 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
BobD
Joined: 05 Jan 2016
Posts: 112
Location: Sheffield UK
|
 Posted: Sat Feb 09, 2019 1:39 am Post subject: Arplast PV50 Propeller Motor |
 |
|
The 6V Electric Motor on the Arplast PV50 propeller on my Europa has failed. Having researched the forums, there has been talk about replacing the 6V Motor with the 12V model, and I am putting together a MOD request to the UK LAA to do this. It seems sensible, as the aircraft provides 12V to the motor. However, I am not well versed in the skills required to compare the two models, so I hope someone here can look at the attached spec sheet for the motors, and let me know if they can find any reason not to do this. Conversely, any reasons why it may be a good idea would help with my submission to the LAA
The current model is 2224U006SR, and I am looking at replacing this with a 2224U012SR
I also wonder why the original Propeller manufacturer (no longer in business) would use a 6V motor on a 12V system (unless the 12V option wasn't available at the time)?
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
| Description: |
|
Download |
| Filename: |
EN_2224_SR_DFF.pdf |
| Filesize: |
311.77 KB |
| Downloaded: |
352 Time(s) |
_________________
Bob Dawson
Europa XS TG || 912 ULS || G-NHRJ || Dynon Skyview || PilotAware || SmartAss3 |
|
| Back to top |
|
 |
jan_de_jong(at)casema.nl
Guest
|
| Posted: Sat Feb 09, 2019 3:05 am Post subject: Arplast PV50 Propeller Motor |
|
|
If I read this correctly the 6V item has
nominally:
stall current 3.1A (6 / 1.94)
stall torque 21.2 mNm
as used:
stall current 7.2A (14 / 1.94)
stall torque about 50 mNm
The 6V motor will only survive if used infrequently for short periods.
There is a thermal time constant of 6.8 seconds that is of interest in
this regard.
For the 12V item the nominal values and the proposed 'as used' values
are close together. That leads to good reliability, but also to less
than half the torque Arplast apparently wanted.
So. Most likely the 6V item must be used with care and the 12V item is
probably not up to the task.
IMHO.
Jan de Jong
#461 'back to building'
On 2/9/2019 10:39 AM, BobD wrote:
| Quote: |
The 6V Electric Motor on the Arplast PV50 propeller on my Europa has failed. Having researched the forums, there has been talk about replacing the 6V Motor with the 12V model, and I am putting together a MOD request to the UK LAA to do this. It seems sensible, as the aircraft provides 12V to the motor. However, I am not well versed in the skills required to compare the two models, so I hope someone here can look at the attached spec sheet for the motors, and let me know if they can find any reason not to do this. Conversely, any reasons why it may be a good idea would help with my submission to the LAA
The current model is 2224U006SR, and I am looking at replacing this with a 2224U012SR
I also wonder why the original Propeller manufacturer (no longer in business) would use a 6V motor on a 12V system (unless the 12V option wasn't available at the time)?
--------
Bob Dawson
Europa XS TG || 912 ULS || G-NHRJ || Dynon Skyview || PilotAware || SmartAss3
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=487487#487487
Attachments:
http://forums.matronics.com//files/en_2224_sr_dff_206.pdf
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
m.j.gregory(at)talk21.com
Guest
|
| Posted: Sat Feb 09, 2019 5:15 am Post subject: Arplast PV50 Propeller Motor |
|
|
Bob,
Jan is quite correct to warn that you are unlikely to get the stall torque needed to move the blades under flight loads with a 12v rated version of the fitted 6v motor. When visiting the factory of another VP prop manufacturer in 2000, I asked the same question: "Why are you using a 6v motor in a 12v electrical system" and was told that they needed to overdrive the 6v motor to get the torque necessary, but the duty cycle was low and the back-EMF reduced the current as soon as the motor was running.
A number of things need to operate properly for this 6v motor to be reliable in service, in particular:
- The flight loads must not cause the motor to struggle, so that the high starting current lasts for long enough to overheat the motor - this will depend on airspeed, blade shape, lubrication, etc.
- The controller should not cause the system to hunt, i.e. make frequent movements to adjust the blade pitch, especially in the cruise, which can increase the duty cycle well beyond the design limit. The increased temperature and brush wear will be likely to cause premature failure.
- To avoid hunting in the cruise, switching the controller to manual can help, but you then need to keep a check and make adjustments, or switch back to auto when the flight mode changes.
- To find out if the motor is being overloaded, monitoring the drive current would indicate whether it was struggling whenever the controller was demanding a change in pitch, and the frequency of changes would readily show hunting. The controller may well have an indicator light to show when the motor is running.
In short, I would not recommend changing from the 6v motor without knowing that the replacement would cope with the loads, and in any case not before exploring the operation of the controller and propeller in your aeroplane and the flight profiles you follow.
Good luck!
Mike
--
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)aeroelect
Guest
|
| Posted: Sat Feb 09, 2019 5:34 am Post subject: Arplast PV50 Propeller Motor |
|
|
At 05:14 AM 2/9/2019, you wrote:
| Quote: | --> AeroElectric-List message posted by: Jan de Jong <jan_de_jong(at)casema.nl>
|
<snip>
| Quote: | So. Most likely the 6V item must be used with care and the 12V item is probably not up to the task.
IMHO.
Jan de Jong
#461 'back to building' |
Agreed . . .
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
jan_de_jong(at)casema.nl
Guest
|
| Posted: Sat Feb 09, 2019 5:54 am Post subject: Arplast PV50 Propeller Motor |
|
|
Maybe good to mention also that heat production goes with the square of
the current...
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
BobD
Joined: 05 Jan 2016
Posts: 112
Location: Sheffield UK
|
| Posted: Mon Feb 11, 2019 8:38 am Post subject: Re: Arplast PV50 Propeller Motor |
|
|
Jan, Mike, Bob,
Thanks for your input. It appears perceived wisdom is to stick with the 6V motor, so that is what I shall do.
I have spoken to a very helpful lady at the U.K. Distributor (www.ems-limited.co.uk), and I am just waiting to hear about lead times. She did explain that the part number 2224U0006SR of my failed motor is not the original part number provided for the Arplast PV50 and "The 2224U0006SR isn’t a like for like replacement for the 2224U006SR-59, due to the special option “59”, which means that the motor has coils for end/commutator seg secured with special adhesive ". The non-59 has been used by some due to the sometimes lengthy lead time for the -59 (and the price which is £149.33 + VAT, as against "£71.11 + VAT). She says the -59 is likely to have a longer life than the non-59 variant.
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
_________________
Bob Dawson
Europa XS TG || 912 ULS || G-NHRJ || Dynon Skyview || PilotAware || SmartAss3 |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
