Thanks CP that should eliminate all the force on the carriage upon the release. Trying to lift the hood ring off of the hood pin just isn't working, the hinged arm to hold the hood pin will work perfectly.
Thanks again!

A SD with those engines should get up and go.

Demon #2 is ready to cover. This one will get CA hinges. I found a pair of HS225MG's that I'd forgotten about, so a Demon maiden two weekends in a row just got a lot more probable. HS81 on the throttle, just like #1. The fin area might be a bit marginal, only flight testing will tell. Since it's on the hatch, a new fin and hatch are easily made and fitted. I think this one will be black on yellow.

Nice,

I've "designed" a couple deltas with not enough fin and they tend to get bassackwards at launch.
I brought packing tape, ruler, scissors, file folder [card stock], rags and solvent to a couple test sessions and was able to arrive at fin areas that worked. Pretty much the definition of Cut and Try.

This single fin delta looks nice..!

For those eyeballing the proportions and wondering, the forward CF spar is centered on the CG.

Gonna need a BIG delta for this..

"Roarin' Demon"? Demon #2 is ready for the RX, switch and battery. Haven't weighed it yet, but it can't be much different than #1. The maiden will be this weekend. Once trimmed, this thing is going to get passed around like a drunken cheerleader. I may even set it up on a buddy box. I now have everything I need for the electric Demon. I need to bench run it and do some watt-meter pulls with different props to get a feel for it.

[It would also look cool with a rudder......]

My "boss", neighbour, buddy.. is a developing RC flier. Believes in learning by force, but has fun. I had the SImple 400 in the stable at the time, it was a very precise and stable flier except it did about 125 at full tilt and he was scared of it. I had gentle low rates on it and throttled down and he flew a few laps and handed it back nervously.

I buddy boxed it with him next.. I got it to height, and he took over with confidence and pinned it most of the flight.

2lbs,9oz. CG is spot-on with no ballast. Ready!

You've put us all to shame - well except maybe CP - with your productivity..

I go through phases in my building. I'll build like crazy for awhile, then take time off. Sometimes several months. ARF's enable this behavior, plus I don't crash nearly as often as I used to. (Knocking on wood) You just happen to have caught me at the beginning of one of my building binges. I can build 3 Demons in the time it took to assemble and set-up one of my giant-scale warbirds. The Demons are a helluva lot cheaper, too. I need to build another Herr 1/2A P-51 too, as my first one is almost worn out. I think I've solved the problem of stuffing enough battery into an electric Demon. I need to sketch it out fullsize and see for sure. I'll let you know what I come up with, Mike.

Love to see ideas. With an open center bay, i.e. no center CG spar, you can submerge two 2500 3S packs in the root.

Or one 4500 Mah.


The root airfoil came out 2 1/4 inches thick with the outside sheathing. I wanted to keep the wing as thin as possible at the root to keep the frontal area as low as possible. Only the font spar was cut out the rear spar was left in it's original position, with the battery all of the way forward in the picture the front spar is an inch forward of the battery leads (The battery is 6 inches long).

The easy way is to put the batteries where the tank and engine normally go, with a pusher motor at the rear and the radio in between. No need to interrupt the spar. A heavy enough battery would make it work fine. With a single fin used as a handle, launching by the pilot would still be possible. Since a tractor prop is destabilizing and a pusher prop is stabilizing, the fin could be made a bit smaller as well. Just another idea that I had.

Just won an auction on a 32SX on Feebay. $49.00, delivered. Comes with 2 mufflers. Used, but looks very good in the photos. We'll see how it REALLY looks in 4 or 5 days.

Well....good luck!

$32 for a SX delivered great find!

Your right a pusher setup is the easiest and has several advantages. The one down side is the prop is in dirty air and cannot reach it full potential as far as speed. There was only one full sized speed plane built as a pusher, in the aerodynamic forum they really talk it down quite a bit as far as potential for speed applications.
With my setup it balances with the battery back about another inch and a half so most of the battery mass is right on the COG just a bit forward. With the motor I am using the battery has to offset the weight of the electric motor which is lighter than it's glow counterpart.

Still I do like the idea of less fin with the pusher it should really reduce the induced drag considerably and still sounds like an idea worth trying.

Edit to add:
With my Demon using the sheathing as stressed skin pretty much eliminated the need for the forward spar. A a side note my Stingray has no spars, it is all stressed skin construction where the wing is only 3/8 of an inch thick. One of the things Mike Conner and I had talked about was to thin the wing out on the demon even more going out to the tips. That was part of the experiment with building wings 3/8 of an inch thick to start with.

For the purpose of electric versions and IC versions (esp RI) where having the tank on the CG is a plus, and a bigger tank is a good thing for thirsty engines too. I have a version with relocated spars already drawn up and near ready to proto. The working filename is "45RIRE-SD".

I am curious as to the spar treatment you used.

Just got home from the field and I'm waiting for the pizza to arrive. Demon #2 got it's maiden today. I flew #1 first to make sure my thumbs were OK. They were. Fired up #2 and it was howling nicely, sounding even better than #1. I put an APC 8-7 on #2 to see what effect it had on the launch. I still don't think the header is short enough yet, but it was close. Upon release, the torque-induced left turn was much more pronounced. Acceleration was unbelievable. Low passes were easily 10 mph faster than #1 with it's 8-8 prop. Several guys said the speed difference was even greater than I thought it was. Regardless, it was very obviously faster than #1. I didn't put a GPS module in #2. I will correct that mistake shortly. #2 has the ringed engine that was in my Proudbird. The completion pics I posted showed it with a Macs muffler. I changed my mind and put a pipe on it later. Sure glad I did. I didn't fly #1 again the rest of the day. #2 got the living hell flown out of it, 6 or 7 flights (I lost count). As long as I give it the attention it deserves, it's a total no-brainer to fly. Point and shoot with no personality. My favorite kind of airplane. Does only what you tell it and does it instantly. After #1, I knew I really liked the Demon. Today, I fell in LOVE with it. For a while, I couldn't go 20 minutes without flying it. I flew the F-82 twice just to break up the Demon flights. It's a fun all it's own, but paled next to the Demon. Thank God tomorrow's a holiday and I can spend another day at the field blasting around like a madman. I got 2 set-in-stone orders for Demon ARF's today. Wanna sell a Demon? Just fly it. The only question at that point was which engine and what colors. Most fun I've had in quite awhile. Thanks, Mike.

Cool.

Having fun, are we?

Great report!

Great report Mike..!
No doubt this is a great "Motor Sport" once you get interested in the engine and prop work as much as the actual flying.
With the added ability to clock speeds right there at the field and film the results, it has really expanded the hobby for a lot of us.
I'm still mired in a nasty automotive project [building a console and speaker boxes out of plywood and FG] and am looking forward to getting back to some Speed Delta flying.

Oooops.forgot to ask about the single fin. Did you see any signs of "swimming" or fish tailing at any speed...?
What are the dimensions of the fin...?

That Jeep will never fly, Chuck. The only sign that the fin might be too small is the left turn as it leaves my hand. I can level the wings within 10 yards or less of the launch, so I don't think it's worth enlarging the fin. In flight, there has been no wobble, wiggle or any sort of "looseness" that I can detect. Very solid. The Demons are already in the car so I'll measure the fin when I get home from the field and post the numbers. Off to the field.