Flying Project

[Laiky]

Snowmobiles. jet skiis, and dirt bikes. Maybe a used Kart engine? Industrial snow blower? I would try craigslist and e-bay, maybe a jetski or snowmobile board similar to this.

http://minneapolis.craigslist.org/rvs/790439780.html

[burninbriar]

Absolutely interested in pictures of this project !!!

I was checking out my cousin's kids dirt bikes. They tell me all the new dirt bikes are 4 cycle dew to emissions but they seem to be really light weight now days.

[monte55]

I have been figuring and machining a lot lately. The project I am working on...I have no plans..or specs. All I have to go on is some external views (pics). No drawing what so ever. I had to figure out how to make the inside pieces, such as bearing housings, bearing retainers, spacers, bronze bearings etc. Hope it works

The following pictures show the progress of the counter rotating rotor head unit. Remember, this has one rotor above the other, rotating in opposite directions so as not to have rotor torque problems, which would require a tail rotor. I'm sure the mechanically inclined will be able to decipher these pics and the reasons for certain parts. The tapered bearings are the inside bearings on a front axle for an 87 Dodge 3/4 ton Van. The spider gears are out of the same year van. I needed a place to start and I had these spider gears and since I wanted a 1 inch rotor shaft.........after inquiring about the tapered bearings for the same vehichle, it looked like it would work and it did. I also asked you guys your thoughts on a good two stroke engine for this project and got a few suggestions. Sitting in my drive is a 1977 440 CC modified Kawasaki jetski which may be ideal for what I want. Here are the first set of pics.

[monte55]

More pics:

Thanks for looking,
Nick

[burninbriar]

If I'm seeing this correctly, I see one potential problem.
The spider gear is normally a relatively motionless gear, now it will be spinning at a high rate of speed on bushings rather than bearings.

[monte55]

The two small bevel gears rode on a steel shaft.....no bearings, when they were in the rear end. The bushings you see are made from oil impregnated bronze. I bought a 6.5" long x 1" diameter at a cost of about $19.00. Expensive! Anyway they should work and are easily made and replaceable.
I've never machined this stuff before. It oozes oil as you cut it.
We'll see later how it all works.
Nick

[burninbriar]

Its kind of hard to tell what represents what in the pics so far, but it would seem to me that the gear box needs to be under both propellers with a bevel gear on the bottom connected to the inner rotor shaft turning the top propeller and the bevel gear on the top connected to the lower propeller. The spider gears would have to be mounted to the gear box itself to insure the props spin at the same speed but in opposite directions.
Does this come close to describing your plan?

[burninbriar]

It kind of looks like you have the gear box between the propellers. With out a way of controlling the position of the spider gears, I don't see how you can control the speed of the props in relation to each other. In other words, if the gear box is floating between the props every thing could turn in the same direction regardless of the spider gears.

[monte55]

It kind of looks like you have the gear box between the propellers. With out a way of controlling the position of the spider gears, I don't see how you can control the speed of the props in relation to each other. In other words, if the gear box is floating between the props every thing could turn in the same direction regardless of the spider gears.

I have a good mechanical mind but this also had me stumped for about an hour of looking at the pics I had.
First.........the 1" rotor shaft is stationary and does not rotate. The bottom 6" diameter x 5/8" thick round plate which a sprocket will be attached to, to be driven by the engine, the 1/4" x 4" flat aluminum piece, the 3" diameter x 2" tall round aluminum piece with bearings inside, another 1/4" x 4" flat aluminum piece, a 3" round diameter x 1" piece which the lower bevel gear is pinned to all move as one unit. The two smaller bevel gears above are stationary in a level plane but will spin and a 3/8" bolt will hold them on the non rotating shaft. Idler gears if you will.
Second......The top larger bevel gear and all the duplicate pieces for the top rotor blade mount will also move as a single unit around the stationary shaft.
It's very simple but difficult to imagine when we think a rotor shaft must turn.
Does this help? Like I said, I had a problem with this at first.
Nick

[burninbriar]

Makes perfect sense now. I don't think the sprocket is pictured, or at least I don't remember it. Basically you have the inner shaft serving the purpose for the spider gears as I was thinking the gear case housing would do if the inner shaft spun. I didn't realize the inner shaft was to be stationary.
Will the spiders be able to ride in oil when its done, or will they remain exposed?