CafeenMan

How to not install your radio

GrnBrt

My Feedback: (5)

Well finally, someone who agrees with me about those ez-connectors on the control surfaces!!!! Had a guy that flew at one field that used them all the time, warned him but he wouldn't listen and he lost a plane. Now the guy is a real dummy as he shows up with a new plane and you guessed it, all ez-connectors!!!! Now that radio set up tells me that the guy who built that plane hasn't a clue on how to do it right!

Tall Paul

Many of my buddies use EZ-connectors on their primary flight control surfaces on large airplanes.
None have lost planes to this, although they should, theory says.
I'll use them on throttles and small aircraft but nothing larger than a .15 sized sport plane for a control surface.
It depends on the individual realizing what is going on I expect.. and some of the guys I've seen use them are real dim-bulbs, but no problems with that particular style of connector have been observed.

CafeenMan

Tall Paul - I've seen a lot of planes with those types of connectors that do fine. But what I forgot to mention on that page is that I've also seen several planes that had them come loose. In the last few months alone I've seen several trainers (ARF's built by newbies) have the ailerons come loose. Fortunately, they had so much glue in the hinge line that the ailerons wanted to stay neutral - that's a whole other issue.

But the fact remains that those types of connectors have several ways that they can fail that I have personal observed. I see no reason at all to even take the chance just because they might work. In fact, if I were a safety officer, I would simply outlaw them for any flight surface. A solder clevis is much less likely to fail easier to install and costs less. A Z bend is almost as easy as a solder clevis and it's free. Snap links probably cost less and are very easy to use and secure. With all the options that are better, it just makes no sense to me.

I've never had any type of connector fail in all my years of flying except EZ connectors. I've never had one on a flight surface, but I have used them on throttles and nose gear stearing. I won't ever use them again though.

Steve Lewin

Agree about the EZ connectors, I've used them in the past without ever having any problems but I don't like them. However you will keep seeing them because lots of ARTF trainers come with them as standard.

What fascinated me about your page was the suggestion about doing the radio installation before building the fuselage. I can't see how that works at all. Could you expand on it ?

Steve

CafeenMan

It's simple really. You measure the distance of the servo arm from the bottom of the mounting arms on the servo. Use that measurement to figure out where to locate the mounting rails in the fuselage.

Glue the rail supports to the inside of each fuselage side. That's pretty much it. I didn't mean you can actually install the servos inside something that hasn't been built, but you can make it so that when the time comes the rails just drop in and they're dead even.

A little more info is here. Next time I install a radio I'll do another how to.

Charlie P.

I like the EZ connectors for throttle and even use the dreaded servo-saver (an EZ, two springs and two wheel collars - one more set-screw to fail) for a nosewheel linkage shock absorber.

Would never put one on a control surface linkage.

foxx

My Feedback: (2)

Cman I totally agree with you. It is insane to use EZ connectors on anything except may be throttle. I used them once for ailerons and ended up landing with full rudder.

CafeenMan

Actually guys, as much as I don't like EZ connectors, I probably should move that to the second item. Because what I don't like even more than the connectors is the way the servos are mounted. Those grommets are completely crushed and the servos are not even close to being in the same plane. One rail is about 3/8" below the other. You can see the mounting tabs on the servos actually bending under the force of the mounting screws. The whole thing is just bad news.

Also, you can see that the pushrods are being pulled down and that's got to be creating a lot of drag in the system.

I admit that it took me several models to get my act together regarding radio mounting, but now that I know better, I just want to pass it along.

NCC-1701

I agree, EZ connectors on flight surfaces are a formula for a crash. I only use them on throttle cables. For my flight surfaces, In use Z-Bends for pushrods and clevises for pull-pull cables.


Rob

TTARK

I agree about the EZ connectors. I like to use a 90 degree bend with keepers on the at the servo end and METAL clevises at the control surface.

Terry

foxx

My Feedback: (2)

Do you guys know a good place to buy metal servo horns ?

Charlie P.

Sullivan makes them - Tower sells them. I've never used them, but I like other Sullivan products

http://www2.towerhobbies.com/cgi-bin...?&I=LXFV34&P=7

Search on "Sullivan" This is just the smallest of many.

steve-kerry

There's a lot of talk about servo mounting rails here - I haven't used them for years. Here's my method:

1. When you build the fuselage, put a layer of glass cloth on the inside instead of plywood doublers. Glass is both lighter and stronger.

2. Put heatshrink around the servo cases (the same stuff you get around battery packs), then stick them to the glassed fuselage sides with bathroom silicon sealant. This is strong, light, and provides as much vibration resistance as a set of grommets (although vibration hasn't been an issue since I game up slimers ).

3. If you ever want to get the servo out again, just slit the heatshrink.

I've never had one come loose yet!

CafeenMan

Steve - I like the idea you have presented and will try it out on a future project. I have a question though...

If you remove the servo, then how do you remove the silicone so you can put the servo back? My experience with trying to remove silicone is that it's a pain in the butt to remove the stuff and often I can't get it all removed. How do you do it?

steve-kerry

Silicon is wonderful stuff! When the servo is in place it grips like glue, but once the servo is out you can peel the heatshrink off like sticky tape. The silicon can then be rubbed off with your thumb, just roll it off like it was dried rubber cement. Different brands of silicon will vary, but for our purposes they all work pretty much the same.

Try sticking an old servo or nicad to a wall tile as an experiment. Give it time to cure, then see how much force it takes to pull it off - far more than your poor servo will ever encounter in the air.

And don't forget to put the heatshrink on the servo first! Otherwise you have to get a long blade in between the servo and the fuselage side to cut it free. Guess how I know that?

CafeenMan

Hmm... well the reason I asked is because I've used silicone to make wing saddles and I couldn't get the excess off to save my life. But I will give it a try. I also like the idea of glassing the inside of the fuselage instead of using doublers.

What do you think would be the maximum size plane you would use silcone on? I guess it's not just size, but would you trust it in an FAI pattern ship for example?

Also, do you apply it in a thin layer or do you put it on fairly thick? How much can it flex under load?

Mike P

My Feedback: (2)

CaffeenMan,
You and the other posters convenced me!
I just swapped out the EZ connectors on my Miss Texas for 90 degree bends and keepers at the servo. We will never know, but you all may have saved my bird. Thanks.

steve-kerry

Different brands are going to behave differently, some are a lot stickier than others. A bit of experimentation is probably in order.

I normally put a spludge on the side of the servo, spread it out a bit, then press it against the fuselage side. You only need a thin layer, I aim for 1/32 at most but if you've got one of those vibrating noisy things up front, you might need more. I wouldn't go above 1/16 though.

I can't say if it will work with an FAI pattern ship, because I've never flown one! Do a test on a tile or scrap of glass or whatever (a tube of silicon lasts a lifetime) and get an idea of how much flex you will get for different blobs of silicon. You'll soon figure out how much is too much because it squishes out the side when you stick the servo down. For the ultimate stickiness, wipe the surfaces down with meths or alcohol before applying the silicon and don't touch it with your bare fingers afterwards, because fingers are oily. You should find the servo arms break off before the silicon lets go.

If you ever do need to cut the stuff off, remember a new razor blade or scalpel is essential. You can't cut silicon with a dull blade.

Cactus.

My Feedback: (1)

Saw this at the field today, the rest of the plane isnt much better and it gets such a hard life that 90% of you would have seen nothing like it, yet you know this plane will go on and on and on and IF something fails it'll all come lucky.
don't you hate these people.
lets spot the mistakes....

CafeenMan

Philly - I'm thinking about adding a whole new section to my web site called "Bad Examples."

problem is I don't know how people at the field are going to feel about me going up to them and saying, "Say, that's a really poorly done engine installation. Mind if I photograph it and bash it on my web site?"

CafeenMan

PS. I really like the glued on servo arms. Other than being dirty (is that ground up grass???) it looks mostly ok. That servo arm needs to be replaced though.

Cactus.

My Feedback: (1)

it's yellow paint over spray. the yellow and back wire is his aerial
the wood isnt expoxied the best either, the trainer is way over powered with a 36 on a pipe and he flys like a control line flyer, i kid not. i have to video him one day....

there are loads of pics on the club web site of this guys planes, car, engines and such, all taken in good humor, as is this pic which i also uploaded on the club site.
theres lots of good humor pics on the site, go have a look.
www.rcflyers.net

as long as you use good humor your section shouldn't make you public enemy number 1

CafeenMan

I don't think the paint really hurts anything. I wouldn't do it, but there are several guys in our club using external servos that they left mounted and painted along with the rest of the model. Look at the helis. I have a Raptor and the tail rotor servo drips oil after every flight. I've worried about it but the other heli guys say it's not a problem. I'm still not convinced, but so far they've been right. There's really no way to put a servo directly behind the exhaust and keep oil off of it.

I know what you mean about control line. In fact, just two days ago I asked a guy if he had control line engine in his plane. He said, "No. Why?" I asked him if he knew that R/C engines had throttles.

He knew what I was talking about and he's a friend of mine, so he laughed.

Cactus.

My Feedback: (1)

http://www.rcflyers.fsnet.co.uk/gwyn.htm
his own page! on the old "fsnet" club site. not part of the new site but a great collection of his best pics. other members use car trunk rubber seal to stop heli servos vibrating!!!!!