Royal Models DG-808 - Build Log

[thenated0g]

I didnt comment on it but the flaps are actually concerning to me as they have almost no downward travel at all. I was considering making them spoilers as they hinge up. But your idea is better. They are just taped on anyways so not that big of a deal to swap them around.

 

[Konrad]

If using tape or film hinges don’t forget to use a stiff floating plastic index to keep the surface aligned.

TopModel Samsara 3.2 meter glider, build thread on Aloft's Forum.

Here is another post for a "How to thread". The manual is very poor on this topic. After aligning the wing to the fuselage one is to use tight fitting drills to transfer the wing hold down holes to the fuselage. But we are not to tap threads in the hold down plates. Rather we are to use...

forum.alofthobbies.com

 

[gp49]

I didnt comment on it but the flaps are actually concerning to me as they have almost no downward travel at all. I was considering making them spoilers as they hinge up. But your idea is better. They are just taped on anyways so not that big of a deal to swap them around.

Nate, if you set up your controls and couple the ailerons to flaps (or camber adjustment for 'Speed' setting) , just remember you will need to relief some of the flap at the upper side so that the flap can go up.. Silicone hinges maybe?

 

[Mucksmear]

Looking really good! Something I learned from my Alpina (but haven’t corrected yet):

With bottom hinged flaps, even if you don’t plan to reflex them, it’s still good to bevel them so that an upper surface gap remains when u raise the flaps to neutral (gap can be covered with a gap covering tape adhered only to the wing’s TE.

Invariably when u land on a slope site, grass, seeds, small twigs and other debris will end up in that gap just as you are raising the flaps as you touch down. It will bind and buzz your flap servos. Not a perfect solution, but simple enuf.

I may eventually cut off my flaps to bevel their LEs for this, plus I think I’d like to have them follow the ailerons a bit

 

[thenated0g]

Being full span controls, how do you guys usually decide the neutral position of the airfoil? Ruler in the bottom?

 

[Konrad]

I like to use the reflection method. That is I look for something that is straight, that I can see in the reflection of the covering. I then find the surface setting that distorts this straight line the least and call that the in profile setting. I do this reflection test for the top as well as the bottom surface. And if I have to, I split the difference. Now I'm not an aerodynamicist, so remember this advice is worth what you paid.

 

[Hill Hobbit]

To get aileron neutral, put the winglets on, then align the ailerons flush to the winglets. Then align the flaps to the ailerons.
Cheers

 

[Hill Hobbit]

Setting up the ailerons/flaps as above should see the flap roots aligning with the wing roots moulded into the fuselage.
Best of luck, I hope nothing’s warped!
Cheers

 

[thenated0g]

Oh yeah good point @Hill Hobbit I forgot I did have some references on the ends.

 

[Konrad]

I like to define my primary and secondary datums, and maybe my tertiary datums as a function of their importance (criticality). As such "I" think that the surface setting is the primary concern and try to set them to the airfoil profile. I then set the tip to the profile defined by the wing and surface if the aileron goes out that far. I place little or no importance on the root fairing on the fuselage. If I have to, I've been known to reshape the wing to fuselage fairing after flight testing with putty per the writings of Hoerner (expanding radius).

 

[Hawaii Sloper]

What about your quaternary, quinary, senary datums?

 

[Konrad]

All depends on how many planes you want to work in. In the real word 3 usually is enough to define any point in space (position of the surface).

 

[thenated0g]

Finally took a look at my 4 door jeep and one of the wings. Looks like it will fit just fine, with or without the wingtips on. I am considering just taping on the wingtips. I glued the reinforcing rods into the end of the wing. Ill see how much play the wingtips have just sliding them on later tonight.

Took a while to find the correct spot for the servo to sit and radio setup but got the Brake servo installed. I set it up with 90% power/throws so that if i needed a little bit more in one direction, or the servo moved a little while the glue was setting i had some throw to play with.

 

[Konrad]

Looks like the spoiler is fitting real well. I see you call it an air break. While true it usually act more as a spoiler, dumping (spoiling) lift from that section of the wing. The response will be to make the ship feel like it is much heavier. I hope this helps, as it will effect your thinking on how you approach the landing zone and your landings.

 

[thenated0g]

Part of my reason for posting this build log is for others that get the model. The manufacturer calls them "Air Brakes" in the manual on all the ships they make so thats what i will keep calling them. I dont want to confuse people who then start looking thru the instructions for spoilers.

 

[thenated0g]

After the Gorilla Glue set on the wingtip carbon rods, i slid the wingtip on and it is super solid. No movement at all so taping those on should be fine.

Messy shop


Air brakes - Ailerons - Flaps
Because of time i left flaps as is and just went with simple Z bends.


One modification im doing is to skip the included servo covers. The plastic is super thick and it has a really big bump to it, a lot of drag. The size of them will not fit over the holes unless you leave them as they are. So im going to use some if my wider but flat diy ones in 2 thou styrene as all my servos are below the surface.

 

[Wayne]

All good stuff.

 

[thenated0g]

I have a schedule and i have to stick to it lol. Only a few weeks left.

 

[thenated0g]

I think im going to have to diy some kind of rudder hinges. The ones included totally dont work or i have no idea how to make them work.
When snapped on it is extremely hard to move. And just a little bit of movement in either direction pops them off the rudder.

 

[Konrad]

What doesn't work? They don't grab onto the imbedded pin? Sounds like a clearance issue with the relief slot.