HDTenEightyP/NetNews huggingface dataset:
From: cwatters@acorn.co.uk (Colin Watters)
Newsgroups: rec.models.rc
Subject: Help with release agents needed
Date: 25 Jan 93 18:09:06 GMT
Organization: Acorn Computers Ltd, Cambridge, England


Can anyone talk to me about release agents?

I have made a polyester mould that came off its wooden plug very
easily however I can't seem to stop epoxy mouldings sticking to
the polyester mould very badly (I trashed one part of the mould 
at the first attempt!).

I have tried:

1/. Bees Wax rubbed on and polished off - six "coats"!

2/. A silicon spray used to lubricate windsurfer dagger boards.
    (Yes I know about painting problems later with silicon).

Both looked OK before lay up (nice shine) but in both cases the 
epoxy stuck to the polyester mould better than it did to the kevlar
cloth!

When applying wax should it be left to form a kind of solid cost
or polished off like on car bodywork? I find most of it seems to
comes off as a white powder when I polish it even gently. Should 
the mould have the shine taken off first before starting with the
wax? Mine has a high gloss finish.

Ta

Colin





 ---------------------------------------------------------------------------
|            _          | Email: cwatters@acorn.co.uk (Colin Watters)       |
|    _      \ \         |                                                   |
|   | \______\_\_____   |---------------------------------------------------|
|   |-________--_____\  |                                                   |
|            / /        | Do it by remote control !                         |
|           /_/         |                                                   |
 ---------------------------------------------------------------------------
Newsgroups: rec.models.rc
From: cwc51@cas.org (Charles W. Collins)
Subject: COX 0.49 R/C Bee for TRADE
Organization: Chemical Abstracts Services
Date: Thu, 21 Jan 1993 13:05:23 GMT


I would like to trade (and cover the price difference if necessary) a COX 0.49
R/C Bee for an 0.09 or 0.10 R/C model.  The COX is still in the box and has
never been used.  My wife bought the engine to go with a plane that she
purchased for me.  John Moonan from Groton, MA has flown this model plane and
has recommended the move to the larger engine.

Thanks!

Chuck 
 
-------------------------------------------------------------------------------
Charles W. Collins       |  Chemical Abstracts Services  | E-mail address
3419 Cheshire Rd.        |  2540 Olentangy River Road    | cwc51@cas.org
Delaware, Ohio   43015   |  Columbus, Ohio  43202        |
(614) 548-5052           |  (614) 447-3838 ext. 2517     | USA
From: dbraun@cad636.intel.com (Doug Braun )
Newsgroups: rec.models.rc
Subject: Re: Battery Discharge Circuit For Tx/Rx
Date: 22 Jan 93 17:56:28 GMT
Organization: Intel Design Technology

In article <1993Jan22.025009.20035@a.cs.okstate.edu>, worley@a.cs.okstate.edu (WORLEY LAWRENCE JA) writes:

|> I like to discharge 550mA nicads at their rated current, or about 1/2Amp.
|> This prevents any damage that can occur at higher discharge rates.  The way
|> to calculate the size of your power resistor is as follows:
|> Resistor-value(in ohms) = Pack-voltage/Max.current(in Amperes).  So, if you
|> have a 4-cell pack, it's "resting" voltage is around 4.8-5.5 volts, depending
|> on its state of charge.  Plug in R=5/.5 (500mA=.5A), you get 10 ohms.  So, 
|> my discharger for the receiver pack uses a 10 Ohm power resistor.  You must
|> also make sure your power resistor can dissipate sufficient heat.  This is
|> calculated as: power-needed = Pack-voltage x discharge-current.  In this
|> case, 5volts x .5amps = 2.5 Watts.  Now, if you used a 2.5 watt power resistor,
|> (assuming there was such a thing), it would get REAL hot.  I use the equivelant
|> of a 60 watt, 10-ohm resistor, to keep the generated down.  This is accomplishedby using four 10-ohm resistors, wiring two sets of two in parallel, and then
|> those two parallel sets in series.  By wiring two 10-ohm resistors in
|> parallel, you get a 5-ohm resistor that can dissipate twice as much power.
|> Wire two of these in series and you get a 10-ohm resistor that can handle
|> four times the power of just one of these resistors.  I use 15-watt 10-ohm
|> resistors.

One point that was overlooked here is that the Zener diode will dissipate most
of the power, not the resistors.  Also you have to subtract the Zener voltage from the
bettery voltage to properly calculate the resistor value.  As a result you really
want about a 4 ohm resistor.  The resistor will dissipate only one watt, no big deal.
But you will need a two-watt zener diode, which might be a little bigger that
what Radio Shack, etc. carries.   You could use a couple of smaller zener diodes in series.

-- 

"There is no human problem which could not be solved if
 people would simply do as I advise." -- Gore Vidal


 Doug Braun                         Intel Design Technology
                                    408 765-4279

 dbraun@scdt.intel.com

                 / decwrl \
                 | hplabs |
 or maybe:      -| oliveb |- !intelca!mipos3!cadev6!dbraun
                 | amd    |
                 \ qantel /
Newsgroups: rec.models.rc
From: fisher@kay.enet.dec.com (kay::fisher)
Subject: re:tachs
Organization: Digital Equipment Corporation
Date: Thu, 21 Jan 1993 05:17:19 GMT
X-Posted-Via: NEWS-NOTES gateway (a hack!)



: I am at the point of ordering my tach. The two possibilities are the 
: Royal analog tach from America Hobby Center and the Tower Hobbies digi-
: tal tach. They both cost around $30-35. 
: 
: Has anyone used either of these, and which shopuld I buy? Is either 
: one really something to avoid? I'm turned off the Tower unit since it 
: is digital and I've heard the number tends to jump around due to RPM
: not being too constant. Also, its only accurate to the nearest 100 RPM.
: Or is the Ace kit the one to get? What do they go for and where do I 
: get one without having to pay list price?

I had the Tower tach for years.  My only complaint was that if you
forgot it on - then you had to spend a few bucks on a strange size
batteries and take it apart to replace them. 

But it always worked when I wanted it to.

But I sold it at auction because I got a fancier one.
One with NiCads and a neck strap.

I decided the right place for a tach is in your radio so
the Futaba 9VAP is what I use for power planes.  

At $640 it is an expensive Tach but they give you a 9 channel
transmitter and a PCM receiver free :-)

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################
From: torsten@rnivh.rni.sub.org (Torsten Leibold)
Newsgroups: rec.models.rc
Subject: Re: Dead battery?
Date: 26 Jan 93 10:45:17 GMT
Organization: Rhein-Neckar-Informationsdienst Viernheim

mm7q+@andrew.cmu.edu (Michael Oliver Muller) writes:

>    My question: The battery was very low, and so I plugged the unit and
>the transmitter battery pack into the factory supplied recharger
>overnight. Ofter about 24 hours of recharging, the voltage on the
>transmitter pack read at about 5.6 V, according to my Tower Hobbies
>voltmeter (top of the "green" scale). However, the transmitter pack read
>at only 9.5 V, which is rather low (the low end of the "green" scale).
>Also, the voltmeter on the transmitter read only about 80%. When the
>unit was new, the voltmeter read above 11 V, and the scale on the
>transmitter read above 100%.
>    Is my batter dead? Can I fix it? Or should I just get a new battery.
>Is this the expected life?(two years)?

Looks like your transmitter battery pack has a "dead" cell in it,
cause voltage should really be above 10V after recharging.
You should keep an eye on NiCad's during the winter or any time when
you're not using them. They need a frequent recharge to prevent a deep
discharge of one or more cell's. The best thing is to do a
discharge/recharge cycle every 4-8 weeks.

How to solve the problem: Open the battery pack so the contacts of the
cells are reachable and measure the voltage of each cell (at upper and
lower contact point). There should be one, which voltage is much below
1.2 volts. This is the defect cell ! Remove it and solder a new one
(try to get one of the exact type as the old one) in place. That's it.

You could use your airplane covering film to shrink around your
revived battery pack if you cannot get one of those shrinkable hoses.

Hope that helped !

Bye,
  Torsten.

-- 
  +-------------------------------------------------------------------------+
  |   Torsten Leibold, Konrad-Adenauer-Allee 105, 6806 Viernheim, Germany   |
  |  UUCP: torsten@rnivh.rni.sub.org    ..!unido!orfeo!rnihd!rnivh!torsten  |
  +-------------------------------------------------------------------------+
From: jmoonan@ccv1.bbn.com (John Moonan)
Newsgroups: rec.models.rc
Subject: Re: Servo signal structure
Date: 21 Jan 93 13:30:21
Organization: BBN Communications, Cambridge, MA
NNTP-Posting-Host: ccv1.bbn.com
To: mgwheele@crockett.ecn.purdue.edu


	The standard used by almost all the current generation of servos is
a TTL level signal that is zero normally with a positive going pulse that 
varies in width from 1.0 to 2.0 msec.  The pulse rep rate is 60 Hz and servo
neutral is 1.5 msec.  You can see this signal easily if you hook a scope up
to a servo output port on a receiver.  The servo leads are normally +5V (red),
gnd (black) and signal (white or some other color).  There were some brands of
radios that used the inverse of this, i.e., normally +5V with a negative going
pulse.  Don't know of any modern radios that still use this though.

	Its easy to synthesis the signal.  Easiest solution is a pair of one-
shots (74121) where the first runs preset at 60 pps and triggers the second
whose pulse width is contolled by a pot.  555s will also work but usually take
more circuitry.
--

					THANX, John Moonan
					SYSOP, 495th R/C Squadron
					Groton, MA
From: sbixby@cup.portal.com (Steven W Bixby)
Newsgroups: rec.models.rc
Subject: Re: Dead battery?
Date: Mon, 25 Jan 93 10:40:58 PST
Organization: The Portal System (TM)

>    My question: The battery was very low, and so I plugged the unit and
>the transmitter battery pack into the factory supplied recharger
>overnight. Ofter about 24 hours of recharging, the voltage on the
>transmitter pack read at about 5.6 V, according to my Tower Hobbies
>voltmeter (top of the "green" scale). However, the transmitter pack read
>at only 9.5 V, which is rather low (the low end of the "green" scale).
>Also, the voltmeter on the transmitter read only about 80%. When the
>unit was new, the voltmeter read above 11 V, and the scale on the
>transmitter read above 100%.
>    Is my batter dead? Can I fix it? Or should I just get a new battery.
>Is this the expected life?(two years)?

(Klaxons...!)  WARNING - BATTERY UNSTABLE, DO NOT FLY.  REPEAT... ....

:)

The battery may not be dead, but you might have to cycle it a few times
to restore it's working order.  Charge/discharge it 3-4 times, noting
how long it takes to discharge each time.  This is probably best done
with a cycler for best results, especially since leaving the transmitter
on for 2-3 hours at a time may heat up your RF deck more than you want.

But anyway, if you can determine that the pack comes up to normal standards,
then you should be safe to fly, but keep an eye on the pack over time,
it may not be stable.

Considering the price of another pack ($25?), you might be able to rescue
your current one; but considering the price of a replacement plane (???)
you might want to replace it. 

By the voltage numbers you stated, one cell is obviously not charging,
and may not come around, but it's worth the effort of trying.

  -swb-  (Steve Bixby, sbixby@cup.portal.com)
From: shiba@riffnique.csd.sgi.com (Rich Shiba)
Newsgroups: rec.models.rc
Subject: HydraDrive/Stealth
Date: 22 Jan 93 15:48:40 GMT
Organization: Silicon Graphics, Inc., Mountain View, CA

I was just thumbing through the latest issue of RC Car
Action and noticed someone has come out with an adapter
of some sort so that Losi's much-hyped Hyrda Drive will
work with an Associated Stealth tranny.

Anyone have opinions on Hydra Drive in general?  I'm not
at all familiar with it's implementation, and i'm assuming
it is some sort of traction control device (along the
lines of a slipper).  I'm interested in hearing how well
Hydra Drive works (as well as just *how* it works).  Even
better would be if anyone has actually mated one with a
Stealth...think this HydraDrive/Steath idea would be a 
good upgrade?  I race an RC10T.


		-Rich
Newsgroups: rec.models.rc
From: D2KAK@VM1.CC.UAKRON.EDU
Subject: Re: Help with release agents needed
Organization: The University of Akron
Date: Mon, 25 Jan 1993 19:01:02 GMT

In article <21177@acorn.co.uk>
cwatters@acorn.co.uk (Colin Watters) writes:
 
>
>
>Can anyone talk to me about release agents?
>
>I have made a polyester mould that came off its wooden plug very
>easily however I can't seem to stop epoxy mouldings sticking to
>the polyester mould very badly (I trashed one part of the mould
>at the first attempt!).
>
>I have tried:
>
 
The best release agent we've found is called PVA (Poly Vinyl Acetate?).
It is a greenish water soluble liquid available wherever fiberglass
supplies are sold. Another, very good, release agent is Maguires(sp)
Mold Release Wax. This is a high quality carnuba paste wax specially
formulated for pattern and mold making. It is available from most of
the fiberglass supply companys. If you need the address of one of the
companies, E-mail me and I'll get it for you tomorrow.
 
Kraig Krumm (AMA59622)
Canton, Ohio
Newsgroups: rec.models.rc
From: hutto@SMTC.engr.scarolina.edu (Brent Hutto)
Subject: Re: Wind Speed Gauge
Reply-To: hutto@smtc.engr.scarolina.edu
Organization: NIST Southeast Manufacturing Technology Center
Date: Fri, 22 Jan 93 00:12:17 GMT

In article <1jnaclINN9fi@male.EBay.Sun.COM>, frankfx@volkswagon.EBay.Sun.COM (Joe Fenech) writes:
>
>
>
>Who can tell me where to get a hand held wind speed
>detector. I have seen a few on the slopes, but have
>not been able to find out where they come from.
>
>Tx
>
>Joe 

    There is one in the Hobby Lobby catalog for around $16.00, I think.
    Look for their ad in one of the magazines to get their phone number
    or call information for Nashville, TN (they don't have a 1-800 type
    number).
-------------------------------
Brent Hutto
hutto@SMTC.engr.scarolina.edu
Newsgroups: rec.models.rc
From: fisher@kay.enet.dec.com (kay::fisher)
Subject: 1/12 Scale Combat plans
Organization: Digital Equipment Corporation
Date: Fri, 22 Jan 1993 05:17:18 GMT
X-Posted-Via: NEWS-NOTES gateway (a hack!)

I have been following the development of the 1/2 scale combat stuff.

This started with a thing called CRX scale in R/C Scale Modeler magazine.

Anyway around Christmas time a company in Florida (Progressive Miniature Aviation)
had a Zero - ALMOST ready for $55.  This is a full kit.  I was tempted but
shortly after that I saw another reference to Gus Morfis CRX scale stuff
so I finally broke down and called Gus.  Left a message and never got
an answer - so I wrote and asked if he had plans for a Zero and/or a P-47.

His reply was YES on the Zero and the P-47 was in progress and will be 
available in February.

Anyway - if your not familiar with the combat scale stuff ...

1/12 scale.
Engine size = .15 on models of planes with in-line engines.
              .20 on models of planes with radial engines.
No landing gear - hand launch and land on the belly.

One of the greatest crimes in scale is to fly WWII fighters with gear down.
They just never look right.  On the other hand - retracts are heavy and
constant maintenance problems and expensive and slow up building time and...

Anyway - Gus sent me a nice letter and 3 pages of photos specs and prices
for 1/2 scale plane.

Basically he has all versions of P-40,FW-190,F-8F Bearcat, BF-109,Hawker Typhoon,
Zero, Lavochkin LA-5/LA-7, Macchi C.202, Hawker Hurricane, Tony, Mustang, P-38, 
Spitfire and P-47.

Those who have been building these have consistently spend a little extra time on
paint and panel lines so they look great - reference old issues of R/C Scale Modeler
for pictures.

Anyway most plans are $8.50 which INCLUDES shipping except the FW-190, Tony, and
P-38 are $12.50.  The price increase on the FW-190 and Tony are obviously because
he has both the in-line engine and radial engine variants.

Anyway to order call or write

Gus Morfis
4709 Green Meadows Ave.
Torrance CA 90505-5507
        (310)378-5679

P.S.  I ordered my Zero plans the day I got his letter.

P.S.S.  You know I sure would love for this to catch on and see all kinds
        of these at the field.  I don't actually wanna have combat but I
        sure like the idea of hand launch WWII fighters.

P.S.S.S.  I sure would like to have a P-47 also.

P.S.S.S.S.  In fact I would love one of each.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

Newsgroups: rec.models.rc
From: D2KAK@VM1.CC.UAKRON.EDU
Subject: Re: Twist in the Wing
Organization: The University of Akron
Date: Mon, 25 Jan 1993 12:35:19 GMT

Unwarping a wing is probably my least favorite excercise in modeling but
occasionally you gotta do it so heres my procedure.
      Fill your bathtub with HOT water. Now take a brush and brush a little
water over the wing sheeting and wait a few minutes holding the wing in the
steam, coming off of the water. Now, apply a twist in the opposite direction
and block the wing on your workbench with the opposite twist in. After drying
overnight, remove the wing and inspect for strightness. You may have to do this
a few times to get it right. Small warps can be removed when covering, but
you must re-check the wing when you go to fly and then rewarp it. Also, the
wing will probably start to warp as the covering sags during the day.
     The straighter your wing is the better your plane will fly!
If anybody has a better way to do this please post it. I'm always open to
suggestions.
Newsgroups: rec.models.rc
From: bob@harrier.demon.co.uk (Bob day)
Subject: Re: Goldberg Ultimate Recommendations 
Distribution: world
Organization: Harrier Softnet Ltd
Reply-To: bob@harrier.demon.co.uk
X-Mailer: Simple NEWS 1.90 (ka9q DIS 1.19)
Date: Tue, 26 Jan 1993 20:25:03 +0000


My 2p worth...

When trying to decide what to power planes with I use 2 basic rules.

1. If it's an aerobatic scale model like a Pitts or the Ultimate work out
the hp/pound weight of the original, weigh your model and work out the 
required power. Planes like the pitts and ultimate are pretty small, yet 
have 200+++ hp on tap. It's actually pretty difficult to get the same
power to weight ratio in a model Pitts as the full size has so you're
generally looking at a pretty big engine.

Sure a 60 will fly an Ultimate,but it will be sadly lacking in the verticals.
i like my aerobatic planes to emulate the performance of the original, not 
just look like them


2.  Stick in the biggest engine that will fit, without totally blowing the 
wing loading. The left hand stick on the transmitter works the throttle and if 
you pull it backwards it will reduce the engine power. On the other hand you,
you have elevator and ailerons, no seriously you can't get more power out 
of a small engine that's already at full throttle...

A larger engine running at say half throttle will run quieter, use less fuel
and last longer than a small one running flat out all the time....

Anyway as regards the Ultimate, I have a 120 surpass, in mine, it weighs
around 8.5 lbs all up and it still won't do as many vertical rolls from 
take off as the real one is capable of... but it will do knife edge loops.


cheers
-- 
bob

Harrier Softnet Ltd    tel +44-734-731181              I'd rather be playing
Ivanhoe Rd             fax +44-734-734546              with my chopper
Finchampstead          email bob@harrier.demon.co.uk     O  / __________
Berkshire                                               -|-<>     /\======O
RG11 4QQ                                               _/ \_    __\/__
From: jmoonan@ccv1.bbn.com (John Moonan)
Newsgroups: rec.models.rc
Subject: Electric Power Recomendations
Date: 26 Jan 93 14:49:04 GMT
Organization: BBN Communications, Cambridge, MA
NNTP-Posting-Host: ccv1.bbn.com


	I'm a long time wet power flyer but this past summer I decided to build
an electric powered glider for a change of pace.  Ended up building a
Goldberg Electra.  Power is the stock motor with a Master Airscrew 2.5X1
gearbox and 12X8 folding prop.  Battery packs are 6 cell 1400 SCR, 7 cell 1400
SCR and 7 cell 1700 SCE.  It flys great and I've had a lot of fun with it for
the last 6 months.  Has a good climb on the 6 cell pack and very good climb on
the 7 cell packs.  Now the question:

	The motor seems to be drawing about 25-30 amps on a fresh charge. I say
this because it blew 20 amp fuses after about 30 seconds of run but has not
blown a 30 amp fuse yet.  Is this a reasonable current for this motor?  Would
I be better off going to a 3.0X1 gearbox or a different prop?  Am still using
the original motor (has about 40 flights on it) and wondering how much longer I
can expect it to last.  Any suggestions for replacement motor (other then
AstroFlight which are expensive) when the time comes?  Would some of the
modified motors that the car racers use work?  How many turns, etc.??
--

					THANX, John Moonan
					SYSOP, 495th R/C Squadron
					Groton, MA
Newsgroups: rec.models.rc
From: ntaib@silver.ucs.indiana.edu (Iskandar Taib)
Subject: Re: Tachometers 
Organization: Indiana University
Date: Mon, 25 Jan 1993 04:51:32 GMT

In article <LARRY.93Jan23223639@peak.psl.nmsu.edu> larry@peak.psl.nmsu.edu (Evil Engineer doin' it the Cowboy Way) writes:
>>>>>> On Wed, 20 Jan 1993 19:11:20 +0000, bob@harrier.demon.co.uk (Bob day) said:
>
>>> 
>>I believe by "analog tach" it means the readout is an analog scale -
>>needle and dial instead of LCD digits.  The pickup is still optical
>>so you don't have to touch the prop.
>
>Bob> Could well be..... Most of the analog one's I've seen have a
>Bob> rubber cup/wheel which you press onto the spinner...
>
>Bob>  cheers
>Bob>  bob
>
> Good lord, man! Over here in the Colonies we call them things electric
> starters! 8->

I've seen the contact tachometers in science catalogs but they're 
always in the $200-500 range. Not quite the hobby item methinks..
more like something you'd use for making sure one's record player 
is always at 33 1/3 rpm...



-- 
-------------------------------------------------------------------------------
Iskandar Taib                          | The only thing worse than Peach ala
Internet: NTAIB@SILVER.UCS.INDIANA.EDU |    Frog is Frog ala Peach
Bitnet:   NTAIB@IUBACS                 !
Newsgroups: rec.models.rc