Maiden voyage

[Tony Mattson]

Finally a break in the weather long enough to allow a short sail
yesterday for Reliant, her first decent voyage on the pond.

She's a tad underpowered at the moment, at around 70-80 rmp at high
speed, so I'll play around with the pulley ratios to lift the output.
Other than that she seems a happy ship.

She's taken 800g of lead flashing on the floor of the engine room for
some quick and easy ballast, but once the topsides are completed
that'll be replaced with some lead shot a bit lower down in the
bilges.

I've posted a couple of snaps to my photo folder - kiwi paddler/PT
Reliant. Plenty to do yet tho'!

One happy paddler
Auckland, NZ

[Derek Warner]

H Tony - she looks great - the third snap 'turning on the spot' suggests
you have installed the independent motors & mixers etc from our friends
in the UK - my test bench out of water trials with these electronic
modules have been inconclusive & any more than say 15 degrees of rudder
offset appear to have a reversal of one motor which is out of wrack with
Decoy as she also has a BIG barn door rudder

Any comments either way on this would be greatly appreciated

I was also interested to note your comments of 70>80 RPM as being a
little underpowered - from memory you used a scale copy of but non
feathering version of the actual paddles - I cannot tell from your
snaps, but at the current top paddle RPM, do the paddles create a lot of
splash & wash? - or is it a case of just gently Bentley with the
throttle until the vessel is under way?

Another point of interest is the total model weight [from a
transportability & lifting issue]

regards Derek

[Paulrjordan]

CONGRATULATIONS..Tony!

She looks great...very smart in the water and appears to throw a very
nice wake from her wheels indicating they're dipping correctly. Isn't
it fun watching her spin in her own length like the real one did all
those years ago!

> She's a tad underpowered at the moment, at around 70-80 rmp at high
> speed, so I'll play around with the pulley ratios to lift the
> output.

Yes this happens at 70-80 rpm in a smaller scale model. 60 rpm was
around the prototype revs but since you can't scale water you need to
turn quite a bit quicker. My experience with scale floats (blades)
is you need around 120 rpm to get a decent turn of speed although
it's a little overscale at full stick. The other way is to cheat a
little and run overscale floats and I found the percentage increase
in float area pretty well gave a corresponding increase in speed up
to hull speed. Mind you, once you reach displacement hull speed
there's little point in increasing thrust as additional power will be
wasted.

How is she on the turns? Hopefully she's not "sticking down one
side" or rolling. Did you vent the paddleboxes?

> Other than that she seems a happy ship.

And a great looker too!

> She's taken 800g of lead flashing on the floor of the engine room
> or some quick and easy ballast, but once the topsides are
> completed that'll be replaced with some lead shot a bit lower down
> in the bilges.

Yes, low C of G will make her good and stiff in the water. Looks
like you have a winner, Tony. Thanks for posting the pics. So many
of us get a real kick from seeing our fellow members' models develop
and eventually deliver a satisfying performance. It's a triumph we
all share and enjoy. Keep us posted.

Regards

PJ
Victoria, BC Canada

[Tony Mattson]

Derek has written:

<<the third snap 'turning on the spot' suggests you have installed the independent motors & mixers etc from our friends in the UK - my test bench out of water trials with these electronic modules have been inconclusive & any more than say 15 degrees of rudder offset appear to have a reversal of one motor which is out of wrack with Decoy as she also has a BIG barn door rudder>>

Hi Derek, I trust all is well with you.

I have tried both the electronic motor mixer and direct control of each motor thru Tx joysticks (the caterpillar drive approach). I've found the electronic mixer to be a little inconclusive as well but the independent paddle directions suit my purposes. My motor set-up is also pictured in the folder and with this set-up one motor is always running in reverse when under way. I haven't measured the rpms under forward and reverse but suspect that the motors run somewhat slower in reverse than when going in their normal direction. So what I'm finding is greater thrust off one side than the other, likely due to more rpms off one side than the other - this can be adjusted through the Tx slides but requires a fair bit of bias on the rudder slide.

Performance under 'caterpiller drive' is not as biassed so I feel the mixer is playing a part in this. I still need to run a multimeter over each side to check whether there are any voltage differentials between the two circuits so mustn't jump to conclusions yet.


<80 RPM as being a little underpowered - from memory you used a scale copy of but non feathering version of the actual paddles - I cannot tell from your snaps, but at the current top paddle RPM, do the paddles create a lot of splash & wash? - or is it a case of just gently Bentley with the throttle until the vessel is under way?>>

I've used the Graupner feathering paddles, so the paddles are in scale and feathering (but not scratch built). With full power forward I'm getting a little bit of splash and wash on starting, but certainly not a surge of power. As with the multimeter, I need to go 'scientific', check my rpms, trial a couple of different drive pulley sizes and evaluate the results. The feathering wheels certainly leave a very smooth wake and don't scoop water upwards on exiting, so I'm pleased with those at least.

<<Another point of interest is the total model weight [from a transportability & lifting issue] >>

Total weight I think will be around 12kgs if I remember my calcs. Need to reconfirm this.

Lifting from the water proved to be a wee bit awkward as our pond has a boardwalk that is a foot above the water surface, so I may develop some sort of lifting strops or cradle. And with a stand the same the overall width as the model is across the sponsons, this makes carrying from my basement workshop upstairs and out to the car, etc., an interesting adventure (as no doubt other PDers have found!). At least it's only 1:32 scale, and not a 1:24 'Old Trafford' or a 1:12 scale 'Pert' or 'Cracker'!

Will post progress as and when I can make some!

cheers for now
Tony
Auckland, NZ

[Tony Mattson]

Hi Paul,

grateful thanks for the comments - I am a newbie paddler who is absolutely delighted with the results of the hard labour and am constantly reminded that without PaddleDuck resources on the case things could be very different!

The paddle boxes are indeed vented and there's no rolling from side to side on the turn but I do want to up the tempo a bit to that 120 rpm target which may change things a little.

Having reread yesterday's response to Derek, I realised my weight estimate was way out - don't know what I was thinking when I wrote 12kgs - at that rate I should have the world's first side paddle submarine! (Now there's an interesting challenge!!)

Weight should have read 7.6kgs.

Kind regards and will update photos as more work is completed topsides.

Tony
Auckland, NZ