Parramatta Radio Control Aircraft Club

Full Version: Q & A Thread For Newbies & Old Hands Alike!
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Where are you going to get it from Frank. The Australian distributor doesn't import the 140 anymore, I know because I was talking to him yesterday because I need a new fuse for mine. Might have to settle on the 140 3D Monster, which is just a Sukhoi 140 with even bigger control surfaces. I haven't made my mind up yet on what to do, its a shame to bin an aircraft that just needs a new fuse.
Im not getting the sebart , just showing the motor performance . Ill be getting the super n cheaper yak 55m 72" , 2nd. Best choice.
New question.....

Is there a sort of filler I can use to cover over foam? I had an accident that managed to take the nose off a plane. I have managed to glue it back on, but the impact compressed the foam so it is no longer a neat fit. Is there something I can use as a filler to smooth it back out?
(27-03-2013, 03:43 PM)BenR Wrote: [ -> ]New question.....

Is there a sort of filler I can use to cover over foam? I had an accident that managed to take the nose off a plane. I have managed to glue it back on, but the impact compressed the foam so it is no longer a neat fit. Is there something I can use as a filler to smooth it back out?

Yes. It's available from Bunnings for around $5. It's Ready to Use Pollyfilla Interior. Mine is a 100 gram tub and lasts for a couple of years if you keep the lid on and the interior waxy paper over the contents. When you pick up the container you'll think it is empty. There is also another stuff that you can get from hobby shops which is microscopic bubbles of foam that is mixed with an adhesive before use.
you can also buy solid foam cones from spotlight for a couple of dollars , just cut them down to size and bingo , glue the new nose cone on , sand to shape , and paint / or cover .
A question: Can someone please explain differential to me?

I understand the reasons why and wherefore about differentials in land vehicles, but as I have found nothing transfers over to the air.

My assumption is that you'd have the up travel more limited than the down travel of the ailerons, I am sure I'm probably wrong.

I have been setting everything up with a Y harness and running the 'rons off a single channel up to now, but time I started to learn more stuffs I think.
Yeh, you've got the fundamentals mate - differing amounts of up and down travel. Whether you need it on the ailerons is a function of the wing type, amount of dihedral and aerofoil. For example, if you're using one of the KFM aerofoils, airflow might be turbulent above the wing and laminar below - in that case you might want more throw up, than down.
It's sometimes also used when the plane demonstrates an adverse yaw (the ailerons are used to roll in one direction, but the plane yaws against the roll - this happened to me when I built my first trainer off plans and I ... made a few ill-considered alterations to the design).
Thanks Steve.
With adverse Yaw, when you roll in one direction the plane yaws in the other. This is because the up going wing is producing more lift, obviously it needs too, to go up, but it's also producing more drag than the down going wing and the extra drag on the up going wing causes the model to yaw in that direction. differential can be used to over come this as Smuzz suggests, by having more aileron travel on the down going wing (more upward movement of the aileron) and less travel on the up going wing (Less downward movement of the aileron)

I hope this is not confusing, just remembering that for one side of a wing to go up, that side's aileron must go down and it's the down going aileron that causes the most drag.

It's more pronounced if the ailerons are mounted outboard on the wing, because they then have a greater moment arm. It's also more prounounced if the wing has a lot of diheadril. As Yaw couples with diheadril to create roll in the direction of Yaw and this will opose the disired direction of roll
A simple way to add differential without complex radio tuning is to set the zero position on your aileron servo control horns leaning towards the front of the wing slightly... about 10 degrees or just move it forward one or 2 splines on the shaft that way the aileron will physically move a greater distance when the aileron moves upwards and a shorter distance when it goes down... If you are having a little trouble understanding the principal... see me down at the field next time and I will show you how easy it is to set up.
Thanks guys, I do get it, but it is completely barse ackwrards to my assumption, being that the inner wing turns a tighter radius so it needs more throw on it's control surface... car stuff again Tounge

But the two wing type examples here are relevant to the next two planes I have lined up in my progression, the Ultra Stick 25e, because it has ailerons that extend from nearly the wing root to about 2" from the tip, and Seen McCoy's advise to grab the Advance 25e we had (now in my garage) to cut my teeth on before I take up the Suk', because that has the same long control surfaces plus dihedral.

The DX6i has a dualron and differential mix for dummies, so that bit is not a problem, but Gazz, that mechanical trick with the horns is a ripper, so bloody obvious now that you say it... I've already cut the Stick's push rods to length so that will go with the mix.

Just thinking as I type, a good learning experience for me with this might be to maiden big Sticky as is with the y harness and then start messing with differential rate when I am used to it's behavior... but could be wrong about that again...
few questions .
#1 how do you reverse a servo without a servo reverser or tx function ?
#2 on an 8 channel receiver . if i want to use 2 channels for ailerons and 2 channels for elevons how do i do that . ?
#3 BEC / and inline switch . * ok rx battery to switch -to BEC- to rx and an aux to volt display led /or use Y lead from battery to voltage display .
#4 What about your esc i'll be using turnigy K FORCE 120V . If i connect this 12 cell setup to the esc , and the rx supply hasn't been switched on is the esc powered up ? or does it rely on a receiver signal before it starts counting cells ?

receiver ports/plug sockets , 1 throttle, 1 rudder , 2 aileron , 2 elevon , 1 bec power supply ,1 , 1 voltage reader . am i on the right track this negates all Y Leads . and uses 8 channels . with telemetry plugged into the bind port - i hope ?

or the alternative . receiver battery y lead ( 1 to voltage reader - 1 to rx supply .
aileron y lead ( to each aileron servo )
elevon y lead ( to each elevon servo ) - with one servo reversed .1 telemetry module this only uses 5 channels and 3 y leads .

thanks in advance .
i bought an inline sliding switch from JAYCAR , for $2 seem to be a little better quality and bigger more heavy duty than the HK ones , just have to solder it up to battery and receiver leads .
Bloody Hell Frank
These questions and a few more will be answered after these commercials from our sponsors..... or see me down at the field and I show you, that will be much easier than trying to explain it all here.
In the mean time, there are plenty of YouTube videos showing how to pull a servo apart and re-wire it for a reverse rotation but I've never done it myself.
Samste can explain it to you, but once again a visual thing will save a thousand words.
hoping i can use dual channel elevator with one channel reversed on tx . that will solve that problem .
i'll also use dual aileron channel setup .
with VOLTAGE READER i'll use Y LEAD from battery plug . or should i use bec out voltage ?
(26-04-2013, 06:19 PM)wingtipper Wrote: [ -> ]hoping i can use dual channel elevator with one channel reversed on tx . that will solve that problem .
i'll also use dual aileron channel setup .
with VOLTAGE READER i'll use Y LEAD from battery plug . or should i use bec out voltage ?

All you do to reverse a servo is swap the wires to the servo motor and swap both outside leads on the sense pot.

Can show you tomorrow or do it for you tomorrow night.
(26-04-2013, 05:41 PM)gbanger Wrote: [ -> ].... but once again a visual thing will save a thousand words.

Correct - which is why I was suggesting a browse through YouTube.
As long as your radio has the channels Frank we can do what ever you what... once you have been shown for the first time you will be able to adapt it to 18 channels if you need them...
Hi Frank,
I had to reverse a servo on my E-Flite AT6 Texan which uses 2 servos for the elevator and I didn't want to add a servo reverser so I chose to rewire one of the servos.
Have a look for a thread I started called "Servo Info" in the general forum, Link below

http://forum.rcflyingclub.com/showthread.php?tid=288&pid=5077&highlight=SERVO+iNFO#pid5077

Cheers
Chris M

(edit, added Link)
Wayne
Here is the link to the balance boards you need.

http://www.hobbyking.com/hobbyking/store...oduct=8821

Gazz
Thanks Gazz but just for something different, they are on backorder
I am in the process of replacing a wing on a UM T28, and as part of that, I need to glue a servo onto a piece of foam, where the servo has no plastic housing. What sort of glue should I use? Will CA or epoxy damage the servo?

I normally use Hot melt glue to put servos in. If U use epoxy I normally add some filler to thicken it a bit. I never use CA I'm allways worried about it wicking into the servo and sticking up the works.
(22-05-2013, 10:42 PM)BenR Wrote: [ -> ]I am in the process of replacing a wing on a UM T28, and as part of that, I need to glue a servo onto a piece of foam, where the servo has no plastic housing. What sort of glue should I use? Will CA or epoxy damage the servo?

UM planes are made from styro and will melt away if CA is used.
Hot glue could be risky on thin surfaces and the heat could melt it.
Your safe if you use the foam glue/white tubes you get with most ARFs.
http://hobbyking.com.au/hobbyking/store/...l_20g.html
i would use epoxy in this situation
Has anybody used these ESC's before
Are they any good?

http://www.hobbyking.com/hobbyking/store...oduct=4691

I am just about to order a few things I need and they are out of stock of the Kforce speedies I usually use.
I have on in my HK yak it's driving a G160 on 12S
I had it in my ugly stick before And it worked flawlessly
Thanks Jason
I will put a tick in that box then
Hey all, dumb question time.

Is 36mhz still an approved band at MAAA clubs or has it been booted to the kerb?
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