Materials for paddles and drives

[Brian_F]

Hi PD’s,
Having decided to build another paddler, I thought I would build the paddles and drive first, to get the difficult bits out of the way.  I’ve selected George Baker’s Chieftain paddles and drive (per Model Boats, December 1977, pgs 702 – 705, and plan MM1244, which I ‘rescued’ from the loft over Easter), except scaled by 1.25 to give an outer diameter of 175 mm, (versus the 150 mm as drawn).

However, I nearly had a heart attack when pricing up 1.5 mm brass sheet – quoted at £18.40 per square foot.  So I was thinking of making the outer rings out of aluminium sheet – only £6.40 per square foot - along with the paddles, but retain brass for the spokes, hub, paddle brackets, feathering rods, etc.

Any thoughts from PD’s experts out there whether this would a wise decision?

I guess I will have another heart attack when I request a price for the Muffett precision brass gears used in George’s design.

Has anybody purchased a set of these gears recently?

Any lower cost alternatives?
(I have a pair of Monoperm pile motors in ‘stock’ from a previous model – so I won’t get another shock there!)

Thanks in advance for any advice.

Brian.

[Stuart Badger]

Brian!

1.5mm brass is far too heavy in my opinion for paddle wheel rims. Virtually all of the load on a paddle wheel is at right angles to the 'thickness' of the material - so you can get away with using 0.5mm brass or even thinner easily. In fact, from personal experience I would suggest investigating the possibility of using plasticard for the wheel rims, floats and supports and only using brass for the actuating arms etc. There really is no need to indulge in 'Victorian heavy engineering!'

I think we all tend to vastly overestimate the strength of materials needed for certain tasks, and don't forget with any paddle steamer model keeping the paddle wheels light in weight is essential.
Stuart

[Eddy Matthews]

I agree with Stuart.... It's amazing how flimsy the materials can be for paddlewheels - Once they are assembled their strength is unbelievable!  Sort of reminds me of an eggshell.... it will support the weight of a person when the load is applied in the right direction!

Eddy

[derekwarner_decoy]

Hi PD's ....& welcome Brian.......your question of paddle wheel material & also paddle wheel kits is a well documented topic...Stuart Badger completed a resounding example with his wheels for PT Reliant ....others have faulted ....others have fallen into LARGE VOIDS ... myself included

As you note.....

1) the cost of 1.5 mm sheet brass is certainly not inexpensive
2) there are proprietary manufactured wheel kits that provide grossly over scale individual components ie.,  3 mm diameter bolt thread -  I mean @ 1:24 scale = a 3" diameter shank bolt with an 8" AF nut 
3) I have purchased one of the kits & have retained all of the 3.0 mm S/S screws.....the balance will end up in the scrap bin  ...
4) I question the use of aluminium & brass unless you use one of the new age composite metal soldering flux/metal treatments 
5) to produce a full wheel set yourself ....you need access & experience to a small lathe ....near minimum + conventional workshop grinder/drill/sander/linisher etc

So as an alternate I have purchased a 'styrene' wheel kit...& as usual have requested my specialist engineering co from Crewe UK to manufacture a few non standard bits

You may think this small engineering project strange ........ ...buy an OZ kit in OZ.......& then get someone 20,000 km away to  the bits?.....but it always results in  pieces.......thanks Bandit.......

Please read into the following link.....they have 175 mm diameter wheel kits as standard although clearly are not feathering................Derek   

http://www.floataboat.com.au/Newsletters/2009/FAB%20N_letter%20Mar%2009.pdf

[Brian_F]

Thanks Guys for all the replies.  Very useful.  My model of a Director tug proved a disaster through ‘over heavy engineering’.  But later stern wheeler and a quarter wheeler were OK.

My workshop includes a Myford Super 7, vertical mill, etc., - the standard kit for a model engineer - so do not mind starting from raw materials.

I am due to holiday in Australia over the coming Christmas/New Year, so may have a chance to pick-up some bits.   

Brian.

[bill stafford]

gday folks ,
out here in melbourne , blokes are doing paddle wheels in ALL aluminium , bolted together w 2 mm s/steel bolts , or loctite glued together .
 also the plastic wheels of barrys are a very good alternative , a set of paddles in a afternoon !!
regards bill s

[Eddy Matthews]

also the plastic wheels of barrys are a very good alternative , a set of paddles in a afternoon !!
regards bill s

I couldn't agree more Bill - I got a set of Barry's wheels last year for my model of the Sir William Wallace, and I was very happy with them.  Extremely simple to put together, and saved me days of work!

Regards
Eddy

[sandystrone]

All my paddle wheels have been made in aluminium,1/16" for the frames and about .040" for the blades.
I wanted thin blades as they could be sacrificial because the biggest enemy of a model paddler on our lake are lollipop sticks getting into the paddles.

[bill stafford]

all you guys using aluminium to make paddle wheels out of , how do you attach bits ?? i am using araldite , slow dry , wit, so far , good results , but is there a better way ??most of my spokes are a bit fine to bolt on bits
any help , thanks bill stafford

[R.G.Y.]

Bill I use rivets, made from small nails. After inserting in the hole cut off with side cutters, Then gently  tap with a toffee hammer. Geoff