Servo installation info requested
 

I'm looking at installing the Futaba S3003 aileron servo into the wing. I have re-inforced the servo bay with the included ply and the servo fits in quite nicely. However, I'm not sure of the best way to mount it. The manual states that the grommets and brass ferules should be used but there are not many of these supplied with the 6EXA. There are various other fittings included, including small grey strips with two holes in them and some small metal inserts. Are these also used for mounting the servos ? Whatever, I use here, I need enough bits left to mount the other three servos.

Your assistance concerning the best overall strategy is appreciated.

Thanks

RE: Servo installation info requested
 

netdudeuk,
Ok, let's see if we can get you squared away here. For each side of the servo you are going to need 2 of the rubber mounting strips and 2 of the metal grommets. Look at picture #1 and you'll see what I am talking about. You put on if the rubber strips on the top and the bottom of the servo mounting lug. Notice in the rubber mounting strips there is a small split in it, this will line up with a tab on the top of the servo mounting lug. Picture #2 and #3 show how to place the rubber mounting strips. Once you have them in place you will insert one metal grommet into each hole from the bottom of the servo mounting lugs. It's very important that these go in the bottom. In picture #3 you can see the metal grommets in place. Picture #4 show them all in place on the servo mounting lug.

Once you have this all together on both ends of the servo. There is one more point that is very important. When you mount the servo you will place the servo in the mount and then put a screw in each mounting hole to secure the servo in place. When you tighten down the screw you want to STOP when the screw head JUST TOUCHES the rubber. See the last diagram to see how it all should sit. This is very important to do because this setup provides isolation from vibration for the servo. If you tighten the screw too much the servo will no longer be isolated from vibration, and vibration can kill a servo in a heartbeat. So it's very important to no over-tighten the mounting screw.

Please feel free to ask any other questions you may have about this. I hope I was able to clear it up for you.

Ken

RE: Servo installation info requested
 

Ken

Thanks for the prompt and comprehensive answer. It all seems clear but there is one question. Please will you confirm that the metal inserts have the 'flat bit' at the bottom and not at the top ?

I've been doing electric parkflyers for about six months and am now build a nitro trainer. So, there is much to learn. Thanks for the kind offer of additional assistance. With people like you and P C (and all the others too numerous to mention) around I'm sure that there will be decent answers for my (anticipated further questions). Of course, I'm not against doing forum searched first LOL

RE: Servo installation info requested
 

Netdudeuk,
Yes, the metal grommets go in the bottom part of the servo mounting lug. Look at the last diagram that I included. The flat part of the metal grommets must sit between the bottom of the servo mounting lug/rubber mounting strip and the surface that you are mouting the servo to.

Ken

RE: Servo installation info requested
 

Ken, what an awsum response. You get an ATTABOY!


David

RE: Servo installation info requested
 

Yes, he's a top guy :-)

RE: Servo installation info requested
 

BTW, please tell me that you didn't just take those pics !!

Thanks

RE: Servo installation info requested
 

Ken,

If you get any better with the digital pictures and illustrations your going to have to start charging RCUniverse
for graphics!!!

Bruce Bennett

RE: Servo installation info requested
 

netdudeuk,
Ok, I won't tell you. But it's true. I snapped the pictures when you asked your question. It's the only way to get the exact info that I needed!!!! :D

Bruce,
Psst, psst. Say that a little louder, and stand a little closer to Marc (RCAdmin) when you say it!!!! ;)

Thanks guys. But I'm just trying to do my part to help out.

Ken

RE: Servo installation info requested
 

RCKen.. you are the greatest!! Those are great pictures and diagrams. In fact, if you don't mind, and with your permission, I would like to capture them and include them in my club 'Training syllabus'.

DS.

RE: Servo installation info requested
 

Oh, hang on ! I've just detected some shoddy workmanship !!

While I mentioned the S3003, Ken could only be bothered to get out a S3004 :D

That could have had me well confused LOL

RE: Servo installation info requested
 

Picky picky!!! ;):D

RE: Servo installation info requested
 

Of course, he could also have added some graduation marks onto the grid so we know how big it is :D

All joking apart, thanks Ken

RE: Servo installation info requested
 

Hey, wait a minute...

That's MY illustration! :D

CGRetired, you may use any of the images we post here. However, if the image says " © RCUniverse.com " we ask that you add:

"Used by special permission from RCUniverse.com"

RE: Servo installation info requested
 

RCKen and MinnFlyer, you guys are above and beyond. You're good for the hobby. My hat's off to you.

RE: Servo installation info requested
 

Thanks JP, it's nice to know that what we do is appreciated. ;)

RE: Servo installation info requested
 

What you guys do is more than just appreciated, I can tell you that. Everytime I read a post and see either Minnflyer or RCKen as either the author or i a reply, I read every word. You guys have helped me along very nicely in several areas and I appreciate it.

Minn.. I ROGER that request as I have in the past. Anything you give me that I use for any purpose (publish it in our newsletter for example) gets the appropriate credit where credit is due.[sm=sunsmiley.gif]

DS.

RE: Servo installation info requested
 

Ken,

2 questions;

1. Do you predrill the wood (a smaller pilot hole) into which you are placing the screw?
2. How the heck to you tell when you have applied just enough torque to place the screw head onto the rubber, or "bottom" of the groument. Deep in the hulls of those fuses I'm lucky if I can see the darn screw.

Thanks,

Jim

RE: Servo installation info requested
 

Thanks CGR!

DrFrier, How can you tell? You can't.

My basic installation is to tighten down the screw until you see the grommet distort, then back it off a little so that it still contacts the grommet, but the distortion is either done, or diminished.

They don't need to be perfect, just tight enough so they don't move. I've even had times where the servo was in too difficult a spot to get all 4 screws in, so I left one out. Of course, I try to avoid that, but if it happens, I'm not going to lose any sleep over it.

PS, I rarely ever pre-drill

RE: Servo installation info requested
 

DrFrier,
I'm the opposite of Minnflyer in the fact that I do predrill the hole. It's really almost a personal preference and you can do it either way that you like. Once I predrill the hole I will run the screw down the hole, back it out, and use a little thin CA ot harden the threads in the hole.

What Minnflyer said is about how far to tighten the screw down is pretty much right on the money. I usually watch the rubber and if you can see it distorting or "puckering" then you have tightened it too much. Take a look at the attached pictures and hopefully you an get a good idea of what is too much. In the first three picture there two mounting screws for the servo, the screw on the right is properly tightened down and the screw on the left is over-tightened. Now I will point out that the screw on left is a bit over done for "dramatic" effect and this is because I had to "over do it' to make the point.

I've included other pictures just to show how I do pre-drill and use CA on a mounting hole. Also included is a shot of the hardware I use to mount my servos with. I've found that these socket head screws are the neatest thing since sliced bread for mounting servos with. You can get that at [link=http://www.microfasteners.com]Micro Fasteneres[/link] or [link=http://www.rtlfasteners.com]RTL Fasteneres[/link] . IMHO they are well worth the little bit of extra time you take to order them. One of the best thing I like about them is that you don't strip them out like regular screws do. Give 'em a try and I think you'll really like them. I usually buy the assortment boxes that have a good range of hardware that I use for my planes.


I hope this helps

Ken

RE: Servo installation info requested
 

One rubber on top and another on the bottom? I don't think my servo's came with enough to do that on my first plane (NexSTAR), guess I better check out my supply before I put the servo's on my Big Stik! I did go with the socket head screws for this plane after seeing how easy it was for some guys at the local field to take them out.

As usual, RCU is full of GREAT info...thanks!

Mike

RE: Servo installation info requested
 

SkyDemon, the design of the rubber grommets on servos vary from one manufacturer to another, but Ken's pictures give a good indication of what we're talking about.

RE: Servo installation info requested
 

Hey guys, this IS a beginner's forum, right?

Maybe it'd be good to make a couple of details clearer. All the servos I've bought recently included some hardware that I don't see mentioned and that covers a couple of details that're being mentioned here. I took a picture of one servo with that hardware.

This servo mfg provides 3 pieces for each servo mount hole. There is a rubber grommet, a screw, and a brass fitting. That brass fitting deserves the focus here. If you look at the picture it shows the closest mounting hole having a screw in it, and the brass fitting is partially extracted.

The fitting does a bunch of things for us.

First off, it makes how tightly you tighten the screw less important. You still have to get it tight enough, but overtightening is less a problem. The brass usually stops the overtightening by resisting. Most vibration mounts have something just like this arrangement. Look closely at the vibration absorbing motor mounts for example.

Secondly, it provides a widened base against the servo tray that will help keep the grommet from squeezing down into an oversized hole. Not a big deal, but it's there.

Third, it helps keep the screw straight.

Fourth, it helps keep the grommet in those servo mount holes, especially the ones that are slots.

.............

BTW, this servo came with screws with widened heads, like they had washers already "welded" on. That's kewl, but it takes away one very useful help that washers provide.

We have a lot of places in this hobby where we need to tighten screws or bolts and don't have anything other than the resistance to the screwdriver to help us snug up the screws adequately. Washers help this like gangbusters..... Especially when we're tightening up a screw that's compressing soft stuff like the rubber grommets.....

What you do is tighten the screw until the washer is no longer free to move about. Flick it with the screwdriver tip to see. When the washer is first trapped, you can still move it easily with the screwdriver tip. Tighten it a bit. Test it again. When the washer is tight, the screw is tight enough.

RE: Servo installation info requested
 

What DaRock says has some merrit, but I find that most of the time, you will distort the grommet long before the screw meets the Brass insert.

BTW, regarding the screws/washers:

I use screws similar to what Ken shows, but I get them from Du-Bro. They look identical, but the "Washer" part spins freely - like a washer should - but won't come off the screw. I like that. (But they still distort the grommets - Murphy strikes again! )

RE: Servo installation info requested
 

Oops I always put the brass grommets on backwards , I learned something new today
Thanks.