Mississippi 1870 Build

[towboatjoe]

I used flanged bearings for r/c cars for my wheel and to build a realistic operating pitman drive.

EDIT: Found the updated drawing....

[Bill Hudson]

To be authentic the cranks on the paddele wheel need to be quartered. That is they need to be 90 degrees off set from each other.  I think this would be  kind of hard to do with a single motor on a single shaft.

[towboatjoe]

Not only authentic, but if they're not at 90 degree from one another it would create a dead spot and the pitmans would lock up. I noticed this was an old drawing i uploaded that did not show the 90 degree cranks for the pitmans. Somewhere I have misplaced the correct drawing, but this setup does work well with a single motor and the pitmans push back and forth.

[Eddy Matthews]

I can certainly vouch for the fact that Joes system works and allows for the arms to be quartered Bill. It does need to be built accurately as I'm sure he would agree...

Basically it takes the rotary motion of the motor and converts it to recipricating motion - The pitman arms are then attached to the recipricating output and the wheel at which point its converted back into rotary motion.... That made a lot more sense before I wrote it honest!

[Bill Hudson]

That made a lot more sense before I wrote it honest!  --------------------------- :music

[towboatjoe]

I'm glad you said it! HELP! I'm confused??

I found the updated drive drawing so edited the post on it.

[Bill Hudson]

I  have seen  that mechanism some where. Joe do you have it posted on another site?  I think that would really make the model stand out.  Add in valve eccentrics and Wow!

Richard. You really scored on that kit. Would loved  to have had it myself. Is teh hull plastic or did I miss something along the way?  I  still have to design  (and build) mine for the City of Eugene.  

Your boat is going to be a very nice looking one when done.

Bill

Edit:  Sorry about the misspelling etc.  My spell check isn't working and my club hands are really bad this morning. Can't get in  to see neuroligist untill next month.

[towboatjoe]

Bill, i have the drawing and photos in the miscellenous page on my web site http://www.towboatjoe.com/mscl_.htm

I could be somewhere else, I can't remember and things sure seem to have a way of getting around on the net.

[Bill Hudson]

Yep, that is where I saw it. was wracking my brain  to remember where. Wanted top post it here but you beat me  to it. :lol:  Some how I remembered two motors but  I see now how  you use the channel to make it work.  

Nice looking padeel wheeler. Unusal float arangement. Haven't seen  that style before.  

Bill

[towboatjoe]

Here's the helical wheel ofthe real boat. It's also referred to as a herribone design.

Now how about some more photos of the Mississippi build? :yeah

[bundyrap]

Hi All

And thanks for all the input :)

Building is progressing nicely. This is a well thought kit of a fine looking boat lacking only in the instructions. It is basically all there in the instruction sheet with some amusing translations - like most instructions it pays to read them well and understand what they intend before doing it your own way!

I've managed to make a split deck at the first deck level so everything above the lowerdeck will lift off to allow access to the workings. This has caused a few headaches with more to come trying to keep all the deck posts straight and in line.

Thanks for the diagrams and pics ToeBoatJoe. I've had a go at making a similar drive but friction and alignment issues has seen me take the simpler ( less pure - please don't shoot me! ) approach which works well in as far turning the wheel and looking good but the first water test has highlighted some real problems.

The first is with the rudders in front of the wheel -  it just doesn't steer going forwards at all and this was with the top decks off and a large lump of lead along with battery to bring it down to it's water line. Backwards was good even with the breeze blowing but forwards the rudders might as well not have been there.

Second problem is the amount water shipped into the engine room while under way. Reverse was really bad nearly drowning the rudder servo in very short time.

This is a lovely looking boat and a great fun build but I don't want to end up with a show pony. I'm sure there are answers to these running challenges.

My  current thinking is to make a split wheel and have a form of 'tractor' steering similar to my Al Khubar tug which will turn on the spot with it's 2 engines run through a mixer. This would mean running each half of the wheel via a pulley and having dummy pitman rods because they just look so good doing their thing.

Any ideas??

Thanks Guys
Richard

[towboatjoe]

The real vessels had the same problem with steering which is the reason for inventing monkey rudders.
The way they would steer is with the current. They would drift into a bend and reverse the wheel to swing the stern into the turn.

[mjt60a]

One possible solution would be to make the rudders reach deeper below the hull, it doesn't look too good if you display the model on a stand (between sailings) and they could catch on things in shallow water, but it should help.
I've seen on some models where the owner has made detatchable extensions for the rudders which clip on for sailing and are removed for display/transportation, but I don't know how it was done  :?

[derekwarner_decoy]

Hi PD's - TBJ.... what is the typical arc of rudder movement for stern wheelers :?: .... we have read by 'Ronald Parsons'... 'that many OZ paddlers could bring the rudder 90 degrees to the vessel axis'... but this was to shorten the vessel when in a "Lock"

When we think the axis of a rudder divides the flow path of water equally...one half of flow is un impeaded & wants to propel the vessel in the direction of flow, & the rudder accepts the half of the water flow and bounces the flow back off the rudder face at a 90 degree included angle..... :rant ... & the result is the turning motion...not rocket science but  thinking - and having said this Richard you could consider a similar concept  - Derek

[bundyrap]

Hi All
 
I've been playing with the rudder shape and yep it makes an enormous difference even with just one rudder modified. The one in the pic is just a 'concept' version after talking about the best shape with a yachtie mate and it really does work well.  
 
Cutting it from clear polycarbonate on the CNC machine and painting just the original shape somewhat hides the extension. A folding extension is certainly another option. Any thoughts on what might be the best ideal shape and balance area in front of the pivot?
 
Bottom line is steering is very fixable with a deeper rudder and is just a matter of deciding on the least obtrusive looking method. Working the angles more will also be another area to look at Derek. 90 degrees will take some doing but I'll see how much I can get.
 
My next project will be a 16th scale PS Adelaide. 90 degree rudder travel should be easier to organize there and with a motor per wheel mixed electronically, steering I hope will not be such a problem.
 
Hey Derek do you know any details of the 2 paddlers built for Expo 88 in Brisbane? They are the Kookaburra Queens I & II and now work as restaurant  and tourist boats on the Brisbane river. I hope to get down and get to go on them early in the new year but would love to find some drawings of them. They have a beautiful hull shape and would make a fine pair of models.
 
Richard