WARNING TO PADDLEDUCKS..THIS IS ANOTHER LENGTHY PJ POST! Go get a
coffee (or better still a cocktail!)
--- In Paddleducks@y..., MikeDD656@a... wrote:
> I worked in metal packaging for over 20 years and have never seen a
> 'galvanized' tin can. Rather they are tinplated steel cans that will
> rust in a heartbeat. Not a good construction material for boats.
>
> MikeDD656@a...
Hi Derek:
I hear what Mike says loud and clear, and there are a number of
alternatives to tin, such as (my favourite material) STYRENE..which
doesn't ROT or RUST...and is LIGHT and easy to form and glue. And
cutting it is literally a SNAP!
Go to a sign store and ask them if they have any offcuts of thin
styrene sheet in their rubbish dumpster (I have got loads of the
stuff this way). This material is very stable can be rolled and
shaped with gentle heat, and the adhesive little more than ya common
or garden lacquer thinner.
For very thin styrene, I use those "for sale/for rent" plastic signs
you see in the office supply store..however you can find a large
sheet from an Industrial plastics store, which will provide a
lifetime supply.
Styrene is my favourite material for building paddlewheels as well.
I know that Dave (Powell) up here in Victoria has used a combination
of plexi and styrene for the very "torquy" paddle wheels he's put on
his sidewheeler "Talisman". He has come up with a novel design
which, although it doesn't replicate the original, is strong and easy
to construct. I just phoned him and have asked him to post drawings
and description of the sidewheels he made for "Tally"!!
There are many experienced sidewheel Paddleducks who I'm sure will
have comments and improvements on what I write here and KEN from
Paddlewheels UK, who really knows his sidewheelers, has just
completed what sounds like a gorgeous sidewheeler which I'm going to
tell you about in another post. Ken, may we have a few more details
on Sidewheeler "STADT ZURICH" and particularly any info on the
paddlewheel construction?
In the meanwhile here are "PJ's 10 STEPS to PERFECT SIDE PADDLES!
(Now remember I've only done this ONCE before, folks!)
The key to good wheels is to start with a clearly drawn plan of them
at scale. If you havn't already done so, Derek, take your compass,
scribe a 7" circle and start drawing!!!
1) Draw your outside wheel diameter with a compass and determine what
diameter hub axle you are going to use
2) Draw your hub and radiating spokes, often 8. Remember spokes are
sometimes cambered in feathering wheels, but it's not necessary as
most of this detail is hidden either in paddle boxes or below the
water. It's only relevant if you either want to ACCURATELY replicate
a prototype wheel or are making a display only model.
3) Determine the shape of your paddle blades (called floats). Will
they be flat or concave? I've tested both and I'm convinced that
concave floats DO make a difference to thrust performance (in
forward) but are a little more complicated to attach to the wheels.
Mind you even a small lip glued at 45 degrees to the top edge of a
flat float helps quite a bit to "deflect" water down into the paddle
rather than letting it escape over the top.
Easiest way is to glue flat floats transversally across the thrust
edges of the spokes. However, if you want added efficiency and a
really nice "look", consider concave shaped floats mounted through
supports and tie rods. Again, not difficult to create out of styrene.
Although it might also improve for'ard thrust in a sternwheeler, I
don't think their floats were concave (TJ?) and it would be a mistake
to fashion them incorrectly as, unlike a sidewheeler, a STERNWHEEL is
a very VISIBLE part of the model.
4) Once you have designed your wheel on paper, photocopy it FOUR
times. Using lo-tac contact spray adhesive, stick each wheel plan
onto your choice of material.
From an efficiency/weight standpoint, I really do think styrene is
the answer, although it COULD be 1/16 up to 1/8 ply. (BTW styrene is
a breeze to laminate up to the required thickness and becomes
immensely strong.) I don't need to tell you WHY brass (although
beautiful) is a little dodgy for making paddlewheels, unless you have
REALLY figured out your overall weight and prepared to make mods to
the hull in the event the boat floats too low. But I DO KNOW some
brilliant fully operating feathering wheels on LARGE paddlers are made
from brass, I've seen 'em! It really IS a question of weight (as Derek
has now found out first hand)
5) Now cut out the four discs. (If you're using styrene then use
the OLFA circle cutter which makes cutting styrene discs out VERY
EASY!) Lay them on top of each other (clamp if necessary) and drill
the centres to correspond to your axle diameter. Find a bolt which
matches the axle diameter you've drilled. Snug the discs up together
on the bolt with a couple of outside washers and a nut leaving enough
of the bolt to provide a shaft to chuck into the drill. These discs
eventually become the paddle rings (hoops) for your wheels...2 for
each wheel and the supports for your floats.
6) With the four discs chucked tight together on the drill, rotate
them slowly increasing the speed. Check for concentricity...they
should NOT wobble up and down at all nor have any high spots. If
they do, get out some 330 grade sandpaper and start carefully taking
the wows out of the circumferences. OH ya have a LATHE? ..then put
the drill away!!!!!!
7)You now have 4 IDENTICAL concentric discs with a plan stuck to
each, so lock yaself away for a week and start cutting and profiling
each wheel hoop according to the plan stuck to it. When you have
carefully rough cut all the spaces between the spokes, bolt them
together again, matching up the spaces and spokes. Secure them with a
small C clamp with small wasteboards either side to stop the hoops
from moving. IMPORTANT - Mark a point on the EDGE of the four hoops
so they always register properly whenever you unbolt them and so when
you eventually attach the floats to them, the hoops will all line up
again correctly.
Now begins the work of finishing the spokes and inner rings
accurately. With all the hoops still bolted and clamped you can use
a selection of fine modeling files and emery boards to match them
perfectly. The key is ...each hoop MUST be indentical. Because the
4 hhops are clamped there will be far less danger of breakage as you
file them. Make sure the common registration mark is always visible.
9) Now determine the width and area of each float and make one for
each pair of spokes. You have to now decide on the lateral distance
beteen the hoops which support the floats and make a spacing jig so
the lateral spacing between the hoops is always constant.
Note: some Side paddlers (British ones) have the hoops spaced fairly
close together, so the blades really do stick out quite a ways each
side of them (looks neat!). There are a number of variations but I
have NEVER seen hoops supporting the"ENDS" (outer extremity)of the
float. I'm not saying it never happenned, but I have seen sidewheels
done this way and, out of the water, they look a little strange in my
opinion. Check your proto reference carefully for the correct hoop
spacing.
10) Make a spacing jig to fit between the hoops (couple of small
block of wood does fine). Place the axle through the hub and line up
the spokes carefully at the previously mentioned registration point.
Alternating at opposite sides of the wheel, attach your floats
carefully to each pair of hoops making sure there is always a 90
degree angle between the floats, hoops and axles and that the spacer
is snug in place. If you don't get this right, youll notice an
unmistakable WOW when the wheels turn! Everything MUST BE CONCENTRIC
and SQUARE to give smooth spin.
Voila! Wait for the glue to dry (I prefer 5 min epoxy) and then spin
the wheels on axles to make sure they're running true. Because of the
relatively slow revs of the paddlewheels (and the fact on a
sidewheeler they're hidden) a LITTLE BIT of WOW is tolerable! (I dint
say ACCEPTABLE!!!)
Now dress the wheels up and decorate them with rivets and gussets,
paint em, weather them, rust streak 'em and whatever else will make
'em look great when you lift the ship out of the water. If you're
not worried about super detailing, then forget it and just drill the
shaft holes through the hull, install engine(s) and drive train...and
LET'S GO PADDLIN!
There are a number of different ways of building paddlewheels and
each modeler will have their own favorite method. However, I
eventually found a great way of making identical rims quickly...and
which is what I have ultimately used on my "Director".
From just ONE 1/8" thick profiled paddle hoop, a RTV rubber mould was
made and four identical hoops cast in urethane. Each hoop was
laminated with very thin styrene sheet (next time rivets will be
embossed in them) and styrene strip glued as a "tyre" around the
circumference. Strong, light, easy to reproduce if I need more.
Some people prefer to construct each hoop using one plan as a
template. It doesn't matter how you build 'em so long as they don't
wobble (too much!) on their axles.
Ok...hope this all helps, coz I know some of you are a little
intimidated by making paddle wheels...they take time..but OH
Man..they're worth it!!!
PJ
Main Menu
UserBox
Search
