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        Build Log F-9F "Panther" Parkjet

#1 beanie Jan 15, 2009 09:04 PM

F-9F "Panther" Parkjet
1 Attachment(s)
along with 2 other concommitant builds, i decided to work on the F-9F Panther. after having biult the F-9J Cougar, it was only natural to mod the plans to get a panther as well. she is designed and built at 1/13th scale to match the rest of my recent fleet. she is built up using the bulkhead/skin method, primarily with FFF but a little 3mm depron was used here and there.

here are the stats:
Scale: 1/13th (to match up with my 130% MiG-23, 81% MiG-21, F-105D, F-9J Cougar, and F-100)
WS: 34 1/2"
L: 37"
WA: 270sqin
AUW: ??oz
WL: ??oz/sqft
Servos: 3 (aileron x2, elevator x1)
full flying stabs
Motor: Little Screamers Super Park Jet Motor
Prop: 6x4
Batt: 3s1p 2000mah-2600mah
Parts list: FFF, CF spar, hard wood motor mount, 0.055" paino wire, plastic radio antenna tubing, magnets (1/4" dia x 1/8" thickness), 3/16" dia alum tubing, CF tubing that fits inside the 3/16" alum tubing, 1/8" liteply and 1/32" lite ply, PETG if pulling your own canopy.

this bird is being built while building 2 others, so i'll be bouncing back and forth between birds. this is where the beta builders can help speed the process. i'm hoping that flyjumper will post comments and his build pics here when he gets the chance. after the plans are proven air-worthy, i'll eventually post the plans on this first post when available.

ok, here we go...


#2 corsair nut Jan 15, 2009 09:16 PM

dont do this to me ben! :O

#3 beanie Jan 15, 2009 09:23 PM

hey brent!!! how the heck you doin'? how's the baby boy? have you had much time to work on the Cougar conversion to edf? i'm sure this one will be easy to convert if the cougar has been successfully converted.

#4 beanie Jan 15, 2009 09:28 PM

4 Attachment(s)
starting on the wing, i tackled the ailerons first. they are cut free from the wing. then i added 1/4" balsa to strenghten them and to also give a better grip for the floppy disc hinges. after gluing them to their respective places (on the aileron LE and on the wing TE at the aileron location), i lay the pieces flat on the build table and lay a regular sharpened 6mm pencil on its side and run it along the balsa to mark the center line. this helps guide cutting holes for the hinges. i also use this line to sand the aileron LE to a sharp taper.
then, the slot for the CF tube spar is made and the CF spar is glued in place.

#5 FlyJumper Jan 15, 2009 09:41 PM

7 Attachment(s)
Here's my crack at it.
I think I'm building in a somewhat different order than you Ben. But it's coming along, slowly, but getting there. I hope I can get in a few more hours with it in these next weeks.
As of now I've got some basic parts cut out and most of the top bulkheads and skins. Some bulkheads are glued in already and the nose section is already skinned.
I have gotten a little more progress done since I last took photos, but will wait to post those.


#6 corsair nut Jan 15, 2009 09:48 PM

you guys are animals! :O

#7 Waltjg Jan 16, 2009 09:56 AM

OMan,,, another one!!! these guys are machines!!! hehehee... will be watching this too, can't wait to see more! and the plans! Build ON!!! walt

#8 beanie Jan 16, 2009 05:52 PM

8 Attachment(s)
i worked on getting the ailerons done next. nothing special here. very similar to my other designs. i like keeping things hidden, so i use the torque rod/tube setup. the first pic shows i've also tried wrapping the 0.055" piano wire in 1-2 layers of clear tape before theading into the antenna tubing. this takes away some of the 'give' in the tube, though resistance increases a little. nothing the little 9gm servos couldn't handle though.

first pic shows the parts that i typically use to setup the aileron control. in this particular model, i used 1/4" liteply parts to make the aileron control mechanism. in my other more recent builds, i've shifted over to brass tubing smushed flat and hole drilled through. J taught me that. i like that way better and its faster/easier than the liteply method. 2nd and third pics show how the liteply pieces hook up. 4th and 5th pics show the floppy disc hinges that i installed. i have found that hotglue cools too quickly for these hinges. so i like using elmer's glue instead. some have recommended perforating the hinge so that the glue has more grip. i wish i remembered to do that this time. 6th pic shows the individual aileron unit. then, a channel is grooved into the wing to set the torque tube. next pic shows the aileron unit in place. final pic shows both sides.

#9 beanie Jan 17, 2009 02:15 AM

7 Attachment(s)
on to one of my favorite parts of building. i hate working on the ailerons. i dunno why. its never as bad as i think it is, but its a roadblock. i always start on the wing, but it takes a great amount of energy to get myself to start a build even though the plans have been printed up and sitting there waiting for me to start. i've got 2 other plan in this state and 2 other planes already cut out, and in this state.

first, glue the forward planform to the wing. before doing so, i remove the film from wherever the bulkheads and skins plan to touch the planform. pain the rear, but gives a stronger glue joint in my mind.

the next few steps are one of my favorites. i dunno why. maybe its because you can finally start seeing a little of the skeleton of the bird coming to shape. maybe it's a holdover from my balsa days for the same reason. the bulkheads are just glued in place. i march straight down the length of the planform. oh, of note, to help alignment, i often times will place the final bulkheads into the fin and set the fin down on the planform to make sure the bulkheads are in the proper location. once those bulkheads are glued in place, i remove the fin. this way, you're not fighting a potential lining-up problem with the fin down the road.


#10 beanie Jan 17, 2009 09:19 AM

5 Attachment(s)
with the top bulkheads in place, next step is to skin her. i use the method of rolling described in my prior build threads. nothing new or different here. i tend to sand the
1st pic show the first skin in place. 2nd pic shows the 2nd skin in place. since this build, i have begun adding a little strip of 1/4" fff along the edge where the skin will meet. it gives more gripping space for the skin. adds minimal weight. i can't remember who taught me that. i wish i could remember to give proper credit.
before skinning further, i decided to begin installing the radio gear before she gets all closed up. i decided to install the aileron servos 'up-side-down' so that i could reach them via an access panel on the bottom... and hopefully preserve the contours of the upper fuse. the last 3 pics show the aileron setup. nothing different from my prior designs. when she is flipped over again, she won't sit flat because of the servos, so i manufactured a little jig to set her on. basically, its a couple layers of foam glued together with a center section cut out to fit the ailerons so they can hang down without hitting the table. this flat jig is important to make sure one doesn't introduce twist into the airframe when skinning. i made this mistake on my 2 big MiG-21's and they still need fixing because the elevator torque tube is at an off angle.

#11 FlyJumper Jan 17, 2009 02:12 PM

3 Attachment(s)
I too hate connecting the ailerons and linkages. I like to build and see progress like bulkheads and skinning. But the ailerons must be done. :rolleyes:

On this one I'm aiming for a light weight good performance panther. No fiberglass on this one, I might try a light weight covering film though. I did however use two aileron servos on the wings instead of what the plans call for. I'm doing this because I need easy access to the servo's. I always find myself tinkering with their positions, so I felt this would be a good idea. I think that is my only change from the plans.
Also added a cf rod down the wing.


#12 beanie Jan 17, 2009 03:05 PM

i don't think specified on the plans how many servos for the ailerons. if i specified 1, then my mistake. i almost always use 2 aileron servos for the reasons you mentioned. i think the last time i only used 1 aileron servo was in my 1/13th scale MiG-21 when i scaled down from 1/11th. the 1/13th came out pretty small and i wanted to save weight. i think the main difference is that you put your 2 aileron servos on the wings whereas i put mine in the fuse. i think either location will work fine but your location will be much easier to service. me, i'm taking a gamble and hoping that i won't have to service them! :)

#13 FlyJumper Jan 17, 2009 03:08 PM

Yeah, I meant two aileron servos mounted on the wings.


#14 i12flyrc Jan 17, 2009 10:22 PM

Looking good Beanie and Flyjumper. Would like to try this one probably after I get the F-100 done. Need more building space. . . maybe a second work bench . . .

#15 beanie Jan 18, 2009 08:55 AM

7 Attachment(s)
i say build as many work benches as can fit in your house... that way, you can do multiple simultaneous builds! of course, nothing ever gets finished (i'm a prime example of that), but at least you can move ahead on multiple fronts.

so, before more skinning is pursued, next step is to work on the tail. the reason for this is that i try to keep all the servos physically close together so that a single hatch can access them. so before proceeding with covering the next bay which would obscure the receiver, i worked on the tail.

this method is GGRN's method. great method. i try and use it whenever i can. rock solid. sure, it's a little bit more involved than a simple single torque tube, but i've found it to be much more reliable.

step-by-step play call:
-first get the 2 fin pieces and decide which sides will be the inner side. i usually choose the least amount of ink and dimples to be on the outside. i removed the film from the fins
-next, install the 1/4" LE balsa strip to add strength. given that the fin is actually made up of 2 FFF and also supported by 2x 3mm skins, it's debatable whether the balsa is really needed or not. i added just to be safe. if you're looking to save some weight, safe it here.
-next pic just shows the parts of the elevator mechanism. i think on the plans, i call them the stabiltor mechanism. i still don't know the terminology; but you get what i mean.
-ok, next place one side of the fin such that the inner portion is facing up. then put one of the stabilator/elevator box sides into the opening. push it all the way through so that it is flush with the bottom (outer side) of the fin. glue it in place.
-cut out a shallow channel to recieve the elevator control wire.
-next, install the elevator/stabilator mechanism spacer. also, cut a slot in that to allow the sheath for the elevator control wire to pass.
-then, install the elevator control wire sheath. i use antenna tubing for the sheath (at the LHS) and 0.055" piano wire. there is a little bit of play in there which is where the little bit of slop in the arrangement comes from. J gave me some recent good advice to check out the LHS train section for 'plastistruts' to find one with closer tolerances to the 0.055" wire. i haven't had a chance to do that yet, but its on my to-do list. thanks J... always a wealth of info. (oh i forgot to mention, leave the sheath long... we can cut it down to the right length later when there is a better idea of where the servo actually sits).
-once the sheath is in place, then the other side of the fin can be glued in place. for this step, i used 3M Super77.


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