Dan, 34CrNiMo6 is for hard working shafts, and easy to machine in properly sized lathe, given the right treatment is done before machining.

It is NOT stainless steel, and thus, not prone to "self-hardening".

Please google it.

?

I don't know your machining skills, but please contact a shaft machining shop (I did not say ANY machining shop) with your design at hand. This is definitely not a DIY novice job.

?

There seemailer wheel hub bearings lately in this forum, mostly triggered by the Thunderstruck (etc.) base plate designs.The shaft of a propeller has mostly only (bi-directional) axial forces, exept where we cons to be a tendency to choose standard trnect our belt pulley.

A hub bearing is meant to deal with radial forces, and some axial forces.

There are torsional forces too.

My suggestion is to use a double roller spherical bearing, set in a proper housing.

I contacted SKF (the inventor), and they recommended this bearing for this purpose.

(Hmm, maybe I should mass produce a range of housings ? ;-)

?

For corrosion, Dan, your shaft is to be in the engine/motor room, and not submerged (I hope), so it should only be protected for exposure to humidity, like a car body.

A clear Dinitrol spray will do fine.

Priming and painting looks nice, but ehh, not necessary for a simple shaft, right ?!

?

I hope this information will be useful.

P? fre., den 26. mar. 2021 klokken 1:45, Dan Pfeiffer

<dan@...> skrev:

Carsten,? That'll do.? Always good to know.? Thanks.

At first glance to my novice eye the specs the material you specified looks fairly tough to machine.? Is the comparative machining issue with SS due to work hardening??

What would you do to protect the alloy steel shaft from corrosion??


Dan Pfeiffer

?

On 2021-03-23 4:09 pm, Carsten via groups.io wrote:

?

Educated machinist at a nuclear test facility in Denmark.

Worked as production planner and programmer of CNC multiple axis lathes and milling machines for 18 years

Switched to large marine producers, writing procedures for manufacturing, and tested production methods at suppliers

Worked in Asia for 10 years, educating and teaching many of the production facilities of large Diesel engine manufacturers in South Korea and China, and assembly of engines at the shipyards

Made the crankshaft production in China feasible for them

?

Now retired (and actually tired of chinese taking over everything (because of me, partly)).

?

Is that ok for you, Dan ?

?

In short, SS is not easily machined.

Go for my selection, then you'll have an easy time at your lathe.

I'm sure that you can look up the equivalent of my material in a comparison table.

?

Cheers !

?

?

On Wednesday, 24 March 2021, 04:23:21 GMT+8, Dan Pfeiffer <dan@...> wrote:

?

?

>>Hi, Dan

>>I will suggest 34CrNiMo6 alloy for your shaft.

>>>

>>>On Friday, 19 March 2021, 07:07:01 GMT+8, Dan Pfeiffer <dan@...> wrote:

>>>Carsten, You mentioned that I should not bother with stainless steel for my small output shaft.? What would you suggest for that instead??

I found this info:


Is a 4340 a similar alloy? I can get that from McMaster.? Cost is the about the same as SS.? How hard will it machine in my lathe??? I was prepared to machine the SS.? Will this be tougher??

Also, I am figuring you have some background in all this??

Thanks, Dan Pfeiffer

?

?

?

P? fre., den 26. mar. 2021 klokken 1:45, Dan Pfeiffer

<dan@...> skrev:

Carsten,? That'll do.? Always good to know.? Thanks.

At first glance to my novice eye the specs the material you specified looks fairly tough to machine.? Is the comparative machining issue with SS due to work hardening??

What would you do to protect the alloy steel shaft from corrosion??


Dan Pfeiffer

?

On 2021-03-23 4:09 pm, Carsten via groups.io wrote:

?

Educated machinist at a nuclear test facility in Denmark.

Worked as production planner and programmer of CNC multiple axis lathes and milling machines for 18 years

Switched to large marine producers, writing procedures for manufacturing, and tested production methods at suppliers

Worked in Asia for 10 years, educating and teaching many of the production facilities of large Diesel engine manufacturers in South Korea and China, and assembly of engines at the shipyards

Made the crankshaft production in China feasible for them

?

Now retired (and actually tired of chinese taking over everything (because of me, partly)).

?

Is that ok for you, Dan ?

?

In short, SS is not easily machined.

Go for my selection, then you'll have an easy time at your lathe.

I'm sure that you can look up the equivalent of my material in a comparison table.

?

Cheers !

?

?

On Wednesday, 24 March 2021, 04:23:21 GMT+8, Dan Pfeiffer <dan@...> wrote:

?

?

>>Hi, Dan

>>I will suggest 34CrNiMo6 alloy for your shaft.

>>>

>>>On Friday, 19 March 2021, 07:07:01 GMT+8, Dan Pfeiffer <dan@...> wrote:

>>>Carsten, You mentioned that I should not bother with stainless steel for my small output shaft.? What would you suggest for that instead??

I found this info:


Is a 4340 a similar alloy? I can get that from McMaster.? Cost is the about the same as SS.? How hard will it machine in my lathe??? I was prepared to machine the SS.? Will this be tougher??

Also, I am figuring you have some background in all this??

Thanks, Dan Pfeiffer

?

P? fre., den 26. mar. 2021 klokken 1:14, Steven Borg

<steve@...> skrev:

Amazing thoughts! Thank you so much for all this information. I'm plodding along an slowly progressing.? Here are my existing thoughts. Dan, I'm planning on riffing from your plans, spinning the engine to the other side, and doing a few other things.

Here’s my latest thinking for getting my 55’ sailboat on electric. It’s based on all the wonderful feedback here!

After much thought, I’ve decided against using a transmission and am going to go with a pulley system. It’s just simpler, even though I lose the ability to have a neutral (which would allow my auxiliary shaft to be used for an emergency pump). That decision was driven by the advice of the good people on this list. Thank you!

However, I’m planning on mounting my engine the opposite direction of everyone on this list, and I thought I’d explain why, in hopes of getting feedback from folks.

Here’s a very, very ugly diagram, not to scale, made by cutting and pasting.

?

I’m going to go with off the shelf components where possible. That’s one reason for putting the Spindle facing forward – I won’t have to machine it, and it puts the larger bearings where they will accept the forward thrust (which for me is more common).

Initial (potentially incorrect) thoughts:

• Put thrust plate AFTER large belt spindle – given the limited forward and backward slip from the Hub, I don’t think that will cause issues with the belt slipping off (1 ?” belt, I believe)
• Orient the Hub and Spindle with the ‘wheel’ side facing fore – this means no metal working for me, places the biggest bearing where it will take the forward thrust and simplifies installation
• Orient the motor on the fore side of the mounting plate – this is necessary to get the belt and gears on the same side, plus I have more room on this side of the plate if I decide to mount the plate, motor and gears at a 45 degree angle to starboard to get more space in the engine room
• Use the 6000 lb hub and spindle – this gives me the capability to support more thrust.?
  • Rule of thumb of 20 lbs force for every HP gives me 2000 lbs force, which is within tolerances for this hub and associated bearing.
  • Hub:?
  • #42 Spindle:?
• Use a motorcycle kit for my sprockets and belts – I’m looking for a 5 to 1 reduction, and that’s really hard to find on Grainger without having a really small engine sprocket. The Zero motorcycle is an electric motorcycle that provides torque only slightly less than the Hyper-9, so I thought it would be a good solution. It’s made for providing power transmission and has a reduction ration of 4.5 to 1 which is good enough (20 teeth to 90 teeth).
• Tighten with one or two idler pulleys – not sure if I will have enough space to tighten much, so will likely need to get belt pretty close to the right size if I even change the engine sprocket to change the reduction ratio.
  • In the worst case, I can have one pull in, and another pull out, but that's not ideal
• Battery box will be custom built, as I have 48 Lishen (similar to Eve) 280AH batteries that will take up a lot of room. They will end up on the stays with supports to allow walking on them when I drop into the engine compartment.? Should I call that a motor compartment now? ;-)

Thanks so much for everyone on this list. Dan, I'm really happy you started this thread, and Carsten, you have so much wonderful knowledge. And everyone else has such valuable experience and insight.? Thank you!

?

Educated machinist at a nuclear test facility in Denmark.

Worked as production planner and programmer of CNC multiple axis lathes and milling machines for 18 years

Switched to large marine producers, writing procedures for manufacturing, and tested production methods at suppliers

Worked in Asia for 10 years, educating and teaching many of the production facilities of large Diesel engine manufacturers in South Korea and China, and assembly of engines at the shipyards

Made the crankshaft production in China feasible for them

?

Now retired (and actually tired of chinese taking over everything (because of me, partly)).

?

Is that ok for you, Dan ?

?

In short, SS is not easily machined.

Go for my selection, then you'll have an easy time at your lathe.

I'm sure that you can look up the equivalent of my material in a comparison table.

?

Cheers !

?

?

On Wednesday, 24 March 2021, 04:23:21 GMT+8, Dan Pfeiffer <dan@...> wrote:

?

?

>>Hi, Dan

>>I will suggest 34CrNiMo6 alloy for your shaft.

>>>

>>>On Friday, 19 March 2021, 07:07:01 GMT+8, Dan Pfeiffer <dan@...> wrote:

>>>Carsten, You mentioned that I should not bother with stainless steel for my small output shaft.? What would you suggest for that instead??

I found this info:


Is a 4340 a similar alloy? I can get that from McMaster.? Cost is the about the same as SS.? How hard will it machine in my lathe??? I was prepared to machine the SS.? Will this be tougher??

Also, I am figuring you have some background in all this??

Thanks, Dan Pfeiffer

?

On Mar 16, 2021, at 3:01 PM, Steven Borg <steve@...> wrote:

?Dan, this is an incredibly useful reply! Thank you!!

I really like your approach, especially since I don't have an intermediate location to put an inline thrust bearing. (Although it wouldn't be hard to fiberglass one in, it would be difficult to get to when I need to maintain the bearings, etc.)? Plus, as you've mentioned, the cost to Python is substantially higher than building my own integrated to the engine plate (like the Thunderstruck solution).??

Using the eTrailer solution looks like an excellent plan for a DIY solution. I'm trying to evaluate how much thrust I'll need to account for and which solution I should use. The Hyper-9 HV is a pretty beefy motor, and my prop is 24" with a 24" pitch (potentially reducing to 14"-16" when I pull her out of the water next).?

How much thrust are you planning for with your solution?? I notice you're planning to have a non-threaded section after the threads. Is that to attach the belt pulley? I didn't quite understand that part of your solution, but maybe I need to just do some more thinking.

For the belt drive system, I'm considering adding a 3rd pulley for tensioning. Would that be a bad idea?? The motor is heavy, and I'd like to mount it in predrilled holes, rather than make it adjustable. Also, since my propeller shaft will go directly to the motor, I'll need to align it relatively precisely, so don't want to use the thrust bearing / prop shaft assembly for tensioning.? (I suppose this is one reason to use the Python solution...? ;-))

Once again, HUGE thanks, Dan!? This was AMAZINGLY helpful!

:-)
Steve

?

Dan,

?

I have reviewed your drawings. Very interesting, a hybrid boat !

?

When you are using a toothbelt drive, you actually don't need a Drivesaver, as the toothbelt will slip or break in a crash-stop situation. A new belt is far easier (and cheaper) to replace than a Drivesaver coupling.

The inertia in an electric motor (the rotating mass) is far less than by a diesel engine with a big flywheel, and you have no gearbox anymore to worry about.

?

The position of the ME1616 motor is almost free to choose, meaning that you can add a pulley to the shaft almost anywhere until you reach the sterndrive. The distance from shaft centerline to motor centerline is also only determined of the toothbelt length. You don't HAVE to place it in one common frameplate.

?

If you make the motor base adjustable, it is easy to change the belt.

If you make the frameplate with fixed driveshaft and motor shaft, like on your drawing, you likely will add an adjustable bearing roller to adjust the tension of the belt (same like in a car engine, for a camshaft toothbelt). Very handy too, for changes of pulleys for reduction ratio. (The roller must roll on the flat side of the belt, of course.)

I guess a complete roller kit for a car is rather inexpensive.

?

Why use aluminum for the construction?

I know that it easier to cut a thread and drill a hole in aluminum than in steel.

But :

Steel channels and steel plates are much easier to repair if you make a mistake, or something should be re-positioned.

Aluminum welding is no fun, and threads cut in steel are much stronger. You use Helicoils in aluminium constructions, if threads shall be strong and lasting. That requires special tools, so - not for a DIY mechanic.

If you need something done, any workshop in any port can weld steel, and can always find a standard machine tap in the dirty drawers.

?

I would say, that an ME1616 used as a generator might be shooting sparrows with a cannon - an expensive solution. Balmar have some 48V alternators, you can check them out.

?

How is your plan for cooling of the ME1616 for the shaft ? (I assume that you will make a common system for the Kubota and the ME1616.)

?

What kind of battery bank is in your plans ?

?

Do you have a photo of the shaft and of the engine room, as it is now ?

?

?

Cheers,

Carsten

?

?

?

Dan,

?

I have reviewed your drawings. Very interesting, a hybrid boat !

?

When you are using a toothbelt drive, you actually don't need a Drivesaver, as the toothbelt will slip or break in a crash-stop situation. A new belt is far easier (and cheaper) to replace than a Drivesaver coupling.

The inertia in an electric motor (the rotating mass) is far less than by a diesel engine with a big flywheel, and you have no gearbox anymore to worry about.

?

The position of the ME1616 motor is almost free to choose, meaning that you can add a pulley to the shaft almost anywhere until you reach the sterndrive. The distance from shaft centerline to motor centerline is also only determined of the toothbelt length. You don't HAVE to place it in one common frameplate.

?

If you make the motor base adjustable, it is easy to change the belt.

If you make the frameplate with fixed driveshaft and motor shaft, like on your drawing, you likely will add an adjustable bearing roller to adjust the tension of the belt (same like in a car engine, for a camshaft toothbelt). Very handy too, for changes of pulleys for reduction ratio. (The roller must roll on the flat side of the belt, of course.)

I guess a complete roller kit for a car is rather inexpensive.

?

Why use aluminum for the construction?

I know that it easier to cut a thread and drill a hole in aluminum than in steel.

But :

Steel channels and steel plates are much easier to repair if you make a mistake, or something should be re-positioned.

Aluminum welding is no fun, and threads cut in steel are much stronger. You use Helicoils in aluminium constructions, if threads shall be strong and lasting. That requires special tools, so - not for a DIY mechanic.

If you need something done, any workshop in any port can weld steel, and can always find a standard machine tap in the dirty drawers.

?

I would say, that an ME1616 used as a generator might be shooting sparrows with a cannon - an expensive solution. Balmar have some 48V alternators, you can check them out.

?

How is your plan for cooling of the ME1616 for the shaft ? (I assume that you will make a common system for the Kubota and the ME1616.)

?

What kind of battery bank is in your plans ?

?

Do you have a photo of the shaft and of the engine room, as it is now ?

?

?

Cheers,

Carsten

?

?

?

Thanks, Dan !

?

Save your money on stainless (exept the shaft part from cutless bearing to prop).

You have an inboard, and mechanical properties of good ol "rusty" steel are usually better than ss.

?

Could you please provide a sketch of your setup ?

It seems very interesting !

?

Carsten

?

?

On Tuesday, 16 March 2021, 23:54:19 GMT+8, Dan Pfeiffer <dan@...> wrote:

?

?

(sorry if this is a repeat - I posted it 8hrs ago and it never showed up)

I have also spent a lot of time looking for thrust bearing options.? That Python Drive looks like a great solution where there is room to fit it.? Looks like it will leave some room in the wallet too.?

Thunderstruck uses a trailer hub with tapered roller bearings.? It's a good simple and inexpensive solution for small setups (<30hp?).?? I think this is the hub they use:



One issue with these is setting the pre-load on the bearings.? If you have changed the wheel bearings on a car you know what this is about.? Thunderstruck does it by using a fixed collar and bushing on the prop side of the bearing and another bushing on the other side that is held in place by the tapered bushing that holds the toothed belt for the reduction gear pulley.? It's a simple setup with only a few parts and some simple machining on the shaft.

I am fabricating my own belt drive reduction gear for my boat (12kW motor) and I am going to use a trailer hub that's one size larger and available in stainless steel (with a price premium of course).? This is what I am using:


I am going to use a threaded split collar on the shaft to set the pre-load on the bearing.? My shaft will be a more complicated machining (including a threaded section) but I think it will be a better way to set and hold the pre-load on the bearings.?? The two parts I have to make are the shaft and the bushing.? Both will be stainless steel.? The hub will remain stock with no machining.? The bearings are standard hub bearings you can get anywhere.?? All the parts except the bearings will be stainless steel.? And the bearings will be in the grease.? The bushing will have the OD sized to fit the grease seal on the hub that takes the place of the standard cap when it is used on a wheel.? It's a standard grease seal but I had to hunt a bit to sort out fitting it in the hub.?

This could easily be scaled up for larger applications.?? These hubs come in at least two larger sizes in stainless.?

The bearing, reduction gear assembly, and motor will mount to an aluminum plate similar to what Thunderstruck does.? I was going to use a piece of c-channel and that would work well but I wanted more flexibility in the pulley sizing to be better able to fine tune the reduction ratio and the c-channel limits the diameter of the gear pulley a bit.? I am still sorting that part out but I am aiming for about 3:1 for the reduction.? The world of timing belts and pulleys is vast and has been difficult to get a handle on so far.?


Dan Pfeiffer

?

On 2021-03-15 11:29 pm, Carsten via groups.io wrote:

Of course you'll need a double bearing for axial loads in forward and reverse...

P? tir., den 16. mar. 2021 klokken 10:47, Carsten via groups.io

<Carstensemail@...> skrev:

Hi, Steve

?

Consider to make your thrust bearing with a high quality spherical roller thrust bearing, eg. of SKF brand. This can accept torsional forces much better than ball thrust bearings.

Then you don't need the expensive solutions with a lot of rubber (which needs care and replacement when worn).

?

The tooth belt drive (not V-belt, which introduces higher radial forces to the shaft) can be mounted either before or after the thrust bearing.

The housing for the thrust bearing should best be mounted close to the cutlass bearing, to minimize torsional bending of a long shaft.

?

Could you please post some photos of your existing setup of the shaft and cutlass ?

?

Have you considered which prop you will use for your new setup ?

Going electric has a lot of torque at low revs, which is very useful during maneuvering, so the prop should have less pitch and larger diameter, imho.

?

Carsten

?

?

P? tir., den 16. mar. 2021 klokken 4:52, Steven Borg

<steve@...> skrev:

I'm in the process of planning and installing a Hyper-9 motor at 154V with a battery bank of 48 280Ah 3.2V LiFePO4 batteries I received from China. The motor is?rated to be plenty powerful to replace my 100 HP Diesel (which has been removed).? I'll keep everyone posted when it's installed.

In the meantime, I have a related question (maybe for ChristopherH?) around thrust bearings.? I've decided to use a belt drive (like the photos above, but for a single motor and gear.? But without the transmission I had planned on using (with integrated thrust bearings), I'm going to need to anchor the propshaft to the boat.??

Christopher, what inline thrust bearing did you use?? I'm trying to determine if I should build out a thrust bearing somewhere along the prop shaft, or whether I should integrate the thrust bearing into the engine mount, either before or after the belt pulley driving the shaft.? Also, if there's a pre-made thrust bearing for boats, I can't seem to find them (except large ones for giant ships). Does anyone know what they'd be called, so I can search for them.? (Yes, this is an embarrassing, totally newbie, question to ask, but I just can't seem to find them, so have been debating whether to just engineer my own from bearings off Granger or McMaster-Carr).

I'm not sure those questions even made sense, but that's where I'm starting...? Still trying to figure out the best way to get this done!??

This has been an amazing thread!? Thank you!

?

?

Thanks, Dan !

?

Save your money on stainless (exept the shaft part from cutless bearing to prop).

You have an inboard, and mechanical properties of good ol "rusty" steel are usually better than ss.

?

Could you please provide a sketch of your setup ?

It seems very interesting !

?

Carsten

?

?

On Tuesday, 16 March 2021, 23:54:19 GMT+8, Dan Pfeiffer <dan@...> wrote:

?

?

(sorry if this is a repeat - I posted it 8hrs ago and it never showed up)

I have also spent a lot of time looking for thrust bearing options.? That Python Drive looks like a great solution where there is room to fit it.? Looks like it will leave some room in the wallet too.?

Thunderstruck uses a trailer hub with tapered roller bearings.? It's a good simple and inexpensive solution for small setups (<30hp?).?? I think this is the hub they use:



One issue with these is setting the pre-load on the bearings.? If you have changed the wheel bearings on a car you know what this is about.? Thunderstruck does it by using a fixed collar and bushing on the prop side of the bearing and another bushing on the other side that is held in place by the tapered bushing that holds the toothed belt for the reduction gear pulley.? It's a simple setup with only a few parts and some simple machining on the shaft.

I am fabricating my own belt drive reduction gear for my boat (12kW motor) and I am going to use a trailer hub that's one size larger and available in stainless steel (with a price premium of course).? This is what I am using:


I am going to use a threaded split collar on the shaft to set the pre-load on the bearing.? My shaft will be a more complicated machining (including a threaded section) but I think it will be a better way to set and hold the pre-load on the bearings.?? The two parts I have to make are the shaft and the bushing.? Both will be stainless steel.? The hub will remain stock with no machining.? The bearings are standard hub bearings you can get anywhere.?? All the parts except the bearings will be stainless steel.? And the bearings will be in the grease.? The bushing will have the OD sized to fit the grease seal on the hub that takes the place of the standard cap when it is used on a wheel.? It's a standard grease seal but I had to hunt a bit to sort out fitting it in the hub.?

This could easily be scaled up for larger applications.?? These hubs come in at least two larger sizes in stainless.?

The bearing, reduction gear assembly, and motor will mount to an aluminum plate similar to what Thunderstruck does.? I was going to use a piece of c-channel and that would work well but I wanted more flexibility in the pulley sizing to be better able to fine tune the reduction ratio and the c-channel limits the diameter of the gear pulley a bit.? I am still sorting that part out but I am aiming for about 3:1 for the reduction.? The world of timing belts and pulleys is vast and has been difficult to get a handle on so far.?


Dan Pfeiffer

?

On 2021-03-15 11:29 pm, Carsten via groups.io wrote:

Of course you'll need a double bearing for axial loads in forward and reverse...

P? tir., den 16. mar. 2021 klokken 10:47, Carsten via groups.io

<Carstensemail@...> skrev:

Hi, Steve

?

Consider to make your thrust bearing with a high quality spherical roller thrust bearing, eg. of SKF brand. This can accept torsional forces much better than ball thrust bearings.

Then you don't need the expensive solutions with a lot of rubber (which needs care and replacement when worn).

?

The tooth belt drive (not V-belt, which introduces higher radial forces to the shaft) can be mounted either before or after the thrust bearing.

The housing for the thrust bearing should best be mounted close to the cutlass bearing, to minimize torsional bending of a long shaft.

?

Could you please post some photos of your existing setup of the shaft and cutlass ?

?

Have you considered which prop you will use for your new setup ?

Going electric has a lot of torque at low revs, which is very useful during maneuvering, so the prop should have less pitch and larger diameter, imho.

?

Carsten

?

?

P? tir., den 16. mar. 2021 klokken 4:52, Steven Borg

<steve@...> skrev:

I'm in the process of planning and installing a Hyper-9 motor at 154V with a battery bank of 48 280Ah 3.2V LiFePO4 batteries I received from China. The motor is?rated to be plenty powerful to replace my 100 HP Diesel (which has been removed).? I'll keep everyone posted when it's installed.

In the meantime, I have a related question (maybe for ChristopherH?) around thrust bearings.? I've decided to use a belt drive (like the photos above, but for a single motor and gear.? But without the transmission I had planned on using (with integrated thrust bearings), I'm going to need to anchor the propshaft to the boat.??

Christopher, what inline thrust bearing did you use?? I'm trying to determine if I should build out a thrust bearing somewhere along the prop shaft, or whether I should integrate the thrust bearing into the engine mount, either before or after the belt pulley driving the shaft.? Also, if there's a pre-made thrust bearing for boats, I can't seem to find them (except large ones for giant ships). Does anyone know what they'd be called, so I can search for them.? (Yes, this is an embarrassing, totally newbie, question to ask, but I just can't seem to find them, so have been debating whether to just engineer my own from bearings off Granger or McMaster-Carr).

I'm not sure those questions even made sense, but that's where I'm starting...? Still trying to figure out the best way to get this done!??

This has been an amazing thread!? Thank you!

?

On Mar 16, 2021, at 14:42, orest iwaszko <orest@...> wrote:

?

Your speed / amp draw chart looks right on.

My 10 kwt system on 48 volts starts heating up above 3.5 knots and 20 min. on my 34 foot trawler turning the big prop.?

? ? ? Had a conversation with Canadian electric vehicles where it was suggested to go 96 volts?

and keep things cooler.. ?

?Sincerely, Orest?

?Alberni Charters

?250-735-6503.

On Sun, Mar 14, 2021 at 5:43 PM Dan Pfeiffer <dan@...> wrote:

Thanks for the numbers.?

Some more questions.? What did you do for a thrust bearing?? And where did you source the pulleys?? They look almost like they could be stainless in your photo.? Do you recall the tooth counts on the pulleys?

Again, it is a very tidy installation.? Looks great.?? Nice job.? Thanks for sharing the details.


Dan Pfeiffer

?

On 2021-03-14 6:48 pm, ChristopherH via wrote:

Dan,

Can't recall the belt wrap percentage. I did consider this in my design and think I'm likely under the 30%, or close to it. I remember it was right on the edge. It's been 7 years, or so now. It hasn't cause any issues other than occasionally in a docking situation when aggressively changing directions. I think sometimes I can hear a very short period of clogging. Maybe I don't have belt tight enough though. I wanted to have 2 belts, but I had already taxed my non engineer brain enough. I was concerned about having to extend one motor shaft out to allow 2 sprockets on the prop shaft and overloading the motor bearing due to the extension.?

I have done a couple performance runs, but but have found it difficult to get consistent results so these are rough numbers. First number is speed in knots, second number is total DC amps into controllers. My notes say that these were taken with a <5.0 kt head wind on flat water.

3.0 ?- 25.4

3.5 - 34.6

4.0 - 56.8

4.5 - 75.2

5.0 - 104.6

5.5 - 156.7

6.0 - 211.3

6.5 - 360.0

?

Chris

Sent from myPhone

On Mar 14, 2021, at 17:52, Dan Pfeiffer <dan@...> wrote:

This is a very tidy installation.? The only thing I wonder about is the engagement of the belt on the prop shaft toothed pulley.? It does not look like enough but it is hard to tell in the photo.? I think the recommendation for these belts is 30% or 120 deg.??

Do you have performance data?


Dan Pfeiffer

?

On 2021-03-14 4:11 pm, ChristopherH via wrote:

?

Ryan,

2 Sevcon controllers and 2 ME0913 motors electrically separate. One throttle with the signal sent to both controllers. Actually I have 2 throttles, but one is a spare. It can be quickly put in service if the primary throttle fails. Attached are a couple pictures of my installation. Also, a sketch of how I configured the throttle to work with 2 controllers.

?

Chris

?

?

On Sunday, March 14, 2021, 4:37:04 PM EDT, Dan Pfeiffer <dan@...> wrote:

?

?

I think if you look at the Rigging Doctor motor videos you get a look at the drive system.? Looks like just two simple belt drives to the output shaft.??



I don't think you can control two motors with one controller.? The current capacity is not a problem but the controller can't deal with the rotor position data from more than one motor and that's sort of important.? But is there a way to synchronize the controllers??? That would make sense.? Also probably better to have the two anyway for redundancy?

I don't know what happens when one motor fails.? I would think it matters what the failure is.? There are several possibilities.?? Would you get a current load back if there wasn't a load on the motor???? In the above video the Rigging Doctor guys talk about the failures they have seen.? With a dual gear box you might have a more complex problem unless there is a way to mechanically disconnect in the gear box.?


Dan Pfeiffer

?

On 2021-03-14 2:20 pm, Ryan Sweet wrote:

Thanks Dan, this is helpful!?

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I wonder, are electric yacht using a differential or just two pulleys on the same output shaft? The positioning of the motors makes it look like they are using a differential.?

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Any reason that a single Sevcon Gen4 could not drive the two 10kw in parallel?

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I think if one failed, and the gearbox doesn't have a way for idle input to disconnect, the result would be current fed back into the system - and a doubling of the torque the other motor is required to produce??

On Mar 14, 2021, at 11:05, Dan Pfeiffer <dan@...> wrote:

I have been looking at this as well though not for a larger boat but for what it takes for sustained cruising at 6+ knots as I could easily do with my 23hp diesel in my 33 ft boat (12,500 lbs, 28.3' LWL).? That's about 85% of hull speed.? I don't think the 10KW motor (ME1115) is really up to that once you get past 11,000 lbs displacement?? The continuous rating is something like 150 amps or 7200 watts at 48V.? That should get you into that 5.5 to 6 kts range but should you really be running the motor at 100% sustained?? I also wonder how much prop optimization has been done on the examples I have seen data for.?? I suspect that in general most are running smaller props at higher speeds.? But I don't know.?

We need more data.? More, more...

A motor like the Motenergy ME1616 is rated at a peak of 600 amps.?? But the continuous rating is 250 amps with liquid cooling (150 amps without) which at 72V gets you the rated 18kW.? If you plan to run at sustained speeds you need to account for the continuous capacity of the motor.? That is your limit.? Peak is unusable for anything more than a minute at a time. ? You can't run continuously at 600 or even 300 amps even if you have the capacity to deliver that amount of current continuously (like with a big genset).? But if you can get 6kts at 7000 watts that's 60% for the ME1616 and that seems reasonable as far as the motor.? And with an 8kW genset you can do that for as long as you have fuel. ? But without the big genset forget it.? You're looking at 90 minutes with a 300AH bank at 80% DoD.?

Running two 10kW motors parallel (ME1115 x 2) is exactly what ElectricYacht does with their QT20.?? And they run two 12kW (ME1616 x 2) in parallel for the QT30.? I like how they put a water pump on the jack shaft of the QT30.? Both of these use dual belt drives and dual controllers.?


And there are some examples of installations on the youtubes.?
rigging doctor has a QT20 (though I don't think he is a real doctor)
Spoondrifter has a QT30 (not launched yet)

Search on youtube and add the word motor to see a bunch of videos regarding these installations.? These are both in 40-45ish foot boats?? I wonder with these setups what happens if one motor fails.? Will it freewheel or will you have to go in and remove the belt.? I know rigging doctor has run on just one motor when the other failed but I don't know if they removed they removed a belt.?? I also know they spend a lot of time waiting for wind (and that works fine for them).? But I want to be able to motor up the Detroit river and transit the Welland and Erie canals.? That requires sustained speed.? Not so much in the Erie but in the Welland and Detroit river you are dealing with real ship traffic all day long.? That's no time to be puttering along at 3-1/2 kts.?

Spoondrifters has a genset and that is basically going to be? a series hybrid drive.? But I think the genset is on the order of 6-9kW and that won't get them a lot of sustained speed?? The battery bank might for as long as it holds up (not long).?? Regardless, you won't be drawing 600A with anything for very long as the motor won't take it.? Even the ElectricYacht QT30 with two 18KW ME1616 motors will be rated for 500 amps continuous.?? But that's running at 100% and look at what you would need for supply power to sustain that for anything more than 20 minutes.?? Maybe that's getting more practical on a 45 foot boat with the current lithium battery options like EVE 280AH cells.? 48 of those would get you a 72V 560 amp bank for $6,000.? But that's only going to run you at 500 amps for an hour and at that you're abusing the batteries.? And the genset to keep up would need to be 30kW??

I think I might spend more time looking at parallel hybrid setups in a bigger boat like that.?? Beta Marine is getting into that now.?


Look at Nigel Calder's work on parallel hybrids too.?

Dan Pfeiffer

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On 2021-03-14 11:35 am, Ryan Sweet wrote:

So it seems clear that the motoenergy 10kw + sevcon gen4 combo (thunderstruck kit) works great for boats in the 30'ish range, more or less replacing motors around 20hp or hull speeds from 5-7kt. ?

Now I'm interested in skilling-up to take on conversions of larger boats.

Those of you with 40-50' boats, 60-150HP diesels, what are you using to re-power? ??At higher voltages, what are the power curves like? Will a 72v motor draw 600a at top speed (and thus need a *much* larger bank than our 48v systems)?? Anyone experimenting with multi-input/single output transmissions and multiple smaller motors (eg run two 10kw 48v side by side)?? What are the best chargers for 72v/96v systems?

<Screenshot at 2021-03-14 13-32-04.png>

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Of course you'll need a double bearing for axial loads in forward and reverse...

P? tir., den 16. mar. 2021 klokken 10:47, Carsten via groups.io

<Carstensemail@...> skrev:

Hi, Steve

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Consider to make your thrust bearing with a high quality spherical roller thrust bearing, eg. of SKF brand. This can accept torsional forces much better than ball thrust bearings.

Then you don't need the expensive solutions with a lot of rubber (which needs care and replacement when worn).

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The tooth belt drive (not V-belt, which introduces higher radial forces to the shaft) can be mounted either before or after the thrust bearing.

The housing for the thrust bearing should best be mounted close to the cutlass bearing, to minimize torsional bending of a long shaft.

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Could you please post some photos of your existing setup of the shaft and cutlass ?

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Have you considered which prop you will use for your new setup ?

Going electric has a lot of torque at low revs, which is very useful during maneuvering, so the prop should have less pitch and larger diameter, imho.

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Carsten

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P? tir., den 16. mar. 2021 klokken 4:52, Steven Borg

<steve@...> skrev:

I'm in the process of planning and installing a Hyper-9 motor at 154V with a battery bank of 48 280Ah 3.2V LiFePO4 batteries I received from China. The motor is?rated to be plenty powerful to replace my 100 HP Diesel (which has been removed).? I'll keep everyone posted when it's installed.

In the meantime, I have a related question (maybe for ChristopherH?) around thrust bearings.? I've decided to use a belt drive (like the photos above, but for a single motor and gear.? But without the transmission I had planned on using (with integrated thrust bearings), I'm going to need to anchor the propshaft to the boat.??

Christopher, what inline thrust bearing did you use?? I'm trying to determine if I should build out a thrust bearing somewhere along the prop shaft, or whether I should integrate the thrust bearing into the engine mount, either before or after the belt pulley driving the shaft.? Also, if there's a pre-made thrust bearing for boats, I can't seem to find them (except large ones for giant ships). Does anyone know what they'd be called, so I can search for them.? (Yes, this is an embarrassing, totally newbie, question to ask, but I just can't seem to find them, so have been debating whether to just engineer my own from bearings off Granger or McMaster-Carr).

I'm not sure those questions even made sense, but that's where I'm starting...? Still trying to figure out the best way to get this done!??

This has been an amazing thread!? Thank you!

The other mfg of thrust bearings I considered is Aquadrive. I think with both Python Drive and Aquadrive you can also buy a thrust bearing without the CV shaft and have them machine to adapt to whatever shaft configuration you have.

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Chris

Sent from myPhone

On Mar 15, 2021, at 17:06, ChristopherH via groups.io <clh5_98@...> wrote:

I used a Python Drive thrust bearing and CV shaft combination. There is another similar mfg, but i can't recall the name. The bearing at the motor plate is a radial support bearing. The CV shaft runs aft from the motor plate bearing to a small bulkhead in the bilge where the thrust bearing is mounted. From there the prop shaft runs another couple feet to the cutlass bearing. The small bulkhead was already there and used to hold a radial support bearing for the shaft due the length.?

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Chris

Sent from myPhone

On Mar 15, 2021, at 16:52, Steven Borg <steve@...> wrote:

I'm in the process of planning and installing a Hyper-9 motor at 154V with a battery bank of 48 280Ah 3.2V LiFePO4 batteries I received from China. The motor is?rated to be plenty powerful to replace my 100 HP Diesel (which has been removed).? I'll keep everyone posted when it's installed.

In the meantime, I have a related question (maybe for ChristopherH?) around thrust bearings.? I've decided to use a belt drive (like the photos above, but for a single motor and gear.? But without the transmission I had planned on using (with integrated thrust bearings), I'm going to need to anchor the propshaft to the boat.??

Christopher, what inline thrust bearing did you use?? I'm trying to determine if I should build out a thrust bearing somewhere along the prop shaft, or whether I should integrate the thrust bearing into the engine mount, either before or after the belt pulley driving the shaft.? Also, if there's a pre-made thrust bearing for boats, I can't seem to find them (except large ones for giant ships). Does anyone know what they'd be called, so I can search for them.? (Yes, this is an embarrassing, totally newbie, question to ask, but I just can't seem to find them, so have been debating whether to just engineer my own from bearings off Granger or McMaster-Carr).

I'm not sure those questions even made sense, but that's where I'm starting...? Still trying to figure out the best way to get this done!??

This has been an amazing thread!? Thank you!

Of course you'll need a double bearing for axial loads in forward and reverse...

P? tir., den 16. mar. 2021 klokken 10:47, Carsten via groups.io

<Carstensemail@...> skrev:

Hi, Steve

?

Consider to make your thrust bearing with a high quality spherical roller thrust bearing, eg. of SKF brand. This can accept torsional forces much better than ball thrust bearings.

Then you don't need the expensive solutions with a lot of rubber (which needs care and replacement when worn).

?

The tooth belt drive (not V-belt, which introduces higher radial forces to the shaft) can be mounted either before or after the thrust bearing.

The housing for the thrust bearing should best be mounted close to the cutlass bearing, to minimize torsional bending of a long shaft.

?

Could you please post some photos of your existing setup of the shaft and cutlass ?

?

Have you considered which prop you will use for your new setup ?

Going electric has a lot of torque at low revs, which is very useful during maneuvering, so the prop should have less pitch and larger diameter, imho.

?

Carsten

?

?

P? tir., den 16. mar. 2021 klokken 4:52, Steven Borg

<steve@...> skrev:

I'm in the process of planning and installing a Hyper-9 motor at 154V with a battery bank of 48 280Ah 3.2V LiFePO4 batteries I received from China. The motor is?rated to be plenty powerful to replace my 100 HP Diesel (which has been removed).? I'll keep everyone posted when it's installed.

In the meantime, I have a related question (maybe for ChristopherH?) around thrust bearings.? I've decided to use a belt drive (like the photos above, but for a single motor and gear.? But without the transmission I had planned on using (with integrated thrust bearings), I'm going to need to anchor the propshaft to the boat.??

Christopher, what inline thrust bearing did you use?? I'm trying to determine if I should build out a thrust bearing somewhere along the prop shaft, or whether I should integrate the thrust bearing into the engine mount, either before or after the belt pulley driving the shaft.? Also, if there's a pre-made thrust bearing for boats, I can't seem to find them (except large ones for giant ships). Does anyone know what they'd be called, so I can search for them.? (Yes, this is an embarrassing, totally newbie, question to ask, but I just can't seem to find them, so have been debating whether to just engineer my own from bearings off Granger or McMaster-Carr).

I'm not sure those questions even made sense, but that's where I'm starting...? Still trying to figure out the best way to get this done!??

This has been an amazing thread!? Thank you!