And yet EVEN MORE B.O.T. Torture !!!

Yeah, you're probably right. I am gonna re-balance the prop and may install the camera in a small box, lightly packed with foam. Even though it's strapped on top of some foam pads, the rubber bands hold it down pretty tight, and I figure that transmits a lot of vibration to it.

We'll see...

Kim:

You've got me looking at BOT's now but the 117" span presents problems due to limited working/storage space.

Is their a smaller version available?

Kim wrote:Yeah, you're probably right. I am gonna re-balance the prop and may install the camera in a small box, lightly packed with foam. ...

Kim ....
You might consider bubble packs. I think you'll get less vibration than with a semi-solid medium like foam. You may also try mounting the camera near the center of mass --- I've seen stabs vibrate severly due to harmonics as the engine comes up thru the RPM range, similar to the tips of a tuning fork.

I really liked the video, especially the doo-dahs and the changes in wind noise.

andrew

SuperDave wrote:Kim:

You've got me looking at BOT's now but the 117" span presents problems due to limited working/storage space.

Is their a smaller version available?

Yeah, the 3 Meter version IS kinda handy at clearing off shelves and smacking innocent bystanders. I've got a 2-meter B.O.T. (the one in the Traveling Propeller video) that was an abused Swap-Meet Orphan, but I'm thinking it might have been a scratch project.

I did a quick Google of Dave Thornburg (the BOT's designer) and didn't come up with any current info...a little deeper search might turn something. I DO know that BOT's have been built in all sizes, down to micro hand-launch types, but don't know anything about kits that might have been made. You might try a deeper search using Dave Thornburg and Bird of Time to see what turns up.

I do have a plan for his purpose-built hand-launch glider called "Sun Bird"...that I could dig out for you, but it's much smaller and different-looking from the BOT.

I think they're the prettiest sailplanes flying, and also modified a Berkley "Sinbad" glider, giving it the Zaic-type wing of the BOT...call it "Sinbot".

Mr. Thornburg also authored a hilarious/education book called "The Old Buzzard Goes Soaring" that I think would entertain anyone from a fledgling to high-time Glider Driver.

andrew wrote:

Kim wrote:Yeah, you're probably right. I am gonna re-balance the prop and may install the camera in a small box, lightly packed with foam. ...

Kim ....
You might consider bubble packs. I think you'll get less vibration than with a semi-solid medium like foam. You may also try mounting the camera near the center of mass --- I've seen stabs vibrate severly due to harmonics as the engine comes up thru the RPM range, similar to the tips of a tuning fork.

I really liked the video, especially the doo-dahs and the changes in wind noise.

andrew

Thanks Andrew...I will !

The "Waves" in the video had me thinking harmonics...maybe a re-design of the boom/mount is in order too. There was much less "waviness" in the Traveling Propeller video, which used the same camera. Also, maybe a three-blade prop is in order....

Very nice , good stuff.

Kim:

Thank you for the research re: smaller BOT. I'll chase down Thornberg for futher information.

Have perfect place to fly a BOT here in central Washington state.

I like this design. Never had one but have a couple of friends that flew them. They look great flying as the Hobbie Hawk.

dankar04 wrote:I like this design. Never had one but have a couple of friends that flew them. They look great flying as the Hobbie Hawk.

Yeah...ANOTHER cool one !

There is a .010 size one with a 40" WS.
I believe it is called the "teedee bird".
I will see if I can find plans, I am sure I have them somewhere, I find them I have no proem sending them your way Dave.

There is a .010 size one with a 40" WS.
I believe it is called the "teedee bird".
I will see if I can find plans, I am sure I have them somewhere, I find them I have no proem sending them your way Dave.

In my ever-continuing quest to endanger my innocent little cameras, I rigged THIS thing and flew it late this afternoon (ANOTHER beautiful evening put to good use!).

The video is still crunching...any bets on how it turns out?

After my last beam/wing mounted system produced a video that would make a dolphin sea-sick from it's bouncing, I decided to replace the flimsy balsa beam with an aluminum arrow shaft (just another one of those things I have laying around). It turned out fairly well, and I'll crunch the video later today. I did manage to take some still frames from the footage though.

It can be reversed to video from behind or in front of the wing with only an installation or removal of nose ballast to keep the CG happy (DO NOT forget to remove the nose ballast when you mount it forward, lest you have a nearly flat climb and a VERY fast landing!!!!)

Now that I've thoroughly video-documented the near-by subdivision, I may try to take the BOT on the road to video local points of interest. Keep watching the NEWS for me and my BOT to be arrested by Homeland Security for suspicious behavior !
"What you in for, dude?"
"Taking pictures with a toy airplane."
"And they all moved away from me there on the "Group W" bench!" Kudos to Arlo Guthrie!

Area 51 he we come
I know its not local but hey you have flown long distance before right?

nitroairplane wrote:Area 51 he we come
I know its not local but hey you have flown long distance before right?

Yep...there's no Country like Cross-Country !!!!

We could take the Miata with the top down, and swap-up driving and flying !!!! Be cool to have the BOT shot down by an Apache...as long as I get some decent video !!!

Kim wrote:

nitroairplane wrote:Area 51 he we come
I know its not local but hey you have flown long distance before right?

Yep...there's no Country like Cross-Country !!!!

We could take the Miata with the top down, and swap-up driving and flying !!!! Be cool to have the BOT shot down by an Apache...as long as I get some decent video !!!

DO some FPV style stuff and have live relay so you keep the footage without actually needing to recover the camera.

All good stuff Kim keep it coming.
On your pod is there any kind of up or down thrust?

J

John Goddard wrote:All good stuff Kim keep it coming.
On your pod is there any kind of up or down thrust?

J

In designing the B.O.T.'s Power Pod, I utilized the highly technical W.A.G. methodology...finally settling on a T.L.A.R. set-up !

The pod ended up with some "Up" thrust, as most do, and there's not a whole lot of retrimming required after engine shut down.

It's really just an enlarged version of the one sold by Sig for their "Riser" Sailplane. The biggest change is setting it back on the wing to allow a video camera to strapped over the cockpit area if need be.

If the poor B.O.T. thought it was in for a career of thermal chasing when I bought it...it was sadly mistaken! Most of it's flights have asked it to pack some type of gadget aloft !

Maybe it's time to rig it up with a bomb hatch. You can release grain a handful at a time to feed the cattle.

Care to explain your acronyms? I am not that quick this morning.

cribbs74 wrote:Care to explain your acronyms? I am not that quick this morning.

Not to put words in Kim's mouth, but generally:

BOT --- Bird of Time
WAG --- Wild A$$ Guess and it's running mate SWAG --- Silly Wild A$$ Guess (sometimes substituted with simple, scientific or stupid)
TLAR --- That Looks About Right

With a little experience, I've found that TLAR sometimes works incredibly well.

cribbs74 wrote:Maybe it's time to rig it up with a bomb hatch. You can release grain a handful at a time to feed the cattle.

Care to explain your acronyms? I am not that quick this morning.

Nah...the cattle get harassed enough...haven't actually hit any yet...but scared the daylights out of an adolescent, who'd wandered up to the fence, only to have the 2 meter B.O.T. slide by a foot over his head as I tied to stretch a bad approach to my front-yard landing strip!

Man! I can't believe you've never heard of the lofted engineering terms:
W.A.G. Wild-A__-Guess
T.L.A.R. That Looks About Right
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

andrew wrote:

cribbs74 wrote:Care to explain your acronyms? I am not that quick this morning.

Not to put words in Kim's mouth, but generally:

BOT --- Bird of Time
WAG --- Wild A$$ Guess
TLAR --- That Looks About Right

See There?! Andrew Knows !!!!

I see, yes silly me. I know the terms. Given long enough I would have figured it out. It was early no coffee........