Alternator/Fuel pump

[Dave Wolfe]

The walbro gsl 414 gets you down to 3A per pump.

[kmacht]

I stumbled across this thread while looking for a larger alternator solution for the aerovee and just wanted to make a comment about milling the adaptor plate out for the larger stator rather than using a spacer. Doing so will move the rotor closer to the crank but it won't keep you from having to still make spacers and an adaptor for the trigger plate and moving the trigger magnets further out. The new rotor is not only a larger diameter but is also quite a bit wider/thicker as well so just milling the adaptor plate won't work as the part sticks out too far.

To ensure concentricity I turned a flange on the ~1.5" spacer on both sides. One centers up the new rotor and the other engages both the flywheel as well as the crankshaft adaptor that's held on with the gland nut. This makes it so everything from the crank to to the rotor is concentric when assembled.

I'm still working on mounting the trigger magnet plate but am weighing parts while I go and the larger alternator and adaptor pieces will add around 5.3 pounds above the stock aerovee assembled weight. I put a bore through the center of the 1.5" spacer to cut some weight and likely could have taken a little more off the 4" O.D. but am happy with being around 5lbs and didn't want to push it.

Once I finish and do some flight testing next year I will post some 3d models of the adaptor parts if anyone else wants to make them. I have an old manual mill and lathe that I used to make the parts but there are plenty of companies out there that will make parts for you if you provide them the model.

Keith
#554

[Wingman]

Keith,

Glad to see you are giving this a try. You are correct that one still needs to make a spacer/adapter plate for the mag trigger plate. If you look at my pictures, you can see I did that also. My suggestion to mill out the engine mounting plate was just to get it all closer to the engine rather than being completely aft of the plate. My thought is that it would reduce some of the added weight also, which you have confirmed by your indicated weights. When I reweighed mine after completion, I added almost 7 Lbs. Still better than an automotive alternator but too heavy for the Sonex.

Mine is still running flawlessly and the extra amps have been adequate for all of my equipment with some to spare. With all electrical equipment on at once you will hear the load on the engine. It creates a slight drop in RPM.

I will look forward to seeing your improved version. sounds like you are putting more engineering into than I did.

MN Wingman

[kmacht]

I tried messaging you but the pm system doesn't seem to work on this site. For the voltage regulator did you use the one that came with the new rotor/stator or did you use something different?

[Wingman]

I used the one that came with the rotor/stator. It seems to be doing a fine job. Mine runs right at 14 volts at cruise power and anything above about 1800 RPM.

[Bryan Cotton]

I tried messaging you but the pm system doesn't seem to work on this site. For the voltage regulator did you use the one that came with the new rotor/stator or did you use something different?

It works for me!

[kmacht]

Not sure what’s up with the PMs but for me they just sit in the outbox and never actually send.

I finished up mounting the alternator yesterday. I just need to machine a longer trigger magnet holder of some sort. I posted some additional pictures over on the Facebook group.

[Wingman]

Nice! That's looking very similar to my setup. It would appear you are installing all aft of the X-plate as well? The picture looks like you haven't milled out the X-plate either. It will work fine this way.

I'm getting ready to pull my engine due to a low oil pressure issue that I suspect is an internal case problem. While I have it off I am going to get my X-plate milled out so I can mount the rotor right to the crank. I'll post more pictures after I get that done. Probably won't be done until late spring or early summer.

[kmacht]

I considered milling the x plate but it would have left very little material between the alternator hole and the starter hole. That web there takes a lot of the bending force from the upper right engine mount and I wasn’t comfortable with how little left there was going to be. The rotor is also too wide and would still need the standoffs from the x plate to mount the stator. To get around the concentricity issues I turned the flanges on the spacer to be a slight slip fit to the crank flange, flywheel, and rotor and then drilled the 8 holes all together as a single assembly on the mill using a rotary table. The whole assembly runs true within .002.

Keith
#554

[Wingman]

Very good! You're probably correct regarding the milling out of the plate. I haven't measured it to see how much would be left after enlarging the opening. I'm glad you considered that. Now we know.

The spacer I used also has a flange that helped with alignment. I drilled mine just with a drill press rather than using a milling machine. Mine is also running about.002-.003 within true. When I had the rotor milled out to fit the spacer flange, the rotor itself seemed to be about 2 mills out of round.

That should run fine for you. I don't have any noticable vibration from mine.

On a side note, I'm currently pulling my engine apart for a low oil pressure issue. I think I have a flawed case. I'm losing pressure somewhere internally. I've been through everything else, so...?