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Jun 03, 2018, 06:19 PM
Jer. 29:11
jeffsch's Avatar
Thank you! The fear of possibly undercontrolling and the actual fear when overcontrolling a new model is most stressful.
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Jun 04, 2018, 11:27 PM
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Dave--Jeff just turned me on to this thread. I'm one of his groupies from the club build. I just shared with him a template for doing a scale dihedral, and he said, "Come on over!", so I'll share the info here, in case anyone wants to do a scale dihedral wing. Dick's design has a dihedral of about 1.4 degrees. The full-scale bird has a 4 degree dihedral as measured through the center of the wing. I decided to go with the scale dihedral, so I cooked up a template in Photoshop that can be printed out and traced around on 1/8" plywood. The wing cores that Jeff made in his kits are cut from 18" X 2" blocks of Dow blue extruded polystyrene (Styrofoam). To set the blocks up to get the root dihedral angle after they're wire-cut with the cores inside, measure in 1" from the outer end, and prop that spot up 1-3/16" to get the 4 degree angle. Place two verticals flush with the bottom of the root end, and on both sides of the foam block, and sand or hot-wire cut the angle into the foam, back to the verticals. The wing joiner template was designed around the cores themselves, separate from their husks. Afterward, I realized that the husks get included in the process, so the wing joiner may need to be cut off about 1/16" at both ends.
Jun 05, 2018, 11:47 AM
Registered User

washout?


I'm getting ready to cut the wing cores for the Panther out of 2" Blue Foam: Question do the original cores have any washout cut into them? I'm thinking that a 1/4 -3/8" washout wouldn't be a bad thing. Thoughts ??????
Jun 05, 2018, 01:46 PM
Registered User
Oarlock--the original doesn't have any washout. There's very little taper from the root to the tip. However, hot wire cutting foam is the easiest way to induce washout in a wing, and washout certainly can't hurt, so if that's what you like, then go for it.
Jun 09, 2018, 01:46 PM
Jer. 29:11
jeffsch's Avatar
Took my Panther out for its first flights yesterday morning, and all went well.

I balanced the model at the wing spar (per plans). Since the battery is attached to one side of the fuselage, I added weight to the opposite wing tip until it balanced laterally.

The recommended control throws are a great starting point -- thanks Dsegal! The model wasn't overly pitch sensitive and had enough authority for stall testing and a smooth landing.

With the FMS 64mm 3S 11 blade EDF, the model didn't have enough power to take off by sliding along the grass. Full power and a healthy underhand toss was enough for a nice take off. The model climbs smartly on full power and cruises on much less.

The model flies where you point it -- once trimmed, I didn't notice any self-correcting tendencies.

I tried a power-off stall at altitude; the model dropped its nose and recovered with the application of power and airspeed.

The model glides well. To land, I found I needed to keep just a touch of throttle and was able to grease it in.

I used 3S 2200mah batteries and kept flights to 3 minutes. At this long, the batteries are still above the voltage cutoff, so I may extend the flight timer.

This is turning out to be a good model. I'm really glad we picked it for our RC club's build. Thanks to Dick Sarpolus for the design.
Jun 09, 2018, 08:39 PM
Registered User
You go, Jeff! I'm (sort of) right behind you.
Jun 12, 2018, 04:29 PM
Registered User
By the way, the wing joiner I posted in #17 doesn't take into account the two spars. Just lay a spar on the paper printout, mark the lines at the top and bottom on both sides, and cut the paper template out at the corrected size. At least you have the correct dihedral angles.
Jun 12, 2018, 08:12 PM
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And here's a trick I realized I could do without cutting a new wing joiner. Just take the one in the kit, take my template to get the correct scale angle, and mark it on the original joiner, about 1/3rd of the way down. Cut that out, and switch it around to the bottom, and glue it in place. Voila!
Jun 12, 2018, 08:13 PM
Registered User

Successful Maiden, but no pics


Maidened my Panther tonight. Wind was 15 - 20 from the North, so I had one of the Old Hands have the Xmttr. I fitted it out with a old Detrum 70 mm and a 2200/3S. Flew out my hand at about 2/3 throttle. About two clicks of UP trim and it flew on rails. Loops, rolls and stalls were no problem for Don. He flopped it down on the grass without a problem. Postflight: the Battery was barely warm after 3 1/2 minutes and showed 41% when I charged it. I'm stoked now and when the wind goes down I'll get my turn on the sticks
Jun 12, 2018, 08:19 PM
Jer. 29:11
jeffsch's Avatar
Looking good Jay. (Your resistor is a hoot!)

Congrats on the maiden Oarlock! Sounds like a 70mm EDF is just the ticket.
Jun 12, 2018, 10:12 PM
Registered User
Way to go on the maiden, Oarlock! Did you put washout in the wing? I'm also using a 70mm fan, so I'm expecting extra va-va-voom!

Hi Jeff! Glad you got a kick out of the resistor. Really, doesn't it remind you of something Leonardo Da Vinci would have come up with? Actually, that's what I call it, not what Harry Higley called it.
Jun 13, 2018, 09:34 PM
Registered User
Washout: Well, I laid everything out thinking that 1/4" W/O would suffice, attached the patterns to cores, cut them then realized that I had used the CL on both ends of the cores. So, no washout on this wing, but it flew well. I will get my poop in a group and remember the W/O on my next wing. My next Panther will not look quite as crude as the current one does.
Jun 13, 2018, 11:16 PM
Registered User
So the "crude" explains why no pictures? Seriously, I have no room to talk. This build is making me tired, and I thought it was going to be easy. And you're going to do another one? You're the man, Oarlock! Do the washout, and see if there's an improvement in flying. It would have to be outstanding, as it sounds like your "on rails" maiden was quite spectacular! And in 20 mph winds to boot.
Jun 14, 2018, 08:19 AM
Registered User
I guess that "crude" is a relative term. I just don't like all the leads and wires hanging out in the breeze. I am planning on cutting new cores and sheeting them and maybe extend the 1/32 ply a little further aft as the tail feathers seem to be a little floppy. I am thinking that a 4S battery pack might make this thing a screamer.


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