HDTenEightyP/NetNews huggingface dataset:
From: fisher@kay.enet.dec.com (kay::fisher)
Newsgroups: rec.models.rc
Subject: Thermals don't travel at prevailing wind speed
Date: 28 Jul 92 05:17:18 GMT
Organization: Digital Equipment Corporation
X-Posted-Via: NEWS-NOTES gateway (a hack!)

>          <<< Note 3.4 by ::mkfeil@bcrki9 "mkfeil@bcrki9.bnr.ca ()" >>>
>                       -< Re: More R/C Gliding........ >-
>
>In article <1992Jul22.233354.6431@rtsg.mot.com>, svoboda@rtsg.mot.com
>(David Svoboda) writes:
>> forth across the region, always turning into the wind.  The thermal moves 
>> downwind, a little slower than the wind speed.
>
>Please explain. How can a thermal bubble move slower than the average
>speed of the surrounding air mass?

The same way bubbles get to the surface of a river.  If they only
went down stream they would never come up.  If they come up then
obviously they aren't going down stream as fast as the rest of the
river.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################
Newsgroups: rec.models.rc
From: rimbold@apollo.hp.com (Robert Rimbold)
Subject: Re: Anyone make the Nats?
Date: Wed, 29 Jul 1992 20:11:44 GMT
Organization: Hewlett-Packard Corporation, Chelmsford, MA


Well, I *almost* went! :-) I had to leave for a job out of the country on
the day before the Nats. That morning I was at our local field with my
roommate, Mike Mungavin, test-flying his Quickee 500 pylon plane.  You see,
he'd just finished covering it the night before and put the radio in that
morning. He had to leave for the drive to Westover in a couple of hours and
the Doddger/Nelson combination was working good.  In fact, it was working
great until the radio stopped responding. Wham! :-( Later on, we counted
the number of flights on his 250ma flight pack and figured he'd flown one
too many.

He took it in stride (well, after a while :-) and finished 15th with his
backup plane.

I know of three other people that lost their pylon planes during their
pre-race tuning that same morning. Maybe tuning the day before a race is
like saying "I think I'll take one more flight before I go home.."
     You're gonna crash. :-)



'Rob
-- 
---
Rob Rimbold, Hewlett Packard VAB Technical Consulting
Email: rimbold@apollo.hp.com
Work: (508) 436-4528
From: wolgamot@milton.u.washington.edu (Greg Wolgamot)
Newsgroups: rec.models.rc
Subject: Re: Looking for.......
Date: 31 Jul 92 16:57:15 GMT
Organization: University of Washington, Seattle


I'm interested in finding more about the Bluejacket brand of model ships.
Does anyone know about whether this company still exists?  I got the name
from a model ship building book, and the kits look to be of very high
quality.  If anyone knows where I can send for a catalog, I would greatly
appreciate it.  Thanks!
                                        -Greg
From: jlw@world.std.com (James L Walker)
Newsgroups: rec.models.rc
Subject: Changing crystals (was Re: Crystals AM & FM)
Date: 24 Jul 92 15:08:44 GMT
Article-I.D.: world.BrwFEL.GtH
Organization: The World Public Access UNIX, Brookline, MA

In article <1992Jul23.165042.19769@usceast.cs.scarolina.edu> hutto@smtc.engr.scarolina.edu writes:
>In article <1992Jul23.115921.4298@lmpsbbs.comm.mot.com>, bobwo@ecs.comm.mot.com (Bob Woodhouse) writes:
>>Hello,
>>
>>I have ofeten seen advertisements for pairs of radio crystals in R/C
>>magazines where crystals marketed for AM radios sell for about $10
>>a pair and those marketed for FM radios sell for about $20 a pair,
>>all in the same ad.  Maybe the crystals really are different, but I
>>really doubt it.  In all the time I have played with crystals, a
>>crystal was pretty much a crystal, and maybe something like closeness
>>of actual frequency to nominal frequency or stability over temperature
>>changes could be real differences among various crystals.  It seems
...
>
>    The reason you can't use AM and FM crystals interchangably is
>    that many modern FM receivers are dual conversion with a 1st
>    IF of 10.7MHz (maybe it's 9MHz, who cares).  Therefore an FM
>    dual-conversion receiver crystal will be on a different LO
>    frequency than an AM single-conversion (455KHz IF) receiver
>    crystal.  Boy, I can still talk that hardware talk after all
>    these years in the computer business.  Must be some brain
>    cells still alive after all :-)
>
...

All this radio stuff is pretty foreign to me, but I can say that when
I looked into changing the freq. on my radio I was told that dual
conversion recievers are tricky.  I was told that there are two
frequency ranges for dual-conversion reciever front ends.  The high
frequencies convert down to a standard frequency and the low
frequencies convert up to a standard frequency.  Basically if you pop
a ch. 40 crystal and replace it with a ch. 16 crystal in a
dual-conversion FM reciever you are asking for trouble.  Also, the
dual-conversion crystal is not the frequency it's marked with since it
is used to convert from the frequency it's marked with.

Hopefully the radio experts on this net are now outraged enough to
flame the heck out of me and give us the real story... :-)

-- Les Walker.
Newsgroups: rec.models.rc
From: svoboda@rtsg.mot.com (David Svoboda)
Subject: Re: 1991 Gold Sticker on R/C
Keywords: Conversion to narrow band, 1991 Standard
Organization: Motorola Inc., Cellular Infrastructure Group
Date: Mon, 27 Jul 1992 20:15:45 GMT

In article <1992Jul25.232528.249@amd.com> som@angelo.amd.com (Somnath Viswanath) writes:
|
|	I am just starting of in R/C and have an old TOWER Hobbies 
|	6 channel AM Radio. Most clubs require the Radio to have a 
|	1991 sticker (GOLD). Tower Hobbies apparently do not modify 
|	the set. 
|
|	Is there any where else I can get my set modified ?
|
|	Is it worth it ? Some of the new sets are approx. $130-$160.
|
|	Any thoughts ? 


Try 	Kraft Midwest, Inc.
		115 E. Main, Northville, MI  48167
		313/348-0085	FAX 313/348-4175

They will do service and sell parts for many brands, including
obscure ones.  Call them and discuss your problem.

		Dave Svoboda, Palatine, IL
From: jt34@prism.gatech.EDU (THOMPSON,JOHN C)
Newsgroups: rec.models.rc
Subject: Re: New kind of cover finish for R/C airplan.
Date: 30 Jul 92 12:21:41 GMT
Organization: Georgia Institute of Technology

This brings up an interesting question about coverings in general and how they
compare. Anyone want to post a comparison of all the available coverings for
general consumption? The duraplane is covered in something called durahide.
I don't know anything about this stuff but it sounds tough. You might try
contacting the ARF manufacturers directly.

Newsgroups: rec.models.rc
From: rusty@masc.rice.edu ( Robert Kelley)
Subject: Re: Hover achieved... with my Glider!
Organization: Dept. of Math. Sciences, Rice University
Distribution: na
Date: Wed, 22 Jul 1992 09:01:49 GMT

In article <1992Jul21.124330.26940@linus.mitre.org> m14494@mwvm.mitre.org (Mike White) writes:
>Was out flying my Goldberg Electra last night.  Getting braver, and tried 
>flying in something more than a flat calm.  The breeze was maybe 5 or 10 
>mph, and there was a little bit of ridge lift comming over the top of a 
>small rise.  With maybe 1/4 power, the Electra would just hover motionless 
>about 20 feet up, for a minute at a time!  What a hoot!
>
>I did have one nasty surprise: I'm using the Futaba 4NBLE radio, the one with the electronic speed controller built into the receiver.  It works great, but... the radio has a thermal cutout, and when you operaten at low power levels for a while, the regulator chips heat up, and the the protection circuits shut down the motor.  So, it was quitting about halfway through each flight;  I had to land, let the receiver cool off, then launch and run the rest of the battery charge.  Think I'm going to put in
>
>
>
>air scoops to keep the receiver cooler.
>
>
>
>************************
>* These are my opinions only.*
>************************


I would like to call the net's attention to the line beginning, "I did have
one nasty surprise, though."  This actually translates into about ten lines
of mostly uninformative gibberish.  Will whoever this person's sysadmin is
either compel it to mend its ways or remove it from the net?  RSK
From: skywalker@DINO.QCI.BIOCH.BCM.TMC.EDU (Timothy B. Reynolds)
Newsgroups: rec.models.rc
Subject: Re: Hamilton Hobbies
Date: 27 Jul 1992 13:34:18 GMT
Organization: X-Ray Crystallography / Howard Hughes Medical Institute

As one of the final customers I hate to see HH lock the doors but
it's understandable. At least John will still be on the net.

Thanks John !

tim
12
US-55

Newsgroups: rec.models.rc
From: bobwo@ecs.comm.mot.com (Bob Woodhouse)
Subject: Anderson Connectors
Organization: secure_comm
Distribution: usa
Date: Tue, 21 Jul 1992 17:49:09 GMT

Hello,

I will mention the following discovery for the consideration of those
who have always desired to own Sermos-like connectors, but who were
discouraged by the lack of color choice in the Sermos.  During a chance
visit to a local, yet huge (much, much huger than Radio Shack) electronics
parts store, I noticed a connector that looked like it might suffice for
R/C car purposes.  These connectors are made by Anderson Electrics and
had some name like Anderson Power Plugs or something like that.  They are
incredibly similar to Sermos connectors right down to the words molded
into the plastic (says something like Anderson Electrics).  The fact that
these Anderson connectors were only half the cost of Sermos' made me
suspicious of their quality, but I took the risk.  The Sermos-sized
Anderson connector is the "15/30" amp version.  There are scaled-up
versions of the connector for higher current draws;  these are not suitable
sizes for R/C.  The cool thing is that there are red, black, gray, white,
green, blue, orange, and perhaps other colors available.  I wonder
how many people will "do a double-take" when they see blue and orange
Sermos between my motor and ESC (actually, they were out of blue, so I got
gray, but blue would be the logical choice here).  I hope that this information
finds a use somewhere.

A Good Day,
Bob Woodhouse
Newsgroups: rec.models.rc
From: potter@watson.ibm.com (David Potter)
Subject: Re: Which Mechanical Retracts?
Date: Mon, 27 Jul 1992 20:47:25 GMT
Disclaimer: This posting represents the poster's views, not necessarily those of IBM
Organization: IBM T.J. Watson Research Center

In article <l71q77INNj1g@phakt.usc.edu> wiegley@phakt.usc.edu (Wigs) writes:
>
>What is all the hardware you need for pneumatic retracts?
>the retracts, I guess an air cylinder which you mentioned, and probably an
>activation mechanism to open/close the air valve.
>

At the last meeting of MAAW (our local club here in Westchester north of
NYC), a P40 with electric retracts was displayed.  The builder was
really happy with their performance, very scale.  They go up and come
down slowly, like the real thing.  They cost about $140, and run off the
battary already in the plane. I think they were made by KWI, but i can't
be sure.  If people really want to know more, i will have contact the
builder to ask questions.  I am new here, and i don't recall peoples
names. 

-- 
*                tuktusiuriagatigitqingnapin'ngitkiptin'nga, David Potter
From: bdm@druwa.ATT.COM (Brian Millham)
Newsgroups: rec.models.rc
Subject: Question about AMB system
Date: 23 Jul 92 17:22:02 GMT
Distribution: rec

Hi all,
	I am currently working on lap counting software.  I currently do
not support AMB, but I'm in the process of supporting it.  I spoke to
BoLink about getting some info on how to interface with their hardware,
and the response was, "You can't.  You have to use our program."
I don't think that it was a case of they won't tell me, I don't think that
they know themselfs.  I really don't want to call AMB, since I don't
speak Dutch :-)

	They did send me the info on how the RS232 interface works, so
I'm working on that now.  I'd really like to be able to interface with
the PC card also.  So far, I figured out that the card seems to be
at port address 0x1b0 - 0x1b3.  Unfortunately, I don't have a card
handy, and the one that I have access to is on an ancient IBM PC at
a track, so it will probably take a while via trial and error to figure
out the interface.

	Any suggestions?  Anyone in Holland reading this who could
contact AMB for me?  Thanks.
--
Brian Millham     Kitty, Ferrah, Dr. Pepper, Fletch, and Buddy
AT&T Bell Labs     ^     ^ ferrets    ^,        ^  cats    ^
Denver, Co.       Dragon's Lair, Kick Man, Sinistar, New World, High Speed
bdm@druwa.att.com  ^ laser disc       ^ video ^        ^ pinball ^
Newsgroups: rec.models.rc
Subject: Re: Thermals don't travel at prevailing wind speed
From: mken1@cs.aukuni.ac.nz (Mark Steven         Kendall        )
Date: Tue, 28 Jul 1992 22:03:53 GMT
Organization: Computer Science Dept. University of Auckland

In <1992Jul28.042041.926@nntpd.lkg.dec.com> fisher@kay.enet.dec.com (kay::fisher) writes:

>The same way bubbles get to the surface of a river.  If they only
>went down stream they would never come up.  If they come up then
>obviously they aren't going down stream as fast as the rest of the
>river.

Say what!
Haven't you heard that horizontal motion and vertical motion usually occur
independently, by your assumption if someone jumped out of a fast moving plane
(going horizontally) they would fall slower than someone who jumped out of
a stationary plane (ie stalled or equivalent).  I think NOT!!

As to why thermals don't travel at prevailing wind speed, in my experience they
generally do.  It may not be the same speed as the wind on the ground, but that
doesn't mean that the wind is the same up higher.  If the thermal is produced
by a cloud I presume that the wind loses some force when trying to move a cloud
and therefore the cloud travels slightly slower than the wind.  The other type
of thermal I have flown in doesn't go anywhere, normally caused by something on
the ground, the wind just affects where it is at a certain height.

Mark

------------------------------------------------------------------------------
The man who paddles with Jake             |  What was that ?? Raft ?? Whe....
the Snake, and fits 5 Kayaks              |
on a 3 door Mazda 323 !!                  |
------------------------------------------------------------------------------
From: gwp@dithots.Gwinnett.COM (George W. Pogue)
Newsgroups: rec.models.rc
Subject: For Sale: Dominator Dirt Oval Car
Date: 21 Jul 92 16:39:34 GMT
Organization: Deep In The Heart Of The South!



  For Sale:

  1 - Custom Works Dominator 4WD assembled with titanium parts including:
      LightSpeed 16S (30000-35000 rmp - Used as practice)
      Trinity Torkzilla 12S (47000 rmp - Raced only twice)
      LiteSink Heatsink on the motor mount (Cooooool is the word)
      Futaba Magnum AM FP-T2PD Digital Proportional System
      Crystal Sets for Channels 68, 76, 72, 70
      Team Losi Spurs: 96, 100, 108
      Team Losi Pinions: 18, 21, 24, 26, 30
      Tekin BC100L Peak Charger
      Victor Engineering IQ-Power-1 AC/DC Convertor (for Tekin BC100L)
      Novak 410-MXC Hi Frequency ESC with Regeneration Circuitry
      Four Sets of Matched - Pushed - Sanyo 7-cell 1700SCE Packs
          These sets are brand new and unused. Already soldered together.
      One Set of OffRoad Nobby Tires (For Very Bad Tracks)
      One Set of Green Foam Tires
      One Set of Hard Rubber Tires mounted on foam
      Two Semi-Identical Wedge Bodies painted in a hot pink and black 
          design. One is for show and one is for racing. The racing 
          body is race legal (the show is not... air dam is too high and
          too long).
      One Kyosho 7-Cell 8.4V and one Sanyo 7-cell 1700SCE practice packs
      Soldering Iron, extra bolts, nuts, two extra servos, all the
      lube and oil you would ever need.

      The car and two bodies are carried in an Extra Large Field Bag
      for ultimate protection and intimidation. To complete the package, all
      spare parts and components are carried in an extra large parts and
      accessory unit that is organized by levels of trays. 
      
      Price: $650 (+ $50 S/H) = $700 

      All offers will be considered!

      (404) 497-1674 home
      (704) 422-5792 work
      gwp@dithots.Gwinnett.COM

      bill

      


-----------------------------------------------------------------------------
 gwp@dithots.Gwinnett.COM (George W. Pogue)   Opinions and Comments are My Own!
 Deep In The Heart Of The South!     
 User Posts: 30    System Posts: 276    Waffle Version: 1.64
-----------------------------------------------------------------------------
Newsgroups: rec.models.rc
Subject: Indoor R/C
From: frank@evax2.engr.arizona.edu (Frank Manning)
Date: 22 Jul 92 18:13:52 MST
Reply-To: frank@evax2.engr.arizona.edu
Distribution: world,local
Organization: University of Arizona, College of Engineering and Mines, Tucson

Does anybody have experience flying indoor R/C? I'm curious about what wing
loadings would be reasonable for flying in a 55 x 25 meter (180 x 82 ft)
gym.

In one reference I've seen, they recommend an upper limit of 0.122 g/cm^2
(4 oz/ft^2) for wing loading. An IMS indoor contest in 1980 had an upper
limit of 0.0915 g/cm^2 (3 oz/ft^2).

Those limits seem a bit low to me. For the larger wing loading, a 30 degree
bank and coefficient of lift of 1.0 that gives you a turn radius of only 4
meters. Airspeed is 4.8 meters/sec. I would think you could get away with a
larger turn radius, although it's hard to say without actually trying it, I
guess.

Is that reasonable? Or is my coefficient of lift to optimistic? Any
comments?

I've tried to use a Microsoft flight simulator to get a feel for the
problem, but I haven't had much luck setting up the simulator properly.

Reference:  Poling, Mitch. _Building and Flying Electric Powered Model
Aircraft_, 1984, page 73.

-- Frank Manning                                -- "For every vision
-- College of Engineering and Mines             -- there's an equal and
-- Civil Engineering 100, University of Arizona -- opposite revision."
-- Tucson, AZ  85721    frank@evax2.arizona.edu --             -Unknown
Newsgroups: rec.models.rc
From: fsjinho@pike.lerc.nasa.gov (Jinho Lee)
Subject: Re: concept 10
Organization: NASA Lewis Research Center [Cleveland, Ohio]
Date: Mon, 27 Jul 1992 16:57:56 GMT

	I posted a note about a month ago saying that even Tim Lampe of
Great Plane could not keep the Concept 10 from exploding in mid-air!  This
is really a fragile helo and must be treated as such!  This problem isn't 
as common in electric power helos because they are really marginally powered!
to start with!  It must also be remembered that the outside guts cannot be
controlled by the pilots!  This can also contribute to the failure of the
head!
					Jinho
 

-- 

-----------------------------------------------------------------------------
Jinho Lee			|     phone: 216-433-4000
NASA Lewis Research Center     	|    
Cleveland, Ohio  44135         	|     email: fsjinho@pike.lerc.nasa.gov 
-----------------------------------------------------------------------------
From: johnson@nrtc.northrop.com (Greg Johnson)
Newsgroups: rec.models.rc
Subject: slope soaring helicopters (was Re: Helicopters....)
Date: 27 Jul 92 22:20:52 GMT
Reply-To: johnson@nrtc.northrop.com (Greg Johnson)

Rob Weinberg writes:

> Would it be theoretically possible to have a non-powered slope-sailing
> helicopter? After all, real-life one-man gyrocopters are powered by a
> forward-pulling propeller, with the main rotor unpowered but just generating
> lift due to the air-stream moving over it and spinning it . . .

There is a fantastic slope soaring site named Bluff Cove on the Palos Verdes
peninsula in Southern California near where I live.  Bluff Cove is a
naturally formed bowl overlooking the beach.  Standing on the edge of the
bowl, you can look down a 200- to 300-foot cliff to the ocean below.
Stiff sea breezes get trapped in the bowl, and a Venturi effect accelerates
the wind and re-directs it straight up.  Truly awesome soaring.

People fly (unpowered) models of F-20's, P-51's, etc.  They go back and forth
in a sort of U-shaped pattern, exchanging altitude for speed back and
forth.  At the bottom of the U, the airplanes scream past the fliers at eye
level.  On either side, they slingshot some 150 feet up in the air.  At the
top, they do graceful hammerheads and do it the other way.

It seems you could fly a brick at Bluff Cove.

Anyway, back to your question, I've heard that someone used to auto-rotate
his R/C helicopter and glide it at Bluff Cove.  The story goes that he would
take the engine out of his helicopter.  He would get the blades spinning
by hand, and hold the heli over the edge.  The up-rushing air would
get the blades spinning fast enough to support the helicopter in autorotation.
He would then let the thing go, and autorotate back and forth along the
lip of the bowl.

A Bluff Cove local who claims to have seen this said that the guy usually
ended up crashing the helicopter.  (This tended to lend veracity to the
story in my mind.)  Either the heli would descend below the lip and he
couldn't recover the altitude, or he would semi-crash land the thing at the
end of the flight.

An autorotating helicopter can achieve a glide ratio of about 3 or 4 to 1.
I've done numerous auto's with my Shuttle, and by varying pitch and
forward airspeed you can get the thing to descend amazingly slowly.  So,
I think it would be physically possible to `slope soar' a helicopter at
a place like Bluff.

The thing that makes me somewhat skeptical about the above story is the
described starting/launching technique.  I think it would be better to go
ahead and start the engine, fly out over the edge, gain a little altitude,
and then hit throttle hold and see how it goes.  Then when you're done, or
if you get in trouble, turn throttle hold off and land the thing.

(To try something like this, it would doubtless be necessary to coordinate
with the local R/C soaring club, get temporary exemptions from the town
council, and who knows what else.  However, to try something like this and
get video footage of it would in my opinion be `way cool,' and worth the
hassle.)

Greg Johnson
johnson@nrtc.northrop.com
Newsgroups: rec.models.rc
From: mkfeil@bcrki9.bnr.ca ()
Subject: Re: More R/C Gliding........
Reply-To: mkfeil@bcrki9.bnr.ca ()
Organization: Bell-Northern Research, Ottawa, Canada
Date: Thu, 23 Jul 1992 22:13:08 GMT

In article <1992Jul22.233354.6431@rtsg.mot.com>, svoboda@rtsg.mot.com
(David Svoboda) writes:
> forth across the region, always turning into the wind.  The thermal moves 
> downwind, a little slower than the wind speed.

Please explain. How can a thermal bubble move slower than the average
speed of the surrounding air mass?

See ya!
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.|
Newsgroups: rec.models.rc
From: ntaib@silver.ucs.indiana.edu (Iskandar Taib)
Subject: Re: Which Mechanical Retracts?
Organization: Indiana University
Date: Thu, 30 Jul 1992 17:05:06 GMT

In article <1992Jul27.204725.19323@watson.ibm.com> potter@watson.ibm.com (David Potter) writes:
>In article <l71q77INNj1g@phakt.usc.edu> wiegley@phakt.usc.edu (Wigs) writes:
>>
>>What is all the hardware you need for pneumatic retracts?
>>the retracts, I guess an air cylinder which you mentioned, and probably an
>>activation mechanism to open/close the air valve.
>>
>
>At the last meeting of MAAW (our local club here in Westchester north of
>NYC), a P40 with electric retracts was displayed.  The builder was
>really happy with their performance, very scale.  They go up and come
>down slowly, like the real thing. 


Hmmmm...

I've heard one can do the same thing with pneumatics by using a 
restrictor in the line, eg. a crimped tube. 

Also reminds me. Late august will bring the world Scale champs
to Muncie. Yaay!






-- 
-------------------------------------------------------------------------------
Iskandar Taib                          | The only thing worse than Peach ala
Internet: NTAIB@SILVER.UCS.INDIANA.EDU |    Frog is Frog ala Peach
Bitnet:   NTAIB@IUBACS                 !
Xref: sparky rec.models.rc:3022 sci.electronics:13414