HS-65MG Rebuild Instructions

[rdlohr]

HS-65MG Metal Gear Kit Install

Watch the Finless Servo Repair 101 video http://video.helifreak.com/?subpath=finless/generic&filename=servorepair101.wmv

This is a supplement to that video made specifically for the newer HS-65MG Servo



1) Remove the servo from the heli far enough to work on it.
2) Remove the servo horn and 4 tiny head long Philips head screws on back of servo
3) Remove the case from over gear side (not electronics side)
4) Pull all gears straight up off. Do not lose any small axels



5) Clean off all grease from bare servo making sure to remove any broken gear remnants.
6) Make sure the flat side of the potentiometer is centered as shown in the above picture. (If you forget, the last gear will be hard to align on it)
7) Remove bearing from the old largest gear output shaft. Use a knife and or screwdriver and slowly work your way around and around till it slides off.




8) Clean the bearing with alcohol and then pack the bearing with white lithium grease using your fingers to work it into the gear
9) Press the bearing over the new largest gear output shaft till it fully seats
10) Press the black stop into the largest gear. I used a vice to carefully seat it.


11) Lay out your new gears in the order shown in preparation for installing. Take care to do this in a clean area to avoid contaminating the new gears with grit.


12) Place each gear in as shown one by one making sure to lightly coat both sides, teeth and shafts with white lithium grease. When putting on the largest gear, take care to line up the detent in the gear with the slotted shaft.






13) Make sure the servo cover is cleaned out of grease and remnants of old gears


14) Put the cover back on install the four long screws you removed.
15) Power up the rebuilt servo and try it prior to reinstalling it on the heli. Assure there is no buzzing or clicking and assure it moves smoothly.

Here’s what a bad gear looks like. Notice the missing tooth. I found the broken off tooth in some grease in the servo cover.


16) Save the good gears in a bag for reuse later.

Good Luck
Rick

[Finless]

I am going to STICKY this for a while

Bob

[rdlohr]

Thanks Bob. Put it wherever you think is best. Putfile is pretty cool. Click a pic!

Rick

[bryguy17]

for one, i'd like to add a tip i figured out doing this recently, my ball link pliers work perfectly for removing the bearing from the final gear. keep in mind i use the cheapo spring steel ones, but they fit perfectly.

also, i'd like to pose a question (2, actually): has anybody else had trouble with the first metal gear in the train being too big? mine felt a bit jammed up when i had all metal gears in the servo, but when i replaced that particular gear with a karbonite one, it all freed up.

Q2: is silicone grease okay to lube the gears with? or is lithium grease a necessity

[DominicD]

rdlohr is sticky enough all on his own. Good work !!

[rdlohr]

Originally Posted by HFG

rdlohr is sticky enough all on his own. Good work !!

Thanks much!

Rick

[glucoseboy]

Thanks for this post Rick. (Nice Pics!)

[Funky]

Very nice! Thanks Rick

[theglennster]

Nice informative post Rick this has been missing for a while.

I would like to add a little tip I found sometimes pressing the bearing on the new gear can be very tight if not impossible due to manufacturing tolerances and you are at risk of damaging the bearing just pressing it with your thumbs so I found use an old (or new) clutch bearing sleeve (V1 not sure about V2) is the perfect fit so you apply pressure to the inner race, you can even do this in a vice or G clamp or just tap it home until it bottoms out.

BTW Rick how on earth did you take out a metal gear WOW ??

Cheers
Glenn

[bsoder]

Oh, it's definitely possible..

[rdlohr]

Oh yea. My crash was simple from about 5 feet up. Major boom strike had the force required to do it.

Rick

[vinljp]

Had a bad flying day 2 weekends ago when my heli went out of control during a tight turn. Had sufficient altitude to regain control but just couldn't. Post mortem showed that my aileron servo had stripped.

I would think that the servo stripped caused the crash.
Does anyone has such experience?

How would one tell whether did the gear stripped in mid flight or during a crash?

My Servo is Hitec HS-56HB.

[rdlohr]

Not sure how you could tell, but every strip I have had was the result of a crash, not the opposite. Maybe it was the result of a previous crash that weakened the gears.

Rick

[BarnOwl]

Originally Posted by vinljp

Had a bad flying day 2 weekends ago when my heli went out of control during a tight turn. Had sufficient altitude to regain control but just couldn't. Post mortem showed that my aileron servo had stripped.

I would think that the servo stripped caused the crash.
Does anyone has such experience?

How would one tell whether did the gear stripped in mid flight or during a crash?

My Servo is Hitec HS-56HB.

Rick is right: I NEVER had a metal gear strip yet in flight, however I DID experience stripping carbonite gears in flight.
I changed my 65 carbonites to metals a long time ago as they went. I actually got three sets of extra metal gears for my HS 6975's on the T-Rex 600 but have not used one replacement for almost a year. Never stripped metal gears yet! (Knock on wood, I have a lot of that here.......:wink

[damyxz]

Another tip when rebuilding servos, Be sure not to put grease on the potentiometer tracks or it will mess up the servo centering ability. I also make it a point to clean the potentiometer tracks with deoxyit spray cleaner and then sprayit with deoxyit gold. This makes the contact of the potentiometer better and it is lubed too, making it last longer and center really good. I get the deoxyit spray from radioshack and I have been using this spray for my studio mixers for flawless sound recording.

[rdlohr]

Originally Posted by damyxz

Another tip when rebuilding servos, Be sure not to put grease on the potentiometer tracks or it will mess up the servo centering ability. I also make it a point to clean the potentiometer tracks with deoxyit spray cleaner and then sprayit with deoxyit gold. This makes the contact of the potentiometer better and it is lubed too, making it last longer and center really good. I get the deoxyit spray from radioshack and I have been using this spray for my studio mixers for flawless sound recording.

Interesting tip. I never payed much attention to the pot when I had the servo apart. I just lube the gears. I'll look at it next time.

Rick

[flyboy320]

Originally Posted by damyxz

Another tip when rebuilding servos, Be sure not to put grease on the potentiometer tracks or it will mess up the servo centering ability. I also make it a point to clean the potentiometer tracks with deoxyit spray cleaner and then sprayit with deoxyit gold. This makes the contact of the potentiometer better and it is lubed too, making it last longer and center really good. I get the deoxyit spray from radioshack and I have been using this spray for my studio mixers for flawless sound recording.

Thanks for that. You stopped me from throwing away an old HS65 I had swapped out because of "jittery" movement. I did as you suggested, and now it works great

[ChasHeliCop]

Never mind, found the answer

[rdlohr]

Originally Posted by ChasHeliCop

Never mind, found the answer

neverminded...

[Dood]

I changed my 65's to metal gears about a month ago.
I documented it with pictures as well.

The tool that served me well was my ball link pliers.

A ball link pliers to press on the bearing


and a ball link pliers to press in the plastic insert