well HF got it wrong on their spec. it is 15" ws as well. they are exactly the same plane. I think the HF plane is better than the acrobipe for 2 reasons. no hole in the rear for rubberband rod and rubber band instalation and white fuse. that way you can have a white plane w/o paint. only downside to the HF plane is the motor mount is square where as the Acro bipe was round and easy to remove. Plus side to the HF plane you get props for use with electric. I think I paid 10.99 each for my acro bipes from the store of wounder. they had a expensive shipping thing too. but I got around that by ordering 5. I think in time the local stores will have the plane. or I will order something else form them and have a few planes added into the order to get over the 50 dollar mark.

I went out and got a few more Ligthenings to replace the one that flew away. I went ahead and did a few measurements. The ff weight is 1.5 ounces or 40 grams.

The battery is not soldered in. There is a plastic door, at the bottom, that can be opened to remove the battery. I put the battery on a quick charger. Unfortunely, it didn't auto cutoff like it was supposed to and the battery got way overcharged. It seems a clear liquid ozzes out when this happens. Looks like water. Well I cleaned up the mess and decided to test the duration, anyway. The battery seemed ok and ran the motor for over 6 minutes. This 250mAH Ni-MH 1/3AA cell weighs 7 grams. I am thinking about replacing it with a AAA Ni-MH. I am thinking that you can definitely get a 12 minute flight on a 600mAH AAA cell (~11grams). And that's full throttle for 12 minutes. I also found a 800mAh AAA that weights 13 grams.

I tried to get a thrust measuremet, for the first time. Put the fusalege in a cup on my digital scale. Got 6 grams. I thought that was really low, so I tried a different method. I already had a jig with a lever arm which I used to get higher resolution measurements on my digital scale. I hung the plane on the arm, with the prop facing down. This is because I didn't want any of the propwash hitting the scale. Well I got double, which kind of makes since to me. So I am going with 12 grams of thrust for the stock motor and prop.

Originally Posted by Thatovalguy

You know whats even cooler is that the flight pack could hit the street for less than a GWS costs. Thats really cool for 2 servo's that can be made to weigh 3gr's and a Rx that can be made to weight 3gr's or less.

When? When? When?

Waiting to buy...

DPN

I just received a shipment with several of these, DO NOT ORDER THEM WITH HEAVY OBJECTS! My new roofing nailer crushed two of them.

Observations:
Nice Pants
Prop is larger than the sky runners, but looks similar
Motor and mount easy to remove, Stock Motor pulled .6A with a single lipo but was heavy
Charging Jack separates easy from lower wing mount with some persuasion
There is room for material removal,
I will probably split the seam to enclose remote actuators if the first one flys with the big BS actuators outside the fuse

I will publish the weights of the components tonight if anyone is interested.

My first edition with the wheels and pants weighs 55.5g RTF with a JMP setup, motor from a broken ministick, and an etec 250 battery. I pulled a lot of plastic and foam out, if this one works, I should be able to get my next one lighter. I am using a single cell, but may try the 2cell board I have if I need it.

Fritz

Yes, I ordered three of them with NOTHING else, and my shipping box could have held five of them (too big), and had about 20 peanuts in total. Two plane boxes were damaged pretty good from the bouncing around, but only one plane. Harbor Freight's shipping dept. needs some training...


phil in austin

I'm starting my bipe project. Over the weekend I went to UBHobbies and grabbed a couple Acro-bipes. I couldn't help getting a funcraft Mustang $10 and a couple 16" Guillow's models as well. A P-40 and a Hellcat for $7 ea. These are great prices. In the store these guys told me they can offer excellent shipping prices all over the world. If you are non-USA, contact them for shipping info at: themodelmaster@ubhobbies.com You can't beat their prices.

So now I have a couple GWS pico servos and Rx on the way. I'll be using my EDP with 0303 prop and a 5A ESC. Not including batt, the electrics should come in at less than 40 grams. I will be using a 2 servo setup for elev and ailerons... no rudder.

Hopefully, acro-bipe #2 will get setup with a ~15 gram CDROM motor which I expect to pull a max of ~1.5A.

In both setups, I plan to use a 2s lipo batt.

Question #1:
What lipo should I buy and where should I buy them. I'm thinking the Kokam 340 are too big, but they are more versitile (20C discharge). Could I get by at 1.5A with the 125mAh or should I go up to the 250 size?

Question #2:
Those of you who have built this plane (or the HF bipe). What do you consider the "do not exceed" AUW? I get the impression from other posts that this plane will fly at 4.0 oz (115g) but it's very fast and hard to control. I'm striving to build an indoor model for the gym. Can you "gym fly" this plane at 3.0 oz (85g) ??

Hi Rex;

I think I'll be setting mine up similar to yours - I'm putting in a GWS R4P with Cirrus 4.4 servos...

I did get the Kokam 340, and though I think it's a pretty good match for power and duration, size-wise, yes, it's pretty big but thin. No matter, though; I think I'm just going to sling mine sideways under the fuse in a big "drop-tank" sort of setup. E-Tec seems to make their batteries smaller and thicker, so they don't take up so much area.

My motor setup will probably pull a little over 2A. 125mAh probably aren't an option for me, but I could go with the 250. I may stop by the hobby shop soon, too, and see if the Thunder Powers come in a reasonably-sized 350...

Happy flying!
Dan.

That's cool.

What do y'all think about weight? Is there a sweet spot?

I have one of the biplanes, with a LPS GWS power system [white gear 6:1] and uses a 6x3 orange GWS prop Weighs 3.1 ounce with two 250 lipo Just ordered 16 for all the local guys, will cost only $11 each. Only problem is they are backordered until Oct 15

Originally Posted by fmhans

I just received a shipment with several of these, DO NOT ORDER THEM WITH HEAVY OBJECTS! My new roofing nailer crushed two of them.Fritz

Just in case anyone missed this important life lesson, I'm bumping it!

Flight report - it's good!

I finally finished my conversion; not that it was that difficult, just that my time is that squeezed right now. Actual build time was only a few evenings, discounting scratching my head a couple times.

Here's her specs:

AUW: 80g
Wing Loading: 7.5 oz/ft
Battery: 2 cell Kokam 340 mAh Li-Poly
Motor: Stock GWS B2C with, I think, 6:1 gearing
Prop: 7060
Rx: GWS R4P
Servos: 2 Cirrus 4.4's for Elevator and Ailerons
GWS 2A Speed Control

I pretty much used the plane stock. The stock elevators were used with a small piece of wire for a joiner. Plenty of room for the servos on the inside. I will definitely shorten all of the ESC wires next time, though. The somewhat heavy stock struts were also used. I used a Dubro micro horn on the elevator, with Dubro micro aileron linkages (a little bit overkill, especially at the top of the torque rods. I'll build these myself next time, to save room and weight). Quarter-inch balsa strip ailerons were added to the bottom wing. The B2C fits in the motor cage, by knocking out a chunk of the fuse. Indelicate handling with a drill bit led to mine sticking out the top. A small balsa panel keeps the motor in place. The batteries attach with velcro pretty near the front of the plane. I left off the landing gear for the initial flight.

The flight handling was just fine for a small plane, though I was a bit wobbly with it at first, and it's a bit faster than I was looking for. Made several circuits over the small field. CG was a little forward, I think (being safe). Pulled off a sloppy roll or two. Pulled off some really sloppy loops, or more like vertical stalls. I may bump up the ATV on the elevator.

Got several minutes of enjoyable flying in. Motor still seemed strong when it got dark.

The plane slowed pretty nice and glided in for a good landing, using the batteries as a "skid pad"! Not sure I want to continue that trend... Looked cute, though, landing sort of tail-up.

Pictures will follow, as soon as I can dig my camera out from all my vacation stuff...

D.

Originally Posted by Big Foot 48

Just in case anyone missed this important life lesson, I'm bumping it!

Just contact Harbor Freight and report the damage that was due to inadequate packing. You did take pictures, right?

Here's my Acrobipe from UBHobbies (see above for link).
GWS EDP with 0303 prop.
GWS 5A ESC
GWS pico Rx
GWS pico servo's X 2 (no rudder servo).
iRate 2s 300mAh 10C Lipo batt

AUW = 3.8 oz
WOT = 1.5 A

Build info:
Use a very sharp xacto blade to cut away the top engine cowl and large section including pilot. These fuse parts are now held in place with some extra rare earth magnets left over from CDROM coversions. Using aileron arms for control horns, servo install is easy. Use masking tape to remove yellow paint on wings.

Flight report,
Yippeeeeeee! I think my plan to use big ailerons (bottom wing only) helps this little guy fly slow. It flies great. One more final CG check and I gave it a toss over tall grass expecting the worst and off she went just as straight and smooth as could be. A couple clicks on the trim and hands off flying was achieved on the first flight. By the end of the 1st full battery charge I had accomplished several rolls, loops, hammerheads. ROG launch and landing, some touch and gos, and several uneventful crash landings into the short grass of a baseball diamond including a couple cartwheels. Full throttle climb is a bit less than 45 degrees but very healty just the same. I estimate stall speed (SWAG) to be about 5 mph. It's a very nice and slow flyer.

Every battery change requires re-trimming the model due to slight CG changes. This bipe is very short coupled and small changes in CG make a big difference in the air.

My battery choice allows me to put the battery inside the fuse. This is not possible with the Kokam 340mAh which is slighty too big. It sure is cute in the air. My co-workers were astounded watching it fly.

Here is a shot with fuse access panels removed.

Beautiful work! I like the color scheme in particular...

I was about to put the EDP with a 3x prop on mine, but I made enough "room" for the B2C when the drill bit escaped me. Does the real Acrobipe have a plastic housing in the front? The HF model does, to hold the motor. I didn't realize until later that the top and bottom of the housing were open to the foam, so the drill bit was really overkill.

I have another plane waiting - the EDP may go in that one.