I bought some 3mm Depron for a project and had some left over so I found a micro biplane on RCGroups and converted the PDF to a Sketchup file and cut out one of these amazing little planes.

http://www.rcgroups.com/forums/showthread.php?t=516219

I don't have anything to power it (yet), but it was fun to build and look at.

I used a 1/32" bit for this since the foam is so thin.

Be sure to check the thread for paint schemes, build instructions, and credits.

NOTE: This SU file has been superceded with a new improved one so I have deleted it from this posting. See the rest of the thread for the lastest version... Attached files

 

Here are some more photos of the finished plane outfitted with electronics and motors stripped from an Air Hogs X-Twin which you can buy at Target .

Two pager motors, a 27 mhz receiver, LIPO and transmitter all for $29. I cut the canopy from the packing material from the Air Hogs package.

Plus I still have a little foam jet to put a bit of lead weight on the nose and give to my Grandson for a toss around glider. Attached files

 

Just as with the Phlatprinter, there is always another good mod just around the corner....

While trying to fly this little jewel, I noticed a bad tendancy for it to dive when you try to hand launch it. The RCGroups forum indicated a lot of folks have had the same problem.

Just holding it in the palm of my hand I could feel it try to nose over when thrust was applied, so I added motor support brackets to the lower wing and fastened the motors to the bracket which brings the motor shafts evenly between the two wings.

Now I can hold the plane in the palm of my hand, throttle up a bit and just toss the plane lightly upward from my hand and it is airborne! Sweet!

So I reworked the SU file to include the new motor mounts and at the same time I decided to make it for two planes since two will fit on one sheet of foam.

Here is the revised SU file and a few pictures of the mod....

Oh by the way, I would have run the wires for the motor on top of the wing but the motors were already installed for the top wing earlier. If I were to build another one, it would have the wires hidden better because they could run across the top of the bottom wing right into the fuse and receiver. Attached files MicroUltimage.skp (894.9 KB)Â

 

2 mm might be better yet. You want to keep it as light as possible. I added landing gear this morning which made it a bit too heavy although it still flys good. I may try to experiment with milling a bit to see if I can get it a bit lighter still.

 

Great little biplane! I learned to fly on a Tiger Moth and still love biplanes. I've done a couple of bi-wing saucers too. This looks like a great next biplane for me. I have a 2 gram single cell brushless motor that would work great on this one. Does the Air Hog gear use thrust vectoring to steer? What do you think is the AUW?

 

KX-5, I started out on a Tiger Moth as well. I am flying a Baisden Bipe most days. It is an Eflite Ultimate with a few changes, well quite a few changes actually. It is sooo graceful.

So the little Micro intrigued me and is my first micro build.

The AUW is 28grams. I have not weighed it since adding landing gear, so it will be a few grams heavier now.

The Air Hog components are pretty weak, but it flys around just fine in no wind. It uses differential motors to control turning. There is no rudder or elevator, just throttle and differential control of the two motor speeds to effect turns.

If you were to use your 2g motor, you would also have to add an actuator or some way to implement rudder control.

I think this would be a good plane to scale up just a little and put real servos and a single motor on it. I have a 5g and a 10g motor, a 6A ESC, and lightweight Spektrum receiver that I may just use on a little larger version. But I think they might be too much for the Micro size.

 

Flash, I know the following can be determined in the SketchUp file, but what is the wing span and area for the micro?

 

Wingspan is 12" x 2.5" give or take (angled). You can scale it to any size you like in SU, but you have to change all of the tabs and slots if you do that.

 

That gives a wing loading of about 2.4 oz/sq ft. with a weight of 1 oz. I have made a 10" micro saucer that weighs in at 1.4 oz AUW with 2 servos. Wing load was about 3.5. This gear should work pretty well with the 12" biplane. I think i'm going to try an RET version of this. Thanks for posting the plans.

 

Flash, I'm a bit confused on the bit and material size in the SketchUp file. It shows:

Material Thickness = 6.35 mm
Bit Diameter = 3.175mm
Tab Width = 6.35mm

This looks like 1/4" material and 1/8" bit. :?:

 

The Material Thickness should be set to 3mm and the bit Diameter to 0.7937mm according to my SU file.
Not sure why it did not come out that way for you. I used a 1/32" bit and 3mm Depron, so that is what you need to setup.

 

What did you end up with as the CG location?

 

CG is about 1/2" behind the leading edge top wing outside edge.

 

Pre-Flight pics. I've completed a 15" wingspan version of your micro bipe. I'm using a 2 gram brushless with a 200 mah single cell lipo, two 2.5 gram servos for RET control. I needed a little more nose length for the battery and CG. AUW= 1.5 oz. Unfortunately, the winds are 15 to 20 mph so a test flight today is probably not going to happen.







Attached files

 

Awesome! That combination sounds like it will be a good one. The airhogs parts really just don't do it for me.

For one thing, there is a 1 to 1 1/2 second latency in the controls and the motors just don't put out enough thrust to be exciting.

I have been meaning to scale this up a bit myself.

But you really will have to wait for very calm winds on these little fellows.