Electric Mite (Guided Mite V 2.0)

[pease1]

OK, while waiting for my new props I decided to go ahead and make the 2nd version of my Guided Mite. This one is slimmer and contains many other nice changes to work better for Electric Microflight. Details and additional photos can be found on my Electric Mite Page (http://pease1.sr.unh.edu/aew/rc/emite/)

Cad Plans are in the works - I made this version from my plans.

Comments are always welcome...

http://pease1.sr.unh.edu/aew/rc/emite/DSCN1082_sm.jpg

[pease1]

Well darned thing wouldn't balance out - no matter what I did it was too tail heavy. I figured since I had to go back to the drawing board (well CAD) anyways I might as well see if it could fly - It couldn't.

I'm 90% done with mark-III. I moved the servo bay more forward and built the battery
compartment so it can go all the way to the front. This one will balance for sure.

The great thing is it builds in only 4-5 hours since it's such a simple design.

Al

[ 06-16-2001: Message edited by: Allan Wright ]

[pease1]

Version 3.0 is a winner. I went through all four of my 9-volt NiMh batteries at the field today and the thing flew great. I did trim the wing out with a 1/16 shim under the trailing edge so I'll work that change into the plans. Looks like it's time to CAD up the wing and get the plans out to the masses!

Al

[ksblaze]

Looks nice, Allan. What is the fuse material?

Karl

[jimwalker]

I'd be interested in those plans. That plane just has something fun about it....

[pease1]

Fuse is all 1/16" sheet over three 1/8" sheet formers. I did make one with 1/16" sides and 1/32" top and bottom which worked fine. It's a rugged little plane. I've bounced it a couple times trying different battery combinations that were too heavy or too underpowered. It seems to work best with the Rayovac 9-vold NiMh batteries - I get about a 5 minute flight of good power on them.

The GWS 4x2.5" prop direct drive on the GWS-A carbon brush motor is a winning combination. The motor heats up a little but not much more than on a stock litestick.

I need to add the wing to the cad drawings and I'll send a few people advance copies to 'debug' the plans. Jim Walker - you're on the list!

Al

[ 06-19-2001: Message edited by: Allan Wright ]

[pease1]

OK I finished the plans. I'm sending them to a select few people to review and help me refine the instructions. After that I'll do either a webpage or an article for this site with them.

Al

[pease1]

Here's one last Electric Mite picture. This one under construction, but taken next to my transmitter for size comparison purposes.

http://pease1.sr.unh.edu/aew/rc/emite/DSCN1117_sm.jpg

[pease1]

Bought a decent scale. All up weight with the 9-volt NiMh batteries is 5.2 oz (152g) That makes the wing loading 4.23oz/square foot. This is with the prototype which is heaver than my latest version built from my new plans.

*UPDATE* Latest prototype came out to an all up weight of 141 grams (4.97 oz).

I did try a 7 cell 280mAh NiMh pack today and boy did that make the thing fly nice and fast. Loops from level flight were nice and round, airspeed was up and duration was more like 7-8 mins instead of 4-5. It doesn't slow down quite as much with the extra weight but still flies nicely.

[ 06-26-2001: Message edited by: Allan Wright ]

[pease1]

Well I seem to be putting on a one-sided conversation on this thread - I hope I'm not boring anyone :eek:

Well we had a storm here but after it passed a friend dropped by to see my planes for the first time. Not willing to dissapoint I took the mite out to the local high-school track where I like to fly. My friend was nice enough to snap some photos and take some movies with my digital camera. To see them saunter over to my Electric Mite Page (http://pease1.sr.unh.edu/aew/rc/emite)

Al

[jimwalker]

I'm listening!

Thanks for the plans, I hope to get to build one soon. I just moved so it could be a while before my wife lets me off the hook from "honey do's".

I have the radio gear just sitting there begging for a plane. 2 HS-55's, GWS reciever, FMA mini 5 ESC and a 8 cell 120mah NIMH pack. Just need the motor and prop. Can you recommend the cheapest place to get the carbon brush GWS motor and 5" prop?

Happy Flying

[pease1]

Balsa products has the replacement motor - $10 for carbon brush model (I think). They carry GWS props but don't seem to have the 4"x2.5" listed in their catalog or website. Todd's Models carrys the prop for $1 each. Pick up a few since they're thin and will break if you ditch the plane. Luckilly the nose is nice and strong so you don't usually have to do much more than just pop on a new prop. Mine has survived several hard knocks including a collision with a cement building when my ESC cut out at a bad time.

Al

[pease1]

Oh and Jim, check your mail before starting on the plane - I sent you more information.

[pease1]

DON'T buy the motor without the pinion.

The motor with the pinion works best with the 4x2.5 prop. You ream out the opening in the prop a little with a hobby knife or drill and it's a press-on fit for the pinion. A drop of thick CA holds it on nively. Balsa products carries the carbon brush motor with pinion.

Alternatively you could figure out how to mount the prop on the motor without pinion but this would be more difficult.

[jimwalker]

I've got the plans now and am ready to start building. I looked at Todd's Models website and he has the carbon brushed motors without a pinion gear for 9 dollars. He also has the GWS 4x2.5 prop you recommended for a dollar. How did you mount your propeller onto the GWS motor for direct drive setup? Do I need an adapter or anything? Let me know so I can get this stuff on order and have it here when the plane is ready....

Thanks again for the plans and help, I'm looking forward to flying this fun little plane!

[jimwalker]

You were right Allen, I emailed Todd at Todds Models and he said as far as he knows there isn't any available adapter to mount GWS props directly to the shaft of GWS motors.

Oh well, I guess I'll do it your way, I just hate whittling on props and having to order a few parts from several different places. The shipping charges are murder!

Thanks again...

[pease1]

Balsa products informs me that they carry a GWS pack that has the carbon brush motor and two 3x2 props together. I haven't tried the 3x2 props on the mite yet, but it might be a workable solution. I have also urged Balsa products to carry the 4x2.5 props just so that I can get everything I need for a mite from one source

Motor, prop, servos, receiver, wheels and ESC (although they carry GWS line not Castle Creations which I prefer)

I'm anxious to hear your results, I've set up someone to cut a sample run of kits, I just want to hear back from a couple of my test builders before I send in the plans and my order.

Al

[ 07-02-2001: Message edited by: Allan Wright ]

[pease1]

I got another e-mail from Balsa Products and they'll be getting the 4x2.5 props. Funny GWS says that they're for the 280 direct drive and they're too hot for the IPC motor, but I find that they're fine. YMMV, you may get shorter life out of your motors with the hot prop, but so far I've had good service, at least 20 flights on my first carbon brush motor with no apparent damage.

Al

[jimwalker]

I wonder how long it will take them to stock the new prop. If it will be in the next week or so, I'll just wait and get the motor and prop from them....

[pease1]

drop them an email and ask - they're quite helpful and quick to respond. All in all I've always been sastified with their service. You may want to get the pack with the carbon brush motor and the 2 3x2 props and just add some 4x2.5 props to try out the GWS reccomended direct drive props.

They also carry the GWS pico servos and 4R receiver.

I don't get a cut from them - the only association with them I have is that they know my credit card # by heart! LOL :D

If I make a kit of this I plan to include the prop and wheels just to simplify things. The motor/servos/receiver/esc will be up to the builder though.

[ 07-03-2001: Message edited by: Allan Wright ]

[jimwalker]

Hey Allan,

Balsa Products has a 4.5 x 4. Is it worth a try or do you think that would really fry a carbon brush GWS direct drive motor?

[pease1]

No way - the 4x2.5 is really too much for the IPC direct, a 4.5x4 would toast it within a minute.

Even the 4x2.5 is exceeding GWS's specs for the motor. They heat up hot hot, but I haven't fried one yet. Balsa products has the carbon motor with 2 3x2 props, that's what I plan to try next build. I reccomend you go with that if you can't get the 4x2.5

Al

[pease1]

[ 07-13-2001: Message edited by: Allan Wright ]

[jimwalker]

Allan,

Here's the latest on my guided mite exploits:

1) I have a good set of plans.

You said you used Turbo Cad to draw the plans, correct? I tried loading them into AutoCad V14 and it just complained and gave me an error message. Next I downloaded the free version of Turbo Cad and sure enough it loaded. Unfortunately I couldn't figure out how to print tiles on my ink jet printer. Maybe you could help me out for future reference. My friend at work agreed to try his hand at it and AutoCad 2000i thought your files were just fine (go figure??). He printed it out on the plotter and the scale was perfect.

2) I ordered the parts.

I decided to just order the carbon brush motor and 3x2 props from balsa products. I expect shipping confirmation any time now.

3) I have everything else I need and hopefully will begin construction this weekend.

I'll keep you posted!!

Jim

[jimwalker]

Yet another update Allan,

I did indeed start on my "Guided E-Mite" this weekend. The fuselage is framed up and ready for the final top and bottom planking. I also have the tail feathers cut out and ready.

My GWS motor and two 3x2 props arrived Saturday. I opened the box and sighed. The 3x2 GWS props are push-on just like B-2 motors and had a very small hub. The GWS motor was ordered with a pinion as you suggested, but there was no way to make it work as you described, i.e. whittle out the prop hub to fit the pinion gear. Well, out came the dremel tool. I slowly destroyed the brass pinion gear with an emery wheel, being careful not to injure the motor shaft. Finally the pinion slipped off and the motor shaft only had a few nicks. The prop pushed right on and I connected a 1.5v dry cell to break it in. I measured the prop and it is slightly larger than 3 inches, 3.25" to be exact. Since the prop diameter is so much less than your original mite, I changed your plans a little by streamlining the nose of the fuselage. I did this so the smaller prop will protrude farther past the nose.

I have all the parts and I hope to be flying my Mite by next weekend, weather permitting.

Jim

[pease1]

Sorry about the confusion, I though I was clear on this. The pinon is required for the 4x2.5 prop only. The press-on props work without the pinion gear and balsa products sells the GWS 'set' of 2 props and a pinionless motor.

Let me know how the streamlined nose works with the smaller props. If well I'll consider modifying my plans for this powerplant.

[ 07-23-2001: Message edited by: Allan Wright ]

[hector375]

So, any idea when the rest of us are going to be able to get our hands on the plans?

I'm looking forward to building and flying one of these as well. Sounds like this is going to be one sweet plane. :cool:

[pease1]

Hector, you have mail.....

[jimwalker]

Here's the latest,

I finished everything but the wing last night. All gear is installed and ready to go. The prop looks sooooo small on this plane. I guess I'm just used to geared motor systems. I'd previously broken in my new GWS motor on a 1.5 drycell so it was ready for a full power run. After I'd gotten everything installed, I fired up the motor. I think I might have a "Guided Shrike" as in missile! The thing literally jumped off the work bench before I could shut off the throttle. Once again, this is a first for me with direct drive. I'm used to low rpm geared systems with large props. That little prop on the GWS motor SCREAMS. I just hope I don't have a pylon racer when I'm done.

Anyway, the wing looks very simple and I'm going to cover it with reynolds plastic wrap. Should be done tomorrow some time and if the wind will let me, I'll attempt a test flight.

Happy Flying!

(P.S. hope I'm not boring everyone with these updates)

[pease1]

Sounds great! The drag from the wing will slow it down some, and I have found it will fly at 2/3rds throttle quite nicely. It's faster than a litestick, that's for sure, but you'll be able to handle it!

Photos Photos Photos!

Al

[pease1]

It was a bad weekend for my mites. I managed to crumple the wings on both my mites, trying to fly for my brother in some insane wind. Well that's what I get for pushing it. Luckilly the wings build up in a couple hours for me so I'll be back in business soon.

AL

[jimwalker]

Here's the pictures...

http://www.rcmicroflight.com/upload/mite1.jpg

http://www.rcmicroflight.com/upload/mite2.jpg

Flying weight is 122 grams, (4.29 ounces).

Gear Manifest:

GWS carbon brush motor w/3x2 direct drive prop.
GWS R4P reciever.
2 Hitec HS-55 servos.
FMA mini 5 ESC.
8 x 120 mah Nimh cells.

Building comments:

Very simple and straight foward assembly. I "skinnied" up the nose a little from the plans so the small prop would have as much clearance as possible. I personally don't like sheeted trailing edges, though there's nothing really wrong with that design. Because of my personal preference, I used some precut trailing edge stock from the hobby store and notched in the ribs. I used the mylar leftovers from my Tiny kit to cover the wing.

In future editions of the plans, a diagram for the optional landing gear would be nice. I just "eyeballed" it and came up with a workable shape out of music wire. It took me a few tries though and the diagram would have saved some time and sweat.

I used the lightest wood I could find and was pleased with the completed all up flying weight. If I had some 280 Nimh cells I think I would still be in the weight range Allan achieved with his prototypes. All I have are the 120 mah Nimh's I listed. This is my lightest plane to date.

Flying:

The wind finally died just before dark yesterday, so I plugged in the battery and headed out to the front yard. Against my better judgement I set my new creation down in the street and did a control check. I knew I should really make my first test flight in a wide open field, but I didn't want to wait for another day.

With the neighbors watching curiously, I gave it 2/3 throttle and watched it taxi slowly at first. I decided to go for it and slid the throttle wide open. A few more feet and I was airborne! It was faster than I expected and I was a little nervous. I started a turn back toward myself and barely missed a light pole. I pulled back on the stick panicking slightly and the little guy tried to go vertical and stalled. No problem, I just backed off the stick and it settled back in with no attempt to snap at all. I flew past myself downwind and almost flew into a tree!! I gave it full rudder and it banked sharply. I gave it up elevator to do an aileron type turn with the plane banked over and was surprised at the planes nimbleness. It picked up a lot of speed from such a tight turn and ballooned into a slight stall, but once again the little plane settled right down when I backed off the stick. Heart pounding, I brought it in for a nice soft landing about 15 yards past myself. One neighbor said to the other, "That'll get your horn blowing" and they both chuckled.

Summary:

Next flights will be in an open field until I get comfortable with this spunky little plane. Still to be determined is what kind of flight time I get with 120 Nimh's and the 3 x 2 prop at this lighter weight. I'll keep you posted. Finally I think this is a good candidate for plan of the month on RCMicroflight. It's easy to build, cheap to make and equip, and best of all, it is looks like it's going to be a blast to fly!

Jim

[ 07-30-2001: Message edited by: Jim Walker ]

[flyingbuddy]

Congrats Jim!
Allan, before you make the changes to the fuse, consider that with that big fuse and tiny prop, it reminds me of a GeeBee R1, hmmm...
(I can feel your fertile mind ticking...) ;)

[flyingbuddy]

Jim,
You are not boring us with your posts by any means. My problem is keeping the different forums straight. I didn't discover these other forums (Park Flyers, Photos, Plan Of The Month) until recently. Doh!
Your above description is just what we need in this bulletin board and is worthy of publication in R/C MicroFlight.
I might add that you must be the guru of posting photos on this board, considering how difficult (finicky) it is. What is the procedure that works for you?
Thanks

[pease1]

Awsome report Jim and beautifull build! I find doing laps around a football field is no problem for the Emite, it has suprisingly good speed. :D I find that a 280mAh 7-cell NiMh pack has to be pushed all the way to the front of the battery compartment to make the CG work. A 9-volt Rayovac can be a little back from the front.

I'm glad you had success with it! I'll adjust the plans for the 3x2 prop setup that GWS reccomends for direct drive since you had good luck with it. I plan to trim down the fuselage and nose little more too to cut weight. I think if I slim it down and mount the servos infront of each other instead of beside each other that will work.

Landing gear diagram - I will add to the
plans. My CF gear didn't hold up as well as
piano wire, so you made the right choice. Better to have to re-bend it than break it off!

Trailing edge stock on the wing - I use T/E stock myself, but wanted to draw the plans for the simplest of stock requirements so went with the square TE then sand to shape for the plans.

There's a real sence of pride when your design ends up as a flying model in someone else's collection - thanks a TON!

[pease1]

So Jim,

Didja fly last night?

Al

[jimwalker]

Allan,

No, Drat it, it was windy all evening. I spent all my free time charging packs and looking outside hoping the wind would die...

My golf league plays tonight, so it'll be Wednesday before I can try again.

John,

Thanks for the accolades (blush).

To upload a picture make sure it is no bigger than 800 x 600 resolution (there are many free programs to do this on the internet). Next, when you enter this board you will see the hyperlink to upload a picture. Follow the directions, they are pretty straight foward. The only place that is confusing, is where you must name your uploaded file. Be sure to include the suffix of your photo's file type. For example...

Airplane.jpg

Jpegs are the most common internet picture files. If you don't get the ".jpg" on there it's no good. When the dialog box pops up with your picture code, right click and copy it. Now when you are entering your message, click the "image" button and paste your bit of code into the dialog box that appears. When you click OK you should see it appear in your message. Don't disturb it and finish typing your message as usual.

Let me know if you still have problems...

[jimwalker]

I got to fly last night so here is my final report on Allan's prototype...

Due to my recent move, it's been over a month since I've had any real stick time. With the wind being marginal yesterday evening, I was hesitant but decided to go ahead and packed up my trusty S280 Virus and the Guided Mite. I drove down the street to the desert at the edge of my edition where I would have plenty of room. I was still unsure of the wind (and the pilot) so the Virus took to the air first. A few minutes later I was feeling confident again and decided to land. The wind was coming across the street I was using for a landing strip, but I flared my Virus perfectly and rolled it to a stop just a few feet away. This really boosted my confidence and out came the Mite.

I tried to ROG but the cross wind tipped it over. I quickly retrieved my Mite and gave it a hand launch at full throttle. Immediately it tried to nose over and I had to apply constant up elevator to stay in the air. After a several tense seconds of fighting the Mite and trying to adjust the trim tab simultaneously, I had it flying level. There was no respite though as it still wanted to make a sharp right hand turn. Several more seconds and I finally had my Mite flying straight and level. I backed off the throttle and the fun began!!! It didn't take long to figure out that I could keep my Mite very close because of it's combination of stability and agility. I did a couple of loops right over the neighbors roof top and strafed some curious onlookers with total confidence. Finally the plane did a few hard twitches letting me know power was low (I'm using an FMA SC5 which has no cutoff) so I backed off the throttle. One more tight circle to line up and I chopped the throttle for a quick flaring landing right at my feet. The onlookers were very impressed (so was I)...

In summary, moving the battery pack toward the tail should solve the nose down condition. The tendency toward a right turn must be from the tork of that high-rev'ing little prop and I'll just leave in the left trim, it wasn't that much anyway. Not having a watch, I'm not sure of the total flight time. I estimate 3-4 minutes with the 8 cell 120 mah Nimh pack I'm using. That was only the 3rd or 4th cycle on those new cells, so I anticipate a sharp increase in flying time for the coming flights. Even if there isn't an increase, I know this little bird could definitely stand a heavier pack and still fly great! Bottom line is....

What a fun plane!!!!

[pease1]

Wow thanks for the report Jim. One thing I have found you need to watch is warping of the tailfeathers when you paint them. I had one mite need a lot of trim because the tail had a very slight warp in it making a perfect airfoil shape (figures eh?) right were I didn't need one.

I'll cad up the changes to the nose to work with the smaller reccomended prop and build a final prototype with lots of photos. Hopefully I can put them to good use.

I'm still waiting to hear feedback from my other 3 test builders too before making the plans 'final'.

I'm glad you're enjoying your Mite. I'm so comfortable with mine that they are my 'warm up' planes now!

Al