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[Trucker]

Hi, All
Im looking into using belt drive from motor to prop shaft, mainly because theres a lack of space under the shafts and the flat bottom hull of my build to have the motor and shaft inline, after a frustrating afternoon trying to find whats available for boats im asking you guys can you point me to a supplier and advise me to what knowlege i need to arm my self with in order to get the right bits.


Trucker

[Colin Bishop]

Technobots has a good selection of belt drive components.

https://www.technobotsonline.com/

Belt drive has a lot going for it. It is easy to install and quiet and it offers the opportunity to gear down the motor for greater efficiency.

You don't have to use toothed belts. 'O' Rings work well as long as they are not pulled too far out of shape,

Colin

[Trucker]

Thanks Colin
Thats a great site, im going to look into it deeper tomorrow once ive got the dimension and requirements of the motor shafts.


Trucker

[GG]

Trucker,
         Might be worth looking at "Pulley Power" in the Tutorials section?


Glynn Guest

[tonyH]

Look up HPC Gears Ltd. They make excellent pulleys and very fine toothed belts plus loads of other stuff www.hpcgears.com and certainly get one of their catalogues

[Trucker]

Thank you very much gents for all your input, theres certainly food for thought, the links were both good and some surprising with cost,


Trucker

[nemesis]

PM sent, nemesis

[Fastelectrics]

Have a look on Ebay for GT2 belts and pulleys.

[Adam]

Unless you have a very small boat I would always go for timing belts, not O-rings.

You have to put too much tension on O-rings to keep them from slipping.
Not good for your engine bearings and your propeller shaft bearings

https://www.maedler.nl/

[Colin Bishop]

You have to put too much tension on O-rings to keep them from slipping.
Not good for your engine bearings and your propeller shaft bearings

I wouldn't altogether agree with that, most of my boats have smooth belt drive including this one at 48 inches. It's a matter of getting the tension right and not much is needed. You would have to do a lot of sailing to unduly wear the bearings.

Colin

[Ralph]

I run my Slipway Yorkshireman with 600 motors on a 3:1 reduction using O rings (4 blade 45mm props, 6v supply to 12v motors).  When I made the pulleys I machined a "V" section into them rather than a "U" which would have matched the cross section of the O rings.  I think the V section gives a better grip on the O ring and I've certainly never had any problems.  Having said that, my rowing boat uses a tooth belt drive (ex RC car).


Ralph

[Tug Fanatic]

I wouldn't altogether agree with that, most of my boats have smooth belt drive including this one at 48 inches. It's a matter of getting the tension right and not much is needed. You would have to do a lot of sailing to unduly wear the bearings.

Colin

Colin

Are you confusing O-ring drive with belt drive. I have had a number of models powered with O-rings and yes if they have any power you do need real tension on the belts. The last tug that I built with O-rings had 3 for each motor. I have never had a motor problem which I guess is due to the heavy duty motors that I use but I have always been very careful to lubricate the top shaft bearing.

Belt drives work without much tension, and thus bearing wear, and are very preferable in my opinion. 

[Colin Bishop]

It is very easy to put too much tension on an 'O' ring as the smaller and thicker they are the more they resist being pulled out of shape. This makes it more difficult to find the sweet spot. I have in fact used both 'O' rings and conventional smooth belts such as those that are found in electromechanical equipment such as record players etc. The small diameter 'O' rings, such as 1.5mm, are actually very flexible and suitable for small models. I provided for double pulleys in my Fishery Cruiser but found that only single belts were needed (see below) these were 2.5mm diameter. I should point out that the Fishery Cruiser is easily driven with quite small props and only draws 2.5 amps at normal speed despite being 48 inches long. If I were building a big tug with a large prop then I would certainly look at timing belts as a lot more power is being delivered.

In a different context the 2nd image below shows 2.5mm nitrile 'O' rings in the final drive of my paddler. These are 85mm and 65mm overall diameter.

Colin

[SailorGreg]

Another source that I have used in the past is Motionco. Very good selection of bits and good service.
Greg

[Colin Bishop]

Yes, some of the bits for the paddler came from Motionco

Colin

[John W E]

Hi there,


Has anyone mentioned MFA Como Drills for their belts and pulleys?   I have used these a few times and also used them when I built the paddle tug Forceful.   Seem to remember they were very quick posting them to me, next day sort of thing.

[Trucker]

this is really interesting for me to read through again, it highlights to me that tension seems to play a big part in having success, so, how about having adjustable legs for the motor once mounted, im thinking a brass bolt on each corner which can be locked off using another nut.


Trucker

[Colin Bishop]

One way of doing it is to mount the motors so they can be slid sideways to alter the tension (as in the Fishery Cruiser) and tightened in the correct position. If you look carefully at my paddle steamer photo above you can see black 'strips' under the motors. These are 'Makerbeams'

https://www.technobotsonline.com/makerbeam.html

They are slotted bars which accept captive nuts so that items (such as motors) can be screwed down on to them and adjusted by sliding if needed. On my paddler I have used them in a fore and aft configuration but there is nothing to stop you mounting  them across the hull so the motors can be tightened down in the right place. The photo below shows my paddler motor mounting in detail. You can see that the motor mount is tightend down onto the Makerbeams which are glued to a wooden base attached to the hull. Clever stuff!

Colin

[Circlip]

Strange how long it's taken for the toy trade to emulate an industrial standard for motor adjustment. The'll be re re inventing ball and socket drive couplings soon.


  Regards  Ian