Come and get it - MicroMoth plan!! - RC Groups
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Aug 23, 2002, 10:25 PM
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Chris3D's Avatar

Come and get it - MicroMoth plan!!

Here it is:

Give it a try and let me know if you run into trouble or find any typos or anything.

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Aug 23, 2002, 10:43 PM
in persuit of low wing loading
Gordon Johnson's Avatar
That is a very nice plane, plan, and construction notes. Hopefully a lot of people will use this to get into scale RFFS-100 based planes. Thanks for going to the effort, and making this available to everyone.

Aug 23, 2002, 11:19 PM
Registered User
FLB's Avatar

Nothing special to say. Just thanks to share all that work. Gordonjohnson has already found the good words.


Aug 23, 2002, 11:40 PM
Senior Member
Paul Penney's Avatar
Fabulous peice of work! A good quality artical and plan.

With your permission I would like to host it on my site as a free plan.

Aug 24, 2002, 12:01 AM
Registered User
Chris3D's Avatar
Thanks everyone, I'm more than happy to make it available, and I too hope it inspires more scale models for the RFFS-100.

Paul, sure thing, but there may be some updates to the plan based on any feedback I get. Hopefully a few people will build it and let me know if anything is unclear. Just keep an eye on this thread to see if it gets updated. Maybe for the time being, you could just link to the file on my site.

Aug 24, 2002, 12:33 AM
Grand Poobah of Nothing
Trizza's Avatar
Lovely work Chris! Great plan. Great model.

The plan is sitting in the out tray of my printer now. I guess I'll have to go get some more 1/32 balsa
Aug 24, 2002, 01:42 AM
Registered User

Great plan man

And sure helps those that R trying to get themselves into the micro flight world

Beautifuly made, and a wonderful model.

Aug 24, 2002, 02:47 AM
Registered User
jk's Avatar
that is simply beautiful!

and thanks for the well documented instructions!

Aug 24, 2002, 08:34 AM
Registered User
Fly_joy's Avatar
THANK YOU for a great contribution to the micro community.
Aug 24, 2002, 08:49 AM
Registered User
Chris3D's Avatar
Thanks again, everyone, for the kind comments.

A quick note to anyone building one - the CG as indicated on the plan is incorrect. The first version of the plane I built had the top wing almost directly on top of the bottom wing - not set forward as in this version. I just test flew the plane this morning and it was a bit hairy... I've already re-located the battery up into the cowl beneath the motor, which will hopefully correct the problem. As soon as I can test fly it again, I'll update the plan.

This shouldn't necessitate any major changes, but I'd hold off on gluing in the firewall (F1) until I can verify that the problem is fixed. If the CG still needs to be moved forward after moving the battery into the cowl, moving F1 forward slightly should do the trick, as it will also move the motor forward with it.

Sorry for any inconvenience...
Aug 24, 2002, 04:57 PM
Registered User
Chris,thankyou for posting your plan.
I have started building, but I am in the U.K. I an not allowed to use 72Mhz, so I am using an I.R. system.
Keep up the great work,
Best regards,
Aug 24, 2002, 06:05 PM
Registered User
Chris3D's Avatar
Thanks Trevor, make sure you have the latest version of the plan. I just updated it a few hours ago with the battery relocated into the cowl, but haven't been able to test fly it as it's been too windy.
Aug 25, 2002, 09:54 AM
Registered User
Hi Chris3D

Great job on the MicoMoth. I downloaded the plans. What amount of dihedral is used on the wings?

Aug 25, 2002, 10:04 AM
Registered User
Chris3D's Avatar
Hi everyone,

I just updated the plan (no changes to the actual plan from yesterday, just a few changes to the construction notes). Regarding the CG, it's perfect where indicated, and I needed to add 2 pennies to the nose to get it to balance there. This likely wouldn't be necessary if the plane is colored with markers or something lighter than the watercolors I used. For every gram added way back on the tail, it takes about 4 in the nose to compensate... If you're using NiCads, all this is irrelevant, as the plane can be easily balanced by moving the battery forward or back between F1 and F2.

As soon as my battery is charged, I'll fly it again and try to get some in-flight photos...

Aug 25, 2002, 10:13 AM
Registered User
Chris3D's Avatar
Hi Dale, make sure you grab the latest version of the plan, I just updated it a few minutes ago. Regarding the dihedral, mine has about 3/4 of an inch at the wing tips, but that was a bit excessive and I corrected this in the plan before I posted it a few days ago. I'd say 1/2 inch at the tips would be plenty. For more scale appearances, the bottom wings should have a little more dihedral than the top.
Aug 26, 2002, 09:46 AM
AMA 697691 / FAA 13675

It looks great! Thanks for sharing this with everyone.

Latest blog entry: Greg's Web Hangar
Aug 26, 2002, 09:50 AM
Living Room Aviator
drliu's Avatar



That is some very fine work. Although I'm still devoted to living room flight (hopefully bedroom-sized flight soon), you inspire a real desire to throw loading level optimization out the window and just build a terrific-looking plane.

What is the smallest area that you would estimate you can enjoyably fly the Micromoth?

Aug 26, 2002, 11:52 AM
Registered User
Chris3D's Avatar
Thanks Greg and David. I'd say anything less than about 40' x 60' would start getting tight. It can certainly fly in less, but it'd just be constant turning. Once this Moth gets a little beat up, I'll try to fly it in my front yard, which is more or less a triangle about 60' long and about 50' at one end. The main problem is that it's overhung by trees everywhere - clipping a branch and spiraling into the ground won't hurt as much if the plane is getting old... I'd love to have something that could fly in my living room, but it's simply too small. Plus, I've always been partial to scale models.
Aug 26, 2002, 02:26 PM
Registered User
RC_AV8R_181's Avatar

joining the wings


I've started to build the micro-moth as my first micro rc plane (so of course it will fly perfectly ) and would like to ask a few questions:

1. How do I attach the wings panels together, and give them dihedral?

2. What should the wingspan be? Mne is about 13.5"

3.Is anyone selling a used rffs-100 system?

Thanks for making this great plan available,

Aug 26, 2002, 03:37 PM
Registered User
Chris3D's Avatar
Hi Ben, make sure the CG is no further back than indicated on the plan and it should fly very nicely. As they say, a nose heavy plane flies sluggishly, a tail heavy plane flies once. Also, make your first flight on a very calm day. I've flew mine in some light breezes today and, while it handled them better than I would have expected, there were several times when I recovered from an unintentional wing-over just inched from the ground.

Answers to your questions:

1- Just glue the wings together using CA. There's a slight curvature in the wing root that, once butted together, should provide the dihedral. The ribs should be glued into both wing sections before they're joined together.

2- Each wing is 7 inches so, accounting for the dihedral, 13.5 to 13.75 sounds fine. There should be about 1/2 an inch or of dihedral at the wing tips.

3- I can't imaging why anyone would ever want to do that!!
Sep 03, 2002, 08:28 PM
Registered User

Landing Gear details


Can you provide some more detail about the landing gear. The dimensions of the "V" and how you attach the rear wire into the wing/fuselage would really help me.

Also, what's the wheel diameter?

Many thanks!

Sep 03, 2002, 10:36 PM
Registered User
Chris3D's Avatar
Sorry about that, I'll have to update the plans with this info. I honestly just winged it as far as length of the gear and diameter of the wheels, so this may not be terribly true to scale.

From the forward fuselage, the gear is 1 1/4 inches to the loop around the aluminum tube. It then proceeds 1 5/8 inches to the far side of the fuselage and enters 1/4 inch back from the leading edge. You'll have to put a small bend after it clears the bottom edge of the fuselage so it can pass cleanly up and into the fuselage directly beneath the wing. In both front and back, the wire should penetrate the fuselage about 3/8 of an inch. A reinforcing block isn't really necessary in the back, because any force would try to push the wire up through the bottom wing, and because the side of the fuselage is directly above the wing, there's little chance of that happening. The diameter of the wheel is 3/4 inch, again, just a number I pulled out of thin air, but it looks right.
Sep 03, 2002, 10:42 PM
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Chris3D's Avatar
Woops, I forgot to attach a close-up of the gear...
Sep 03, 2002, 10:45 PM
Registered User
Chris3D's Avatar
And, like an idiot, I again forgot to attach the picture...
Mar 12, 2003, 01:21 AM
Who Says Penguins Can't Fly?
aeropenguin's Avatar
Chris, It is useless thanking you becasue everyone took everything I could have said right out of my mouth. Those plans are priceless! I went to this indoor meet, and it totally changed about how I think about micro and sub - GWS pico servo planes. I found this really cool bipe of someone's there, and when I did some research on it, I found out that about 10 people have done it and it works.
Now you are *feeding* me with plans for these little guys, and now I can't even think of the gigantic Great Planes Giles I was dreaming about.
I got a few questions:
1. Can this be scaled up a bit?
2. Which actuators would you recomend?
3. Can you give me a link to where I can buy one or how to make the one said above?
4. Which motor would you recomend? Where could I find it?
5. would I gear the motor, and how, and which prop to use?

I think that your watercolor paint idea is genious - easy to apply... but does it fade out over time or bleed when water gets on it?

Last edited by aeropenguin; Dec 10, 2003 at 01:12 AM.
Mar 12, 2003, 09:11 AM
Registered User
dhurd's Avatar
All the gear Chris used to put in his Moth and Pitts can be found by clicking on the banner at the top of this forum ( Give us a call and we would be willing to help you out with getting you what you need and answering any questions you may have.

Mar 12, 2003, 09:26 AM
Registered User
Chris3D's Avatar
Hi Aeropengiun, glad you like the Moth and Pitts, and I'm glad to hear others are building them.

To your questions:
1: Yes, they can certainly be scaled up. Someone scaled the Pitts up to 24 inches and, if I recall correctly, it flew fine. I'd say you could still use 1/32 wood anywhere up to about 18 to 20 inches, above that you'd probably want to use 1/16th.

2: I use the standard DWE coils and they work fine. If you'll be scaling it up, you might want to use the Bob Selman/DWE coils (because they supposedly increase the output force by 40%) or the larger Bob Selman ones.

3: Not sure exactly what you're referring to here - the plane or the actuators... Laser cut kits of the Moth and Pitts will be available from DWE at some point, but you can build them now using the plans obviously. You can get the actuators from DWE or Bob Selman

4: I've been using the KP00, it's a perfect match for the RFFS100. You can get it at DWE as well.

5: The KP00 is a motor/gearbox/prop combination.

6: The watercolors didn't fade but it didn't provide terribly vibrant colors in the first place. They're also somewhat heavy - I had to place 2 pennies in the nose to balance the original Moth, and only 1 for the new moth, which was colored with food coloring. I'm sure the food coloring will fade a bit, but being yellow over yellow wood, it shouldn't be that noticeable.

Now get building... ;c)
Last edited by Chris3D; Mar 12, 2003 at 01:46 PM.
Mar 12, 2003, 01:07 PM
aka: A.Roger Wilfong
gnofliwr's Avatar
One suggestion on really light weight coloring if you're trying to do a solid color is to use Rit fabric dye.

The technique I use is to cut the pieces to size, dry fit, take them apart and then finish sand them. Once they're sanded, I throw them in a pan of Rit dye - the longer you leave them in, the deeper the color will be. Finally, air dry them and assemble as normal. If you're really careful with the glue, you could dye them after assembly - but I've never tried it.

I've used this technique on 1/4A-A boost gliders and the total weight gain for the wings and tail surfaces was less than I can measure with a 1 gram resolution scale.

- Roger
Mar 12, 2003, 05:36 PM
Who Says Penguins Can't Fly?
aeropenguin's Avatar
Wow. I hadn't expected so many replies!
Well, I decided that with so many components available for retail, I wouldn't have to scale up. If it flies the same, then the smaller, the more fascinating and interesting.

Hmm, DWE looks like they have a *lot* of good coils. Which specifically would you recomend? I like it to be the smallest (in weight and dimentions) possible so they are less noticable (in the flying and looks).

3. - I am talking about the actuators - who would want to buy a kit when you have plans like these??? They look really easy.

gnofliwr, sounds good! I don't know though, I think that watercolor is a lot easier. I will think about it though.

About the motor, what a relief! I don't know anything about this super-sub micro stuff, so if anything comes as a combo, that is just wonderful!
How fast does the plane fly?
Does all this apply to both the tigermoth and Pitts? If so that would be awesome! Less stuff to worry about, less neccesary to study, etc.

Would I need an ESC?

Which reciever would you recomend?

I cannot repay you enough if you answer all these questions. I am just entering all this micro stuff, I thought everything below a GWS servo and reciever had to be handmade. Now a whole new world is opened up for me - the world of indoor micro RC!

Last edited by aeropenguin; Dec 10, 2003 at 01:18 AM.
Mar 12, 2003, 06:10 PM
Alfredo Rubio's Avatar
WOWWW!!! Chris, you did it again, thanks for this great plan, I am shure it is a fine flyer.


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