1/8th Miss Llumar Double Wing

[Doby]

Ok, Heres one open for suggestions and opinions.

My Llumar came close again to a blow-over this weekend so I'm thinking of adding a second, adjustable front wing

On the way home from the pond, I stopped by the local RC Heli club and asked if anyone had a bad day! Some of the members took me to their fields garbage can and there in front of me was what I was looking for, one slightly used blade

Any thoughts on mounting/adjusting, its going to be in between the sponsons, just looking for any ideas I haven't thought of yet.

[SJFE]

If it where mine (& I'm guessing here) I'd cut the 2 small ones off the cockpit and replace them with the adjustable rotor blade sections. It makes sence to me at least.

[G Doggett]

Adding a front wing will definately hold the nose down but is a lot of work so I would try the following items first.
Is the c/g too far back ? - should be 1.5 - 2 inches behind sponsons.
Is there enough lift from the prop? - might need to angle it down or run it deeper.
Can the rear wing be adjusted to provide lift? This worked well on my old 1/8 Tosti Asti hydro.
Finally you might need to add weight to the front of the sponsons to move the c/g forward.
On my FE H & M Spider, which was designed for NiMH cells, when I went to lipos it was way to flighty but this was solved by adding 125 grams ( 4.4 oz ) inside the tip of each sponson.
I experimented with stick on mag wheel weights adding more until it stayed on the water and then added the same weight using lead shot and epoxy inside the sponson tips.
Worked for me, and is much easier than adding a wing.
Graham.

[Doby]

Thanks Graham, the CG is pretty much bang on and I would hate to add extra weight as its a bit on the "portly" side already. The rear wing has no adjustment capability. The prop angle seems fine, I still have to experiment with props though.

I have to keep in mind that this was designed to go about 30-35 Mph max in its original gas configuration, and I'm pushing it to almost double that.

Its time to get creative

Possible soluton below.

[G Doggett]

The carbon fibre wings do look cool and will certainly help provide down force.
Because of their small relative size compared to the hull surface I think you will have to have them angled up at least 20 degrees, at least thats what I found when I was trying to tame my Tost Asti.
If you were to add this to the full trailing edge of the front wing instead it would have much greater effect and therefore could be smaller.
Sorry to harp on about it but if the hulls angle of attack was altered by raising the transom with a deeper strut, you will be surprised how this helps prevent hydros taking off.
Graham.

[Doby]

I'll look into that further Graham, Thanks.

[Mich. Maniac]

Hey Doby I dont have any area of mounting advise but looking at the beauty of the boat I would hate to see it get torn off in blow over. I like the mounting of the last pic and it looks safe from any "snagging" in a blow over. Which I know you are trying to correct with it but, I wouldnt mount it on top of sponsons or anything and if you feel you need to I would make it outta raw basswood incase of blow over the wing will shatter rather than pull your mounts out creating jagged holes or cracks.

[Doby]

Thanks for Mich!, I agree that they are in a reasonably save place in that location!

I've pretty much decided on the last pis or the final mounting place, now I just have to get up the nerve to drill more holes in the hull

[wickedgmc]

I have the gas version with a little work on the top of the motor and it runs about 45 mph. I found by lowering the rear 2 screws on the strut 2mm that it put the nose in the water pretty good and did not slow it down any, before that the front hopped around from side to side alot

[62 bugzilla]

wing

Has anyone made the wing adjustable using a sevo off a 3rd channel so you could adjust it while driving. I know the real boats use a adjustable wing on theirs and they adjust them all the time. I would think for example going into the wind you could pull the bow down and away from the wind pull it up almost like adjustable trim but using the canard. I also like the air brakes an the saw rigger to slow him down.

[Jeepers]

just cut the original front wing out and make it adjustable!

what I did on my H&M Lifter for the front wing, was drill a hole all the way through the sponsons (inner and outer) and use brass tubing glassed and glued into place, then I drilled a hole through the wing and inserted brass tubing through it. I then polished a piece of piano wire and inserted it all the way through both sponsons and wing, trimmed it slightly shorter than the width of the hull and epoxed both holes on the ouside of the sponsons, the wing will now pivot and just use adjustable brackets on the underside of the wing.

[SJFE]

Has anyone made the wing adjustable using a sevo off a 3rd channel so you could adjust it while driving.

Bugzilla I posed this same question. I was informed that while in full scale hydros an active control surface is effective. Models are a different story. You do not have the reaction time needed to keep a model from blowing off the water. If it's going to go over it will and there is nothing we as drivers can do about it. Our only options are a fixed adjustable wing and proper setup /

[G Doggett]

I have seen a 1/8 hydro set up with an adjustable front wing controlled by a gyro.
If the front lifted the gyro would kick the wing up to push the nose down again.
It was one of those situations where it was a great idea in theory but proved to be too complicated and just something else to go wrong.
An adjustable wing that is set at the best position after experimenting seems the best option.
My first rule is always 'keep it simple'.
Graham.