Steve Hargreaves - Moderator Posted February 6, 2012 Share Posted February 6, 2012 Interesting stuff Bob....especially the last two.....quite a difference given they use the same power train.... My idea was that, like the Electric Database you would download a spreadsheet & fill it in before sending it to a dedicated email address for collation into a larger spreadsheet... I've emailed David Ashby to get his take on it so lets see what he thinks Quote Link to comment Share on other sites More sharing options...
Ben B Posted February 6, 2012 Share Posted February 6, 2012 Of course without stating what dB meter was used, when it was last calibrated, what setting it was on, how many metres ,which side of the plane it was etc etc it's all a bit theoretical. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted February 6, 2012 Share Posted February 6, 2012 Agreed but in the land of the blind the one eyed man is King....... Half a loaf is better than no bread...... A rolling stone....(contd on page 97) Quote Link to comment Share on other sites More sharing options...
IanR Posted February 6, 2012 Share Posted February 6, 2012 Hello, Steve +1 re small dia rear mounted props. These surely make a much louder and more penetrating noise than the vast majority of engines. And yet, because they're electric, they're allowed on my club's site at any time, whilst engines are limited to 3 half days per week. If anything is going to cause trouble I can't help thinking that they'll probably be the culprits. Ian Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted February 6, 2012 Share Posted February 6, 2012 I would agree with you completely Ian....noise is very subjective & even though it might be at a very low level on a dB(A) scale it might be extremely irritatiing because of the frequency and/or what it implies..... Personally I love the sound of a Merlin engine at whatever dB(A) you might care to play it at... ..but I can't stand the buzz of a mosquito in my room at night even though I doubt it would register on a sound meter...... Quote Link to comment Share on other sites More sharing options...
Tony Richardson Posted February 7, 2012 Share Posted February 7, 2012 My home field went through a very trying two years due to a noise complaint, even though we are now council approved with a lot of concessions from the the club, reduced flying hours/ reduced membership/ and some stringent noise levels none of us are foolish enough to think we cannot be touched, please tread very carefully Steve, nothing is as it would seem in this day and age.Something I don't think I have seen mentioned is exhaust position is you can point it up, you will be surprised how much this reduces exhaust noise, I have an OS 52fs mounted in a Rascal 40 swinging a 12x6 APC prop at a touch over 10,000 rpm and it is extremely quiet, on the other hand the Multiplex Sonic Liner turning two 6x3 APC props at around 18,500 rpm gives a much more buzzing sound at full chat due to the higher rpm and the resonance from the airframe. Bigger props ( to a degree ) and lower rpm are really the way to go always keeping in mind the capabilities of the engine/motor. Keep em flying, wheels on the bottom please. Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted February 7, 2012 Share Posted February 7, 2012 Posted by Steve Hargreaves on 06/02/2012 14:42:40: Interesting stuff Bob....especially the last two.....quite a difference given they use the same power train.... My idea was that, like the Electric Database you would download a spreadsheet & fill it in before sending it to a dedicated email address for collation into a larger spreadsheet... I've emailed David Ashby to get his take on it so lets see what he thinks Yes, sounds pretty useful Steve but I'm not sure you'll get quite the response as you've seen from the electric database but I can certainly find space, no problem at all. Quote Link to comment Share on other sites More sharing options...
Mike Hawkins Posted February 7, 2012 Share Posted February 7, 2012 Kind of lucky at my club. I think the limit is 98dB, we are about 5km from the nearest town and surrounded by hills and an army base. I seem to remember reading a number of articles in Airborne (Australia) and RCM&E on limiting noise. Simple stuff such as having the muffler outlet point up instead of down will not reduce the volume output but can reduce the volume heard at ground level. Two models in the air can increase the overall sound level by 3dB, so whilst both models may comply with sound limits, together they may exceed them. Anyways, if you have the time, check out the MAAA Noise Policy. Probably similar to the BMFA info, but the layout is less painful. Quote Link to comment Share on other sites More sharing options...
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