MTK

Bob's right on the mark with the Tech Aero IBEC. Ed came up with an outstanding little gizmo that does exactly what it's supposed to. The filtering Ed uses in the device just about eliminates any RFI from the CDI unit getting back to the RX. Cost is about what you'd pay for the extra battery and switch harness

Installed as instructed, ignition is activated from the TX (retract channel is convenient On-Off switch), and requires no extra switches or anything like that in the model. The LED light is fairly bright and can be seen easily in daylight.

It eliminates the need for a separate, TX activated "OPto Kill Switch", a second battery as Bob stated, and a second switch. Also, if your TX allows preset default settings in the event of signal loss, you can preset the TX to kill the IBEC (retract channel or other). Of course, if for some reason the linkage came off on the carb in flight and your engine just wouldn't die, rather than waiting for the tank to be burned off as one would have to do in a glow application, just flip the switch assigned on the TX when you are ready to land.

It is an excellent safety device and I highly reccommend it. Between the two of us (Bob and me) we have about 500 flights on them, trouble free. Many other guys are running the device and by now the flights must be several thousand

Sbach342Guy

Sounds good to me. I'll add it to my ever growing wish list.

Sbach342Guy

How much weight have you guya used to balance this thing with a DLE-30? I started the engine for the first time today. It sounded great and started pretty easily...once it got primed anyway.

Sbach342Guy

Also, what throws and expo should I use for a pattern type setup? I have no intention of doing any 3D flying. The manual lists 3D throws which will make this a bit twitchy for me I think.

MTK

Don

Did you decide to run the DLE on pipe? I'd be interested in your set up if its piped. Particularly interested in the wrap around header

I don't know if any one else is using a DLE in their Xtra. Most everyone I have heard from is using the SAP or electric. My SAP equipped Xtra has needed about 6 ounces of nose weight to fly reasonably well (pattern like) and could probably use another 3 to trim out better. Mine weighs in at about 11 3/4 lbs now.

Been giving some thought to removing the SAP and putting the ZDZ40 F3A in to remove the dead weight and add even more pop.

Sbach342Guy

I'm using a canister muffler. Thought pretty hard about using the ES30 tuned pipe but since this is my first gas plane I decided to keep it simple...and cheap. The ES30 is $200 and doesn't come with a header.

Harvey Mushman

My Feedback: (10)

Will a 10S 5000mAH pack fit? I see most are using two 5S packs.


vbortone, which instrument panel do you have? (photo in post#99)

MTK

Do you mean a single 10S?? I doubt you will have any fit problems. Fuse is a cavern inside
2 5S packs are normally used by the pattern crowd. Either way it won't be a problem

tarts

Hi MTK

I just got mine and I will be using a DLE-30 with ES pipe. I also need to make it as light as possible, do you have any updates how your lightening upgrades have worked? Is the thin tail gear wire holding up or your CF/balsa Firewall? What would you do different?

It seems that new versions have all closed firewall box (no hole cut on top side) and it's also shorter, which allows the DLE 30 with back carb to be mounted with no modifications.

Im also planning to make a soft mount, kinda. Not the conventional type but I'm using rubber grommets. partially because to save weight. (a picture will come later)

MTK

My mods all worked great, except they took too much weight from the nose. The plane flies tail heavy. Stab is heavy at around 9 ozs so if you can make a new stab at about half the weight of the original, it will balance better with the lightweight DLE up front.

Canopy is also heavy at 10 ozs. I build a new mold and glass canopy weighs about 2/3rds the weight of original part. If you want to buy a glass canopy from me, PM me

tarts

I'm in europe so i would have to make my own if i wanted. I weighted mine and surprisingly it was 220g (7,7 oz). That's a big difference I'd say.

kochj

My engine box seems to be 1.25 inches too long...
6.25 from wall to prop hub, places my engine hub 1.35 PAST the cowl !....

ANYONE else, notice that the cowl has NO right thrust built into theres???
MINE has NONe and is way off....

I even tried placeing the end up and moving engine to match cowl. and center it....Horrible results....

Anyone else have theres like this???

I have have many diff. planes and have NEVER had this happen before....

MTK

Here are a couple snaps of the fiberglass canopy. The white coat is epoxy primer, Klass Kote. Excellent stuff.... sands easily and feathers as it should.

As shown, fiberglass work weighs in at 3.6 oz and the balsa internal structure adds another 0.4 ozs. so AUW as is, is 4 ozs flat. After final paint and spring lock attachment install, weight should be no more than 5 ozs or about 50% the weight of the original

tarts

wow it looks good.
What did you use to make the outer mold?

MTK

Thank you! The original canopy was used. The plastic is adequately smooth to use as a plug as is. You can see edges of the mold in the picture showing the balsa internal support structure

tarts

I have polyester resin based gelcoat. Could I cover the canopy with that using some "mold release" wax, and then cover with glass to make the mold? I'm worried that the polyester will melt the canopy. Or should I use epoxy based gelcoat ( "Klass Kote"?)

MTK

I don't use polyester based resins to build molds. I use epoxy exclusively. The "gel" coat is typically a very hard resin such as West Systems or Pro Set. These are expensive (about 75$ per quart), so the less you use the cheaper the molding process.

The reinforcing layers are added with a cheap resin such as Aeromarine epoxy which is around 50$ per GALLON. There are other cheap epoxy sources like US Composites. These resins are adequately hard and stiff (but not as hard setting as the premium resins) and work great as reinforcing layer resins. These control mold cost

I lay down 1 layer of 1 oz first to settle the base gel coat and then 4 layers 9 oz glass cloth as follows: first and last layers are orthogonal. Middle two layers are on bias. Produces and very stable stiff mold. I finally add some thin plywood framing to the outside to hold the mold in the orientation I want, to make lay-up easy for me

tarts

Here are the pictures I promised.
Added weight comparing to regular hard mount is 28g. I could make it a little more lighter if I'd use carbon components, but this is still untested so we'll see how it works first.
The brown and white tape is teflon tape that I used to lessen the friction between washers and firewall.

kochj

I am not cutting you...But, I wouldn't do a soft mount connected to the Carb. screws...
too great of chance to suck air.... when flexing.... the carb/case seal...

Also...having the that interference (rods off the carb) can effect performance...or so the experts say...

They even recess the mounting screws for clean air flow...
Not sure if the same matters for planes, but a engine, is a engine...

kochj

Matt...
Is the gell coat like TOOLING epoxy?

Here is my firewall...
cut it and moved back..
Also, centered the engine on the MIDDLE line, as so the cowl lines up with the spinner, and the prop to the cowl...
The picts were Before I made the change... to move the engine center line..

MTK

Not not really. It is the regular laminating epoxy with filler added. I don't have a problem with tooling grades but for the amount of parts I pull from any mold, it doesn't make sense to use tooling type gel coat.

My version of gel coat is simple: epoxy such as West Systems of Pro Set (Both are Gougeon Bros products and both cure very hard), about 1/2 tsp of carbon powder per 75-80 grams mixed epoxy, about 1 tblsp milled glass, and about 1 tsp fumed silica to thicken a bit. The gel coat should be somewhat loose but thixotropic enough to stay put. It is applied with a mediun soft brush and allowed to kick off. It has to be stable but tacky

Then a second layer is applied over the stable but still tacky first. That is allowed to cure fairly well before applying the reinforcing layers. You don't want the reinforcing layers to telegraph through to the mold surface.

I am sure there are other methods that guys use that work well for them. This approach has worked well for me for a very long time for the kind of layup performance I want.

If I were to go into higher volume production (not going to happen BTW...too much like work and no longer a hobby), I would do things differently (aluminum molds are superior in every practical way but much too expensive).

Take a look at my Derivative thread in the Pattern Forum. I just finished casting the fuse mold for that model

Sbach342Guy

Maidened my Extra today. Even with dual rates set pretty low this thing was a bit more sensitive than I expected. Landed her pretty much immediately to reduce aileron travel. Second flight was a bit better but I should have adjusted elevator by the same amount as the aileron. Only did two or three passes before landing since the engine sounded like it was running a bit rough. It stall on final approached so I had to do a dead stick landing. Put a few more tanks of gas through the engine on the ground but didn't get to attempt a third flight. I had the field to myself the first two flights but someone showed up when I was getting ready for a third. I prefer not to have an audience when I maiden a new plane. Maybe tomorrow...

tarts

But I was very pleased with the way it preforms. For the first time I set up the expos to 55%. Even with full trows the plane is not very abrupt, but it will be if you want to. All the manoeuvres are very smooth, very close to simulator. It tracks good too. I have only noticed that in upright harrier it wants to tilt left quite badly.

Mine came 5044g. But I had to add one extra battery pack( 3 packs on the plane right now) to make it slightly nose heavy(about 5135g ATM). In the future I'll remove ignition battery and install a CF spinner (about 45g) to keep it balanced so it will be about 5090g. That is perfectly fine for me since F3A rules are not so strct here and there seems to be plenty of thrust with this DLE-30/ES30G combo.

Sbach342Guy

Got out for a quick flight tonight since there ended up being zero wind. Engine sounded a little weak on the ground and even worse in the air. I've only gotten three flights on the DLE-30 and it was already in dire need of a tune up. No dead sticks or anything but it was running super rich. Anyway, with the tweaked low rates this thing was much easier for me to fly. When I got home I yank off the cowling so I could fiddle with the H and L needles. After a few adjustments mainly to the L needle it was running great again. Weather is supposed to be good again tomorrow so hopefully the wife will let me out again for a bit. I should be able to really fly it now that the engine is running well.

MTK

Have wanted to run a DLE 55 in my new pattern plane design, but before commiting, i wanted some run time on the DLE. What better test bed than the Xtra?

Here are some pics of the retrofit. Out came the SAP180 and later the ZDZ40. Graduated up to the 55cc. Here we go with the soft mount build and installation