jmess73

I posted earlier that I recently aquired a DD. I didn't get any paper work with it, I was wondering if someone could give me the proper control throws and CG placement, also any tips that might help get me started with this particular plane? I have flown fast planes before, not quite this fast though, I have also hand launched many different styles too, but again not quite like this one, any help would be greatly appreciated.

Jeremy

Cyclic Hardover

My Feedback: (3)

The closest I have to that is a Shrike. Good friend has a DD with a hot Rossi up front. I recall him once saying, you don't need much throw. After seen it fly many times, that thing will roll 20 times before you realize what happened. Did you do a search in this forum on the plane?

wdennie

the paper work i have and i flew mine like this, it all possible throws with 100% expo on airlerons and 60% on elevator, now this is negative expo, they fly really well with this setup and only need very little control input to move the plane you will be satified with it

Razor-RCU

My Feedback: (50)

Red Alert! If you fly with minimal throws make sure that when you come in to land, that you have enough elev. to flair--- In other words set-up your dual rates so you can have a little more on launch (to correct from left thrust prob.) and more on landings when there is LITTLE air moving over your control surf.

While in flight tiny throws are enough for most-

I have never tried 100% expo. (maybe 40%) but I am used to small control movements (read- finger movements-) and I like having a ton for landing and for fast rolls- I even have triple rates on my 9C but I cant say I use 'em all the time-

Mike Connor

My Feedback: (5)

Jeremy,

The plans show the CG range from the center of the front spar to 1 5/8" in front of that position. The Dust seems to fly best with the CG at the rear part of this range as the forward CG limit requires a lot of elevator for landing. The manual suggest a starting point of 100% expo for ailerons and about 60% for elevator. A good starting point is 3/8" up and down for ailerons throws and 1/4" for elevator. A forward CG should use 3/8" for elevator. The above info is from the manual or plans.

The manual also has you assemble the spars, ribs, leading edge, motor mount and trailing edge being held together with rubber bands. Make sure it is straight and glue with thin and medium CA. I used only CA glue except for fuel proofing and the fin tabs for more working time.

My first Dust balanced at the forward CG limit with a large engine and I did not have expo or dual rates at the time. 3/8" elevator was hardly enough for landing but more throw got very touchy at high speeds. Moving the CG back to just in front of the front spar and expo made things better.

jmess73

Thanks for the info, I'll check it out. For the record I did not build this one, I got it off Ebay. It came with a Jett engine, I'm not sure wich one , but it looks like a quickie jett 40, besides looking at pics from Jetts website, how can I tell which one it is? Any tips on hand launching? I'm flying a Tufflight Predator and launch that with no problems, but this one doesn't have the same type of vertical fin.

Jeremy

Mike Connor

My Feedback: (5)

It looks like a Quickie Jett to me. Bob should chime in to confirm it though. With that muffler you will probably have the best luck with the 8.75" and 8.8" pylon props. I would seriously consider investing in a Red Jett carb. With well over 100 flights on a Jett powered Dust I still wouldn't like to fly it with out a throttle. Just getting it to a launch location/position at full throttle could be dangerous at full throttle as there is not much to hang on to. I usually had someone launch mine by holding both wing tips and just letting go while pointed about 30/45* up. Others do launch their own but I suspect not in high wind conditions. There are two Dust launch videos on my site.

jmess73

If your sugesting that my engine doesn't have a carb with a throttle, it does, do quikkie jett motors come without a throttle on their carbs?

Jeremy

HighPlains

My Feedback: (1)

Quickie engines (Jett and Nelson) do not have carbs like a normal RC engine. They have air valves used to shut down the engine at the end of the run. You tune the engine with the valve wide open (down 500-800 rpm from peak). However, you can "throttle down" by closing the air valve somewhat. The mixture will go rich, and the engine will drop down off the pipe and run at about half power. Launch it there, then open the air valve and hold on...........

FlooredCOBRA

One thing.

I am not sure what all types of planes you flwon before but the DD is fast. May be one of the fastest prop planes you ever flown. It will for sure put a smile on your face!

Easiest way to launch is 35-45' up and a slight tilt to the right. Have who ever launched the plane just let go of it not toss it. I found it works best of you dont give it a shove. Or if you launch by your self hold thumb between elevons and launch same angle.

Let us know how your first flight went and what you thought of the speed!

bob27s

My Feedback: (19)

That is indeed a quickie-jett .40 428 pylon engine. Distinquished by the carb/airvalve, spraybar installation, Nelson style glow plug, and the shorter/fatter Q-500 muffler. Hard to tell from the photo if it is an R1 or R2 crankcase.

It does NOT have a fully functional carb. That black carb is an air-valve carb. Although you can roll the 'throttle' back a little bit (no less than 3/4 throttle), the function is mainly as an engine shut-off. If you try to pull the throttle back much past 1/2, the engine will quit.

Jett's true 2-needle r/c carbs are colored red, and the fuel inlet is up near the center line of the carb block.

The engine must be propped so it turns over 19K rpm on the ground. Preferably it should hit a ground peak rpm over 19,500 rpm.

The APC D-1 series 8.75x9W and 8.8x8.5 are good props to start with. If the engine is in good shape, either one will peak near 19,800 on the ground. You want to launch them slightly rich somewhere just near 19,000 rpm. If the engine is a bit worn, you may want to back off on the prop a bit. It will run fine, but the important part is to get the rpm up into the correct range.

Any questions...... feel free to post, pm or drop me an email

Bob

Mike Connor

My Feedback: (5)

You mean red, right?

bob27s

My Feedback: (19)

DOH ! Yes, red. [X(]

jmess73

Wow, I'm glad you posted that, I would have FREAKED!!! when my engine wouldn't run like a normal engine /carb setup! Ok then how the heck do I start it?????? This is going to require a very steep learning curve for me! I can get a normal carb for it right? Will it make a performance difference? I would gues that Jett also services there engines, would it be a good idea to send it in?

Jeremy

Rudeboy

Put on the glow power, close off the muffler outlet, and hit it with a strong starter. It should fire after a second or so, when the fuel has reached the engine.

You can get a nomal carb from Jett, and it will cost you a few hundred rpm off the top end. It may be a good idea though, because no throttle on that thing will make for some "interesting" flying...

You can also get a head that accepts normal glow plugs from Jett.

jmess73

Whats the advantage if changing the head? Is it just a cost thing? It might help to what kind of glow plug is in it now, so I can get some replacements, and where to get them.

Jeremy

Rudeboy

It's not really a cost thing... Nelson plugs aren't that expensive... It's more a matter of being able to pick up a plug whenever and where ever you want.
Nelson plugs can be had at [link=http://www.pspec.com/]Performance Specialties[/link] and [link=http://www.pacifier.com/~dcady/]Darrol Cady[/link], to name couple. They cost little over 3 bucks... like I said, it's not a cost thing.
If you don't mind ordering 10 or 20 plugs in advance, then by all means, stick with the Nelson plugs, as they offer slightly better performance compared to standard plugs. Jett advises the Nelson HD plug for the Q500 engine...

bob27s

My Feedback: (19)

You can run it as is if you want. Im sure you will have not trouble.

Startings is easy. Start off (initially) with the needle about 4.5 turns out. Get the engine a bit "Wet" first by choking ... put your finger over the muffler outlet, and spin with the starter. Then remove your finger, and spin it again a bit. Hook up your glow....use the starter - it will fire nearly instantly. Let it run there for 10 seconds. Turn the needle in for peak rpm (briefly), then quickly back off 800. Launch the aircraft.

After that, simply back the needle out 1/2 half turn from where it last ran. start the engine. Wait about 20 seconds, then turn the needle back in the 1/2 turn where it was

If you set up the engine properly, the fuel system is ok (and you do NOT fly it out of fuel..shut it down on time), and you do not get a lean run, the plugs will last quite a while. My practice Q-500 has had the same plug in it for 40 flights.

Perf Spec, Dub, or Darrol can supply you with plugs. They cost about the same as regular plugs. Order the HD type.

You can purchase the 2-needle r/c carb if you desire. All of the current carbs feature the remote needle arrangment. Just drop Dub a note for the current pricing. [email protected]

The conventional plug head button is available too - this must be fitted to the sleeve, so it would be best returned for service to make that change. However, even a good K&B-HD or Merlin plug will not last nearly as long as a Nelson plug in the 428 engine. That's the reason we do not use them. Its worth keeping the Nelson style plugs.

Bob

jmess73

Thanks for all the help, I'll let you know how I make out.


Jeremy