Today's Message Index:
----------------------
1. 12:50 AM - Re: Propeller/engine vibration (JohnFrance)
2. 01:54 AM - Re: Re: Propeller/engine vibration (David Watts)
3. 04:02 AM - Re: Propeller/engine vibration (Bud Yerly)
4. 04:17 AM - Re: Re: Propeller/engine vibration (Bob Harrison)
5. 05:43 AM - Re: Re: Propeller/engine vibration (David Watts)
6. 06:44 AM - Re: Re: Propeller/engine vibration (Bob Harrison)
7. 08:33 AM - Re: Propeller/engine vibration (Paul McAllister)
8. 10:09 AM - LG06 Shock,Absorber Needed (Bill Henderson)
9. 11:41 AM - Re: Fuel Tank Leak (graeme bird)
10. 08:29 PM - Re: LG06 Shock,Absorber Needed (spcialeffects)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Propeller/engine vibration |
Dear Dave and Bob,
thank you for your feedback regarding the vibration problem.
Dave, did your vibration appear "out of the blue" like mine did?
My engine is a Rotax 912 UL with only 334 hours on it and according to the serial
number it is one of the few fitted with a 15 degree clutch and has a TBO of
1200 hours. If I get the gearbox shaft changed at the same time it would extend
TBO to 1500 as all other work has been carried out.
Not the best time to be down, right at the height of the flying season!
Regards,
John
Do not archive
--------
Europa mono Nr 192
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444726#444726
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Propeller/engine vibration |
John,
Yes the vibration appeared "out of the blue" on the 20th May and it got no worse
and no different from the moment it started until last week, when it seems that
it may now be cured.
My Rotax agent thought it may be the splines on the gearbox prop shaft and although
he showed me that they still appeared to be perfect he is now of the opinion
that just reassembling them on different splines may have cured my problem.
(This though makes me feel that there may be some slight undetectable wear in
the splines that will rear it's ugly head again in the future!!!)
Dave Watts
G-BXDY
> On 14 Jul 2015, at 08:49, JohnFrance <77alembert@gmail.com> wrote:
>
>
> Dear Dave and Bob,
> thank you for your feedback regarding the vibration problem.
> Dave, did your vibration appear "out of the blue" like mine did?
>
> My engine is a Rotax 912 UL with only 334 hours on it and according to the serial
number it is one of the few fitted with a 15 degree clutch and has a TBO
of 1200 hours. If I get the gearbox shaft changed at the same time it would extend
TBO to 1500 as all other work has been carried out.
>
> Not the best time to be down, right at the height of the flying season!
>
> Regards,
> John
>
>
>
> Do not archive
>
> --------
> Europa mono Nr 192
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=444726#444726
>
>
>
>
>
>
>
>
>
>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Propeller/engine vibration |
John,
During a descent especially the prop to gearbox/engine combination causes a vibration
when the prop windmilling force and drive force are nearly equal.
If the slop in the gearbox due to a worn slipper clutch or just the gear lash becomes
too much you get vibration and noise all the time. On taxi even.
To test: If all is smooth at cruise and takeoff when the prop is pulling, simply
hold your speed constant and reduce power (throttle) until the vibration starts.
On the Airmaster AC200, go to MANUAL and move the prop to a course setting.
If it stops the vibration, as the prop begins to pull, it is just normal
gear box lash.
In a descent, my Airmaster/914 will vibrate and I either pull more power off to
force the windmilling prop to compression brake, or change the pitch to a course
setting to allow the prop to pull.
Common areas to feel this: High speed descent with small power reduction or in
the pattern at 4000 RPM / 17 inches turning base leg. Either ceases with power
lever movement to get the prop to fully brake, or pull.
Regards,
Bud Yerly
Sent from my iPad
> On Jul 13, 2015, at 7:06 PM, Robert Borger <rlborger@mac.com> wrote:
>
>
> John,
>
> I agree with Dave Watts. First place Id look is the gearbox. Have a good Rotax
tech go through the various checks in the maintenance manual. I bet you need
new Bellville springs. Hopefully, nothing further needs replacing.
>
> Blue skies & tailwinds,
> Bob Borger
> Europa XS Tri, Rotax 914, Airmaster C/S Prop (75 hrs).
> Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
> 3705 Lynchburg Dr.
> Corinth, TX 76208-5331
> Cel: 817-992-1117
> rlborger@mac.com
>
> On Jul 13, 2015, at 3:29 PM, JohnFrance <77alembert@gmail.com> wrote:
>
>
> Hi All,
> during a recent flight I experienced (propeller!) vibration at the start of the
descent when I reduced power. This was after about two hours in cruise flight.
The frequency was quite high and I could feel a tingling sensation in the
feet in contact with the rudder pedals which makes me think the vibration is coming
from the propeller/engine combination.
> Upon landing I made a close inspection of the propeller and everything seemed
normal except for some flies and bugs. After cleaning, during the next flight
I experienced the same problem. The vibration is at its worst at 4800 rpm and
reduces slightly at 5000 but it is still noticeable.
> Before I start taking everything to pieces does anyone have an idea what could
cause this sudden change?
> Regards,
> John
>
> --------
> Europa mono Nr 192
>
>
>
>
>
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Propeller/engine vibration |
Hi! John /David /All ,
If your engine/gearbox set up includes a propeller strike engine protection
drive clutch(Slipper Clutch) you may find that the peaks of the drive lobes
have eroded spots of the flame hardening on the mating surfaces in the
valleys which is part of the gear pinion machining. (Entire gear and pinion
pair replacement usually needed about 1Kfor parts alone!) I believe that
the mating surface loading of this device when under light loading, with the
lobe peaks centred has too small surface contact, is not getting adequate
high pressure lubrication from the approved engine oils.
For instance under heavy thrust loading in normal flight the lobe surface
has a much larger contact surface having moved up the drive slopes from out
of the valley's . On throttling back the lobes move back to the limited
surface area contact position giving the intense surface pressure loading
where the erosion is happening . ( This has all been reported to the LAA
with photographs with no response .) I had the services of the ROTAX service
engineer in dismantling and reassembling but chose to carefully dremel the
offending places of erosion before reassembly and torque setting.
On any engine oil change I am now adding a full can of Holts STP high
contact pressure additive by carefully mixing it hot with the new engine oil
before pouring it into the oil tank . All sign of metal contaminant on the
magnetic plug have now stopped(Multiple checks and also at EVERY oil change)
and the vibration is now minimal . The engine has completed in excess of
200 hours with this set up but the vibration (although very much minimised
and probably un-noticeable by anyone else!) is slightly there in a very
light load condition (just above idle). No further contamination has been
detected on the magnetic plug.
Flight engine RPM landing control is the key to keeping away from the very
light loading position and an full idle setting to lose speed on approach
rather than a low power setting is in my opinion the answer.
My first notice of vibration prompted me to check the magnetic plug and
conduct an investigation since it failed the visual check.
Best regards to all
Bob Harrison G-PTAG Rotax 914
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of David Watts
Sent: 14 July 2015 09:54
Subject: Re: Europa-List: Re: Propeller/engine vibration
John,
Yes the vibration appeared "out of the blue" on the 20th May and it got no
worse and no different from the moment it started until last week, when it
seems that it may now be cured.
My Rotax agent thought it may be the splines on the gearbox prop shaft and
although he showed me that they still appeared to be perfect he is now of
the opinion that just reassembling them on different splines may have cured
my problem. (This though makes me feel that there may be some slight
undetectable wear in the splines that will rear it's ugly head again in the
future!!!)
Dave Watts
G-BXDY
> On 14 Jul 2015, at 08:49, JohnFrance <77alembert@gmail.com> wrote:
>
>
> Dear Dave and Bob,
> thank you for your feedback regarding the vibration problem.
> Dave, did your vibration appear "out of the blue" like mine did?
>
> My engine is a Rotax 912 UL with only 334 hours on it and according to the
serial number it is one of the few fitted with a 15 degree clutch and has a
TBO of 1200 hours. If I get the gearbox shaft changed at the same time it
would extend TBO to 1500 as all other work has been carried out.
>
> Not the best time to be down, right at the height of the flying season!
>
> Regards,
> John
>
>
>
> Do not archive
>
> --------
> Europa mono Nr 192
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=444726#444726
>
>
>
>
>
>
>
>
>
>
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Propeller/engine vibration |
Hi Bob
The parts you seem to be describing are not the slipper clutch, although I
and everyone I have spoken to during the period of my vibration problem,
assumed that it was.
These parts are the dog drive system and are present on all the 912UL and
912ULS and 914 engines. They are held in contact by the Bellville washers
and incorporate the 15 or 30 degrees of movement that we have to regularly
check for in the Friction Torque Test.
On engines with a slipper clutch the output part of the dog drive system is
much larger and incorporates a clutch drive system within it, a bit like a
motorcycle clutch. This output dog drive is splined on to the Propeller
Drive Shaft.
When I had my gearbox at the Rotax Service Agent I asked him to show me how
it all worked and with the parts on the bench it all became very clear.
Dave Watts
G-BXDY
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Bob Harrison
Sent: 14 July 2015 12:17
Subject: RE: Europa-List: Re: Propeller/engine vibration
Hi! John /David /All ,
If your engine/gearbox set up includes a propeller strike engine protection
drive clutch(Slipper Clutch) you may find that the peaks of the drive lobes
have eroded spots of the flame hardening on the mating surfaces in the
valleys which is part of the gear pinion machining. (Entire gear and pinion
pair replacement usually needed about 1Kfor parts alone!) I believe that
the mating surface loading of this device when under light loading, with the
lobe peaks centred has too small surface contact, is not getting adequate
high pressure lubrication from the approved engine oils.
For instance under heavy thrust loading in normal flight the lobe surface
has a much larger contact surface having moved up the drive slopes from out
of the valley's . On throttling back the lobes move back to the limited
surface area contact position giving the intense surface pressure loading
where the erosion is happening . ( This has all been reported to the LAA
with photographs with no response .) I had the services of the ROTAX service
engineer in dismantling and reassembling but chose to carefully dremel the
offending places of erosion before reassembly and torque setting.
On any engine oil change I am now adding a full can of Holts STP high
contact pressure additive by carefully mixing it hot with the new engine oil
before pouring it into the oil tank . All sign of metal contaminant on the
magnetic plug have now stopped(Multiple checks and also at EVERY oil change)
and the vibration is now minimal . The engine has completed in excess of
200 hours with this set up but the vibration (although very much minimised
and probably un-noticeable by anyone else!) is slightly there in a very
light load condition (just above idle). No further contamination has been
detected on the magnetic plug.
Flight engine RPM landing control is the key to keeping away from the very
light loading position and an full idle setting to lose speed on approach
rather than a low power setting is in my opinion the answer.
My first notice of vibration prompted me to check the magnetic plug and
conduct an investigation since it failed the visual check.
Best regards to all
Bob Harrison G-PTAG Rotax 914
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of David Watts
Sent: 14 July 2015 09:54
Subject: Re: Europa-List: Re: Propeller/engine vibration
John,
Yes the vibration appeared "out of the blue" on the 20th May and it got no
worse and no different from the moment it started until last week, when it
seems that it may now be cured.
My Rotax agent thought it may be the splines on the gearbox prop shaft and
although he showed me that they still appeared to be perfect he is now of
the opinion that just reassembling them on different splines may have cured
my problem. (This though makes me feel that there may be some slight
undetectable wear in the splines that will rear it's ugly head again in the
future!!!)
Dave Watts
G-BXDY
> On 14 Jul 2015, at 08:49, JohnFrance <77alembert@gmail.com> wrote:
>
>
> Dear Dave and Bob,
> thank you for your feedback regarding the vibration problem.
> Dave, did your vibration appear "out of the blue" like mine did?
>
> My engine is a Rotax 912 UL with only 334 hours on it and according to the
serial number it is one of the few fitted with a 15 degree clutch and has a
TBO of 1200 hours. If I get the gearbox shaft changed at the same time it
would extend TBO to 1500 as all other work has been carried out.
>
> Not the best time to be down, right at the height of the flying season!
>
> Regards,
> John
>
>
>
> Do not archive
>
> --------
> Europa mono Nr 192
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=444726#444726
>
>
>
>
>
>
>
>
>
>
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Propeller/engine vibration |
Hi! David,
You may be right, except the torque loading to which you refer as well as
loading the clutch also contains the lobes of the dogs within their working
range and it is this resultant surface contact pressure which in my opinion
is too high for the PEAKS of the lobes giving a concentrated surface point
load when in the valley much reduced when up the driving slope.
Really antiquated principles .....my 1936 Vellocette OHC has a similar drive
between engine sprocket and gear box drive sprocket, protecting shock of the
cylinder power stroke through the primary drive chain.
For the many, the understanding of what I wrote was more intended as a guide
where to look for surface erosion and a remedy.
Without my dogged refusal to put my hand in my pocket the agent was content
to order a pair set of gears and Rotax would be 1000 in pocket as a result
!
Regards
Bob H G-PTAG.
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of David Watts
Sent: 14 July 2015 13:40
Subject: RE: Europa-List: Re: Propeller/engine vibration
Hi Bob
The parts you seem to be describing are not the slipper clutch, although I
and everyone I have spoken to during the period of my vibration problem,
assumed that it was.
These parts are the dog drive system and are present on all the 912UL and
912ULS and 914 engines. They are held in contact by the Bellville washers
and incorporate the 15 or 30 degrees of movement that we have to regularly
check for in the Friction Torque Test.
On engines with a slipper clutch the output part of the dog drive system is
much larger and incorporates a clutch drive system within it, a bit like a
motorcycle clutch. This output dog drive is splined on to the Propeller
Drive Shaft.
When I had my gearbox at the Rotax Service Agent I asked him to show me how
it all worked and with the parts on the bench it all became very clear.
Dave Watts
G-BXDY
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Bob Harrison
Sent: 14 July 2015 12:17
Subject: RE: Europa-List: Re: Propeller/engine vibration
--> <ptag.dev@tiscali.co.uk>
Hi! John /David /All ,
If your engine/gearbox set up includes a propeller strike engine protection
drive clutch(Slipper Clutch) you may find that the peaks of the drive lobes
have eroded spots of the flame hardening on the mating surfaces in the
valleys which is part of the gear pinion machining. (Entire gear and pinion
pair replacement usually needed about 1Kfor parts alone!) I believe that
the mating surface loading of this device when under light loading, with the
lobe peaks centred has too small surface contact, is not getting adequate
high pressure lubrication from the approved engine oils.
For instance under heavy thrust loading in normal flight the lobe surface
has a much larger contact surface having moved up the drive slopes from out
of the valley's . On throttling back the lobes move back to the limited
surface area contact position giving the intense surface pressure loading
where the erosion is happening . ( This has all been reported to the LAA
with photographs with no response .) I had the services of the ROTAX service
engineer in dismantling and reassembling but chose to carefully dremel the
offending places of erosion before reassembly and torque setting.
On any engine oil change I am now adding a full can of Holts STP high
contact pressure additive by carefully mixing it hot with the new engine oil
before pouring it into the oil tank . All sign of metal contaminant on the
magnetic plug have now stopped(Multiple checks and also at EVERY oil change)
and the vibration is now minimal . The engine has completed in excess of
200 hours with this set up but the vibration (although very much minimised
and probably un-noticeable by anyone else!) is slightly there in a very
light load condition (just above idle). No further contamination has been
detected on the magnetic plug.
Flight engine RPM landing control is the key to keeping away from the very
light loading position and an full idle setting to lose speed on approach
rather than a low power setting is in my opinion the answer.
My first notice of vibration prompted me to check the magnetic plug and
conduct an investigation since it failed the visual check.
Best regards to all
Bob Harrison G-PTAG Rotax 914
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of David Watts
Sent: 14 July 2015 09:54
Subject: Re: Europa-List: Re: Propeller/engine vibration
John,
Yes the vibration appeared "out of the blue" on the 20th May and it got no
worse and no different from the moment it started until last week, when it
seems that it may now be cured.
My Rotax agent thought it may be the splines on the gearbox prop shaft and
although he showed me that they still appeared to be perfect he is now of
the opinion that just reassembling them on different splines may have cured
my problem. (This though makes me feel that there may be some slight
undetectable wear in the splines that will rear it's ugly head again in the
future!!!)
Dave Watts
G-BXDY
> On 14 Jul 2015, at 08:49, JohnFrance <77alembert@gmail.com> wrote:
>
>
> Dear Dave and Bob,
> thank you for your feedback regarding the vibration problem.
> Dave, did your vibration appear "out of the blue" like mine did?
>
> My engine is a Rotax 912 UL with only 334 hours on it and according to
> the
serial number it is one of the few fitted with a 15 degree clutch and has a
TBO of 1200 hours. If I get the gearbox shaft changed at the same time it
would extend TBO to 1500 as all other work has been carried out.
>
> Not the best time to be down, right at the height of the flying season!
>
> Regards,
> John
>
>
>
> Do not archive
>
> --------
> Europa mono Nr 192
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=444726#444726
>
>
>
>
>
>
>
>
>
>
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Propeller/engine vibration |
Hi John,
I had something similar happen. Out of the blue I started getting
vibrations when I throttled back and it turned out to be the carbs being
out of balance. I don't know why it suddenly turned up but I balanced them
and life was good.
Paul
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | LG06 Shock,Absorber Needed |
Well, I've been building on my Classic Monowheel so long the LG06 shock
absorber has started flaking apart. I now have a big pile of red
underneath the plane.
Just wondering if anyone in the US has a new or slightly used LG06 that
they might want to sell (red or black). If you do, please let me know
what you're asking and approximate shipping to Atlanta.
Thanks,
Bill
A010 Monowheel Classic
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Fuel Tank Leak |
I had a leak from the vent flange too. Solved with new rubber.
I also have around an 80mm hole in the top between the headrests for the fuel level
sensor (air world) and I believe some have one sensor for each side so its
not structural and you could inspect/repair via those holes
--------
Graeme Bird
G-UMPY
Mono Classic/XS FFW 912S/Woodcomp 3000/3W
Newby: 180 hours 4 years on the Mono
g(at)gdbmk.co.uk
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444763#444763
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: LG06 Shock,Absorber Needed |
Hi there, I too am building a classic. I have an original, never fitted, red rubber
block but am in the UK so if you have no luck in finding one in the states
I may be your plane B.
Many thanks Frank
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=444778#444778
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|