RunRyder RC
 5  Topic Subscribe
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 1335 views
HelicopterScale Model RC Helicopters › vario R22 tail gearbox issues
04-08-2017 03:43 PM  8 months agoPost 1
helphelp

rrNovice

united kingdom

My Posts: All  Forum  Topic

Hi, had a suprise yesterday with my R22 had made physical checks as I always do to links and visible gears etc, on spool up thought the tail seemed a bit louder than usual and then it let go no drive, I am just relieved that I did not get in the air.

I thought it would be a grub screw on the claw fitting but on stripping down the tail gearbox i was astonished to find one of the bevel gears the output shaft one worn almost flat gearbox full of grease.

Having looked at the forums it seems this gearbox is prone to failure the model has not flown that much so I was not expecting to find this it was all shimmed and felt ok these are the newer VR22 mechanics.

My thoughts are since converting to electric and removing the clutch is the gearbox getting a bit to much punishment now I do have a fairly slow
spool up set.

Is there a direct swap gearbox from another manufacturer or better gears than the vario ones which I would have expected to be hardened.

The gears are 19 teeth and 22 teeth.

Thank you.

PM  EMAIL  Attn:RR  Quote
04-08-2017 08:25 PM  8 months agoPost 2
Mojave

rrElite Veteran

Palos Verdes, Ca. USA

My Posts: All  Forum  Topic

I'm sure you'll find a lot of input regarding these gear sets. I have found on my Vario TR gear boxes that the gears rarely run true. So when the gear back lash (shimming) is set properly to allow them to run smoothly, the brass spacer is not long enough to prevent the TR shaft from moving inboard. The shaft can move in/out slightly during tail rotor pitch changes. This loads and unloads the gears. I used to shim between the brass sleeve and the bearing, but these days I just machine a spacer (to replace the brass unit) that's the correct length to take up the slop. I also use high pressure bearing grease, not the lithium grease. I know some folks are modifying gears from other manufacturers, to replace the Vario gears. You might want to PM Darrell Sprayberry for info regarding this mod.
Barry

All helis and planes have an expiration date stamped on them...you only find it after you crash!!

PM  EMAIL  GALLERY  Attn:RR  Quote
04-08-2017 08:47 PM  8 months agoPost 3
helphelp

rrNovice

united kingdom

My Posts: All  Forum  Topic

R22 tail gears

Thank you Barry.

PM  EMAIL  Attn:RR  Quote
04-08-2017 10:21 PM  8 months agoPost 4
aashu

rrKey Veteran

scotch plains, NJ

My Posts: All  Forum  Topic

Interesting

This is interesting. Does this happen on all type of gear boxes vario has or just on vr22.

Garden State, NJ

PM  EMAIL  GALLERY  Attn:RR  Quote
04-08-2017 10:50 PM  8 months agoPost 5
PETER ROB

rrElite Veteran

Devon UK

My Posts: All  Forum  Topic

I have built and rebuilt many R22's, if the gearbox is built correctly, shimmed and spaced, then fine tuned so that there are no hard spots the gearbox's rarely give any problems, other than wear from usage
Also worth a note the gears for the R22 are 18 driving 18,Vario, bog standard
The 22t driving 19t, set up is a speed up gearing and does not wear well, in any gearbox,
This is not an opinion, but knowledge gained from my love of the Vario R22, next to the Vario trainer the most forgiving helicopters ever
Peter R

PM  EMAIL  GALLERY  Attn:RR  Quote
04-09-2017 02:45 AM  8 months agoPost 6
Mojave

rrElite Veteran

Palos Verdes, Ca. USA

My Posts: All  Forum  Topic

Agree 100% Peter, it's all in the shimming. You need to find the sweet spot where the shaft runs smoothly through the high points in the gear. I have had this gear box in 5mm and 6mm configurations in many helis and I've also built them for friends. I can say that I have yet to find a gear set that runs true.
Barry

All helis and planes have an expiration date stamped on them...you only find it after you crash!!

PM  EMAIL  GALLERY  Attn:RR  Quote
04-09-2017 09:11 AM  8 months agoPost 7
PETER ROB

rrElite Veteran

Devon UK

My Posts: All  Forum  Topic

The sweet spot

Barry, not sure how you achieve the smoothest running
Personally, I first build and shim the gearbox, using on 2 bolts to secure the end plate
Then release the end plate, and move the output shaft one tooth tighten and turn, then run the gearbox (lathe), keep moving the output shaft to find the best meshing, then re shim
I then fill the gearbox with graphite grease, run it again in the lathe for at least 15 mins (length of a flight), to get it up to running temperature
Check for backlash when at full running temperature this should be minimal
I know when it is close to perfect when the gearbox will hang when running, without any support
Finally wash out the grease with white spirit/turpentine, to remove any crap in the box rebuild and re lubricate
Worth a note there are 2 holes in the gearbox, when mounted on the helicopter with these holes upper most, one, you don't get grease dripping out, two it is easy to pump grease through the box using a plastic syringe
Lapping in a gearbox is always good practice, came from the early days of car racing when we would rebuild are own straight cut gearbox's
Peter R

PM  EMAIL  GALLERY  Attn:RR  Quote
04-09-2017 08:10 PM  8 months agoPost 8
helphelp

rrNovice

united kingdom

My Posts: All  Forum  Topic

R22 gears

Peter, are you saying that I should replace the gears with 18 teeth for both to avoid premature wear.

PM  EMAIL  Attn:RR  Quote
04-09-2017 08:16 PM  8 months agoPost 9
modtron

rrKey Veteran

Oxford. UK

My Posts: All  Forum  Topic

Strange how Vario say 19T & 22T in the R22 manual !

modtron
Oxford UK

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
04-09-2017 08:31 PM  8 months agoPost 10
payne1967

rrElite Veteran

uk

My Posts: All  Forum  Topic

I have no idea on the gearing in my R22, Peter may be able to comment on it as he knows the model

since owning the model I've only ever cleaned out and re-greased the tail gearbox, the gears are in perfect condition
if you are wondering on its usage, it has flown 35.5 hours since I replaced the servos two seasons ago
the servos were replaced as one cyclic servo failed in flight, the other three other coped well to get the R22 landed with no damage

www.alcesterhelicopterclub.bmfa.org

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
04-10-2017 01:16 AM  8 months agoPost 11
Mojave

rrElite Veteran

Palos Verdes, Ca. USA

My Posts: All  Forum  Topic

Peter, I follow a very similar process. I also set up the gearbox with the side bearing plate installed. I play with the shimming of the gears until I get it to run smooth, just past the high point in the gear. I lube it and spin it with a high speed air drill motor to break it in. Disassemble, inspect and re-lube etc.. I like your use of the lathe, but I don't always have access to the lathe at work, so I improvise. I set the lash by feel.

What I was trying to explain in the previous post was that often times when I find that sweet spot in the gears, there is side slop between the brass sleeve and the bearing. This allows the side (driven gear) gear/shaft to move inboard during TR pitch changes. This changes the lash setting and puts friction load on the gears. So, I simply machine my own sleeve to remove the excess slop. It has nothing to do with my setting of the lash. Vario makes the brass spacer to a nominal dimension, but the gears are rarely nominal themselves. It's just my fix for tolerance stack up. You could just add additional 909XX or 91310 spacers and achieve the same result.
Barry

All helis and planes have an expiration date stamped on them...you only find it after you crash!!

PM  EMAIL  GALLERY  Attn:RR  Quote
04-10-2017 08:45 AM  8 months agoPost 12
PETER ROB

rrElite Veteran

Devon UK

My Posts: All  Forum  Topic

I am not telling you to fit anything, from my experience 22t driving 19t does not fare well on large Vario petrol models, the 22t driving 19t is a speed up gear, not needed on the R22 if it is set up correctly
Since building my first Vario R22 back in 1909, the gearbox had 95/5 (5mm shaft) and 95/6 (6mm shaft, both gears had 18t,(photo) the helicopter has not changed, mechanics have but the running gear remains the same
there has been a 95/7 19t driving 95/5 18t this worked ok
MODTRONThere have many mistakes in the Vario manual reprints, probably in the cut and paste department
If you check the R22 gearbox 1003/80, in the spares listing you will find 95/7 and 95/5, no mention of the 22t gear
Surely the proof is in the building, and flying
I built Dave Payne's R22 12 years ago, the gearbox has had replacement bearings, one of the R22's in my hangar was built in 2007, still on the same gearbox bearings and it has had 2 engine changes so over 200 hours flying I would guess
Mojave,Barry just filling in the gaps for those who have never rebuilt a Vario gearbox
Some thing else to not the input gear some times needs a shim
Peter R

PM  EMAIL  GALLERY  Attn:RR  Quote
04-10-2017 10:22 AM  8 months agoPost 13
goodhunting

rrApprentice

Slovenia ... somewhere in Europe

My Posts: All  Forum  Topic

"Since building my first Vario R22 back in 1909,..."

Man I thought I was an older chap... but some of you guys out here make me feel like a youngster again.... "ya'll" deserve all of my respect and admiration.

And for the record I learned a lot... again... so thanks

Klem

PM  EMAIL  GALLERY  Attn:RR  Quote
04-10-2017 04:19 PM  8 months agoPost 14
modtron

rrKey Veteran

Oxford. UK

My Posts: All  Forum  Topic

Sorry PETER, you have it wrong this time !

Most of the manuals were updated some time ago and the parts list was checked over.
R22 kit - Pt.No. 7022
Mechanics - Pt. No. 470/22 & 23
The tail gearbox that comes with this mechanics set uses both 19T (42/18) and 22T (95/2) gears.

If you wanted to look here ....
http://variomodels.com/fileadmin/us...4/470_22-23.pdf
and then go to page 10, you will see for yourself.

ps - by the way, there are also more than 3 of the large Hughes 300 in the UK !

modtron
Oxford Uk

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
04-10-2017 05:58 PM  8 months agoPost 15
PETER ROB

rrElite Veteran

Devon UK

My Posts: All  Forum  Topic

Nigel,
Not sure why you have to try and prove me wrong all the time
The re print was because the VR 22 front mount mechanics were discontinued, and replaced by the Bell 47 mid engined type mechanics
Looking at the build plan it does state 22t 19t
The only difference between the Vr22 mechanics and Bell47 mechanics is the shift in engine position, the running gear remains the same, I know because I use the old VR22 running gear in the new design Bell 47 frames and base plate
If you read my post instead of trying to find fault with them you will read I do not tell other people what to use, but only write about my experiences
Because there was no change in the running gear, I could see no reason to pay extra money for the 22t gear when it was not needed, or supplied with the 18t driving 18t, gearbox 1003/80
Today with 2 flying R22's, and 2 Bell 47's one turbine one Petrol, all have 18t driving 18t
So maybe you could tell me who is now right me who regularly fly's these machines or you who read a building plan?
As an aside my neighbour who has been flying his Bell47 for years is still on the same gears he built it with 4 years ago
You are correct about the number of Schweitzer 300's in the UK, John White told me this week that he thought there were about 5, but even he was not sure, but you being the know all about everything will know the exact number
Peter R
Addendum, the petrol Bell 47 has 22t driving 19t, the turbine has one to one mesh I did not take the gearbox apart, reason for the turbine gears is that the speed up is done on the output from the turbine
The reason for needing the speed up gear is because of the difference in head speed between the R22, up to a 1000 with metal grips and 832 on the Bell

PM  EMAIL  GALLERY  Attn:RR  Quote
04-10-2017 08:57 PM  8 months agoPost 16
helphelp

rrNovice

united kingdom

My Posts: All  Forum  Topic

re gears R22

Well, this has turned into a lively debate and I would like to thank everyone for the contributions but I am now more confused than before.

Can someone please tell me what gears to order.

Regards.

PM  EMAIL  Attn:RR  Quote
04-10-2017 09:17 PM  8 months agoPost 17
payne1967

rrElite Veteran

uk

My Posts: All  Forum  Topic

I would use the same gear ratio that you have now

along side my R22 with the old VR22 mechanics
I own a Bell 47G3 the gears are whatever was supplied with the kit from Vario
as with the R22 I've only ever cleaned and greased the tail gearbox gears and they are still in as new condition

make sure the gearbox is 200 percent clean before you fit new gears and only replace them as a pair

www.alcesterhelicopterclub.bmfa.org

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
04-11-2017 03:48 AM  8 months agoPost 18
Mojave

rrElite Veteran

Palos Verdes, Ca. USA

My Posts: All  Forum  Topic

Peter, Roger that, thanks for the info. Just putting my spin on the GB assembly process. We all have our own tricks and all roads eventually lead to Rome...
Barry

All helis and planes have an expiration date stamped on them...you only find it after you crash!!

PM  EMAIL  GALLERY  Attn:RR  Quote
04-11-2017 06:00 AM  8 months agoPost 19
PETER ROB

rrElite Veteran

Devon UK

My Posts: All  Forum  Topic

Helphelp, do you have a name?
If you follow Dave's advice, buy 2 sets of 22t 19t, because you will certainly need them, on the R22
I do not usually tell people what to fit, but as you asked 19t driving 18t, would be a good compromise
Also buy new bearings, if your gears are gone then the bearings will not be far behind
Follow Dave's advice and make sure you strip and clean all the box, white spirit will remove the grease and crap easily
We have told you how we rebuild our gearbox's, if you follow the advice you should not go wrong
Good luck
Peter R

PM  EMAIL  GALLERY  Attn:RR  Quote
04-11-2017 05:47 PM  8 months agoPost 20
helphelp

rrNovice

united kingdom

My Posts: All  Forum  Topic

re R22 tail gears

Thank you Peter and everyone else for helping.

PM  EMAIL  Attn:RR  Quote
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 1335 views
HelicopterScale Model RC Helicopters › vario R22 tail gearbox issues
 Print TOPIC  Make Suggestion 

 5  Topic Subscribe

Monday, December 11 - 4:09 am - Copyright © 2000-2017 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online