Belt driven outboard

[Michael Lewis]

Does any one remember who made the belt driven outboard? If I'm not mistaken it was composite. I'm not sure but I think it was MRP. would like to find one because it had a lower c/g. I would like to try converting a bullit drive or something comparable for fast electrics. Any pics or the part would be very helpful.
Thanks
Michael

 

[Grimracer]

The ABC tunnel! I had one.. some time ago now.. VERY EARLY Horizon Distributing sold that if I remember right.

 

[Michael Lewis]

Thanks Grim, appreciate the info. And your right it was some time ago. I guess I'm getting really old lol.
Michael

 

[Wasted wages]

Hey Michael,

Joern Markset has a lot of nice stuff for gear driven outboards...I would contact him to see if he can help you out,, his machine work is top notch..

 

[Michael Lewis]

Thanks Frank, missed your post yesterday.
I'll have to get with him. It's something that I've been thinking about for a bit . Instead of the electric motor straight up and the adapter adding to that height why not mount it on its side with a gear and a belt to a ball bearing supported stubshaft keeping the c/g very low.
I don't know sounds crazy but who knows lol.
Michael

 

[Brandon Atwell]

@Kris Flynn , got a picture of that unit Sam worked up with the belt drive?

 

[Daniel's Racing]

Remember those weird things.

Engine with crank facing forward with pulley. The front of the prop shaft had another pulley.

 

[Kris Flynn]

PMP I think it was called (Stark) made the first bet drive unit I have seen...it had a vertical, upsidedown motor.


This will be the MRP unit you are talking about
https://www.worthpoint.com/worthopedia/rc-boat-motor-nitro-s-max-abc-hobby-496648159
Sam Smith has developed his own Belt drive setup which mounts to his Stealth lower units...I will find some pics of that setup, or he will add them here I am sure

 

[Christian Lucas]

Hi,
have one from ABC , converted to electric , early AVEOX brushless motor . Runs good but you need a tunnelski in front of the belt gear of the propshaft to keep the water away from it. Otherwiese it will shovel a big rooster from the belt an a second from the propeller. Than you have a big show but less performance. There was also a full scale belt driven outbord with Ople (GM) engine.
Have fun.

Happy Amps Christian

 

[Michael Lewis]

Christian, yes that's exactly what I was looking for! I saw one on a tunnel many, many years ago and I like the fact that it has a much lower c/g than any standard electric setup. And yes kris that was the same place I found it.
Would also like to see the Sam Smith design you speak of. I would really like to see something like this engineered in aluminum. The composites were OK but for racing I don't believe that they would hold up to well.
If I was an engineer I would be at the table designing something for the fast electrics.
Unfortunately I'm not, hell I can't even draw a good stick man lol.
Michael

 

[Christian Lucas]

Hi,
glad to surprise you . With only one belt the c.g. can be lower.
, i will show you some ideas later.

Happy Amps Christian

 

[Michael Lewis]

Would appreciate it Christian. I'd like to see what you've got!

Thanks
Michael

 

[Christian Lucas]

Hi Michael,

some crazy ideas to build outborder motors.
You see the pictueres with the twin motor and twin propeller outborder. As the contra rotating propellers the skeg fin can benvery small as the propwalk force is zero.
The outrunner motor with the gear is also a futur project. The 2:1 gear will rise rpm to moore comon rpm in modelboating.
Other is the twin contrarotating twin on the Prather tunnelboat.
Very strange is the blue OS outrunner motor with the big propellerwheel. This is like a gear up to higher rpm. But the bigger hub will place the propellerblade so fahr outside where they become high speed propellerblade . This is a something like gear up ratio 2,5 : 1 , so when the motor spins 40000 rpm the propellerblade with the bigger hub will rise the Propshaft speed up to 1000000 rpm. with easy.

Happy Amps Christian

 

[Michael Lewis]

Wow Christian that's some wild looking drives!!! As far as the overdrive system I don't think I would want to be anywhere near it when it spooled up lol.
I know years ago the full scale hydroplanes used overdrive to get the rpm needed. But the had to go to smaller props. An overdrive could be awesome in the right boat like a hydro...
Years ago we would gear down to spin bigger props and more pitch.
With today's motors you don't have to but I still think a 30 or 40 thousand rpm motor geared to 20 to 25 at the prop might work...
The twins look good and like you say you eliminate prop tork. I would still like to see an aluminum lower setup like the composite one you have. It could even be geared up or down to suit different people or boats.
Some cool stuff you guys are working on.

Michael