and I'm afraid to remove it.  It (over)powers a GP PT-40 and has
never missed a beat.  It probably never goes above 3/4 throttle except at
take off.

Russ "who passed his check flight in August" Nixon
From: sbbrown@magnus.acs.ohio-state.edu (Stephen B. Brown)
Newsgroups: rec.models.rc
Subject: Re: Another Fiberglassing Question....
Date: 19 Nov 92 17:42:07 GMT
Article-I.D.: magnus.1992Nov19.174207.17446
Organization: The Ohio State University Radio Observatory

In article <1992Nov19.155543.547@news.columbia.edu> liggio@cunixf.cc.columbia.edu (Vincent J. Liggio) writes:
>... thinning the epoxy before applying it.  To do this mix
>about a 1:1 ratio of isopropyl alcohol with your epoxy...

Can you use drugstore-grade rubbing alcohol or do you need a
reagent grade isopropanol?  My intuition (not that it's worth
much) suggests that the 30% water in rubbing alcohol wouldn't
mix well with the epoxy.  Also, I'm curious whether ethanol
(i.e. denatured alcohol) would work also.
-- 
Steve Brown, N8HFI              sbbrown@magnus.acs.ohio-state.edu
Chief Engineer, The Ohio State University Radio Observatory ("Big Ear")
Newsgroups: rec.models.rc
From: etxjema@kk270.ericsson.se (ETX-TT-K Andersson Mikael)
Subject: Attacker 28 now airborn!
Organization: Ericsson
Distribution: rec
Date: Mon, 16 Nov 1992 07:56:07 GMT

Yes, at last I've tried my attacker 28 with an OS32fABC.

Saturday morning, 11 am. perfect conditions,
temperature 0 degrees celcius, cloudy but no wind. Pack the car, all equipment packed ? 25 minutes drive to the field. Still perfect conditions.
Put the plane together, check controls. Fill her up. Start the new engine. Break in the engine one tank. fill her up again, check idle and throttle response, seem to be ok.
Stop the engine and fill it up again. Now I'm at the point of no return.
Taxi out to the field, check the controls again, check the setting of the engine again.

Concentrate.

Full throttle and away she goes. After 10 metres she's airborne.
Need some elevator trim and rudder trim and then she's stable.
I fly around for a while and then tries a touch and go. The touch is ok but on the way up the engine stops and I succed with an emergency landing. No damage.
Fix the trim, and then up again. 

The roll rate is ok and the response of the elevator is also ok. I haven't tried any aerobatics yet. The engine seems to work fine. But the tank may be to small,
6-7 mins in the air on one tank. The only big problem is with the landing gear.
The landing gear is placed to close to the center of gravity. This means that the plane will stand on the nose very easy. This will be fixed until next weekend.

The problem this time of the year is that it's getting dark so early. After 3 a'clock pm there's just to dark for any flying. 


Mikael 
------




-----------------------------------------------------------
Mikael Andersson               Ericsson Telecom AB
-----------------------------------------------------------
Al Bundy: "Why go out for milk, when I have a cow at home ?"