extra to servo fitting

[nigel newby]

As an aside to my other thread, how should one attach the servos?

I know how to on the ones that the grommet covers both the top and bottom of servo, but looking at what I have it is a flat piece of rubber and brass ferrules.

So does the rubber go to the bottom of the servo with the brass going upwards. See photo of bits

Thanks Nigel N

[Dave Hess]

The rubber is hollow. It clips over the end of the servo, then you put in the ferrules and screw it down. I put in the ferrules from underneath so that the flange rests on whatever you screw it to without the sharp end cutting in.

Edited By Dave Hess on 23/11/2018 18:24:57

Edited By Dave Hess on 23/11/2018 18:28:36

[Alan Gorham_]

Dave has answered your question but just FYI that picture is a fake Futaba s3003 servo.

[Martin Harris - Moderator]

It's amazing how many people put the ferrules the wrong way up - experienced modellers as well as beginners. The principle is that there is a fixed length to slightly compress the rubber and allow a small amount of movement when the screw has tightened against the ferrule. As Dave states above, the brim is designed to spread the load against the servo bearer.

[Ace]

The servo it's self looks like it takes 4 individual square hollow rubbers, however the rubbers in the picture look like they fit top and bottom at one end. If they are not hollow then you are missing two rubbers.

[Levanter]

Hello Nigel

I know the type of rubber you are talking about and the ones in the photo are different. There are a number of different types.
The type in the picture is one at each end under the lug of the servo.

Alan

Could you help us by saying why you have identified the picture showing counterfeit servos.

Levanter

[Martin Harris - Moderator]

I suspect that they could be counterfeit - markers are supposed to be shiny cases, white output shafts and incorrect lugs - although Futaba do supply the "flat" rubbers, they seem to come with servos that have drilled flanges rather than the open type shown which use the "corner" rubbers.

Where did your servos come from Nigel - reputable dealer (in which case I may be wrong) or from a dubious source?

P.S. Levanter posted while I was writing this - I wasn't trying to answer for Alan, whose post I'd missed as well!

P.P.S. Those who follow my link above will see an example of incorrect ferrule orientation!

Edited By Martin Harris on 23/11/2018 19:13:12

[nigel newby]

Thank for advice so far. I have read the article on fake servos. You will all be pleased to know that mine are genuine. The photo I showed was from an online site to save me taking piccys.

Here are piccys of my servos.

I would not worry about the white output shaft, but I checked the bottom of the servo and the wiring on the PCB is that from Futaba. So all is ok there. I will just put the rubber grommets on the bottom with the brass but pointing up. At least I now know how to check for dodgy servos. Thanks a lot Nigel N

[Martin Harris - Moderator]

Intrigued to know why you wouldn't worry about the white output shaft when every reference I've found gives this as an indication that it's a fake. They do look more like the real thing than the earlier picture but could you share why you are certain that these are genuine? There are reported to be many fakes now with the correct mounting holes but to my knowledge the genuine ones have always used black output shafts.

It may help others if they are suspicious of servos that they are looking at...

[Keith Berriman]

Nigel N. On the sevos I fitted with those grommets yes bottom rubber brass ferule upwards and rubber gromment on top as well for the fixing screw to pull down onto it with the washer

[Bob Cotsford]

There should be 4 rubber plates giving two for each end, one under the lug and one on top. The ferrule goes through both rubbers from underneath trapping the lug in between.

[nigel newby]

OK Martin I can see what you are saying but, that is only one thing about the servo.

Firstly according to the article the screws are correct.

 

In the article the screws were about 3mm of thread. 3mm is not a lot, I don't really do metric, but theses threads are over 1/2 an inch, so lets say 13mm. As the genuine ones have.

Next is the shape and colour of the housing. Mine have the correct shape. I.E. not square at the front, but sloping.

Also they are matt and not shiny.

Next inside the gears are the same, not with the coarse gearing on the output as in the fakes.

Also it does not have the big brass bush as the fake does. The teeth on the final output are also correct in that they are not coarse teeth, but fine teeth. It also has the solid holes ,not with the cut outs in, which is what started this thread.

 

Next the is the pcb board. This is the same as the genuine, in that the 3 wires are fixed at the front of the board and it has a grommet sealing it.

 

Just because it is white is not reason to say categorically that it is a fake All the other gears are white. I dare say that it all depends what colour they are supplied with when they were built. These servos are at least 10 years old if not more, so who knows what other changes have been made in that time. But if it is a fake, then it has been bought upto the Futaba standard.

 Although looking at my original photo, that is now not showing as I deleated it from my album, and have now put back but does not show. That one does look very much like a fake.

Nigel N

Edited By nigel newby on 24/11/2018 11:40:18

Edited By nigel newby on 24/11/2018 12:00:43

[nigel newby]

Bob and RC Fly, thanks for that. That is what I needed to know. The pack of spares arrived with 20 ferrules and twenty rubbers. So I really need twice as many rubbers as ferrules. I might just snip out the gap in future as I have loads for that sort of servo.

Nigel N

Edited By nigel newby on 24/11/2018 12:01:54