Design & build of Pencam-class photo platform - Page 5

Karl B² · Aug 01, 2003, 12:53 PM

Thanks, Keith. First flights are about a week away.

Here's the wing construction. Span is now targeting just over 60". The flat center section is about 34", with 15" polyhedral tip panels. The CF tape spar caps are 48", and will extend unbroken across the dihedral breaks to halfway out the end panels.

I have the center panel complete save for the top sheeting, and the spar is every bit as strong as I hoped. It's just flexible enough that washout can be added via setting the Solite film.

Wing construction photos will follow.

Karl

Karl B² · Aug 01, 2003, 03:04 PM

Overview of most of the center section. The large bays will be diagonally braced with the leftover kevlar thread once the wing is complete.

I was going to add ailerons, but will keep the weight and complexity down for this version.

Karl B² · Aug 01, 2003, 03:06 PM

Rib/spar closeup.

RMihara · Aug 01, 2003, 04:20 PM

Hi Karl,

Your project is coming along nicely

Now hurry up and get it done so you could make a kit for all of us!

Roger

Karl B² · Aug 01, 2003, 06:23 PM

I'm hurrying!

I have to take a break every three days to shed my CA skin...

I'm finding out that it's just a little more complicated when the structural details have to be figgered out as I go.

Karl B² · Aug 03, 2003, 12:37 AM

Wing is nearly complete. After installing the last tip sheet & internal bracing, sanding will go quick, then covering.

Karl B² · Aug 03, 2003, 12:38 AM

quarter view:

Karl B² · Aug 03, 2003, 12:41 AM

With the top sheeting in place, there's almost no torsional flex. Fortunately I found this out on the center section, so I blocked up the tip panels for approx. 3/16" washout at the end.

Karl

Karl B² · Aug 05, 2003, 06:08 PM

Complete! Wing is held with a CF dowel in front, and a single socket head bolt in the rear. I'd like to have a 1/4 turn lock type of fastener, as I have to remove the wing to get at the battery, but this will do for now.

Karl B² · Aug 05, 2003, 06:15 PM

After John (Extremeone) had the issue with transparent covering tinting his images, I was concerned that my plan for yellow transp. would affect the images. I wrapped the covering around the wing, held it so that the sun shone on the lens through the covering, and took a bunch of test shots. Doesn't seem to be a problem, so I went ahead. (Besides, I didn't want to have to wait on an order for more covering.)

First flights might be tonight. With the battery centered on the plate, the CG is about 1/3 chord back from the LE. I'll shift it forward for the first flights. I've also gone from a 9x4.7 to an 8x6 APC-sf prop.

Not ready to be nervous, but I'm sure I will be by the time I start loading the car...

Karl

Trikster · Aug 06, 2003, 03:20 AM

That looks great! I hope all goes well and that you end up with quality pictures. If so, you will have lots of people clamering for plans/kit. GL on the maiden!

KeithLuneau · Aug 06, 2003, 05:37 AM

Lookin good as usual! I like that white wingtip for orientation. Should come in handy for those high altitude flights.

Ironsides · Aug 06, 2003, 07:13 AM

Karl:

Good looking bird.

David

Karl B² · Aug 06, 2003, 02:55 PM

Thanks guys. Batteries are charging as I type this, and the winds are light enough for a maiden this afternoon if the rain holds off.

I managed to reroute the ESC wiring so that the battery can be disconnected by removing the aft lower hatch. Still need the wing off to change batteries, but power on/off is pretty easy with just a magnetically secured hatch.

Plenty of ideas in mind for mods/next generation:

- reduce dihedral and add flaperons to center section for better confined landing areas
- enlarge fin/stab (the original area calculations were correct, but the wing grew from 380 to 565 sq. in. and the tailboom was shortened for mounting reasons.)
- simplified fuse design & construction methods. Building and designing around the crutch was handy, as I could place components and build the fuse around them. Unfortunately, the parts count is high and not worth the minor strength/weight improvements it yields.
- provisions for the PJS series of outrunner brushless. I'd really like to be able to shoot while the motor is running...
- size the fuse for the upcoming micro CCD cameras now becoming popular.

I doubt I'll ever kit this, but plans &/or a short kit (laser cut parts) might be an option.

Excuse me, my batteries are done and I have a plane to maiden. Knock wood!

Karl

FLYWINGFAN · Aug 06, 2003, 03:11 PM

Good Luck!
-Sam

Aug 01, 2003, 12:53 PM	#61
Karl B² half fast Join Date: Jan 2003 Location: Western Wisconsin, USA Posts: 4,254	Wing Section Thanks, Keith. First flights are about a week away. Here's the wing construction. Span is now targeting just over 60". The flat center section is about 34", with 15" polyhedral tip panels. The CF tape spar caps are 48", and will extend unbroken across the dihedral breaks to halfway out the end panels. I have the center panel complete save for the top sheeting, and the spar is every bit as strong as I hoped. It's just flexible enough that washout can be added via setting the Solite film. Wing construction photos will follow. Karl Attached Thumbnails 9.4 KB · Views: 342

Aug 01, 2003, 03:04 PM	#62
Karl B² half fast Join Date: Jan 2003 Location: Western Wisconsin, USA Posts: 4,254	Overview of most of the center section. The large bays will be diagonally braced with the leftover kevlar thread once the wing is complete. I was going to add ailerons, but will keep the weight and complexity down for this version. Attached Thumbnails 51.6 KB · Views: 294

Aug 01, 2003, 03:06 PM	#63
Karl B² half fast Join Date: Jan 2003 Location: Western Wisconsin, USA Posts: 4,254	Rib/spar closeup. Attached Thumbnails 33.7 KB · Views: 291

Aug 03, 2003, 12:37 AM	#66
Karl B² half fast Join Date: Jan 2003 Location: Western Wisconsin, USA Posts: 4,254	Wing is nearly complete. After installing the last tip sheet & internal bracing, sanding will go quick, then covering. Attached Thumbnails 44.1 KB · Views: 255

Aug 03, 2003, 12:38 AM	#67
Karl B² half fast Join Date: Jan 2003 Location: Western Wisconsin, USA Posts: 4,254	quarter view: Attached Thumbnails 46.3 KB · Views: 255

Aug 01, 2003, 04:20 PM	#64
RMihara Aerial Shutterbug Join Date: Nov 2001 Location: San Mateo, California, United States Posts: 4,912	Hi Karl, Your project is coming along nicely Now hurry up and get it done so you could make a kit for all of us! Roger

Aug 01, 2003, 06:23 PM	#65
Karl B² half fast Join Date: Jan 2003 Location: Western Wisconsin, USA Posts: 4,254	I'm hurrying! I have to take a break every three days to shed my CA skin... I'm finding out that it's just a little more complicated when the structural details have to be figgered out as I go.

Aug 03, 2003, 12:41 AM	#68
Karl B² half fast Join Date: Jan 2003 Location: Western Wisconsin, USA Posts: 4,254	last one tonight With the top sheeting in place, there's almost no torsional flex. Fortunately I found this out on the center section, so I blocked up the tip panels for approx. 3/16" washout at the end. Karl Attached Thumbnails 27.4 KB · Views: 254

Aug 05, 2003, 06:08 PM	#69
Karl B² half fast Join Date: Jan 2003 Location: Western Wisconsin, USA Posts: 4,254	Complete! Wing is held with a CF dowel in front, and a single socket head bolt in the rear. I'd like to have a 1/4 turn lock type of fastener, as I have to remove the wing to get at the battery, but this will do for now. Attached Thumbnails 37.0 KB · Views: 220

Aug 05, 2003, 06:15 PM	#70
Karl B² half fast Join Date: Jan 2003 Location: Western Wisconsin, USA Posts: 4,254	After John (Extremeone) had the issue with transparent covering tinting his images, I was concerned that my plan for yellow transp. would affect the images. I wrapped the covering around the wing, held it so that the sun shone on the lens through the covering, and took a bunch of test shots. Doesn't seem to be a problem, so I went ahead. (Besides, I didn't want to have to wait on an order for more covering.) First flights might be tonight. With the battery centered on the plate, the CG is about 1/3 chord back from the LE. I'll shift it forward for the first flights. I've also gone from a 9x4.7 to an 8x6 APC-sf prop. Not ready to be nervous, but I'm sure I will be by the time I start loading the car... Karl Attached Thumbnails 35.3 KB · Views: 230

Aug 06, 2003, 03:20 AM	#71
Trikster Zoom, zoom... Join Date: May 2003 Location: Roseville, CA (Sacramento area) Posts: 3,482	That looks great! I hope all goes well and that you end up with quality pictures. If so, you will have lots of people clamering for plans/kit. GL on the maiden!

Aug 06, 2003, 05:37 AM	#72
KeithLuneau Live FPV FTW?! ;) Join Date: Jan 2002 Location: Central Louisiana Posts: 2,387	Lookin good as usual! I like that white wingtip for orientation. Should come in handy for those high altitude flights.

Aug 06, 2003, 07:13 AM	#73
Ironsides Registered User Join Date: Jan 2003 Location: Toronto, Canada Posts: 1,282	Karl: Good looking bird. David

Aug 06, 2003, 02:55 PM	#74
Karl B² half fast Join Date: Jan 2003 Location: Western Wisconsin, USA Posts: 4,254	Thanks guys. Batteries are charging as I type this, and the winds are light enough for a maiden this afternoon if the rain holds off. I managed to reroute the ESC wiring so that the battery can be disconnected by removing the aft lower hatch. Still need the wing off to change batteries, but power on/off is pretty easy with just a magnetically secured hatch. Plenty of ideas in mind for mods/next generation: - reduce dihedral and add flaperons to center section for better confined landing areas - enlarge fin/stab (the original area calculations were correct, but the wing grew from 380 to 565 sq. in. and the tailboom was shortened for mounting reasons.) - simplified fuse design & construction methods. Building and designing around the crutch was handy, as I could place components and build the fuse around them. Unfortunately, the parts count is high and not worth the minor strength/weight improvements it yields. - provisions for the PJS series of outrunner brushless. I'd really like to be able to shoot while the motor is running... - size the fuse for the upcoming micro CCD cameras now becoming popular. I doubt I'll ever kit this, but plans &/or a short kit (laser cut parts) might be an option. Excuse me, my batteries are done and I have a plane to maiden. Knock wood! Karl

Aug 06, 2003, 03:11 PM	#75
FLYWINGFAN Registered User Join Date: Sep 2002 Location: Minneapolis MN Posts: 1,653	Good Luck! -Sam

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