On May 26, 2021, at 09:49, Dan Pfeiffer <dan@...> wrote:

?

Its a spline.?? Very common on transmission shafts.?? Allows for a slip fit and very high torque capacity.??

?

On 2021-05-26 11:40 am, Ryan Sweet wrote:

Hello,

I am evaluating an EV kit and I see this shaft on a drive motor... notice the female toothed grooves in the shaft... and I’ve not seen this before nor can I figure out what it is called.

Does anyone know the right way to describe this kind of fitting and what the corresponding male part looks like (say, for mounting a pulley)?

Thanks,
-Ryan

Hello,

I am evaluating an EV kit and I see this shaft on a drive motor... notice the female toothed grooves in the shaft... and I’ve not seen this before nor can I figure out what it is called.

Does anyone know the right way to describe this kind of fitting and what the corresponding male part looks like (say, for mounting a pulley)?

Thanks,
-Ryan

?

Any idea how the 4 knots will work in wind/wave sea conditions ?

That may limit the range.

?

?

On Wednesday, 26 May 2021, 13:01:01 GMT+8, Ryan Sweet <ryan@...> wrote:

?

?

Yep John it would be really hard to find a DC power supply at a reasonable price that would supply enough amps continuous compared to a battery. ?It's also hard to get a setup from generator to battery charger(s in parallel) that will keep up with battery consumption, but the approaches Dan outlines are both routes that should work.?

?

If your stumbling block is initial cost of the battery bank, I'm not sure that these approaches will save you a whole lot of money, but what either approach will do is give you a path out of the range limitation of a smaller battery.?

On May 25, 2021, at 21:41, Dan Pfeiffer <dan@...> wrote:

?

Yes, I think what you describe can work but from what I have found (and been advised by Thunderstruck) you need/want the battery in the system rather than powering the motor controller (of whatever type - AC, DC, BLDC,...) directly from the generator.? But the battery can then be smaller.?? It is not a solution to head offshore with but for the way most people use their boats I think it can work.

I would look at propane or dual fuel generators rather than gasoline.? Propane on the boat has the same issues as gas with regard to accumulation in the bilge but it is a lot easier to swap a propane bottle at sea in rough weather than to re-fill the gas tank on a portable generator from a gas can.?? I know of one 6-1/2 ton monohull that runs with a 2000 watt propane generator and reports 4 kts and 8 hrs on a 20lb bottle (about 4.5 gallons of propane).? You would use about 4 gallons of diesel in that boat over 8hrs at 4kts.? So that cost per mile is about the same??? A 20lb propane refill is about $20 and so is 4 gallons of marine diesel?

As far as the power supply, the charger is exactly what would do the job.? You run the propulsion motor from the battery and you keep the battery topped up with the charger that is running from the generator.?? If you want to go 4 kts you need a 2000 watt generator and a 2000 watt charger.?

There is a boat in Seattle that a list member here has that is running three 2500 watt Thunderstruck chargers from a 220V AC diesel genset to get 7500 watts for about 6 kts I think.?? The Thunderstruck chargers can run up to four from one controller so the system is scalable.?? But note that it is running at 220V.? Those chargers only deliver 1500 watts at 120V.?? So to be a practical solution you really need the 220VAC genset.?

?

I don't think a 3000W power supply would be more cost effective and with a charger you should have the controller to properly manage the system and not blow anything up. ??

I have in mind a similar system to the one is Seattle but I am looking at a 48VDC genset to take out the middleman of the chargers.? I am planning on using a BLDC motor for the generator and a 12kW diesel (Kubota 722).? But it will require a beefy rectifier and regulator and I have not gotten to the research on that yet.? That's phase 2 or 3 and I am a few weeks away from getting phase 1 up and running which is the electric propulsion part.? I am almost done with machining the running gear.? After that's up and running I'll start working on the genset.?

For what it's worth, I have a 13kWhr battery and estimate I will have a 25 mile range at 4 kts.? If I add a propane generator to power the charger (a possible interim solution while I get the 48VDC genset built) I hope to be able to run at 4kts with zero draw on the battery.? I should have real data in a couple months.

Dan Pfeiffer

On 2021-05-25 11:05 pm, john via groups.io wrote:

?

Yes, power is power.

The thought was that it's relatively cheap to buy a portable generator and carry a can of gas as backup.

?

Looking at this a different way...

?

If I go with traditional 48V motors (maybe even 10Kw so that I have plenty of room to grow) - can I power those (at low power) from a DC power supply running off a portable generator?? ?Is it possible to buy a 2000W or even 3000W 48V DC power supply that runs off 110VAC?? ?This would (in theory?) allow me to run off a very small battery bank, or no battery bank at all initially.

?

Then there's the electrical question:? If I connect a 3000W power supply to a small lithium battery (which would be very unlikely to have exactly the same voltage - higher when charged, lower when discharged - will I blow up anything?

?

I'm assuming a 3000W power supply would be significantly more cost effective than trying to find a 3000W charger (which would be massive overkill, and likely damage a small battery bank).

?

John

?

?

?

?

On Tuesday, May 25, 2021, 09:53:32 PM CDT, Dan Pfeiffer <dan@...> wrote:

?

?

Setting aside efficiency differences it still takes the same amount of power to move the boat at a given speed.? AC, DC, gasoline, diesel.? Doesn't matter.? The boat wants what the boat wants.?? Higher voltage will be lower amps.?? Lower voltage will be higher amps.? The watts remain the same.?? The sizing of the wires may change but the power needs remain the same.?

An AC motor can indeed be used with a controller that allows for forward and reverse and all the rest.? Your battery bank challenge will remain.?? It may even get larger from more losses through added inverter stages.??

The generator can also work.? For a 6 ton boat you'll need something in the neighborhood of 2000 watts to go 4 kts??? Doesn't matter where you get it or what conversions in may go through making it's way to the propeller.?? If you're going to loose half of it on the way you need to start with 3200.?? An AC motor will work but it won't pick up the check at lunch.?

Dan Pfeiffer

On 2021-05-25 9:19 pm, john via groups.io wrote:

?

?

This is probably a really silly question, but....

?

Is it possible to find a 120V AC motor that can be speed controlled (and maybe even reversed??) for at least a proof of concept on a boat?

?

For those of us that prefer electric motors to gas or diesel engines, but are challenged by the investment of a huge battery bank, wouldn't it be cool if we could run an AC motor off an inverter from whatever battery bank we have handy, and use a generator to supplement - or just run off the generator entirely at first?

?

We've discussed the efficiency gain of running off a higher voltage / lower current.

I'm guessing that there just isn't a suitable way to control and/or reverse an AC motor??

?

John

?

?

?

?

Another what-if...

?

Rather than trying to go 3000W @48V from 120V -?

Amazon has a 1200W 12V power supply that runs on 120AC.

Assuming(!!) the ground is not tied to the AC ground - can I tie 4 of these power supplies in series to generate the 48V?

?

It looks like the Thunderstruck TSM 2500 dual charger setup would allow you to connect two 25A chargers in parallel.? Am I reading correctly that I could get a max of 50A @ 48V (2400W) out of that?? For $1260.

?

On Wednesday, May 26, 2021, 12:01:01 AM CDT, Ryan Sweet <ryan@...> wrote:

?

?

Yep John it would be really hard to find a DC power supply at a reasonable price that would supply enough amps continuous compared to a battery. ?It's also hard to get a setup from generator to battery charger(s in parallel) that will keep up with battery consumption, but the approaches Dan outlines are both routes that should work.?

?

If your stumbling block is initial cost of the battery bank, I'm not sure that these approaches will save you a whole lot of money, but what either approach will do is give you a path out of the range limitation of a smaller battery.?

On May 25, 2021, at 21:41, Dan Pfeiffer <dan@...> wrote:

?

Yes, I think what you describe can work but from what I have found (and been advised by Thunderstruck) you need/want the battery in the system rather than powering the motor controller (of whatever type - AC, DC, BLDC,...) directly from the generator.? But the battery can then be smaller.?? It is not a solution to head offshore with but for the way most people use their boats I think it can work.

I would look at propane or dual fuel generators rather than gasoline.? Propane on the boat has the same issues as gas with regard to accumulation in the bilge but it is a lot easier to swap a propane bottle at sea in rough weather than to re-fill the gas tank on a portable generator from a gas can.?? I know of one 6-1/2 ton monohull that runs with a 2000 watt propane generator and reports 4 kts and 8 hrs on a 20lb bottle (about 4.5 gallons of propane).? You would use about 4 gallons of diesel in that boat over 8hrs at 4kts.? So that cost per mile is about the same??? A 20lb propane refill is about $20 and so is 4 gallons of marine diesel?

As far as the power supply, the charger is exactly what would do the job.? You run the propulsion motor from the battery and you keep the battery topped up with the charger that is running from the generator.?? If you want to go 4 kts you need a 2000 watt generator and a 2000 watt charger.?

There is a boat in Seattle that a list member here has that is running three 2500 watt Thunderstruck chargers from a 220V AC diesel genset to get 7500 watts for about 6 kts I think.?? The Thunderstruck chargers can run up to four from one controller so the system is scalable.?? But note that it is running at 220V.? Those chargers only deliver 1500 watts at 120V.?? So to be a practical solution you really need the 220VAC genset.?

?

I don't think a 3000W power supply would be more cost effective and with a charger you should have the controller to properly manage the system and not blow anything up. ??

I have in mind a similar system to the one is Seattle but I am looking at a 48VDC genset to take out the middleman of the chargers.? I am planning on using a BLDC motor for the generator and a 12kW diesel (Kubota 722).? But it will require a beefy rectifier and regulator and I have not gotten to the research on that yet.? That's phase 2 or 3 and I am a few weeks away from getting phase 1 up and running which is the electric propulsion part.? I am almost done with machining the running gear.? After that's up and running I'll start working on the genset.?

For what it's worth, I have a 13kWhr battery and estimate I will have a 25 mile range at 4 kts.? If I add a propane generator to power the charger (a possible interim solution while I get the 48VDC genset built) I hope to be able to run at 4kts with zero draw on the battery.? I should have real data in a couple months.

Dan Pfeiffer

On 2021-05-25 11:05 pm, john via groups.io wrote:

?

Yes, power is power.

The thought was that it's relatively cheap to buy a portable generator and carry a can of gas as backup.

?

Looking at this a different way...

?

If I go with traditional 48V motors (maybe even 10Kw so that I have plenty of room to grow) - can I power those (at low power) from a DC power supply running off a portable generator?? ?Is it possible to buy a 2000W or even 3000W 48V DC power supply that runs off 110VAC?? ?This would (in theory?) allow me to run off a very small battery bank, or no battery bank at all initially.

?

Then there's the electrical question:? If I connect a 3000W power supply to a small lithium battery (which would be very unlikely to have exactly the same voltage - higher when charged, lower when discharged - will I blow up anything?

?

I'm assuming a 3000W power supply would be significantly more cost effective than trying to find a 3000W charger (which would be massive overkill, and likely damage a small battery bank).

?

John

?

?

?

?

On Tuesday, May 25, 2021, 09:53:32 PM CDT, Dan Pfeiffer <dan@...> wrote:

?

?

Setting aside efficiency differences it still takes the same amount of power to move the boat at a given speed.? AC, DC, gasoline, diesel.? Doesn't matter.? The boat wants what the boat wants.?? Higher voltage will be lower amps.?? Lower voltage will be higher amps.? The watts remain the same.?? The sizing of the wires may change but the power needs remain the same.?

An AC motor can indeed be used with a controller that allows for forward and reverse and all the rest.? Your battery bank challenge will remain.?? It may even get larger from more losses through added inverter stages.??

The generator can also work.? For a 6 ton boat you'll need something in the neighborhood of 2000 watts to go 4 kts??? Doesn't matter where you get it or what conversions in may go through making it's way to the propeller.?? If you're going to loose half of it on the way you need to start with 3200.?? An AC motor will work but it won't pick up the check at lunch.?

Dan Pfeiffer

On 2021-05-25 9:19 pm, john via groups.io wrote:

?

?

This is probably a really silly question, but....

?

Is it possible to find a 120V AC motor that can be speed controlled (and maybe even reversed??) for at least a proof of concept on a boat?

?

For those of us that prefer electric motors to gas or diesel engines, but are challenged by the investment of a huge battery bank, wouldn't it be cool if we could run an AC motor off an inverter from whatever battery bank we have handy, and use a generator to supplement - or just run off the generator entirely at first?

?

We've discussed the efficiency gain of running off a higher voltage / lower current.

I'm guessing that there just isn't a suitable way to control and/or reverse an AC motor??

?

John

?

?

?

On May 25, 2021, at 22:35, john via groups.io <oak_box@...> wrote:

?

Another what-if...

Rather than trying to go 3000W @48V from 120V -?

Amazon has a 1200W 12V power supply that runs on 120AC.

Assuming(!!) the ground is not tied to the AC ground - can I tie 4 of these power supplies in series to generate the 48V?

It looks like the Thunderstruck TSM 2500 dual charger setup would allow you to connect two 25A chargers in parallel.? Am I reading correctly that I could get a max of 50A @ 48V (2400W) out of that?? For $1260.

On Wednesday, May 26, 2021, 12:01:01 AM CDT, Ryan Sweet <ryan@...> wrote:

Yep John it would be really hard to find a DC power supply at a reasonable price that would supply enough amps continuous compared to a battery. ?It’s also hard to get a setup from generator to battery charger(s in parallel) that will keep up with battery consumption, but the approaches Dan outlines are both routes that should work.?

If your stumbling block is initial cost of the battery bank, I’m not sure that these approaches will save you a whole lot of money, but what either approach will do is give you a path out of the range limitation of a smaller battery.?

On May 25, 2021, at 21:41, Dan Pfeiffer <dan@...> wrote:

?

Yes, I think what you describe can work but from what I have found (and been advised by Thunderstruck) you need/want the battery in the system rather than powering the motor controller (of whatever type - AC, DC, BLDC,...) directly from the generator.? But the battery can then be smaller.?? It is not a solution to head offshore with but for the way most people use their boats I think it can work.

I would look at propane or dual fuel generators rather than gasoline.? Propane on the boat has the same issues as gas with regard to accumulation in the bilge but it is a lot easier to swap a propane bottle at sea in rough weather than to re-fill the gas tank on a portable generator from a gas can.?? I know of one 6-1/2 ton monohull that runs with a 2000 watt propane generator and reports 4 kts and 8 hrs on a 20lb bottle (about 4.5 gallons of propane).? You would use about 4 gallons of diesel in that boat over 8hrs at 4kts.? So that cost per mile is about the same??? A 20lb propane refill is about $20 and so is 4 gallons of marine diesel?

As far as the power supply, the charger is exactly what would do the job.? You run the propulsion motor from the battery and you keep the battery topped up with the charger that is running from the generator.?? If you want to go 4 kts you need a 2000 watt generator and a 2000 watt charger.?

There is a boat in Seattle that a list member here has that is running three 2500 watt Thunderstruck chargers from a 220V AC diesel genset to get 7500 watts for about 6 kts I think.?? The Thunderstruck chargers can run up to four from one controller so the system is scalable.?? But note that it is running at 220V.? Those chargers only deliver 1500 watts at 120V.?? So to be a practical solution you really need the 220VAC genset.?

?

I don't think a 3000W power supply would be more cost effective and with a charger you should have the controller to properly manage the system and not blow anything up. ??

I have in mind a similar system to the one is Seattle but I am looking at a 48VDC genset to take out the middleman of the chargers.? I am planning on using a BLDC motor for the generator and a 12kW diesel (Kubota 722).? But it will require a beefy rectifier and regulator and I have not gotten to the research on that yet.? That's phase 2 or 3 and I am a few weeks away from getting phase 1 up and running which is the electric propulsion part.? I am almost done with machining the running gear.? After that's up and running I'll start working on the genset.?

For what it's worth, I have a 13kWhr battery and estimate I will have a 25 mile range at 4 kts.? If I add a propane generator to power the charger (a possible interim solution while I get the 48VDC genset built) I hope to be able to run at 4kts with zero draw on the battery.? I should have real data in a couple months.

Dan Pfeiffer

On 2021-05-25 11:05 pm, john via groups.io wrote:

?

Yes, power is power.

The thought was that it's relatively cheap to buy a portable generator and carry a can of gas as backup.

?

Looking at this a different way...

?

If I go with traditional 48V motors (maybe even 10Kw so that I have plenty of room to grow) - can I power those (at low power) from a DC power supply running off a portable generator?? ?Is it possible to buy a 2000W or even 3000W 48V DC power supply that runs off 110VAC?? ?This would (in theory?) allow me to run off a very small battery bank, or no battery bank at all initially.

?

Then there's the electrical question:? If I connect a 3000W power supply to a small lithium battery (which would be very unlikely to have exactly the same voltage - higher when charged, lower when discharged - will I blow up anything?

?

I'm assuming a 3000W power supply would be significantly more cost effective than trying to find a 3000W charger (which would be massive overkill, and likely damage a small battery bank).

?

John

?

?

?

?

On Tuesday, May 25, 2021, 09:53:32 PM CDT, Dan Pfeiffer <dan@...> wrote:

?

?

Setting aside efficiency differences it still takes the same amount of power to move the boat at a given speed.? AC, DC, gasoline, diesel.? Doesn't matter.? The boat wants what the boat wants.?? Higher voltage will be lower amps.?? Lower voltage will be higher amps.? The watts remain the same.?? The sizing of the wires may change but the power needs remain the same.?

An AC motor can indeed be used with a controller that allows for forward and reverse and all the rest.? Your battery bank challenge will remain.?? It may even get larger from more losses through added inverter stages.??

The generator can also work.? For a 6 ton boat you'll need something in the neighborhood of 2000 watts to go 4 kts??? Doesn't matter where you get it or what conversions in may go through making it's way to the propeller.?? If you're going to loose half of it on the way you need to start with 3200.?? An AC motor will work but it won't pick up the check at lunch.?

Dan Pfeiffer

On 2021-05-25 9:19 pm, john via groups.io wrote:

?

?

This is probably a really silly question, but....

?

Is it possible to find a 120V AC motor that can be speed controlled (and maybe even reversed??) for at least a proof of concept on a boat?

?

For those of us that prefer electric motors to gas or diesel engines, but are challenged by the investment of a huge battery bank, wouldn't it be cool if we could run an AC motor off an inverter from whatever battery bank we have handy, and use a generator to supplement - or just run off the generator entirely at first?

?

We've discussed the efficiency gain of running off a higher voltage / lower current.

I'm guessing that there just isn't a suitable way to control and/or reverse an AC motor??

?

John

?

?

On May 25, 2021, at 21:41, Dan Pfeiffer <dan@...> wrote:

?

Yes, I think what you describe can work but from what I have found (and been advised by Thunderstruck) you need/want the battery in the system rather than powering the motor controller (of whatever type - AC, DC, BLDC,...) directly from the generator.? But the battery can then be smaller.?? It is not a solution to head offshore with but for the way most people use their boats I think it can work.

I would look at propane or dual fuel generators rather than gasoline.? Propane on the boat has the same issues as gas with regard to accumulation in the bilge but it is a lot easier to swap a propane bottle at sea in rough weather than to re-fill the gas tank on a portable generator from a gas can.?? I know of one 6-1/2 ton monohull that runs with a 2000 watt propane generator and reports 4 kts and 8 hrs on a 20lb bottle (about 4.5 gallons of propane).? You would use about 4 gallons of diesel in that boat over 8hrs at 4kts.? So that cost per mile is about the same??? A 20lb propane refill is about $20 and so is 4 gallons of marine diesel?

As far as the power supply, the charger is exactly what would do the job.? You run the propulsion motor from the battery and you keep the battery topped up with the charger that is running from the generator.?? If you want to go 4 kts you need a 2000 watt generator and a 2000 watt charger.?

There is a boat in Seattle that a list member here has that is running three 2500 watt Thunderstruck chargers from a 220V AC diesel genset to get 7500 watts for about 6 kts I think.?? The Thunderstruck chargers can run up to four from one controller so the system is scalable.?? But note that it is running at 220V.? Those chargers only deliver 1500 watts at 120V.?? So to be a practical solution you really need the 220VAC genset.?

?

I don't think a 3000W power supply would be more cost effective and with a charger you should have the controller to properly manage the system and not blow anything up. ??

I have in mind a similar system to the one is Seattle but I am looking at a 48VDC genset to take out the middleman of the chargers.? I am planning on using a BLDC motor for the generator and a 12kW diesel (Kubota 722).? But it will require a beefy rectifier and regulator and I have not gotten to the research on that yet.? That's phase 2 or 3 and I am a few weeks away from getting phase 1 up and running which is the electric propulsion part.? I am almost done with machining the running gear.? After that's up and running I'll start working on the genset.?

For what it's worth, I have a 13kWhr battery and estimate I will have a 25 mile range at 4 kts.? If I add a propane generator to power the charger (a possible interim solution while I get the 48VDC genset built) I hope to be able to run at 4kts with zero draw on the battery.? I should have real data in a couple months.

Dan Pfeiffer

On 2021-05-25 11:05 pm, john via groups.io wrote:

?

Yes, power is power.

The thought was that it's relatively cheap to buy a portable generator and carry a can of gas as backup.

?

Looking at this a different way...

?

If I go with traditional 48V motors (maybe even 10Kw so that I have plenty of room to grow) - can I power those (at low power) from a DC power supply running off a portable generator?? ?Is it possible to buy a 2000W or even 3000W 48V DC power supply that runs off 110VAC?? ?This would (in theory?) allow me to run off a very small battery bank, or no battery bank at all initially.

?

Then there's the electrical question:? If I connect a 3000W power supply to a small lithium battery (which would be very unlikely to have exactly the same voltage - higher when charged, lower when discharged - will I blow up anything?

?

I'm assuming a 3000W power supply would be significantly more cost effective than trying to find a 3000W charger (which would be massive overkill, and likely damage a small battery bank).

?

John

?

?

?

?

On Tuesday, May 25, 2021, 09:53:32 PM CDT, Dan Pfeiffer <dan@...> wrote:

?

?

Setting aside efficiency differences it still takes the same amount of power to move the boat at a given speed.? AC, DC, gasoline, diesel.? Doesn't matter.? The boat wants what the boat wants.?? Higher voltage will be lower amps.?? Lower voltage will be higher amps.? The watts remain the same.?? The sizing of the wires may change but the power needs remain the same.?

An AC motor can indeed be used with a controller that allows for forward and reverse and all the rest.? Your battery bank challenge will remain.?? It may even get larger from more losses through added inverter stages.??

The generator can also work.? For a 6 ton boat you'll need something in the neighborhood of 2000 watts to go 4 kts??? Doesn't matter where you get it or what conversions in may go through making it's way to the propeller.?? If you're going to loose half of it on the way you need to start with 3200.?? An AC motor will work but it won't pick up the check at lunch.?

Dan Pfeiffer

On 2021-05-25 9:19 pm, john via groups.io wrote:

?

?

This is probably a really silly question, but....

?

Is it possible to find a 120V AC motor that can be speed controlled (and maybe even reversed??) for at least a proof of concept on a boat?

?

For those of us that prefer electric motors to gas or diesel engines, but are challenged by the investment of a huge battery bank, wouldn't it be cool if we could run an AC motor off an inverter from whatever battery bank we have handy, and use a generator to supplement - or just run off the generator entirely at first?

?

We've discussed the efficiency gain of running off a higher voltage / lower current.

I'm guessing that there just isn't a suitable way to control and/or reverse an AC motor??

?

John

?

?

?

Yes, power is power.

The thought was that it's relatively cheap to buy a portable generator and carry a can of gas as backup.

?

Looking at this a different way...

?

If I go with traditional 48V motors (maybe even 10Kw so that I have plenty of room to grow) - can I power those (at low power) from a DC power supply running off a portable generator?? ?Is it possible to buy a 2000W or even 3000W 48V DC power supply that runs off 110VAC?? ?This would (in theory?) allow me to run off a very small battery bank, or no battery bank at all initially.

?

Then there's the electrical question:? If I connect a 3000W power supply to a small lithium battery (which would be very unlikely to have exactly the same voltage - higher when charged, lower when discharged - will I blow up anything?

?

I'm assuming a 3000W power supply would be significantly more cost effective than trying to find a 3000W charger (which would be massive overkill, and likely damage a small battery bank).

?

John

?

?

?

?

On Tuesday, May 25, 2021, 09:53:32 PM CDT, Dan Pfeiffer <dan@...> wrote:

?

?

Setting aside efficiency differences it still takes the same amount of power to move the boat at a given speed.? AC, DC, gasoline, diesel.? Doesn't matter.? The boat wants what the boat wants.?? Higher voltage will be lower amps.?? Lower voltage will be higher amps.? The watts remain the same.?? The sizing of the wires may change but the power needs remain the same.?

An AC motor can indeed be used with a controller that allows for forward and reverse and all the rest.? Your battery bank challenge will remain.?? It may even get larger from more losses through added inverter stages.??

The generator can also work.? For a 6 ton boat you'll need something in the neighborhood of 2000 watts to go 4 kts??? Doesn't matter where you get it or what conversions in may go through making it's way to the propeller.?? If you're going to loose half of it on the way you need to start with 3200.?? An AC motor will work but it won't pick up the check at lunch.?

Dan Pfeiffer

On 2021-05-25 9:19 pm, john via groups.io wrote:

?

?

This is probably a really silly question, but....

?

Is it possible to find a 120V AC motor that can be speed controlled (and maybe even reversed??) for at least a proof of concept on a boat?

?

For those of us that prefer electric motors to gas or diesel engines, but are challenged by the investment of a huge battery bank, wouldn't it be cool if we could run an AC motor off an inverter from whatever battery bank we have handy, and use a generator to supplement - or just run off the generator entirely at first?

?

We've discussed the efficiency gain of running off a higher voltage / lower current.

I'm guessing that there just isn't a suitable way to control and/or reverse an AC motor??

?

John

?

?

?

?

This is probably a really silly question, but....

?

Is it possible to find a 120V AC motor that can be speed controlled (and maybe even reversed??) for at least a proof of concept on a boat?

?

For those of us that prefer electric motors to gas or diesel engines, but are challenged by the investment of a huge battery bank, wouldn't it be cool if we could run an AC motor off an inverter from whatever battery bank we have handy, and use a generator to supplement - or just run off the generator entirely at first?

?

We've discussed the efficiency gain of running off a higher voltage / lower current.

I'm guessing that there just isn't a suitable way to control and/or reverse an AC motor??

?

John

?

?

?

This is probably a really silly question, but....

?

Is it possible to find a 120V AC motor that can be speed controlled (and maybe even reversed??) for at least a proof of concept on a boat?

?

For those of us that prefer electric motors to gas or diesel engines, but are challenged by the investment of a huge battery bank, wouldn't it be cool if we could run an AC motor off an inverter from whatever battery bank we have handy, and use a generator to supplement - or just run off the generator entirely at first?

?

We've discussed the efficiency gain of running off a higher voltage / lower current.

I'm guessing that there just isn't a suitable way to control and/or reverse an AC motor??

?

John

?

On May 17, 2021, at 10:01, john via groups.io <oak_box@...> wrote:

?

Carsten,

The BIGGEST problem is that they haven't been run or cared for in the past 20 years.? I had a retired buddy that was "car friendly" helping me with them (and paid him a few $$, which worked for both of us).? My objective, beyond just getting them to run - was to get them back into great, reliable shape.

First, rebuilt the carbs, then rebuilt the raw water intake pumps, new hoses, belts, plugs, starters.? New electric fuel pump to replace the mechanical fuel pump.? New water circulation pump, new intake manifold (on port engine - probably on starboard too).? Pulled the heads on the port engine and had them machined, and new valves put in (old valves were all shot, with little or no compression on most of the cylinders). New lifters, new rods.? Port engine is now running - though clattering loudly (not a valve adjustment - maybe a lifter or rod that wasn't adjusted properly?) - so still need to get a mechanic that really knows what he's doing to look at it and finish the job.

Starboard engine will start and run if primed, but also has bad compression on 3 cylinders - so need to pull the heads and have valves done on it.? Old buddy was much less expensive than a "real" mechanic, but has too many other things to do to be available on a reasonable basis.? I've dealt with most of the boat shops at one time or another, and don't trust any of them to do a decent job.? ?I've got one last guy to try - but he's swamped with work after the freeze we had this past winter took out a bunch of engines....

I would LOVE swapping out all the potential sources of problems of the gas engines for electric motors that just run, don't freeze, and don't have so many holes in the bottom of the boat.? ?But...? ?repowering with electric would probably cost (WILD swag) $30-50K to get old motors out, new engines in, and minimal battery capacity.? If I can find a mechanic that can pull and re-install the heads, and tweak things - I should be able to be back in business for around $5K - keep the boat good as original condition (resale value maintained), and be able to scoot down the lake if I need to at some point.

I have toyed with putting motor brackets on the swim platform, and getting a second Torqeedo 4.0.? ?That would cost another $4-5K for the 2nd motor (I have one), and several thousand for a minimal battery just for proof of concept.? And I'm concerned that two Torqeedo's on the swim platform wouldn't be able to give me enough differential thrust to manage the boat at the dock (at least without adding a bow thruster).

Sigh.

John

On Monday, May 17, 2021, 11:06:37 AM CDT, Carsten via groups.io <carstensemail@...> wrote:

John, just curious, what's wrong with the Chev's ?

(I know, not related to electric...)

On Monday, 17 May 2021, 21:37:19 GMT+8, john via groups.io <oak_box@...> wrote:

Carsten,

I think the bad reverse performance is mainly an issue of the outboard having to fight against the hull and keel.??

I previously had a Catalina 27 with a 10hp 4-stroke outboard in a motor well (behind the keel and rudder).? Same thing - did great in forward, but very limited power in reverse.? If I had a strong north wind, I wasn't able to back into it with sufficient control to safely leave the marina.

This may be somewhat also due to the prop being less efficient in reverse (due to cup design).? But I suspect fighting the keel was the bigger issue.

I really wish the economics were better for electric.

I currently have a Chris Craft Commander 410 with two Chevy V8 454 big block engines that are not healthy.? I still believe the engines can be brought back - but finding a good mechanic that will show up and get the job done on my lake is proving extremely frustrating!? ?I've thought more than a few times about repowering the boat with electric (probably mostly hybrid, running off a generator - to keep the cost of the battery bank within reason).? Butttt....? ?Getting those two V8 blocks out of the engine room below the main salon will be extremely difficult.? Plus - best possible speed will still be limited to 5-6mph - slower than a trawler, and slower than many sailboats.? I've gotten used to the Dark Side, and prefer a cruising speed of 7-10mph, and really like the option of being able to get up on plane if I need to so that I can get somewhere in a hurry if necessary.

I have taken a LOT of inspiration from this web site:??, as his boat is very close to mine (his is a few years older, and mine has the flybridge - meaning more drag, weight, and windage - but at least in the ball park).? But it also serves as a good reality check.

John

On Monday, May 17, 2021, 01:22:14 AM CDT, Carsten via groups.io <carstensemail@...> wrote:

Thanks, John

I may reconsider that solution, as you said the reverse was not good. Probably because of the pod ?

When anchoring, I need full reverse power to dig the anchor.

I guess that yellowchair does not need the full reverse power, if he already does well with his present configuration.

Two T4.0's is a bit over my budget, as it is more than I paid for my Maxi 87 1976 boat :-)

I also considered to get rid of my saildrive and make two shaft drives (!!)

By doing so, there is redundancy, and high maneuverability.

Anyone here with two shaft drives on their boat ?

Cheers,

Carsten

On Monday, 17 May 2021, 11:22:18 GMT+8, john via groups.io <oak_box@...> wrote:

Carsten,

If you're really going to go that route, I'd recommend two Torqeedo T4.0's.

I mounted one as an experiment on an Catalina 30.? One Torqeedo would push the boat at very slow speed. Reverse was abysmal.? I could get by with it as an emergency backup when my Atomic 4 gas engine failed, and neeed to get into my slip once returned to the marina.

However, a single 15-20hp outboard gas engine would be MUCH more cost effective, and get the job done more practically.? I know this is an "electric boat forum", and I own 2 Torqeedos, and have done a fair amount of experimenting with them.? But they're a very expensive solution that is significantly more complicated than a gas outboard.

John

On Sunday, May 16, 2021, 08:19:25 PM CDT, Carsten via groups.io <carstensemail@...> wrote:

What is your use of the Torqueedo now ?

It seems that you only use it for docking, slow motorsailing etc. as it is a small configuration for your 5T boat.

How about two Torqueedos, one starboard, one port ?

Doubled power, and far better maneuverability when docking.

You just need to buy/find one more T2.0, more batteries, and make the new (retractable) brackets.

No hazzle with mounting an inboard.

Just an idea, as I am considering making two on my mono 4 tonner too.

Carsten

On Monday, 17 May 2021, 03:43:33 GMT+8, yellowchair@... <yellowchair@...> wrote:

I have a 28 foot, 5 ton, Tyler Twister (long keel) with a Torqeedo 2.0 mounted on a home made bracket on the (transom hung) rudder. Due to the steeply angled transom, there is no ideal way to mount an outboard, so I am contemplating going back to an inboard engine. What do you guys think of using the Torqeedo 2.0 as an inboard engine? Perhaps a belt drive to the propeller shaft? I'm sure this would void any warranty, but would it work? Would cooling be an issue? Any comments appreciated.

On May 16, 2021, at 5:22 PM, HF via groups.io <incorridge@...> wrote:

?Hi Eric and others,
$200 for a 45W (if the performance claim is accurate) panel is more than $4 per Wp.? Rigid Si panels go for around $1 per Wp.? Flexible mono- and poly-Si panels are also available for $1 to $2 per Wp.? But I'm not sure how their performance holds up if you bend them many times.? If the PowerFilm is a-Si, it probably doesn't degrade in response to getting bent back and forth multiple times.? So what you're paying for is the flexibility of the panel and its ability to continue working once you bend it.? If you don't need this feature, the rigid panels are a better value/$.
-Halden