Miles Aerovan 36" span scratch build

[baz49exe]

You must have patience in lorry loads Bill.
I'm amazed at the time, skill and ingenuity which you put into hand building all the very complicated engineering in your superb models. I could never have that amount of patience ( or skill) as I'm already wanting to get on to the next build when I'm half way through the present one.

[pmullen503]

Originally Posted by baz49exe

........
I'm amazed at the time, skill and ingenuity which you put into hand building all the very complicated engineering in your superb models. .......

++1 on that!

What I'm impressed by is how much is added to a relatively small model.

[Bill G]

Thanks for the comments Barry and Pat. Barry I have the same problem with wanting to start the next build, as soon as I start the current one. The same goes for flying, where I often fly them only once, and move on. I have to build a new model each time I want to get a flight in.

Started on the sheeting, which you have to be in the right mind frame to apply, if that ever happens. The hardest part is getting started however, and much of the fuse is now sheeted, including some of the higher effort areas. With the curved areas previously inset planked, the sheeting should provide ample sculpting thickness to end up with smooth curves.

[baz49exe]

Bill, the sheeting looks very smooth indeed. I enjoyed the description of super fast finger work using cyano.
All my balsa sheeting work was before cyano ( it probably didn't exist then or I didn't know about it) using white wood glue and hundreds of pins. That was a nightmare to plank with.
How modern materials have changed the building process.

[Bill G]

Originally Posted by baz49exe

Bill, the sheeting looks very smooth indeed. I enjoyed the description of super fast finger work using cyano.
All my balsa sheeting work was before cyano ( it probably didn't exist then or I didn't know about it) using white wood glue and hundreds of pins. That was a nightmare to plank with.
How modern materials have changed the building process.

I can see how inset planking got started. At least that way you could pre-fit the pieces with no pins needed, and then glue the seams with slightly thinned white glue. Applying white glue to the framing and then pinning or weighting the entire sheet in place would be tedious. I'll get a bit of a break with the wing, as the top side sheet can be thin CA glued from the underside. Applying the bottom sheet using my thick CA method is a different story. It will likely be done in several sections. I broke the fuse bottom into sections, so the sheeting pace there was a bit more relaxed than heavyweight boxing.

[Bill G]

I have a fully sheeted wing now. The wing construction has been interesting, using a changing section like the full scale. The full scale uses a NACA 23018 changing to a 2412 at the tips. I used a 23012 for the inner section, which is similar to the 23018 section. Setting washout angles was not quite as simple as using rulers and a protractor across a flat bottom wing. As best as I can tell, I have about 2 degrees. A bit of clamping and adjusting was done with the upper wing panel sheet across the wing panels, before gluing it in place.

[Bill G]

Placed everything on the scale for an AUW of 15.5oz, less battery, receiver, covering, and a small area to be completed at the tailboom attachment. The balance point is close to ideal, and it appears that cg should be set with roughly a 2s-1000 and no added ballast. The motor harnessing is now also in place. A 20oz or under AUW should be achievable, where the lower the better of course. I have a few models this size and even a bit smaller in the 19-20oz range that fly well, although I wouldn't want to be any heavier.

[pmullen503]

Cool! The sheeting/planking looks great.

[Bill G]

Originally Posted by pmullen503

Cool! The sheeting/planking looks great.

Thanks Pat. It's actually faster, easier, and more exiting that covering too. I'm at that lovely covering stage now, where only a little bit is done at a time. I try to finish the more difficult areas first, giving some motivation to finish the job. The nacelles and tail feathers are finished, with the rudders working.

[DHC Beaver]

She's lookin' good,Bill.If I may ask,what is the covering you're using?Some of my Ente will have to be painted,so i have to find a covering that's a close match to my paint.
I don't think the flap travel will be a problem.I have found(sometimes at a high cost) even 20 degrees of flap makes a huge difference to the landing speed.In fact,my problem always has been to keep enough speed in hand to prevent a stall.
Looking forward to the finished product

[baz49exe]

Great silver finish Bill. That has to be a real advantage of using your preferred covering material.
Like the motors nestling in the nacelles in the background as well. Looking good!!!

Barry

[Bill G]

Thanks Barry. DHC Beaver the covering is Parklite, which has become my preferred silver covering. It's easier to work than Monokote, and paints well also. It has an interesting adhesive that is gummier than other iron-on coverings I've used. You have to completely cut through it with a sharp knife or scissors, or the adhesive will pull away from the covering when you attempt to remove a cut away piece that has not been completely cut through. Some advantages are that I believe it will seal well for seaplane hulls, and it also adheres at a low temp, so you have to be careful not to stick it together, like Coverite Microlite. I applied it to clear plastic on my Avro Type F fuse sides, where it was ironed down at a low enough temp so as to not warp the plastic. I would have no issue with using it on foam at lower temps, like Coverite Microlite that also has worked well on foam.

The fuse covering went pretty well, where the idea was to work the covering around the bottom fuse corner rounds as far as possible, without wrinkles or using relief cuts. I managed to just barely get it onto the flat fuse bottom without wrinkling, at which point it was trimmed off. The bottom was then able to be covered across the flat area, without having to work covering around the bottom fuse corner rounds.

For the elevators, I probably should have just said elevators, versus elevator flaps. The flaps will have plenty of travel. The "v" elevator pushrod setup is a bit limited in throw, so more was used in the up direction versus down. There's still a reasonable down amount, although it may need more if I were to try to fly the Aerovan inverted. I could get more down throw from the setup simply by widening the pushrod exit slots in the stab bottom with a knife, but it doesn't seem necessary.

[Bill G]

Nothing terribly exciting, just a few more pics:

[pmullen503]

So cute! Nice covering job.

[Bill G]

Thanks Pat. I'm glad to be almost finished covering also.
After adding the flaps, the wing appears massive. A 13oz/sq-ft wing load or maybe better should be in range, which will hopefully make this a reasonably slow flyer.

[pmullen503]

Originally Posted by Bill G

Thanks Pat. I'm glad to be almost finished covering also.
After adding the flaps, the wing appears massive. A 13oz/sq-ft wing load or maybe better should be in range, which will hopefully make this a reasonably slow flyer.

I would think you could find a partial flap setting that would allow a nice slow cruise. I have my Beech D-18 set up that way on a 3 position switch. Up for (non scale) aerobatics, a partial setting for a nice scale cruise, and down for landing. My Beech is 16oz/sq-ft but larger so the cubic load is probably similar.

Can't wait to see all parts assembled.

Merry Xmas!

[HO-229]

Looks Great Bill...

Dave

[Bill G]

Thanks for the comment Dave.

Originally Posted by pmullen503

I would think you could find a partial flap setting that would allow a nice slow cruise. I have my Beech D-18 set up that way on a 3 position switch. Up for (non scale) aerobatics, a partial setting for a nice scale cruise, and down for landing. My Beech is 16oz/sq-ft but larger so the cubic load is probably similar.

Can't wait to see all parts assembled.

Merry Xmas!

Pat I had similar thoughts about having the flaps partially applied for slower flight, although I'm not sure if I could have a middle setting with the transmitter I'm using. That and a few other issues are things that the DX6i I have are lacking in, including more model memories. It will be interesting to experiment and see how the flaps work partially applied. The plane's almost all together now, with a few farings to be installed and covered.
I guess it's onto Happy New Year now!

[xmech2k]

Looks great, Bill! How did I miss this progress?

Anyways, I feel your pain with the Dx6i limitations, so I upgraded to a Dx8! (OK, so I [I]felt[I] your pain!) It's a world of difference!

[HO-229]

Always a joy watching you craft aircraft Bill…
That tail arrangement on full scale aircraft has been problematic at low speed with the critical engine out… not that it matters much for RC
Saro or Blackburn made something very close to that aircraft in the years following WWII, it was designed with the intent to ferry autos.
It has been a while friend, life has a way of pulling us in other directions, some good, and some not so good but all are part of God’s plan
Dave

[Bill G]

Xmech I'm due for a DX7 or 8. When I first got the 6i it was a big deal just to use the DSM2 micro gear. 10 models seems like a lot, but goes quickly, as I just stripped a receiver from a good flying Guillows C172 last night for the Aerovan. It was targeted since the C172 will be fine without the programmable features. If I took a receiver from one of my unflown models, then it would probably never have a chance of ever being flown. Some of my models that may never be flown again are spared from receiver pirating, since the receiver would be a real pain to get out, and even worse to ever reinstall one if I wanted too. ...and then there's the thought of ever having to reprogram them, like the Dayton Wright Rb1

Dave the Bristol Freighter would be a good car carrying subject. I thought about it, when I chose this subject. They used them to transport several cars across the channel along with their drivers. There's a nice plan for the Freighter on outerzone.uk. Similar in size and construction to the Aerovan: http://www.outerzone.co.uk/plan_details.asp?ID=1217

[pmullen503]

Originally Posted by Bill G

Pat I had similar thoughts about having the flaps partially applied for slower flight, although I'm not sure if I could have a middle setting with the transmitter I'm using. That and a few other issues are things that the DX6i I have are lacking in, including more model memories. It will be interesting to experiment and see how the flaps work partially applied. The plane's almost all together now, with a few farings to be installed and covered.
I guess it's onto Happy New Year now!

Looks good.

It is possible to do 3 position flaps on a DX6i using the gear and flap switches and the mixes available. IIRC it's not intuitive. Probably easier to adjust the the linkage for the "up" setting to give a slower cruise speed if feel you need to. Having a TX where you can map the flaps channel onto a pot is really nice to work out flap settings. Something to look for in a new TX.

[Bill G]

Originally Posted by pmullen503

Looks good.

It is possible to do 3 position flaps on a DX6i using the gear and flap switches and the mixes available. IIRC it's not intuitive. Probably easier to adjust the the linkage for the "up" setting to give a slower cruise speed if feel you need to. Having a TX where you can map the flaps channel onto a pot is really nice to work out flap settings. Something to look for in a new TX.

Correct, the settings are not that straightforward. The same goes for my ditching the dual aileron function, since it uses the flap channel. This plane shouldn't need differential, but it can be good to have a bit without having to go the mechanical route. I may be able to reassign the gear channel to the flap switch, while still having the flap channel available for the differential mix as per the Spektrum dual aileron function, but again it's a hassle. Of course there's always simply using the gear channel for the flaps, but again that's not technically correct, and if you flew a number of planes with flaps, it would be confusing.

On the scale, the plane weighs 17.25oz without battery, and will weigh between 19-20oz AUW depending on the battery used. Couldn't ask for better balancing, as there will be no lead used. An 800mah puts it at around 25%, moving the CG a bit forward with a slightly heavier battery. I generally don't fly long flights, and a 1000mAh will probably be about right. Although the motors call for 2s lipo, I may use a 3s with a bit of throttle conservation. The Heads Up RC 250 Sport outrunner calls for a 2s lipo with GWS 6040 props, but I believe it would tolerate 5" props on 3s, at a bit less than full throttle, although the scale 6" props look better. At managed power, I believe that even the 6040 GWS props would not overload the motors on 3s, as 100W should be more than adequate for this plane.
Motor used:
http://www.headsuprc.com/servlet/the...0-Sport/Detail
Given the wing loading and AUW, I don't think this plane will require anywhere near full power. It's reminding me of the GWS Islander that I gave to my flying buddy, that flew around reasonably well on anemic 300 brushed motors with 5" props. I installed heli outrunners with 4.5" props in the plane for him recently, and it's far overpowered now.

I'll have some pics up soon, as the plane is nearly complete now.

[Bill G]

Finished at around 19oz AUW with lipo batt, give or take a small amount depending on the battery used. I also cleaned up the canopy mold a bit, in the event that I'll ever make another. With all the snow here, it's tempting to attempt a flight with all the added ground padding. I probably would want to rog, although it is possible to get a reasonable grip on the wide fuse, behind the main gear struts. Counting the flap area, the wing loading is in the 11-12oz range, which should hopefully float reasonably well. The model may get G-AILM blue registration markings, as it is a full scale silver Aerovan with round windows.
http://www.retrogreen.co.uk/lightaircraft/aerovan.htm
The wrinkled ply on the full scale provides a good excuse for any of waves found on the model.

Now the question, what next? I had been interested in the American Gyro Crusader, but it's too similar to this plane for a next build.

[pmullen503]

Looks great.

Here's a project for you: Edgley Optica


I've thought about attempting it with a painted canopy though you might be able to get a battery under the seat and use a clear canopy. Maybe even a pair of smaller, thinner batteries in the wing. At 40" WS the fan is almost 6" in diameter. I was thinking ducted prop rather than an EDF.

Loads of interesting structural challenges, right up your alley!