Information Overload - Where do I start?:)

[Modular Hippo]

The Golden motor 20kw would require almost 400A continuous at 51v. I'm not sure there is a single motor controller that can provide that continuously. Most of the controllers I was looking at advertised their peak current, with sustainable current being 40% of that (ie: "500A" controller can do 200A continuous).

Is one of the reasons I decided to go to a dual motor/controller setup. The redundancy is a huge benefit, but sustainable power is the real driver.

Note also where the motors get their peak efficiency. The Golden motor 10kw has peak efficiency of 87% at around 5kw. Something important to factor when calculating range.

Not a bad idea, Lynch has a similar setup called 'Swordfish Twin Drive'. As the lynch motors are air-cooled and not brush-less I have decided against it BUT the concept could be used with 2 Golden Motors if there is a Vector or Sevcon motor controller that could handle a dual setup (emailed Golden Motor the question just out of curiosity). I doubt there are any of the shelf dual motor cradles on the market so would probably have to design this in 2D CAD and have it laser cut. The images could be a good platform to start from.

 

[digimer]

The picture on the bottom right is the closest to what I have in mind, even the same kind of belt (timing belt style, iirc). ABYC does not allow brushed motors, so that's another reason not to use those.

I've got my first 10kw motor and the Kelly controller on order... Will be 4~6 weeks before they arrive, not that there's a big rush as I still need to pull the old diesel. Really looking forward to finally getting the batteries into their final assemblies and installed on the boat!

 

[Modular Hippo]

The picture on the bottom right is the closest to what I have in mind, even the same kind of belt (timing belt style, iirc). ABYC does not allow brushed motors, so that's another reason not to use those.

I've got my first 10kw motor and the Kelly controller on order... Will be 4~6 weeks before they arrive, not that there's a big rush as I still need to pull the old diesel. Really looking forward to finally getting the batteries into their final assemblies and installed on the boat!

Motor on order, that is awesome! Congratulations - I guess safer to order one unit, run tests and confirm theory before adding another one to the mix? All three images are from the same setup, just different perspectives - thought I add them all to give you best overview possible. I went back to the drawing-board and started to look at 96v | 20Kwh motor solution but would mean having to change my whole 48V configuration and it also looks like it would draw a ridiculous amount of watts. I believe that your realization of 'peak efficiency of 87% at around 5kw' is key to the solution. That together with the correct gearing (seen 28 to 72 pulley in some places) surely should give enough torque & Prop RPM? Suspect you knew this already but got the following response in relation to running 2 motors - ''And yes,it is workable to put 2 sets of 48V 10KW motor kits on one boat and control them with one remote throttle.Some of our clients had similar designs. We can provide you the motor,controller, throttle and simple accessories.'' - So intrigued by this side of the project that I forget to continue build on actual boat

 

[digimer]

Motor on order, that is awesome! Congratulations - I guess safer to order one unit, run tests and confirm theory before adding another one to the mix? All three images are from the same setup, just different perspectives - thought I add them all to give you best overview possible. I went back to the drawing-board and started to look at 96v | 20Kwh motor solution but would mean having to change my whole 48V configuration and it also looks like it would draw a ridiculous amount of watts. I believe that your realization of 'peak efficiency of 87% at around 5kw' is key to the solution. That together with the correct gearing (seen 28 to 72 pulley in some places) surely should give enough torque & Prop RPM? Suspect you knew this already but got the following response in relation to running 2 motors - ''And yes,it is workable to put 2 sets of 48V 10KW motor kits on one boat and control them with one remote throttle.Some of our clients had similar designs. We can provide you the motor,controller, throttle and simple accessories.'' - So intrigued by this side of the project that I forget to continue build on actual boat

Exactly, and it lets me spread the pain of the purchase cost out also. I can use the first as a template of sorts for preparing the mounts and wiring for the future second motor/controller, so when I am ready, I can just drop them in. The only task then will be confirming / sorting out anything that is related to parallel operation.

I still strongly recommend staying at <60v if you can... Victron kit (assuming you're using them) only goes up to 48v-class, likely for the same ABYC (and the Euro counterparts) compliance.

As for prop gearing, ya that's still to be sorted out. One of the winter tasks will be mounting the motor on the bench and checking the RPM at various throttle positions, and then using that to determine what pulley ratio I'll use for ideal prop speed. I'm getting a new prop, so once I know what specific model/size I'm getting, I'll talk to the vendor to confirm what that ideal RPM will be.

 

[Modular Hippo]

Exactly, and it lets me spread the pain of the purchase cost out also. I can use the first as a template of sorts for preparing the mounts and wiring for the future second motor/controller, so when I am ready, I can just drop them in. The only task then will be confirming / sorting out anything that is related to parallel operation.

I still strongly recommend staying at <60v if you can... Victron kit (assuming you're using them) only goes up to 48v-class, likely for the same ABYC (and the Euro counterparts) compliance.

As for prop gearing, ya that's still to be sorted out. One of the winter tasks will be mounting the motor on the bench and checking the RPM at various throttle positions, and then using that to determine what pulley ratio I'll use for ideal prop speed. I'm getting a new prop, so once I know what specific model/size I'm getting, I'll talk to the vendor to confirm what that ideal RPM will be.

Not settled on Victon yet, but my mind is set on 48v anyways so at least have that cemented.

Ordering a motor, controller and cooling kit from GM end of this month - Should give what I need to push forward in this area for now.

Read the below on another forum, suspect you probably already knew, but passing it on anyways as all 'positive' info in relation to design path:

''There are 3 great reasons for using gear reduction.
It’s easier on the motor to spin the prop which means there is less current draw from your batteries.

If by unfortunate chance you hit your prop, the pulley and belt will absorb the impact vibration from the prop-shaft. If the prop-shaft is directly linked to your electric motor the chance of damage is significantly more should an impact occur.

Gear reduction produces Torque. The torque produced by the output is inversely proportional to the amount of gear reduction. Say what? In short, if you have a 2:1 gear ratio then the prop speed turns 1/2 as fast but has twice the torque! It’s physics.''

 

[digimer]

Not settled on Victon yet, but my mind is set on 48v anyways so at least have that cemented.

Ordering a motor, controller and cooling kit from GM end of this month - Should give what I need to push forward in this area for now.

Read the below on another forum, suspect you probably already knew, but passing it on anyways as all 'positive' info in relation to design path:

''There are 3 great reasons for using gear reduction.
It’s easier on the motor to spin the prop which means there is less current draw from your batteries.

If by unfortunate chance you hit your prop, the pulley and belt will absorb the impact vibration from the prop-shaft. If the prop-shaft is directly linked to your electric motor the chance of damage is significantly more should an impact occur.

Gear reduction produces Torque. The torque produced by the output is inversely proportional to the amount of gear reduction. Say what? In short, if you have a 2:1 gear ratio then the prop speed turns 1/2 as fast but has twice the torque! It’s physics.''

The idea of the belts acting as a damper on a prop strike is not something I thought of, that's a great point!

I've got my Kelly controller in hand now, and waiting for the motor to arrive next!

Madi

 

[Nobodybusiness]

Just like yourself I am building for live aboard and crossings hence wanting to get this bit right. I tend to always 'over-design' everything (structural) to make sure that I can feel safe - as you say, guess I need to apply the same for the motor. problem so far is not knowing where 10 kw motor sits in the range of output. Been looking at the below 2:

Motenergy ME1302 (DLC-28) Brushless 15 kW - 38 kW Liquid-Cooled PMAC Motor 48-120V

<p><span style="color: #ff0000;"><span style="color: #2f2f2f;">These patented axial flux motors are designed to work with sinusoidal (sine wave) controllers such as the Sevcon Gen4.</span><strong></strong></span></p> <p><br /> <strong>Features</strong><b

www.electricmotorsport.com

HPM 20 KW Liquid Cooled BLDC Motor - Golden Motor North America - Canada and USA

Model: HPM-20KW -- High Power BLDC Motor. Voltage: 72V/96V/120V. Rated power: 20-25KW. Peak power: 50KW. Speed: 3200-6000rpm.

goldenmotor.bike

I used one of their 3kw air cooled motors for a ATV and it worked quite well.

If you have a 48v battery bank you would be using almost 500 amps to push that to full.

It can use up to 96v but that would mean your bank would have to be configured as such or combine 2 48v banks somehow.

Not to mention finding a controller to push that many amps continuously.

 

[Skypower]

The idea of the belts acting as a damper on a prop strike is not something I thought of, that's a great point!

I've got my Kelly controller in hand now, and waiting for the motor to arrive next!

Madi

Hi Madi
You could use some brand of a “drive saver” between your shaft coupling. This may galvanic isolate your prop, shaft and perhaps a few other things so you need to figure out if that is desirable for your application. A small jumper can correct that or a brush on the shaft so current doesn’t go through the gearbox bearings. Once you know measure the dive coupling you can use something like this;

 

[digimer]

Hi Madi
You could use some brand of a “drive saver” between your shaft coupling. This may galvanic isolate your prop, shaft and perhaps a few other things so you need to figure out if that is desirable for your application. A small jumper can correct that or a brush on the shaft so current doesn’t go through the gearbox bearings. Once you know measure the dive coupling you can use something like this;View attachment 169461

In my case, the shaft will be held in place by a pair of thrust bearings connected to the hull. There will be two pullies on the shaft, with belts connecting the two motors (one belt per motor). So a drive saver wouldn't work in my case, but as Hippo suggested, the belts themselves should play the same role. This will also totally isolate the prop and shaft from the boat's electrical system (though I may bond the shaft intentionally, still need to decide on the new wiring plan).

 

[Skypower]

In my case, the shaft will be held in place by a pair of thrust bearings connected to the hull. There will be two pullies on the shaft, with belts connecting the two motors (one belt per motor). So a drive saver wouldn't work in my case, but as Hippo suggested, the belts themselves should play the same role. This will also totally isolate the prop and shaft from the boat's electrical system (though I may bond the shaft intentionally, still need to decide on the new wiring plan).

If you are using timing belts, be very careful to never let them get too loose so that the belt can climb out of the drive cog. Some belts are so strong that they don’t break but something else does. If a Harley with a Gates Polychain belt gets too loose and climbs it’ll rip the final drive right out of the gearbox or damage the rear axle…..but the belt will be just fine. Multi V belts can slip without damage with sudden, momentary loads. Different belts have different efficiencies so if you’re designing you got to do research.

 

[Modular Hippo]

The idea of the belts acting as a damper on a prop strike is not something I thought of, that's a great point!

I've got my Kelly controller in hand now, and waiting for the motor to arrive next!

Madi

Hmmm.... been recommended the EZ-B481000 (EZKkontrol) from Golden Motor, is 'Kelly' a brand/model and if so what was your reasoning behind picking that one. Worried now that I said yes to something which maybe was not the best controller.

 

[Modular Hippo]

I used one of their 3kw air cooled motors for a ATV and it worked quite well.

If you have a 48v battery bank you would be using almost 500 amps to push that to full.

It can use up to 96v but that would mean your bank would have to be configured as such or combine 2 48v banks somehow.

Not to mention finding a controller to push that many amps continuously.

Thank you - Happy to hear ATV worked as planned I have settled on 48V, as you say finding controller and other components for a 96V system would be tricky and costly (especially as I already have started of with a 48V design)

 

[Modular Hippo]

In my case, the shaft will be held in place by a pair of thrust bearings connected to the hull. There will be two pullies on the shaft, with belts connecting the two motors (one belt per motor). So a drive saver wouldn't work in my case, but as Hippo suggested, the belts themselves should play the same role. This will also totally isolate the prop and shaft from the boat's electrical system (though I may bond the shaft intentionally, still need to decide on the new wiring plan).

Just sharing my work around this as something I am doing might be of use or just spark ideas My boat (although not complete yet) is designed for a combustion engine where the shaft goes directly to the gearbox. To save the gear-box/engine on accidental impact there is a plate that cater for an Aqua-drive that should reduce vibration transfer to hull (I also guess that the Aqua-drive will assist with discrepancies in alignment of prop shaft and motor). As I am going for a similar setup as Digimer where the shaft is not directly connected to the motors I might be 'overkill' but think I will stick to design anyways.

 

[Modular Hippo]

If you are using timing belts, be very careful to never let them get too loose so that the belt can climb out of the drive cog. Some belts are so strong that they don’t break but something else does. If a Harley with a Gates Polychain belt gets too loose and climbs it’ll rip the final drive right out of the gearbox or damage the rear axle…..but the belt will be just fine. Multi V belts can slip without damage with sudden, momentary loads. Different belts have different efficiencies so if you’re designing you got to do research.

Hi Skypower - Very good points, thank you mentioning this as something I also have had on my mind. I have seen processional 'Toothed belts' solutions that operate without an active belt tension functionality. I guess that if the pulley and teeth have a good match then hopefully just something you need to service at set internals as long as tensed correctly at installation. There are other things I have thought about and that is the difference in friction between none-Toothed belt solution and Toothed belt solution and if the difference is large enough to pay attention to. I guess it is either a none-Toothed solution with an active tensing solution attached (spring loaded wheel or similar), or a good Toothed solution without. As you say, will need careful considerations

 

[Skypower]

One other thing: Timing belts can whine at speed. At what speed, I don’t know so have to research. I do know a 1” wide at 6k rpm will dive me crazy, it’s the air popping out of the pulley grooves. Multi groove are silent…. Unless they are slipping.

 

[Modular Hippo]

The idea of the belts acting as a damper on a prop strike is not something I thought of, that's a great point!

I've got my Kelly controller in hand now, and waiting for the motor to arrive next!

Madi

May the fun begin - Order placed for motor number one (Golden Motors). Motor, Controller, and some components for liquid cooling (not sure if they are the best but were affordable enough to take a chance).

 

[Skypower]

May the fun begin - Order placed for motor number one (Golden Motors). Motor, Controller, and some components for liquid cooling (not sure if they are the best but were affordable enough to take a chance).

Cool!
It’s fun to experiment with different components. You never always know what will corrode and some things did that shouldn’t have. I’ve had many happy accidents, but always had a fallback plan and for the what if’s. I always carried a response kit for leaks and flooding. It had a selection of hose clamps, mechanics wire, self tapping screws & driver, medium soft rubber square assortments, underwater sealants(works submerged) underwater epoxy putty, wood and foam tapered plugs. It was used many times but not on my own boat. A water alarm is mandatory! One primary that reports to the helm. Also it’s important know about it as early as possible so it’s easier to find the source. Just buy a 5 pack of water leak alarms from Amazon and place them throughout low in the hull where bilge water should never be. To reduce bilge water, use GTU Gore packing in the stuffing box. Learn the proper way to cut and stagger the seals. You may actually find it difficult adjust the nut to get the desired 1 to 2 drips per minute while underway. As long as the box or shaft doesn’t get warm, don’t worry about it being reduced to just weeping. Do “burp” the box after a haul out to get the air out of the shaft log, it does need water to lubricate. I don’t recommend “dripless” shaft seals, however if you already have one, have it inspected and make sure it’s in perfect condition. If it fails, it is catastrophic. You will need response kit containing a pipe wrench to stop the prop shaft from windmilling, a passenger car inner tube cut for a long wide strip of rubber and a roll of mechanics wire to staunch the flow by wrapping around the shaft/gland. For any boat, have at least two manual/automatic controled bilge pumps, each one appropriate for the size boat. Those things are the most unreliable devices I’ve ever seen so have two. Don’t mean to scare you, however if you’re ready for it, it’ll probably never happen.

 

[digimer]

If you are using timing belts, be very careful to never let them get too loose so that the belt can climb out of the drive cog. Some belts are so strong that they don’t break but something else does. If a Harley with a Gates Polychain belt gets too loose and climbs it’ll rip the final drive right out of the gearbox or damage the rear axle…..but the belt will be just fine. Multi V belts can slip without damage with sudden, momentary loads. Different belts have different efficiencies so if you’re designing you got to do research.

Noted! I've not decided on what belt to use yet, but I'll keep that in mind. Thanks!

 

[digimer]

Hmmm.... been recommended the EZ-B481000 (EZKkontrol) from Golden Motor, is 'Kelly' a brand/model and if so what was your reasoning behind picking that one. Worried now that I said yes to something which maybe was not the best controller.

The documentation for the Kelly had detailed pinouts, and my questions to Kelly's email got useful answers. That's the biggest reason I chose them. A little more detail; They seem to do decent regen, and had a water-cooled option. Generally googling around seems to show the Kelly's are better built, but that's not something I can say super strongly myself (yet).

 

[digimer]

Just sharing my work around this as something I am doing might be of use or just spark ideas My boat (although not complete yet) is designed for a combustion engine where the shaft goes directly to the gearbox. To save the gear-box/engine on accidental impact there is a plate that cater for an Aqua-drive that should reduce vibration transfer to hull (I also guess that the Aqua-drive will assist with discrepancies in alignment of prop shaft and motor). As I am going for a similar setup as Digimer where the shaft is not directly connected to the motors I might be 'overkill' but think I will stick to design anyways.
View attachment 169868

In my case, the prop shaft ends in a coupler on a V-drive. I want to have to pullies forward of the thrust bearings so that I can swap belts without dismounting the prop shaft, so the solution I need to come up with is, I think, going to be a little unique for my setup.