Mark:
I understand how hard it is to track your boats regen capabilities without a direct view of the current meter. I'm hoping add a meter that is easier to view from the helm and experiment with throttle positions this season.
As for regen with a folding prop. ASMO Marine (now Clean e Marine) engineers demonstrated regen on a boat using a folding prop:
From what I heard I think you rev up the motor to unfold the prop and then back it down until you see the regen begin. But, I have no personal experience with this method as I've got a fixed three blade prop.
From: acsarfkram <acsarfkram@yahoo.com>
To: electricboats@yahoogroups.com
Sent: Wednesday, March 28, 2012 4:03 PM
Subject: [Electric Boats] Re: Regen (again)
To: electricboats@yahoogroups.com
Sent: Wednesday, March 28, 2012 4:03 PM
Subject: [Electric Boats] Re: Regen (again)
I'm hesitant to post this because it is information from just one observed experience.
Recently I had to replace my fixed three blade 12x10 prop because one of the blades fell off! I think I hit something but the prop definitely had some pretty extensive electrolysis.
I replaced it with a fixed three blade 13x13. It's working well, I seem to be getting similar readings as the 12x10 - 20 amp draw around 4 knots, top speed a little faster at 5.9 knots (I have seen 6 knots) but where the 12x10 would top out at 5.7 knots with a 90 amp draw the 13x13 is pulling 110+ amps at the 5.9 knot boat speed. Also acceleration is faster.
To the regen issue. To see the regen amps I have to watch my PakTrakr which is not at the helm. With the new prop the one time I actually looked I consistently saw 1.8 - 2.2 regen amps at 6 knots of boat speed, this is at 50 to 51 volts. What I usually do is watch the meter that I have at the helm for voltage. I am still surprised at how much throttle is needed to get the most out of the regeneration capabilities on my boat as evidenced by rising pack voltage.
I'll have to repeat this a few more times before I commit to these numbers but I like what I see so far.
Mark
Santa Cruz
--- In electricboats@yahoogroups.com, Michael Mccomb <mccomb.michael@...> wrote:
>
> i think you are correct that an auto-feathering prop would produce both less drag and less, meaning no, regen at all.... Â a prop that could be adjusted while active (very expensive) would probably produce quite superior regen
>
>
> ________________________________
> From: Carter Quillen <twowheelinguy@...>
> To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
> Sent: Wednesday, March 28, 2012 1:32 PM
> Subject: Re: [Electric Boats] Re: Regen (again)
>
>
> Â
> Tim,
> Â
> The autoprop website said that autoprops feathers to provide 85% "less" drag. If there is less drag from the prop it only stand to reason that there should be less torque being imparted on the driveshaft so you're going to get less spinning and less electricity. Maybe the thing might somehow operate counter intutively and actually spin better with less drag on the boat but my gut feeling is that feathering is not going to help spin the driveshaft better.Â
> Â
> I guess someone will just have to stick one in a creek and see how it spins to be sure.Â
> Â
> Carter
>
> From: Tim <haywardt@...>
> To: electricboats@yahoogroups.com
> Sent: Wednesday, March 28, 2012 2:01 PM
> Subject: [Electric Boats] Re: Regen (again)
>
> Eric,
>
> I do know that you have said that no one is making
> more than a 100watts with regen, and I believe you. I also know that people are making a lot more than 100watts with screw impellers in streams. What I don't know is why it matters whether the water flows or the water stands still and the impeller moves. I suspect blade stall has something to do with it. An autoprop would reduce or eliminate blade stall.
>
> I don't think an autoprop will increase performance at the optimal cruise speed. After all, it will be at one pitch at that point and shouldn't perform any better than a properly pitched fixed prop. I do think it should widen the envelope of performance so that you get better performance over a wider range of speeds. I think it will couple the drive line to the water more efficiently in varying situations.
>
> Mostly I think it might provide interesting data.
>
>
>
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
Recently I had to replace my fixed three blade 12x10 prop because one of the blades fell off! I think I hit something but the prop definitely had some pretty extensive electrolysis.
I replaced it with a fixed three blade 13x13. It's working well, I seem to be getting similar readings as the 12x10 - 20 amp draw around 4 knots, top speed a little faster at 5.9 knots (I have seen 6 knots) but where the 12x10 would top out at 5.7 knots with a 90 amp draw the 13x13 is pulling 110+ amps at the 5.9 knot boat speed. Also acceleration is faster.
To the regen issue. To see the regen amps I have to watch my PakTrakr which is not at the helm. With the new prop the one time I actually looked I consistently saw 1.8 - 2.2 regen amps at 6 knots of boat speed, this is at 50 to 51 volts. What I usually do is watch the meter that I have at the helm for voltage. I am still surprised at how much throttle is needed to get the most out of the regeneration capabilities on my boat as evidenced by rising pack voltage.
I'll have to repeat this a few more times before I commit to these numbers but I like what I see so far.
Mark
Santa Cruz
--- In electricboats@yahoogroups.com, Michael Mccomb <mccomb.michael@...> wrote:
>
> i think you are correct that an auto-feathering prop would produce both less drag and less, meaning no, regen at all.... Â a prop that could be adjusted while active (very expensive) would probably produce quite superior regen
>
>
> ________________________________
> From: Carter Quillen <twowheelinguy@...>
> To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
> Sent: Wednesday, March 28, 2012 1:32 PM
> Subject: Re: [Electric Boats] Re: Regen (again)
>
>
> Â
> Tim,
> Â
> The autoprop website said that autoprops feathers to provide 85% "less" drag. If there is less drag from the prop it only stand to reason that there should be less torque being imparted on the driveshaft so you're going to get less spinning and less electricity. Maybe the thing might somehow operate counter intutively and actually spin better with less drag on the boat but my gut feeling is that feathering is not going to help spin the driveshaft better.Â
> Â
> I guess someone will just have to stick one in a creek and see how it spins to be sure.Â
> Â
> Carter
>
> From: Tim <haywardt@...>
> To: electricboats@yahoogroups.com
> Sent: Wednesday, March 28, 2012 2:01 PM
> Subject: [Electric Boats] Re: Regen (again)
>
> Eric,
>
> I do know that you have said that no one is making
> more than a 100watts with regen, and I believe you. I also know that people are making a lot more than 100watts with screw impellers in streams. What I don't know is why it matters whether the water flows or the water stands still and the impeller moves. I suspect blade stall has something to do with it. An autoprop would reduce or eliminate blade stall.
>
> I don't think an autoprop will increase performance at the optimal cruise speed. After all, it will be at one pitch at that point and shouldn't perform any better than a properly pitched fixed prop. I do think it should widen the envelope of performance so that you get better performance over a wider range of speeds. I think it will couple the drive line to the water more efficiently in varying situations.
>
> Mostly I think it might provide interesting data.
>
>
>
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
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.
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