ARTICULATED PADDLEWHEELS

[DCSmith]

Thank You For the link, it's been bookmarked. The water can get pretty shallow here, so paddle wheels are tempting. The used walking beam boats on these rivers at the turn of the last century.

[fredrosse]

Just finished 20 paddle floats, with the movement levers in place, and compound screw adjusters. These floats (nine on each wheel) will replace the original fourteen lunch trays cut in half for the non-articulated wheels of the Margaret S.

Interesting that this mechanism produces propulsion similar to a single 14 inch propeller turning at a few hundred RPM. Plenty more stuff in the water, and more work than I thought, although that is typical for me.

The compound screw adjusters are similar to a turnbuckle, but with right hand threads on both ends. These allow setting the distance between the nuts with some degree of precision. This is necessary to avoid the potential for binding on the main wheel pivots, which are screw threads. When welding the floats together, there is always some distortion in the weldment, and a misalignment of several thousandths of an inch can cause binding and friction. I need the mechanism to be a friction free as possible, this is one method of dealing with that.

[fredrosse]

After about 100 hours labor, the articulated wheels are in place. Lake Nockamixon Meet was the first trial, the wheels work well, and engine RPM (and output power) is up 16%. But now the boiler is falling short in steam supply capability, and I cannot hold 90 PSIG with full gear / full throttle. Time to add the feedwater heater, that should fix things just right.

The spider shaft mount plates are adjustable, to allow optimum placement of the offset. Once this position is worked out, these plates will be cut down to small oval shapes, and screwed in place permanently.

[Rainer]

Congratulations!

Next year you could join this parade in Dresden with proud...

http://www.youtube.com/watch?feature=pl ... T3s#t=132s

3 m diameter and 2.2 m wide paddels!
http://www.youtube.com/watch?feature=pl ... oOM#t=601s

[DetroiTug]

Fred, Those look good.. Yep, every time something is changed it effects something else.

I was supposed to take mine out today, but the weatherman screwed me up. Called for rain today and it never rained a drop..

-Ron

[fredrosse]

New articulated paddlewheels (also known as "Feathering floats") in the final configuration. This has performance about half way to the performance goal I had calculated: (Simple wheels, 52 RPM, Articulated Wheels, 64 RPM, Design Goal, 75 RPM). This is a good increase in performance, but some further adjustment is in order. This winter I will change the spider links to a little longer length, which is an adjustment that will make the paddles exit the water more vertically, and that should improve the performance a little more.

Picture shows final configuration, with new "Iron Wood" (IPE Wood) strakes that mount the spider bearings. Wow is that stuff Hard, Heavy, Stiff and Strong! At 69 pounds per cubic foot, it sinks in sea water.