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Old Nov 25, 2006, 06:03 AM
gpw
“There’s no place like Foam”
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Wow!!! That fin sure is invisible !!!! Way Way COOL !!!
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Old Nov 26, 2006, 01:10 AM
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Maryland, USA
Joined Mar 2006
896 Posts
Just a quick few words on that little hexTronick motor you guys are talking about. Considering the cheap goober I am I just received Saturday in the mail my 24gm motor ($12) along with a 9amp ESC ($11) and 3s1p 15c 620mAh/460mAh batteries ($13/$14)...all hexTronic items. Yeah, I bit the bullet and placed this order from UH against the recommendations of some. Merchandise seems to be fine and the order only took 5 working-days to make it to my mailbox!

Anyhow, ran a quick test on the motor using my trusty CSRC "budget" 3s 1250's and noted the following:
no-load - .7a
7x6.0RS - 8,100 - 7.5a = 13oz
8x4.3RS - 8,700 - 7.1a = 18oz
8x6.0RS - 7,200 - 8.4a = 15.2oz

Even with these relatively low amp draws the motor did get quite warm. The tube was too hot for me to keep a finger on while the bell remained just touchable (keep in mind that I'm a "wimp" when it comes to fingers and temperature threshold...gotta get an IR). These temps were noted after extended runs at about 80% power (6,200rpm).

Couple other things I might note. The little 9amp ESC did tend to get pretty warm also when not directly in the propwash. Must admit though for a bottom-of-the-barrel ESC it did run quite smooth from start-up to full-on while being decently small and lightweight. As for the batteries, they were delivered well balanced (less than .01v out on one cell of one pack). Testing them after a full charge showed neither battery had any difficulty keeping up with the baseline set by the CSRC battery although they did get a little warm. FWIW - I can push my CSRC batteries to their limit using a BP-8Y and they never even get warm...awesome batteries!

Summary is...I feel this motor should be well suited for the fff planes I have sitting cut out just awaiting carbon (or skewers) before assembly (USAF UFO, 4-S Bipe, 28" Amos Moses, Mini 3DX). Will most likely stick with the 8x4.3RS, being just a bit judicious when using the 460mAh as it is being pushed at 7amps.

Keep up the great work fellas. Love following this thread and watching the ingenuity. gpw, you started another good thing! ;-)

Cheers,
golem
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Last edited by golem; Nov 26, 2006 at 02:08 AM. Reason: added no-load value
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Old Nov 26, 2006, 05:46 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
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Well, so far the UFO is STILL the best flyer and most FUN ....we've tried alot of shapes and this one wins .... by a large margin ...Those Aliens must know some stuff....
Golem ... Thanks for the info!!!! .... we like it too ...

we've been flying this motor on two cells(GWS 8x4) for the lighter planes and 3s (Apc 7x4)for the faster stuff .... always lands cool ...plenty of cooling in the air, I guess...??? Need to check the A's...
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Last edited by gpw; Nov 26, 2006 at 04:36 PM.
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Old Nov 26, 2006, 08:23 AM
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Fairplay, South Park, CO
Joined Sep 2005
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Golem,

The GWS 8x4.3 RS prop looks like the prop to fly, as far as thrust out for amps in.

It also sounds like the $2.00 stick type motor mount with the heat sink built in that goes around the bearing tube would be a good idea for this motor (even though the stick mount offsets the motor.)

Thanks much for the info; I had just placed an order from U.H. in the last couple days.

VIKING
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Old Nov 26, 2006, 05:35 PM
High Altitude Flyer
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Fairplay, South Park, CO
Joined Sep 2005
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MANTA flying OK!

Friends,

The Manta flew fine today; there is good authority from the motor & two paralleled 2S 850 mAH A&T Li-Ion battery packs, turning the 8x4.3 GWS RS prop. It looks great in the air! The vertical stabilizer fin definitely disappears. Even though winds were gusty & irregular, I just had to fly it!

It'll slow down to a hover, then climb out from that attitude easily. Elevon authority is very good; loops can be about as tight as roughly 4 foot diameter. Roll rate is very respectable, if not quite radical. The combination of the clear vertical stabilizer and the tip plates just off the ends of the elevons are very adequate for excellent stability.

Handling is good with the balance at 6-3/4" back from the front edge of the wing on this 20" wide, 24" long MANTA. It took the 3 ounces of the twin batteries to get the balance this far forward; (I'm expecting that balancing a double surface wing would become even more of a challenge!)

One of the most noticable flying characteristics about the flat plate wing (which I built without a cross- spar), is that there is a definite 'camming' as the wing switches from being loaded upwards, to being loaded downwards. Under full power / throttle, it's quite noticable as the wing transitions from up pitch to down pitch... enough so to motivate me to possibly add a C.F. tubular spar across the span of the disc to minimize this, to achieve smoother handling.

All in all, flying the MANTA promises to be a LOT of fun... and it does look cool & quite 'retro' flying by in the air... (that rear cockpit area's rounded, down-sweeping contour reminds me a bit of the back end of an early Corvette Stingray...

For beter visibility / definition, I added a set of 12 fluorescent orange 'windows' around the disc's lower front surface's perimeter. A photo of the resulting appearance is shown below. (This was partially inspired by the group of 6 UFOs actually seen flying by here one night in early October... all had yellowish-orange lights on their FRONT ends as they flew silently past... no other lights... still wondering about that...) Ah, life in the real South Park- always interesting!

VIKING
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Old Nov 26, 2006, 07:06 PM
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Arlington,Texas
Joined Jan 2005
2,239 Posts
GPW I was trying to download the plans from foamfly.com and it seems like I can't connect to the site. Can you email them to me or anybody that has them. PM me for email address.
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Old Nov 26, 2006, 09:03 PM
Look outside the Square
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Gosford, Australia
Joined Jan 2006
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Bass, just tried it from my end and it come up. Might have been down for a short time. I tried it a little while a go and yes it didn't respond.
Try it now

http://www.foamfly.com/gallery/Glen?&page=11

If this link doesn't work for you, PM me.
Regards Box
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Old Nov 26, 2006, 09:03 PM
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Arlington,Texas
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Thanks, working now.
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Old Nov 27, 2006, 07:04 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
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Viking ... That's GREAT NEWS !!!! Now you know , we'll all have to build one ...any chance of plans or should we just "wing it"??? The lights/windows are so cool !!!!
Yeah , I've seen them too , but I'll never tell anybody, they already think I'm CRAZY!!! ......

PS , I've got a light foam kiddy pool surfboard made by Lifelike , that looks like the wing ...oughta fly with enough power...and a nice clear fin ... ???
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Last edited by gpw; Nov 27, 2006 at 07:09 AM.
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Old Nov 27, 2006, 09:04 AM
High Altitude Flyer
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Fairplay, South Park, CO
Joined Sep 2005
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Quote:
Originally Posted by gpw
Viking ... That's GREAT NEWS !!!! Now you know , we'll all have to build one ...any chance of plans or should we just "wing it"??? The lights/windows are so cool !!!!
Yeah , I've seen them too , but I'll never tell anybody, they already think I'm CRAZY!!! ......

PS , I've got a light foam kiddy pool surfboard made by Lifelike , that looks like the wing ...oughta fly with enough power...and a nice clear fin ... ???
GPW,

I had made up my template from the 1962 Frost Patent drawings, scaling it to 20" diameter on poster board, then going directly to the BlueCor. I have not drawn up full plans yet, (& don't use CAD), but once I add in the cross-span spar (spars?) & verify how that improves the handling, I'll see about drafting some plans on graph paper that I can scan and post. I'll especially draft up the tail fin, since it's about impossible to see in any of the photos, as well as dimensions on all of the superstructure & underbelly EPP piece.

I'm very satisfied so far with the Li-Ion battery system's performance; peak static current draw is just under 4 amps per pack at wide open throttle when flying the two paralleled packs... at $.99 per cell for the four cells used in the two packs, that's 'Bang For The Buck", which I know you advocate! Balancing the longer Frost MANTA design & especially the weight of the .030" thick polycarbonate vertical stabilizer required the 3 ounces of batteries way forward; the twin pack setup was my approach to accomplishing the balancing cleanly.

Strange lights on flying objects... saw my first one flying from a light aircraft flying field, about an hour after normal flight operations had ceased for the evening, inside the eastern edge of Fort Bragg, N.C. in the fall of 1970... Twilight time, and then a craft / light that rose vertically & silently to about 1000 feet above the ground level over about 30 seconds, then accellerated instantaneously out of sight, straight up, in less than a second... all silently... (A "vortex drive"??? It certainly wasn't Frost's more conventional vectored thrust design...)

More Later!

VIKING
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Old Nov 28, 2006, 06:50 AM
gpw
“There’s no place like Foam”
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Viking .... when the Aliens finally decide that Bubba or the government is not going to shoot at them , put them in a sideshow ,or sell them some bad location real estate in a hurricane zone ...they might visit more openly .... would be nice to get some new drive technology, this prop and fan stuff seems so ANCIENT ....
We anxiously await your drawings (I don't do CAD either , I do PENCIL.V3)
The resemblence is amazing to the Mini-Jar , by SR-71... It is obvious that this is one of the "elemental shapes " of flying thingies'...not requiring a computer to handle it ... Was Frost enlightened or merely found this shape in a progression of experiments ??? DiVinci had something similar , eh ...Cawley ??? We just need a new power FORCE !!!!
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Old Nov 28, 2006, 08:25 AM
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Fairplay, South Park, CO
Joined Sep 2005
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GPW,

I once knew a guy who claimed to have worked on building a 32' diameter ship which used a 'Vortex' drive... counter'rotating magnetic fields which produced localzed gravitational 'distortions' or 'anomalies'.... a bit complex for RC models, however.

John Keeley, in the 1880s & 1890s, demonstrated a flying platform to the War Department which could levitate, accellerate rapidly in any direction, and cruise at over 100 miles an hour; it used controlled / damped resonances to accomplish it's movement.... again, a bit complex for casual RC flight applications... [The military types from the war department who attended the demonstration commented that "it was interesting, but that they could not see any useful military application"... Keely later died in questionable circumstances, and most of his research material disappeared at the same time....]

So for now, inexpensive brushless electric motors and batteries may remain our options for propulsion systems for a while longer.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I added in the cross-span spar late yesterday; a major winter storm is moving in now, however, so the Manta may not get any more flying in until the end of the week.

VIKING
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Old Nov 28, 2006, 09:01 AM
Use whatcha got!
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Metairie, LA
Joined Sep 2000
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gpw - my templates are roughly the same size as VIKING's... I'll try to remember to bring them over on Thursday...

-mike s.
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Old Nov 28, 2006, 11:11 AM
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Fairplay, South Park, CO
Joined Sep 2005
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Quote:
Originally Posted by msmith
gpw - my templates are roughly the same size as VIKING's... I'll try to remember to bring them over on Thursday...

-mike s.
Mike,

Great! I'm looking forward to seeing yours! I'll offer a few dimensions for right now:

Construction was done with Foam-Safe ("No Odor")FLASH CyA glue and low temp hot melt glue. Some Scotch Extreme cross filament tape was used in a few selected areas for reinforcing, hatch hold-down & hinging, and the under-wing keel surface for landing durability.

My clear vertical fin is 5-1/16" high at the trailing edge; the lower edge, where it's mounted to the BlueCor with a pair of balsa triangle stock rails, is about 8-1/4" long.

My forward gear compartment is 11-1/2" long, with 15/16" high side wall pieces- it's covered above that height. It's a maximum of 3-3/8" wide on the outside dimension just behind the motor, tapering in to about 1-1/4" wide.

The rear cockpit panels are a maximuum of 2-7/8" high, and about 14-1/2" long, attaching into the rear of the forward gear compartment. At their widest spread at their base, they are set about 1-1/4" wide. They are glued to both sides of the clear polycarbonate vertival stabilizer fin with CyA, after having first been glued to the deck / wing with hot melt glue.

The wing cross-spar which I added, was glued in place with CyA late yesterday; it is 19-1/4" of 1/8" O.D. C.F. tube. I 'woodpeckered' with a T-pin through the surface film on the Bluecor on both sides of the tube to allow the thin foam-safe CyA glue to bond into the foam core, & weighted it in place while the glue set. The wing now has MUCH less flex, & should handle much better under full power. (Photo Below of the result.)

VIKING
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Old Nov 29, 2006, 06:41 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
Joined Jul 2002
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I'll be here today .... Consulting job days are becoming variable due to the unavailability of a cheap sushi bar downtown ....
Viking ... Looks SUPER !!!
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