Maximum Driveshaft Angle??

[Terry Heddin]

I am working on my 1/5 scale unlimited hydroplane. This is an older kit that was originally designed for a belt driven prop shaft. I have included a couple pics of the belt drive from the build manual. As a result, the shaft is too close to floor of the boat to connect to the engine, without flexing the shaft. If I raise the shaft to make a good smooth shot to the engine, it will increase the shaft angle in relation to the bottom of the boat. What is a safe angle for the shaft and strut without affecting how the boat runs? Is there a max angle?

 

[Mike Hughes]

I would lose that hard shaft and strut. You will want to have an adjustable strut with a 1/4 flex cable for that setup. It gives you so much more options on trying to get that boat to run well. Ideally the strut should be flat with the riding surface. There are tons of prop available that are setup to run parallel with the ride. With that much angle you just going blow the back out of the water and thing will hop. What is your budget on this build? I think I saw you say you were thinking gas. A moded 30+ Zenoah should get it moving reasonably. I could help you with how it should be setup. I would need some numbers. If you want, you can call me and I can walk you through it on the phone. PM me if interested.
Mike

 

[Terry Heddin]

The holes and such have already been cut for this setup, so I want to use it for now. Turns out there is about 5/16: space between the floor and bottom of the of the hull, so I can cut a small triangle for the starter end (front?) of the motor to let it drop about 3/16".
I have a G260 to try, and then I may upgrade all the hardware to a flex shaft and larger engine. Hoping a G320 will scoot it pretty good. Not racing, just playing.

 

[Mike Hughes]

Anyone that has ever been to my shop will tell you, I aint afraid of any holes or making them. That is an easy patch to cover those up. It is much easier to do that work now. You might have an issue with mounting that PUM260 at the location. Don mention that in another post. I also find it much easier to get the alignment to the shaft perfect on a motor when you start with the motor first. You will need something custom to get that motor to line up with the shaft. I dont know of any universals in the size of 1/4 that would hold up to a gas motor. Good luck.
Mike

 

[Roxyflash]

I’m with Mike that angle at the prop is going to cause running issues.I would pull the drive line out all of it including the strut then put a piece of 11/32 tubing for the new drive line it needs to come out just past of the slot then you can slide a piece of 5/16 tube in the 11/32 stuffing tube the 5/16 will slide into a standard strut which I would mount on transom.Use a 1/4 flex shaft.

 

[Tom Foley]

Twin inline and 5/16" shaft in that big puppy. Single 260 won't cut it .