It's been a while since I've started a thread. In a week or two, I'll be finishing up plans that approximate the shape of a completely scratch built Maule Orion semi-scale. I've had the plans that I've drawn up gradually since I believe about 2 years ago.
Motor is a deeply geared 16/15/3 Mega Motor brushless on what will likely be a 3S lipoly or a 4s A123 pack. 6 channels, rudder, elevator, throttle, ailerons with reflex, and flaps. Light balsa contruction is planned, and it will be a gentle aircraft, not too hot, and not too sedate. Should be nearly the same size as a .40 model. Most likely going to be a tail dragger. No pictures of the plans will be up until I have them finished. I think this thread will help me hold to a schedule and actually get the thing done.
I decided on the gear and prop size about a year and a half ago. I think I have something like 6:1, 7:1, unusually deep for most setups. I'm swinging a big prop so it'll be a bit slower (15 incher at around 5k-6k rpm if memory serves me right), but It will have a fair amount of static thrust. I will also have a very efficient propeller. These mega motor 16/15/3 motors can handle an awful lot more than you might think. Given the right gearbox, you can run a 6s-8s setup. Stay under 45 amps and get plenty of cooling, and you'll be alright. My math said I'd be pulling around 30 amps static if I remember correctly, probably 20 amps in flight in a strong climb. An interesting side note, I went with a full scale fuselage in this model, so by my improper English that means the wings should still be inside the cabin. Actually, I just mean the fuselage will be a unique detail to the model, as it will be larger than those on some .40 size models. The fuselage will not have a whole lot of detail on the inside, however it will have the unusually large window doors the characterize some of the aircraft Maule has released. I think I went with the long nose similar to how the turbine version looks. Not sure though, have to dig up the plans a bit. I only have the rudder and elevator left to draw, next I'll be making a parts list and headed off to the store. I have a nice scroll saw (DeWalt) for cutting out the parts. I'm pretty excited to get to use it for a model... finally!
Alright, the penning is complete and I ran over to staples, got 2 sheets copied AND a digital copy for less than 10 dollars. Not bad! I'd upload the file here, but the file size is too great. Several lightening holes will be made with a scrollsaw, I will probably add more ribs, perhaps some 3/8" x 1/16" balsa strips capping over the 1/16" spars, simplification of unnecessary detail, etc.
I have both PDF and jpg images.
Here, I re-sized the jpeg so there is at least a picture to see:
BTW, the image I was scaling from was not a Maule Orion, it was a Maule M-5... oh well.
If you would like a copy of the plans, PM me with an email address to send it off to.
Ok, building time is around the corner and I have a pile of wood waiting to be turned into a model. I'd most a picture, but it's just a bunch of balsa sticks. Nothing that interesting. As I am limited on space I will start by building the elevator and rudder first, while I usually start kits by building the fuselage first then the wing. Totally reversing the order this time around! Look forward to a few pictures in the coming days.
All the balsa has arrived, and we're off to a start:
Left wing is mostly done, with carving, a spar system and covering left to do... I will probably use an aluminum tube for the spar, and a pin to lock the trailing edge into location. The build is heavier than I anticipated... should still have plenty of power left in the motor.
The image used a flash in the dark, next pictures should look better.
Finished the other side of the model, access hatch is complete, some of forward sheeting is done, now I need more plywood to replace the temporary braces supporting the snout of the model.
I've run some more predictions on motocalc... seems like it will be a fine flying plane. Not sure what prop I want, but if I wanted to kick it up to a 14 x 10 prop, I would be pulling around 32 amps WOT, ~350 watts, 3.5 lbs static thrust and a pitch speed of ~54 mph. Just right. A bit more power with a parallel pack setup. Cruising at half throttle, it can fly for nearly 30 minutes (4s1p), and nearly double that with a 4s2p setup. Got to break out the fish scale and ammeter for reality.
4S1P or 4S2P for in flight... extra cells are for other models. Got a great deal for them at battlepacks. They're much lighter than I expected, and after testing the voltages, the largest deviation I saw was by 3/1000 of a volt. Most are within 1/1000 of a volt of each other. Very high construction tolerances I'm sure. These are the same cells used in the Tesla Roadster. The shrink covering is very pretty, like a fluorescent chartreuse pearl.
The cells have since been soldered together. One note of advice if soldering A123's together, use a powerful soldering iron, and get aluminum flux for the oddball side if the cell. Soldering job worked on that end, but it isn't gorgeous looking. Other side looked normal.
And I wont get by without posting some progress pictures. I have since built up an elevator for the model, I've broken apart the temporary spacers in the inboard wing panels, and brass/copper (of that general type) tubes are curing in a mix of epoxy and microballoons at the inboard wing panels.
I now have I believe 3 1/2 or 4" trexler balloon wheels for this plane too. Wahoo it's going to be a bush plane!
I will be tearing out the balsa where the wing mates the the fuselage (on the fuselage). It's simply too weak for the stresses that it will undergo in flight, I'll be changing it out to basswood, spruce, something much stronger than balsa. The weakest link is like gluing 4, 1/4" square balsa endgrain to four points on the wing of a 40 size model and calling the wing mount good. You'll see what I mean in the picture. At least I got the general shape down.
Progress is slow, haven't been too busy of late, just need to get at it. I finished all the major parts, so it's now a sorta-almost-ready-to-cover model. I'm dreading figuring out how I'll fix the wing mount (probably need fiberglassing... egh) and the nose section (fiberglass again). I guess it's time to man up.
I applaud you for all of your work on this exciting plane. As a young pilot I met and flew the M5 with Mr Maule when the factory was located in Moultre GA. It was a pre Turbo model. but still a great plane to fly. I am now retired and into building RC. Working on a P51 now, but would love to build this exciting Maule. If the plans are still available, I would love to have a set. My Email is "firstname.lastname@example.org". I now reside in Indianapolis.
If i am planking a part that is going to get glassed i fill in the holes with light drywall compound then sand to shape and then glass . It sands easy and is light ,glassing does not mind going over it.. joe