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- Category: Archive 2012
- Hits: 822
- Lost Folding Seat
- Comment on proposed F1A rule change
- Wanted Sokol F1H Kits
- Jim Parker's LDA Story so far
Lost Folding Seat
Just now I discovered that I miss a small folding seat since the SOUTHWEST FAI CHALLENGE, BOULDER CITY, NEVADA. in October.
The seat is a "X" folding seat covered with striped blue nylon cloth. If somebody has found the seat, please can you bring it to Lost Hills during the big 3 WC happening in February, thank you in advance.
Pim Ruyter
Proposed F1A rules change comment
The proposed change to the current F1A rules regarding the use of remote actuation of nonreversible controls is not a good thing for the sport. The addition of remote DT has opened flying and practice fields that previously were not compatible with our sport. The current rule is clear and easy to understand. As the chairman of the AMA free flight rule making board, I have no direct voice in the FAI rule making process. My concern is often FAI rules find their way into the AMA rule book. The use of remote DT is one example. This system is working well and I know of no problems in its application to AMA competition.
What happens after the model has completed its max flight time is a topic for discussion. As long as the model flys free of any outside control influence during the competition phase of the flight, it is a free flying model. Once the max time has been met the flight has ended as far as the competition in concerned. The model can be brought down by means of a DT that is either controlled by an internal timer or external remote control. Once the max has been accomplished the competitor must arrange to retrieve the model in order to fly in the next round. Currently the competitor or their crew must chase the model down wind by means of motorcycles, autos, or on foot. Because the model is no longer being judged as a free flying aircraft what is wrong with flying it home by means of remote control or perhaps an internal GPS based system? Such operations will make smaller flying fields practicable and expensive models will less likely to be lost. This also reduces the need for chase motorcycles. We all know that the chase bike is a tool that can be dangerous and can also be an issue when discussing the use of potential flying sites with property owners.
I believe the entire free flight community will not be well served if this proposal is adapted.
Jerry Murphy
Chairman AMA Free Flight Contest Board
Wanted Sokol F1H kits
Wanted,
2 or 3 Sokol F1H kits
Does anyone have a Sokol F1h kit (s) that they have not built, I would like
to purchase the kit (s)
Robert Sifleet This email address is being protected from spambots. You need JavaScript enabled to view it.)
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Jim Parker's LDA story so far
From FB
Flew my M&K LDA-- very exciting and still in one piece. The airfoil is closer to Brian E's
(version ~2 years ago-- compared to ribs from Peter Alnutt). Flew with no turbulator. Any
suggestion? 60 to 70% back-lower surface? Flying tomorrow and will take chart tape (.004"
thk) and try this if I don't don't learn anything better.
Like · · Share · January 1 at 7:42am ·
Javier Abad Jim, I am using oracover on lower side and icarex upper with 1 tape turb
@ 50% , BE sections.Removed the tape I had before under the spar without any apparent efect.
January 1 at 12:50pm ·
Jim Parker Javier, Thanks for the data point. The wings are covered with MicroLight
(shrink plastic). Think I'll take clear lacquer spray can and try the Roland light spray to
rough up the upper surface.
January 1 at 1:21pm ·
Javier Abad Good idea. I bought one myself, may try it for the lower part.....when I
learn how to get not a smooth finish, would like to have some "drops" or dust spray.
January 1 at 1:25pm ·
Tony Mathews I have seen a new M&K LDA over the Holidays and it is covered in Icarex
"light" (rect pattern) with a upper surface turbulator at about 60 to 70% chord and about .4
mm high. I can post a photo on the LDA group if you want?
January 1 at 5:05pm
Jim Parker Tony-- saw the post of the M&K LDA wing. I asked M&K about covering-- they
stated the photos I received earlier were for a Japaneses modeler and wanted Icarex. I'm not
sure what they are using-- I have not heard from them for awhile. I believe they must have a
plastic covered model because they stated their initial (and limited) testing did not show
any large difference.
January 1 at 6:17pm ·
Tony Mathews Jim, one of our F1A flyers received a new M&K LDA over the holidays and
it is covered in Icarex. I think that I'd be tempted to spray a mylar covered wing with matte
clear acrylic like Roland does to add some surface roughness. Seems like most of these models
prefer a bit of surface texture.
January 1 at 6:37pm ·
Pierre Brun Very nice .Good color combo.Looking forward to Eloy
January 1 at 9:07pm · Like
Jim Parker - LDA chapter 2
Some info my LDA Model
Planform: Standard M&K Long
Wings: M&K LDA- received panels, I jointed and covered
Airfoil: M&K-- similar to BE section-- see photo
Covering: MicroLight (from Coverite) 9 grs per wing half
Stab: M&K LDA airfoil, no coordinates, mylar covering, "Medical flesh tape" turb at 70% on
upper
CG: 47.5% root (I have not calculated the MAC)
Timer: - Black Magic Extended VR
Incidence:
Glide: per M&K 3.6 deg. Per my measurement 2.3 deg but I don't have fancy Rene Sticks and
determining the airfoil entry point to determine the true cord is difficult.
Circle: started with +2 deg like my standard model but adj to near glide setting during first
trim session
Straight tow: 2.2 deg up from glide
OLA: 3.0 up from glide, I had 4.0 but reduced to 3.0
Launch: for .25 sec, 6 deg up from glide
Cruise: I have not measured- 2.5 sec
Bunt .5 sec, 17 deg (24.7 mm), down from glide (much more than standard M&K
Note: this is work in progress. Much more to learn-- my respect for Roland increased greatly
after my first training session! 2 "good" launches out of 20.
· January 1 at 5:35pm ·
Javier Abad Jim, your incidences are mesuared from bottom line, not true
chord.Correct?
January 2 at 1:00am ·
Jim Parker Javier-- my measurements were attempt to measure wing and stab true cord
line angle. Like I said- I estimated the LE entry point. Think I'll make a wing and stab
fixture to clamp on the wing and stab to make better estimate. In today's flying, I reduced
incidence one count (i have not measured it) which stopped the stall that would start with
slightest upset- like the slight roller of the LH south rolling hills.
January 2 at 7:28pm ·
Rene Limberger Jim: you wrote that you had 6deg pitch up over glide. if your glide is
2.3 + 6 = 8.3deg pitch up? What's your hook at?
January 3 at 2:46am ·
Javier Abad I doubt stab can reach top position before cruise comes in.......
January 3 at 2:49am ·
Jim Parker Rene-- opps, glide to pitch-up is 5.8 deg after yesterday's flying trim
change
Thermals, JIM
Jim Parker Javier,
I do think the stab mechanical-servo system is reacting this fast. Look at the photo
on my Face Book page. Looking at the aft bunt drum with the arm pivot as the reference point:
Straight tow : 3 o'clock
OLA: moves ccw to 9 o'clock ( just a bit more angle than straight tow, dis-engages
impulse hook lock-out)
At towline release, moves cw to 12 o'clock (top dead center, TDC, max stab up, 5.8
deg up from glide)
HiTech servo at 5v moves quickly. True, looking at the system work, there are no
visible stopping of the system-- ie looks like one continuous motion.
Do you use an impulse hook? The difference could be the 3 switch impulse with the OLA
I have seen the difference between the pitch-up timing between .25 sec (good straight
up nose) and .35 sec (model on the back) and .15 (nose too low).
Thermals, JIM
Javier Abad Jim,
Javier Abad you are right with your system the drum always pass through TDC :-) I
cannot use an impulse hook because the Aberlenc timer does not support this , so I have to
reverse drum movement after pitch up.
Javier Abad Have you mesuared hook position in respect to CG?
January 4 at 1:42am
Jim Parker Hook is at M&K's recommeded 12.8 mm. Last flight session I determined the
maximum straight tow stab angle-- model will stall / fall off to side on tow up if speed is
not kept-- ie can not softly tow it up like a conventional model. I dropped the stab from
this position for light breeze-- I have not flown is strong breeze yet.
Thermals, JIM
Jim Parker LDA Training session #3 LH Chapter 3
January 7 at 5:17pm ·
Jim Parker
Second LDA training session today. Lost Hills-10 am to 2:00pm zero to light breeze in the
morning, 2-3 m/sec in the afternoon. High over cast sky. Light thermal conditions. 52 to 61
deg F.
Reduced the OLA stab setting to just above straight tow position-- does not "Parachute-hold
me back- rip my arm off". Still using ~6 deg during line release- pitch-up for .25 seconds.
After working out launch settings, I added the flesh-medical tape (ie like M&K) turb at 70%.
Definitely improved stall recover but also slowed the launch down. Had to reduce cruise time
fro, 2.2 sec to 1.9 sec. Think I'll remove and try the thinner chart tape turb at 70%. Maybe
try the Lacquer dry spay too.
My altimeter is not working- Ken Bauer will help next week. Last flight in slightly positive
air was a "That's high".
· Share · January 2 at 7:13pm ·
Tony Mathews Sounds like you are getting there Jim. Jealous of the nice weather :-(
January 2 at 7:20pm ·
Jeff Ellington Did u notice anything different about the field?
January 2 at 7:24pm
Jim Parker Jeff- yes better Thanks for the shrubbery removal-- flew w/o gaiters and
the only a few seeds gathered.
January 2 at 7:37pm
Mike McKeever Good report Jim-won't have ours until MaxMen....have fun.
January 2 at 8:19pm ·
Jim Parker Javier A asked if I thought the the stab was really getting to the pitch-
up position for the my quoted .25 sec.
I do think the stab mechanical-servo system is reacting this fast. Look at the photo
on my Face Book page. Looking at the aft bunt drum with the arm pivot as the reference point:
Straight tow : 3 o'clock
OLA: moves ccw to 9 o'clock ( just a bit more angle than straight tow, dis-engages
impulse hook lock-out)
At towline release, moves cw to 12 o'clock (top dead center, TDC, max stab up, 5.8
deg up from glide)
HiTech servo at 5v moves quickly. True, looking at the system work, there are no
visible stopping of the system-- ie looks like one continuous motion.
Do you use an impulse hook? The difference could be the 3 switch impulse with the OLA
position and single direction rotation of my aft bunt system.
I have seen the difference between the pitch-up timing between .25 sec (good straight
up nose) and .35 sec (model on the back) and .15 (nose too low).
Thermals, JIM
Jim Parker Rene asked about my pitch-up angle of 2.2 deg + 6 deg. This is my error.
Total pitch after yesterday's trim is 5.8 deg-- still quite a bit-- seems to be in line line
with Chris E's comments.
January 3 at 7:41pm ·
Chris Edge Jim, yes your numbers are close to mine. I use between 0.33 and 0.34s of
pitch up time after release. I would like less (say 0.2s) but I suspect I need to move the
hook back to get this. I'm a bit nervous if I do this that I'll get to a position where the
model diverges on tow - not recommended at high speed. My solution so far is to use a very
tight circle turn which brings the model straight very easily. I prefer a bit less than vertical cruise to be honest, I think that way you get a better cuise and less critical bunt
- like Kimmo does. Much still to learn. To go back to an earlier point, I use Icarex top and
Orcacover bottom and use no upper turbulators (mind you, the glide is stlll a bit of an
unknown but seems stable). A view out there is that the rougher surface of Icarex helps
'turbulation' - of course, you do need to use the magic angle ................. CHE
January 4 at 1:54am
Jim Parker LDA chapter 4
LDA Training #3 Lost Hills- 8:30 Light breeze 55 deg F George B, Marty and Amy S, Jeff E
glide- rudder—after bunt, one count stab down and extra glide rudder for 3 second, then stab
to glide position then rudder to glide after another 6 sec
#1 good nose up, short of bunt—legs not warm yet?
#2 Replaced medical tape wing turb (.44mm tall) with chart tape .12 tall- slight over bunt—
warmer legs or less drag?
#3 Very close to last flight
#4 Removed Stab turb (M&K installed, 1mm wide, stretched- .40 tall) tow very unstable- after
several circle set-up decided to RDT on line
#5 added chart tape on stab (.12 mm tall) Tow much better but glide seemed “pitchy”
#6 No changes—glide "pitchy"
#7 Stacked a second chart tape on first stab turb, .26 mm tall—tow good, glide like the when
the medical tape was on stab
#8 no changes- more breeze, good launch- still over bunting—need to add back cruise time
Note- in earlier post I stated I reduced the cruise time from 2.25 sec to 1.85 sec after I
added the med tape wing turb—that was an error—looking at the settings, I had previously
reduced and had some good launched with the cruise at 2.05 sec. so the cruise time reduction
due to the medical tape wing turb was .2 sec—NOT .4 sec. I do think the medical tape is too
thick from my very limited test flights I have done.
#9 Windy- had trouble setting up the model- did two aborts and lost control—RDT to the
rescue—time to say Thanks to Ken B—the zero delay RDT is a definite needed piece of
equipment. If this LDA is leaving the line at 60 mph (88 ft/sec), if pointed down—its in the
ground in 2 secs! If I did not mention- my altimeter is not working so I don’t know—I thought
on the way home that this was OK—one less thing to distract me during this learning phase.
Put the LDA away and flew a conventional short model to get some windy practice in. Next
weekend is the Eloy AZ contest. Ken has loaner Altimeter for me to use so we’ll see.
· about an hour ago ·
Chris Edge Very interesting report - much appreciated. I too use two layers of chart
tape OR one layer of medical tape on my tails. This came from Victor's original 0.3mm thread
turb and I just am too lasy to dope on thread, so I now use the tape. I have had no stability
problame like you report but of course the tail sections are different (I use BE8013).
Uncontrolled towing can also be caused by subtle stalling. CHE
Javier Abad I have 2 questions, when you talk about removing and changing original
M&K medical tape, you are talking about 70% position (original M&K for LDA stab)? and
How do you mesuare the hook position, from vertcal line down from CG or from 90
degrees to the true chord line?
Good luck on trimming.
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about an hour ago · Like
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Roger Morrell