External alternator kit from Rotec Aerosport

[RoelandVerhoeven]

Thank you for sharing your experience with the Rotec Aerosport external alternator kit. It's great to hear that everything bolted up fine and that you were able to make the necessary modifications without too much difficulty.
It's understandable to debate whether to keep the internal regulator or switch to an external regulator. As you mentioned, you have a backup alternator, so the risk of a regulator failure causing a complete electrical system failure is reduced. However, an external regulator can offer more precise voltage control and protection features such as overvoltage protection, which may be beneficial in certain situations.
Regarding the propeller spacer issue, it's good to hear that you were able to find a solution by taking the spacer to a machine shop. It's important to ensure proper clearance between the cowling and the propeller to prevent any potential damage or interference.
Overall, it sounds like the Rotec Aerosport external alternator kit was a good value for you, even with the minor inconveniences.

[bbs428]

Thought I'd follow up on the Rotec Alt kit.

An issue arose when placing the ss7 top cowling on the plane. The bracket as is, allows the big lug of the alt. to be at the 12 o'clock position and in just outboard of the spinner fairing. There's just not enough room for the cowl to fit. You need at least .5 - .6 inch of clearance to clear the top cowl.
Now there is enough material in the bracket to get it to work, but you have to really think out the geometry and have the proper tools to do the job. For the average builder it might be a bridge to far.
I got it all to work nicely but it took the better part of the afternoon to do it.

In the 1st pic you can see where it was hitting, just to the port side of the spinner fairing (the raised portion of the top cowl that mates with the spinner)
2nd pic shows where it was hitting on the alt.

Alt bracket interference.jpg IMG_1756.jpg


I changed the position of the alt to index the lug to the 11 o'clock position. This also moved the alt. inboard which was great because we gained more clearance the further inboard we came. All this took a few hours of carving on a nicely anodized chunk of aluminum to get it all to work satisfactorily. Not a good way to go but the end result is it all works well, although it's not as pretty as before! Lol.

IMG_1757.jpg

There would be no issue for the round cowl.
If you have the skill set - then buy the kabuto (Denso) 45 amp. alt. for $120.00, a gates belt for $25.00 and fabricate your own bracket. The bigger problem IMHO is the pulley, as it will have to be matched and machined to work correctly.

I'll follow up again when I get the engine running and we can test the output and the voltage regulation.

My recommendation if you need more alt. is to use the Rotax alt. kit - $$$$, But no issues.

[patrick.hvac]

Thanks for the follow up. I was watching this with interest.