---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 08/14/12: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:16 AM - Re: Which 55-60 amp alternator (Robert L. Nuckolls, III) 2. 07:08 PM - Re: Which 55-60 amp alternator (B Tomm) ________________________________ Message 1 _____________________________________ Time: 08:16:44 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Which 55-60 amp alternator At 01:23 PM 8/13/2012, you wrote: Bob, Assuming that in order to end up with an externally regulated 55-60 amp alternator, I will probably have to modify an IR model, which alternator should I buy to start with. I'm not sufficiently familiar with the choices to advise you confidently. It would seem that the driving constraint is purely mechanical. Research the parts available to bolt it to the engine including any changes to the stock pulley. Unless you're willing to tackle mechanical integration issues along with electrical, you'd probably want to limit you search to frames already supported by off-the-shelf attach hardware. I want the fans to turn the correct direction (CCW when viewed at the pulley) for use on a lycoming. That used to be a 'thing' to consider with external fans with blades optimized for direction of rotation. [] Modern alternators have internal fans with little if any 'sculpturing' of the blades [] Rotating an alternator 'backwards' in an airplane is unlikely to pose any problems. First, you're exceedingly unlikely to stress your alternator in a manner that produces maximum rated internal heating. The cooling environment under the hood of a car is MUCH worse than under the cowl of your airplane. Further, you're going to be spinning the alternator much faster than the original application design point . . . cooling is not a big issue. I don't want to pay the big bucks for a B&C unit and don't mind doing the work to convert it. You can run it internally regulated . . . you could do a mod similar to that offered by Plane Power for crowbar ov protection and external control of field power. Bob . . . ________________________________ Message 2 _____________________________________ Time: 07:08:37 PM PST US From: "B Tomm" Subject: RE: AeroElectric-List: Which 55-60 amp alternator Thanks Bob, The online alternator vendors don't supply data such as mounting bracket dimensions, pulley diameter etc. they just say it fit a particular make and model car. Can I assume that a 12V 60 amp Denso alternator has the same mounting dimensions as the 60 amp Plane Power that Vans sells? I'm not sufficiently familiar with the choices to advise you confidently. It would seem that the driving constraint is purely mechanical. Research the parts available to bolt it to the engine including any changes to the stock pulley. Fair enough. Anyone have any experience with this? I've already wired the plane for external control and crowbar as I agree with the philosophy. So I would like to keep it this way. Nothing lasts for ever. So my theory is to buy two alternators online for the price of one B & C or Plane power. Mod them both for external control and one will be then be a spare. :) Unless you're willing to tackle mechanical integration issues along with electrical, you'd probably want to limit you search to frames already supported by off-the-shelf attach hardware. Exactly. Still need top know the dimensional data. Anyone have a Vans, B&C, Plane Power 60amp that it will to measure the mounting bracket boss? That used to be a 'thing' to consider with external fans with blades optimized for direction of rotation. [] Modern alternators have internal fans with little if any 'sculpturing' of the blades [] Rotating an alternator 'backwards' in an airplane is unlikely to pose any problems. First, you're exceedingly unlikely to stress your alternator in a manner that produces maximum rated internal heating. The cooling environment under the hood of a car is MUCH worse than under the cowl of your airplane. Further, you're going to be spinning the alternator much faster than the original application design point . . . cooling is not a big issue. OK, makes sense. I will not be concerned with direction of fans. You can run it internally regulated . . . you could do a mod similar to that offered by Plane Power for crowbar ov protection and external control of field power. I'm confused by the above statement. Does that not make it externally controlled or is there a variation on a theme here? Is there a document that describes the PP mod? Bevan ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.