claycookiemonster
Well Known Member
Why not? No belt to worry about.
Why not? No belt to worry about.
Why not? No belt to worry about.
I have no regrets and like the peace of mind with no belt up front to break.
I don't know if you're reading much of the alternator posts on VAF but I've never seen/heard of anyone breaking a belt and its generally once a week someone posts about issues with a pad-driven alternator.
I had a broken belt on a C-152 early in my ASEL flying experience, on a night flight too.
What was the cause?
I recently installed a new engine/prop and ditched my belt driven alternator in my RV8. I opted for the b&c BC410-H. It doesn’t charge at very low RPMs. That’s the only negative that I’ve experienced. I’m VFR only and don’t have high power loads. I only have around 10 hours on the engine, but so for I have no regrets and like the peace of mind with no belt up front to break. The thought of pulling the prop to change a belt wasn’t appealing. Here are a few pics.
Why not? No belt to worry about.
This is what I am doing.
At what RPM do you start seeing charge current flowing to the battery when first starting up?
Ok, so forgive me, because once again, the answers I get here are WAY smarter than the questions I ask. I'm going to restate what I think I've heard to make sure I'm keeping up with you guys.
1. The Vac Pad, since it works off the direct engine RPM may be running at an speed too low to power the systems at idle. Also, the tight space makes mounting a larger alternator challenging.
Actually, B&C has the 462 which is rated at 35-60 amps. It is a bit larger than the 410. I have the Airwolf remote filter and the 462 will NOT work without some mods to the air wolf adapter or possibly a small extension drive. The 410 will fit, and works great.
2. As a result, the battery may be discharging initially to provide what power the under-speed alternator cannot.
True. Realize that as soon as the engine starts and the alternator is brought online, 1000 rpm is adequate for the alternator to produce power, and 1000rpm is not an unusual idle speed on the ground.
3. Question: If I have a system back up battery, for the EFIS for example, then that battery would be initlally discharging too. If all goes well (always something to depend on in airplanes) BOTH the aircraft battery and system back up battery would recharge once the engine comes up to the speed required for the alternator.
True.
4. Is the inability of Vac Pad alternators to provide sufficient power at idle an insurmountable challenge, or is it simply something that has never been needed before, and so it may well be possible once it's attempted?
Not sure how you would get around it. As was previously posted, the pad turns at a slower rpm than the belt drive alternator would be turning, at the same rpm.
That's enough for now, as Monty Python used to say, "My brain hurts!"
B&C wound-field vacuum pad alternator current capability summary ref attached image.
I don't know if you're reading much of the alternator posts on VAF but I've never seen/heard of anyone breaking a belt and its generally once a week someone posts about issues with a pad-driven alternator.
This is what I am doing.
At what RPM do you start seeing charge current flowing to the battery when first starting up?