wayfarerbobby

I bought a 40 size piper cub off e-bay. Nice plane but it has the royal titan servos which won't fit into my slimline hitech RX. SHould I replace these servo's? if so; recommend a replacement. Can a different plug be used? if so; where do I find these plugs?Thanks!

codimasta

My Feedback: (89)

Does the plugs have a tab on it (ie Futaba type) ? Just take a hobby knife and cut them off.. be careful...use of a nail board to smooth the tab that you cut off.. Good luck.

wayfarerbobby

No tabs on these. My camera doesn't take good close-ups but if you can see from the drawing, there is 3 !QUOT!bumps!QUOT! across the top. Also as you can see there is no color coding on the wires. These servo's are well installed in the plane. Seem to be in !QUOT!good condition!QUOT!. I would prefer using them and not going thru the hassle of a new set up inside a tight space. (if you know what i mean)? Thanks for any help.

JohnBuckner

My Feedback: (1)

Your Hitec Rx will accept Hitec S, JR, Airtronics Z and Futaba J (in the case of the J some versions do not even require the removal of the tab) plugs. All these current plugs are of the same polarity.

Your drawing looks like the old style Airtronics plug that along with a number of others is obsolete. This plug in the case of airtronics has the positive and negative lead reversed from all the modern plugs and to be used must be reversed agine with a new style plug installed. Now in the case of Old Royal stuff I,ve no idea what they used but from what you have its most likely as per 'old Airtronics'. Look at the servos lead carefully is there a very narrow white or gray stripe on one of the leads?

John

Sport Flyer

My Feedback: (10)

Definitely looks like the old style Airtronics plug. You should be able to buy adapters that will convert them to the Airtronics Z type, which you should be able to use. The Royal Titan is an okay servo but personally I'd replace them with ballbearing servos for flight surfaces, and use the Royals for throttle on this and future projects.

wayfarerbobby

Thanks for the information!

I guess I'll take the advise of replacing the servo's. To use the Royle's for thottle I still need to find the adaptor. I looked on Tower's site and could not find it. Anyone know where I can find this adaptor?

Just to clear up a question. The grey stripe lead is the positive lead??

Bobby

JohnBuckner

My Feedback: (1)

[quote]ORIGINAL: wayfarerbobby
Just to clear up a question. The grey stripe lead is the positive lead??
[/quote


Yes on the old Airtronics harness that thin light grey or white stripe lead is the positive lead pin#3 All modern plugs now use positive on the center pin.

So if you really want to use those old servos and don,t want to pay half the price of a new servo on adapters that you will probably have dificulty finding, there is a way. Only on the 'old Airtronix' plug, the metal connector pins are removeable from the plastic plug itself buy pushing a pin in a small window on the plug while gently pulling the respective lead out with the metal connector. The procedure is to remove the gray stripe lead and the center wires connector from the plastic body, and reinstall reversed so the gray lead is in the middle position. This makes polarity compatable with all modern Rx's. But one more problem, it still won,t fit! Get out the trusty Dremel and carefully remove the three splines untill it does fit. Now the only thing left is how do you know which direction to plug it in. Easy plug it in and try it, if not reverse it. All modern center positive plugs if plugged in backwards will not harm anything just not work.

The above procedure will work but do consider guys screw around with this old stuff all the time and at best the result ends up with a servo of questionable history/quality that may work for the time being.

John

strato911

If you combine this picture with John's excellent description, I'm sure you'll see what needs to be done to make it compatible...

wayfarerbobby

That's what I love about this hobby, Always learning something new.
Good information on the servo's, I'll still consider replacing the servo's on the control surfaces but really wanted to avoid the work. I still can't find adapters but saw they might be just about as expensive as a new servo.
I'm back to work and will consider all this over the next 7-10 days. Thanks again for all the good advise.

Bobby