I lost two props from my trolling motor. One time we were motor sailing and apparently going faster than the motor could go. The second time the motor was up but occasionally brushing the water on some waves. They clearly just unscrew in situations like that. I was way more careful with it after the second time.
I have a Motoglide trolling motor that I used to use on the launch I have to go between my island beach house and the mainland here in CT. The prop came off too... and it was an incredible hassle getting another one. .. $60.00 with shipping.. I simply bought a new MinKota motor at Walamart for $30 dollars more.. The replacement prop for that motor costs only $12.00
Skip
The temperature on Saturday morning was cold for St. Petersburg – low 50's and forecast to remain below seventy for the day. But the north winds promised to remain around ten knots and the high clouds were breaking up as we let loose the lines and headed into the basin that surrounds the St. Petersburg Municipal Marina.
We were hoping for a short, relaxing day sail in Tampa Bay – our first since buying our Cal29 Play Mate last January. We were not disappointed.
We started out using our Motor Guide 54, which worked well, if a bit noisy on the stern mount, but as we passed green 1 marker the head sail went up and the motor off. From there the day unfolded with chilled blue skies and a sparkling Tampa Bay that was nearly empty. Only a few other sailors had decided to come out for the day.
Connie settled back into sailing after her hiatus of several years without a hitch. She kept us on a broad reach to the southeast until I decided to try some wing-on-wing to the south-southwest. Our goal was to be back to the slip no later than three o'clock, and we nearly made that. We took turns on another broad reach towards St. Petersburg, but my downwind leg required a tack to the north-northwest followed by a short leg into the basin.
We motor-sailed to the slip with both sails up in the light wind, which turned out to be very fortuitous. As we moved dead slow towards the outside pilings that mark the slip, I lost all steering. We started to drift south and, with our minimum forward momentum, towards our neighbor's boat. A shift to full reverse changed nothing, and when I glanced back a the motor the prop was gone.
I called to Connie, who was on the bow, that we were moving back out to the basin as I made a hard turn to starboard that cleared our neighbor's boats, but only barely.
We anchored so that I could change to the MinnKota 50 that I had on board as a spare. That, plus extra props, nuts, and so on will be standard practice from now on.
And so, even with that close call, the day went well. After Play Mate was secure and washed down we found ourselves complaining of a few aches from the day's exercise, most of which were gone after a great night's sleep.
But not our resolve to spend more time out on the water on Play Mate rather than just fixin' her up.
Brad Bates
Play Mate
St. Petersburg, FL
The temperature on Saturday morning was cold for St. Petersburg – low 50's and forecast to remain below seventy for the day. But the north winds promised to remain around ten knots and the high clouds were breaking up as we let loose the lines and headed into the basin that surrounds the St. Petersburg Municipal Marina.
We were hoping for a short, relaxing day sail in Tampa Bay – our first since buying our Cal29 Play Mate last January. We were not disappointed.
We started out using our Motor Guide 54, which worked well, if a bit noisy on the stern mount, but as we passed green 1 marker the head sail went up and the motor off. From there the day unfolded with chilled blue skies and a sparkling Tampa Bay that was nearly empty. Only a few other sailors had decided to come out for the day.
Connie settled back into sailing after her hiatus of several years without a hitch. She kept us on a broad reach to the southeast until I decided to try some wing-on-wing to the south-southwest. Our goal was to be back to the slip no later than three o'clock, and we nearly made that. We took turns on another broad reach towards St. Petersburg, but my downwind leg required a tack to the north-northwest followed by a short leg into the basin.
We motor-sailed to the slip with both sails up in the light wind, which turned out to be very fortuitous. As we moved dead slow towards the outside pilings that mark the slip, I lost all steering. We started to drift south and, with our minimum forward momentum, towards our neighbor's boat. A shift to full reverse changed nothing, and when I glanced back a the motor the prop was gone.
I called to Connie, who was on the bow, that we were moving back out to the basin as I made a hard turn to starboard that cleared our neighbor's boats, but only barely.
We anchored so that I could change to the MinnKota 50 that I had on board as a spare. That, plus extra props, nuts, and so on will be standard practice from now on.
And so, even with that close call, the day went well. After Play Mate was secure and washed down we found ourselves complaining of a few aches from the day's exercise, most of which were gone after a great night's sleep.
But not our resolve to spend more time out on the water on Play Mate rather than just fixin' her up.
Brad Bates
Play Mate
St. Petersburg, FL
David,
Our Chief Engineer at Electric Yacht, Scott McMillan, discarded the chain drive option a few years ago because of the noise issue. Cogged belts still give the option of varying a sprocket size to allow for custom gearing for each installation so that in most cases, you can use your old prop and shaft eliminating the need for haul-out.
Addressing the alignment concern, sprockets are both contained within a body that integrates the motor, the gearbox and the controller, so both shafts are permanently aligned perfectly. You can see photos and other info at http://www.electric
Bill Tomlinson, Electric Yacht.
--- In electricboats@
>
> Personally, I would rather go with the gearbox. Keeps the complexity
> down and makes for a beautiful engine room. I mean look at this:
> http://propulsionma
>
> Still, I can see where the belt/pulley setup has its advantages:
> - each component is relatively inexpensive so spares can be kept on board.
> - parts are available everywhere and from many different suppliers.
> - you even have a reasonable chance of finding what you need in a retail
> store that is open on a long weekend.
>
> Mind you, once the drive system is installed and everything is properly
> sized and aligned, the chances of anything failing are pretty small
> whether you go belt/pulley or gearbox...
>
> James:
> How do the gearboxes hold up over time in a salt air environment?
> Any chance of galvanic interaction with other metal bits?
> And what about field servicing?
> Is there anything an owner can do on his/her own in the field if
> something goes wrong with their gearbox?
> What spare parts would you recommend a prudent owner have in their
> on-board inventory?
> Some closeup photos of "at install time" and "after x seasons" would be
> great (actually, that would be great for all of you electric converts to
> do1).
>
> Cheers,
>
> /Jason
>
> James W. Lambden wrote:
> > David,
> >
> > The gearbox solution will deliver more power, more efficiently than any other solution. Helical gears are 97% efficient and seals account for losses of another percent. Gearboxes have an integral thrust bearing. The cast iron of the gearbox acts as a heat sink for the motor so the motor is capable of running longer at higher loads. There is no possibility of catching fingers or clothing like belts or chains can. Gear noise is minimal with slower turning motors and big slow turning propellors. Gearboxes can be mounted to a stainless plate and put back on the original motor mounts for accurate alignment. Split / Flex couplings offer alignment and make it easy to install.
> >
> > The greatest advantage of the industrial gearbox is the many different gear ratios. They are essential to be able to balance the system for optimum efficiency and power.
> >
> > James Lambden
> >
> > www.propulsionmarin
> >
> >
> >
> > ----- Original Message -----
> > From: dennis wolfe
> > To: electricboats@
> > Sent: Wednesday, November 25, 2009 7:06 PM
> > Subject: Re: [Electric Boats] Bearings and power transmission
> >
> >
> >
> >
> > David,
> >
> > The flange mounted ball bearing has plenty of capacity to take the small thrust loads 6hp can generate and it has a spherical OD so will align itself with the prop shaft. The timing belt does not need a tensioner, just mill slots in the plate to slide the motor to create tension in the belt. The belt and pulley solution is lighter, cheaper and quieter than the gear solutions, plus you can change the ratio by substituting a new pulley and belt.
> >
> > You could use your existing gear box from the ICE too, if you can devise a way to couple the motor to its input shaft plus mount the gearbox to the boat. Not so simple.
> >
> > I think the al plate is a better mounting system - it is more rigid than plywood w/fiberglass, easier to make and won't crush under the bolt heads. You can machine 6061 aluminum with wood working tools, even cut it on a table saw with a carbide blade.
> >
> > Denny Wolfe
> > www.wolfEboats.
> >
> >
> > Message -----
> > From: goldsmithfoil
> > To: electricboats@
> > Sent: Wednesday, November 25, 2009 8:54 PM
> > Subject: [Electric Boats] Bearings and power transmission
> >
> >
> >
> > Hello group, I'm putting together an electric system for an Islander 32' using the MARS brushless set-up. I'm puzzling out the power transmission and motor mounts. First question is about the motor mounting. Looks like most people are using 1/2" AL to mount the motor and shaft bearings. Could heavily glassed ply be used in its place or does the AL acting as a heat sink make it a better choice?
> >
> > Second question is about power transmission. Seems there are three choices: use an existing marine transmission, use an industrial gear box, or set up something with belts and pulleys.
> >
> > I have the gear box from the diesel we pulled, I just worry about it being inefficient and not allowing the prop to spin the motor for regen. Anyone know how efficient small marine transmissions are whether it would be a good way to go? It would certainly be the easiest solution and the MARS motor runs at about the same RPM as the Yanmar did so the ratios should match up well.
> >
> > Second option is an industrial gear box like Propulsion Marine offers, this also looks like a good solution with a minimum of engineering involved.
> >
> > Third option, which I'm leaning toward is setting up a board with the motor and some pulleys to bring the speed down for the shaft. V-belt, chain, or timing belt? One thing I haven't seen anyone address is idlers or tensioners on the belts, there has to be some method of tensioning the belts. Are people just using a slot and leverage before bolting down like an alternator? I've seen spring loaded tensioners for timing belts that looked like a good solution.
> >
> > The other question I have is about thrust, a pulley and belt set up needs some sort of thrust bearing, do the flange bearings I see being used provide that function or is an additional bearing needed in the system? I'm new to the mechanics of power transmission, so I've got these questions.
> >
> > Thanks, I'm looking forward to some discussion on the mechanics of setting up such a system. I've got a good grasp on the electrics, charging, and battery systems, its just the mechanical part I still need some help with.
> >
> > Thanks,
> > David
> >
> >
> >
> >
> >
> >
>
Based on my experience with my Cape Dory Typhoon and a Torqeedo 801L, for your boat, I would look at a 401L (12v) and a Enginer Lithium battery, 40AH for $260, http://www.enginer.
What is your budget? Mine was such that it included buying a Torqeedo with extra battery pack.
http://www.torqeedo.com/us/hn/ home.html
http://greenboatsupply.com/index. html
--- In electricboats@yahoogroups. , "connel42" <connel42@..com .> wrote:
>
> Hi
> I have just joined this group and find the correcpondence very interesting.
> I am currently restoring a Drascombe Longboat which a-is a traditional sailing boat with grp hull.
> The boat is 22 foot long open design
> Length 21' 9"
> Beam 6' 7"
> Weight 880lbs (400kg)
> I would like to fit and electric drive unit and motor but don't know where to start.
> Not looking for speed just gentle cruising and good range between charges and of course budget is limeted.
> The boat will be dry sailed so charging at home is no problem.
> Any advice would be greatly appreciated.
> Regards
> Connel
>
My current thinking is to set up the old Hurth type gear box with the MARS motor directly coupled to it. I like this solution because it will be easier to mount the whole deal, it can go on the existing engine beds. I like the moving parts contained, I know a cage or other cover on the belts could be set up but the enclosed gear box is still a safer set-up. The robust mechanicals of the gear box too I think will be more durable and reliable than a belt set up.
If the coupling of the motor to the gear box is too difficult or there is some other problem I won't have any problem going to a belt set up, its certainly a very good solution. I just happen to have this gearbox already, the belt set-up would be cheaper if building from scratch.
David
Mostly it's the overall size and weight of the package, chain drive can be built with 30 speeds (10r+3f sprockets) in a very light and compact package. A belt with the same power transfer abilities in a single speed, needs an assembly roughly the same size and weight as the chain drive for 10.
I put 400 miles a week on bicycles, and wouldn't think about a belt drive on any of mine (8 at last count), but feel cogged belts do make a lot of sense in a boat application where room is available (and gear changes aren't required or can easily use a gearbox). They are quieter and would last longer in a wet environment.
Only issue with a belt is that they have to be carefully sized, so replacements for each belt has to be carried, with chains as long as they have the same link size you can buy in bulk and cut your own. Belts are also not tolerant of alignment errors, a chain will handle errors that would shred a belt in minutes without a problem. (they will have slightly reduced life, and a bit more noise though)
Ken.
> To: electricboats@yahoogroups. com
> From: matthew@acfr.usyd.edu. au
> Date: Sat, 28 Nov 2009 06:18:56 +1100
> Subject: Re: [Electric Boats] Bearings and power transmission
>> danbollinger wrote:> ------------
> > Cogged/synchronous belts are in the 96-99% efficiency range, so don't discount them. They are lighter, and don't need lubrication.
> >
> >
> Cyclists are still largely using chains and a mechanism to bodily rip
> the chain from one cog to another to change gear as the efficiency of
> the simple belt/chain transmission/gear system is hard to beat.
> The chain systems are in the high 90s% efficient. The hub gear systems
> tend to be some what lower - mid 80s to mid 90s% efficient.
> Like our e-boats, cyclists want maximum power transfer with the minimum
> of transmission losses.
>
>
>--------- --------- ------
>
> Yahoo! Groups Links
>
> <*> To visit your group on the web, go to:
> http://groups.yahoo.com/ group/electricbo ats/
>
> <*> Your email settings:
> Individual Email | Traditional
>
> <*> To change settings online go to:
> http://groups.yahoo.com/ group/electricbo ats/join
> (Yahoo! ID required)
>
> <*> To change settings via email:
> electricboats-digest@yahoogrou ps.com
> electricboats-fullfeatured@ yahoogroups. com
>
> <*> To unsubscribe from this group, send an email to:
> electricboats-unsubscribe@ yahoogroups. com
>
> <*> Your use of Yahoo! Groups is subject to:
> http://docs.yahoo.com/ info/terms/
>
Hotmail: Trusted email with Microsoft's powerful SPAM protection. Sign up now.
Mostly it's the overall size and weight of the package, chain drive can be built with 30 speeds (10r+3f sprockets) in a very light and compact package. A belt with the same power transfer abilities in a single speed, needs an assembly roughly the same size and weight as the chain drive for 10.
I put 400 miles a week on bicycles, and wouldn't think about a belt drive on any of mine (8 at last count), but feel cogged belts do make a lot of sense in a boat application where room is available (and gear changes aren't required or can easily use a gearbox). They are quieter and would last longer in a wet environment.
Only issue with a belt is that they have to be carefully sized, so replacements for each belt has to be carried, with chains as long as they have the same link size you can buy in bulk and cut your own. Belts are also not tolerant of alignment errors, a chain will handle errors that would shred a belt in minutes without a problem. (they will have slightly reduced life, and a bit more noise though)
Ken.
> To: electricboats@
> From: matthew@acfr.
> Date: Sat, 28 Nov 2009 06:18:56 +1100
> Subject: Re: [Electric Boats] Bearings and power transmission
>
> danbollinger wrote:
> > Cogged/synchronous belts are in the 96-99% efficiency range, so don't discount them. They are lighter, and don't need lubrication.
> >
> >
> Cyclists are still largely using chains and a mechanism to bodily rip
> the chain from one cog to another to change gear as the efficiency of
> the simple belt/chain transmission/
> The chain systems are in the high 90s% efficient. The hub gear systems
> tend to be some what lower - mid 80s to mid 90s% efficient.
> Like our e-boats, cyclists want maximum power transfer with the minimum
> of transmission losses.
>
>
>
> ------------
>
> Yahoo! Groups Links
>
> <*> To visit your group on the web, go to:
> http://groups.
>
> <*> Your email settings:
> Individual Email | Traditional
>
> <*> To change settings online go to:
> http://groups.
> (Yahoo! ID required)
>
> <*> To change settings via email:
> electricboats-
> electricboats-
>
> <*> To unsubscribe from this group, send an email to:
> electricboats-
>
> <*> Your use of Yahoo! Groups is subject to:
> http://docs.
>
Hotmail: Trusted email with Microsoft's powerful SPAM protection. Sign up now.
Chains are problematic in a boating environment since they need lubrication and they rust. There is not need to use shifters in a boat, so that feature is moot. And, at higher speeds, like running over a small motor sprocket, they generate noise. They aren't horrible, but they aren't ideal, either.
--- In electricboats@
>
> danbollinger wrote:
> > Cogged/synchronous belts are in the 96-99% efficiency range, so don't discount them. They are lighter, and don't need lubrication.
> >
> >
> Cyclists are still largely using chains and a mechanism to bodily rip
> the chain from one cog to another to change gear as the efficiency of
> the simple belt/chain transmission/
> The chain systems are in the high 90s% efficient. The hub gear systems
> tend to be some what lower - mid 80s to mid 90s% efficient.
> Like our e-boats, cyclists want maximum power transfer with the minimum
> of transmission losses.
>
danbollinger wrote:
> Cogged/synchronous belts are in the 96-99% efficiency range, so don't discount them. They are lighter, and don't need lubrication.
>
>
Cyclists are still largely using chains and a mechanism to bodily rip
the chain from one cog to another to change gear as the efficiency of
the simple belt/chain transmission/
The chain systems are in the high 90s% efficient. The hub gear systems
tend to be some what lower - mid 80s to mid 90s% efficient.
Like our e-boats, cyclists want maximum power transfer with the minimum
of transmission losses.
What is your budget? Mine was such that it included buying a Torqeedo with extra battery pack.
http://www.torqeedo
http://greenboatsup
--- In electricboats@
>
> Hi
> I have just joined this group and find the correcpondence very interesting.
> I am currently restoring a Drascombe Longboat which a-is a traditional sailing boat with grp hull.
> The boat is 22 foot long open design
> Length 21' 9"
> Beam 6' 7"
> Weight 880lbs (400kg)
> I would like to fit and electric drive unit and motor but don't know where to start.
> Not looking for speed just gentle cruising and good range between charges and of course budget is limeted.
> The boat will be dry sailed so charging at home is no problem.
> Any advice would be greatly appreciated.
> Regards
> Connel
>
Cogged/synchronous belts are in the 96-99% efficiency range, so don't discount them. They are lighter, and don't need lubrication.
--- In electricboats@
>
> David,
>
> The gearbox solution will deliver more power, more efficiently than any other solution. Helical gears are 97% efficient and seals account for losses of another percent. Gearboxes have an integral thrust bearing. The cast iron of the gearbox acts as a heat sink for the motor so the motor is capable of running longer at higher loads. There is no possibility of catching fingers or clothing like belts or chains can. Gear noise is minimal with slower turning motors and big slow turning propellors. Gearboxes can be mounted to a stainless plate and put back on the original motor mounts for accurate alignment. Split / Flex couplings offer alignment and make it easy to install.
>
> The greatest advantage of the industrial gearbox is the many different gear ratios. They are essential to be able to balance the system for optimum efficiency and power.
>
> James Lambden
>
> www.propulsionmarin
>
>
>
> ----- Original Message -----
> From: dennis wolfe
> To: electricboats@
> Sent: Wednesday, November 25, 2009 7:06 PM
> Subject: Re: [Electric Boats] Bearings and power transmission
>
>
>
>
> David,
>
> The flange mounted ball bearing has plenty of capacity to take the small thrust loads 6hp can generate and it has a spherical OD so will align itself with the prop shaft. The timing belt does not need a tensioner, just mill slots in the plate to slide the motor to create tension in the belt. The belt and pulley solution is lighter, cheaper and quieter than the gear solutions, plus you can change the ratio by substituting a new pulley and belt.
>
> You could use your existing gear box from the ICE too, if you can devise a way to couple the motor to its input shaft plus mount the gearbox to the boat. Not so simple.
>
> I think the al plate is a better mounting system - it is more rigid than plywood w/fiberglass, easier to make and won't crush under the bolt heads. You can machine 6061 aluminum with wood working tools, even cut it on a table saw with a carbide blade.
>
> Denny Wolfe
> www.wolfEboats.
>
>
> Message -----
> From: goldsmithfoil
> To: electricboats@
> Sent: Wednesday, November 25, 2009 8:54 PM
> Subject: [Electric Boats] Bearings and power transmission
>
>
>
> Hello group, I'm putting together an electric system for an Islander 32' using the MARS brushless set-up. I'm puzzling out the power transmission and motor mounts. First question is about the motor mounting. Looks like most people are using 1/2" AL to mount the motor and shaft bearings. Could heavily glassed ply be used in its place or does the AL acting as a heat sink make it a better choice?
>
> Second question is about power transmission. Seems there are three choices: use an existing marine transmission, use an industrial gear box, or set up something with belts and pulleys.
>
> I have the gear box from the diesel we pulled, I just worry about it being inefficient and not allowing the prop to spin the motor for regen. Anyone know how efficient small marine transmissions are whether it would be a good way to go? It would certainly be the easiest solution and the MARS motor runs at about the same RPM as the Yanmar did so the ratios should match up well.
>
> Second option is an industrial gear box like Propulsion Marine offers, this also looks like a good solution with a minimum of engineering involved.
>
> Third option, which I'm leaning toward is setting up a board with the motor and some pulleys to bring the speed down for the shaft. V-belt, chain, or timing belt? One thing I haven't seen anyone address is idlers or tensioners on the belts, there has to be some method of tensioning the belts. Are people just using a slot and leverage before bolting down like an alternator? I've seen spring loaded tensioners for timing belts that looked like a good solution.
>
> The other question I have is about thrust, a pulley and belt set up needs some sort of thrust bearing, do the flange bearings I see being used provide that function or is an additional bearing needed in the system? I'm new to the mechanics of power transmission, so I've got these questions.
>
> Thanks, I'm looking forward to some discussion on the mechanics of setting up such a system. I've got a good grasp on the electrics, charging, and battery systems, its just the mechanical part I still need some help with.
>
> Thanks,
> David
>
