Mini Delta Foam Rocket Glider Conversion

[Crawf56]

OK, time to balance the model on the Center of Gravity [CG]. To begin, I put a new (un-used) motor in the back.

 

[Crawf56]

Here, my thumb and forefinger are on the model's CG (the one given in the Mini Delta's instructions for flight). I have added weights to the nose until I get it to balance.

Note that I also have my battery in the compartment below the canopy. Looks like I need four of the 7 gram weights.

 

[Crawf56]

So, let's cut a hole in the nose.

 

[Crawf56]

...and fill the hole with weights. And a little hot glue.

 

[Crawf56]

Here is a look at the receiver and battery in the compartment under the canopy.

 

[Crawf56]

The Mini Delta has an All Up Weight [AUM] of 187 grams. Of that, 47 grams is the plugged D12-0 motor.

I hope all goes well, but I am expecting it to be a bit squirrelly on launch, do to the short nose. We shall see.

 

[Crawf56]

Adding the launch lug for the 1/4" launch rod. Initially used 5 minute epoxy, followed with a bead of hot glue on each side.

 

[burkefj]

This comment is just that, a comment, don't take it in a bad way, I know everyone has their own preferences in the way they do things, for me I prefer a straight shot of pushrods and servos perpendicular to the hinge line, I don't like multi bend pushrods and especially don't like when the control horn is at an angle to the hinge line as it puts a sideways stress on the horn and can cause them to come loose...I would have cut a partial pocket into the wing or just glued the servos to the wing so they have a straight shot to the horns. Your method will probably work just fine, it's just not how I would do it because I worry about everything failing. I don't even like ez connectors because the screw can loosen even with locktite...Another note, you could have moved the motor hook forward, and shortened the tube and gotten the motor another inch forward to help CG, but maybe you didn't need that.

Keep going, I like seeing these sorts of conversions....

 

[Crawf56]

OK, here is the Mini Delta on the launch pad.....

 

[Crawf56]

Annnnnnnd ……. it had a 'successful' flight.

Here is my "after flight" pic to prove it.

 

[Crawf56]

The glide after launch was pretty good.

But the launch was another story.

See, I was concerned that I would need a lot of "throw" [elevon movement] on my return glide. So, I had the model set on the 'high' throws of 3/8 inch up/down.

This was waaaaaay too much for launch. For about 2 seconds after the launch, the model seemed to be all over the sky. I finally got it pointed relatively 'up'. Then I had to worry about very touchy aileron roll, but got the model in a good glide angle.

I will adjust the elevon throws to the 'low' rate of 3/16 inch up/down.

 

[Crawf56]

A few other observations:

1) The little experiment was made with existing parts & motors that I had laying around. This is NOT the way to go, if you are interested in getting into rocket gliders.

2) The quick, high thrust of the Estes D motors is quite a challenge, compared to lower and longer thrust of the Aerotech reloads [Dynasoar Rocketry].

3) I conducted this flight out in the middle of nowhere, and it was relatively damp. When you are messing with a new model, make sure you are at a safe location.

 

[burkefj]

Good news, glad it worked ok.

 

[Rktman]

Glad to see all your efforts and revisions paid off with a successful flight, congrats!

 

[Maxout]

Awesome conversion. Would love to see video when you get the flight trim dialed in some more.

 

[Crawf56]

Well, he's dead, Jim:

 

[Crawf56]

So, what went wrong?

After my first flight, I thought I needed to reduce the throws on the aileron & elevator movement. So, that is what I did....

The problem is that I reduced the elevator movement too much. I did not have enough elevator throw to pull the Mini-Delta out of its launch arc.

In a low wind day, it went almost straight up. Arced over, and hit the ground at roughly a 60 degree angle.

The wing and ailerons are relatively undamaged. And the nose could be fixed. But I rather put my time on more viable projects.

 

[Rktman]

Sorry to see the 2nd flight didn't turn out as great. My rocket hospital has lots of patients like that all waiting for attention. They're "someday" projects that I actually get around to occasionally--even if only to peer at them and ponder what to do.