mounting servos?
 

Im now mounting the aileron servo into the wings, but when i was getting the screws i noticed that the servos also came with these rubber cube things, what are these for? do i need them to mount this servo?

RE: mounting servos?
 

Those "rubber things" are called grommets. They are used to isolate the servo from the structure of the plane in order to keep vibrations from the plane destroying the servo. The grommets are placed over the mounting lugs on the servo. Then you place the brass eyelets through the grommet from the bottom. THen you place the mounting screw in and stop as soon as the screw touchs the grommet. Don't tighten it down as tight as it goes or you will negate the effects of the grommet. See the attached diagram.

Ken

RE: mounting servos?
 

oh good thing i asked. thanks so much

RE: mounting servos?
 

Ken, I read your post. I am a fairly new modeler, but when I mount servos, I always put the baseplate of the grommet in the top position. I figure when applying the screw pressure to to servo, the rubber grommet takes the vibrration from the engine and doe's reduce it to the servo and radio gear. To put it on the bottom, on a hard plywwod plate, to me, seems you just as well mount it directly to the plywood and there you are with vibration again.
I know the directions state, the brass washer on the downside, next to the plywood. You will not crush the brass plate in either direction because the screw is the same length either way. Just tighten it down snug, and that's it.
I just think that the rubber grommet provides a vibration reductuion tool, meaning it helps in reduceing engine vibration to the servos and radio, from the airframe itself. I just don't see the point of putting the brass washer on the down side next to the plywwod. If I am missing something here, inform me please!

RE: mounting servos?
 

I'll take a stab....If you mount the brass spacer with the flat side against your screw it will eventually wear into the wood and your servo will vibrate a hole right into the wood. With the brass 'washer' on the bottom this is prevented and the tightness of the screw will never change as you're actually tightening the screw aganist the washer and the plane instead of just pushing it into the wood. You are in essence suspending the grommet and thus the servo between the screw and the brass spacer rather than squishing it against the plane...

RE: mounting servos?
 

Oh, they are called rubber thingymados,use them with brass inserts and screws,they keep the servo in place.Good luck

RE: mounting servos?
 

Hey I should read before I post,good idea rabaraten.

RE: mounting servos?
 

One more thing. Screw the servos down in place then remove the servo. Place a drop or two of fast CA on the wood in each hole and let it dry. Then screw the servo back in place. This hardens the hole and prevents the screw from stripping and the brass from rubbing through. Remember to put the brass spacers in from the bottom.

Mike

RE: mounting servos?
 

Oh damn - I should have read this before my other post in the thread I started. Thanx Ken - now I know what grommets are and how too mount servos the correct way.

I tightened my screws down heavy and not just when it touched the grommet - I think that's probably why it ripped some of the wood. Silly me:eek:

RE: mounting servos?
 

I also place a rubber band (width like that of a #64) around the servo to get spacing between the rails and case so no vibration is transferred from the airframe to plastic case.. Then once installed i remove the rubber band leaving the small area of clerance. I have heard pro and con for this method but I have never had any issues doing this and it seems logical.