#4 3 years ago

Kitshack 28” RTTL false keel

Hi Colin and Dr John

Thanks for the responses, have decided to dispense with the false keel completely.

Have to admit my PhD was in ship control systems, and as part of that I worked on a 6 degree of freedom mathematical model of ship dynamics, my excuse it was nearly 30 years ago. I looked at the work recently and couldn’t cope with the matrix manipulation so have decided to go down the aesthetic route rather than over think the issue.

If it looks right it should work, I’ll take the pragmatic approach, if the boat yaws I’ll add a small keel until it stops! Glad you’ve both reinforced my thinking.

Liked by dave976 and Colin H and

#3 3 years ago

Kitshack 28” RTTL false keel

Hi Neil,

As Colin suggests, it should be possible to reduce the size of the keel substantially; and as you say this should make your model more realistic.

Just ensure you have the motor and battery right at the bottom of the hull and keep the weight of the cabin superstructure to an absolute minimum -- all to reduce swaying and yawing

After all, in the unlikely event that the model is still unstable, - it should be an easy job to add additional wood to restore the kit designer's original intentions.

Good luck - I still have to complete my Veron RTTL I bought right back in 1974!!

Dr John F. Leeds Bradford BBC. 🤞🤞🤞

Liked by dave976 and Colin H and

#2 3 years ago

Kitshack 28” RTTL false keel

Totally agree shipmate, I had the same feeling about mine a few years ago, so cut the keel down along the taper and it looked OK and performed well.
The blue line on the picture shows where I cut it back to, sorry can't post a photo as no longer own the model.
Cheers Colin.

Fair winds and calm waters,
COLIN.

Liked by dave976 and neilw and

#1 3 years ago

Kitshack 28” RTTL false keel

Now I’ve got the hull of the RTTL nearly sorted I’m thinking about fitting the prop shaft. The Veron build instructions, and as I understand it the Kitshack instructions, state that the false keel is required as the prototype boat yawed too much so the keel was added to prevent this.

Have to say I hate this keel, none of the other Vosper boats I own have this fitted and it really is out of scale. You can see in the pic that it does dominate the hull.

I suspect that the yawing was caused by displacement from the Taycol motor fitted in the original plans (ironic that I now have one with another boat) and a lead acid battery. The rudder is fitted too far aft and the prop shaft is at 16 degrees, so I doubt the prop wash will provide much pressure for the rudder so yawing would occur with the ratchet set rudder

I’m considering not fitting the over sized keel and just using a P bracket to support the shaft set at a shallower angle and to use a larger rudder than suggested and move it forwards.

I know there is an incredible amount of knowledge and experience in this group so would welcome opinions on dispensing with the keel.

Liked by dave976 and jbkiwi and

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Kitshack 28” RTTL false keel

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Kitshack 28” RTTL false keel

Kitshack 28” RTTL false keel

Kitshack 28” RTTL false keel

Kitshack 28” RTTL false keel