Calypso motor and ballast queries

[Colin BishopModerator @colinbishop34627]

There is another little trick worth remembering in that because water is (usually) transparent you can float the model just below the indicated waterline and it will still look OK, especially when moving through the waves when the waterline will still be exposed along around 50% of the length of the model anyway. This gives you a little more margin for ballast and extra stability.

Colin

[Nick LewisParticipant @nicklewis66033]

That's definitely worth remembering! Thanks.

Nick

[BRYAN ASTONParticipant @bryanaston57723]

Nick

My calypso floats in the bath on the correct waterline, according to the paintwork existing on the hull. I did not try it out on the lake this weekend because the weather was terrible and I am only a fair weather sailor, and I have not sorted out the rudder linkage yet.

Regards Bryan

[Nick LewisParticipant @nicklewis66033]

No great pleasure in sailing boats in the rain, I'd have thought…

How is your rudder linkage organised?

The plans with Calypso show a single link from the rudder servo to one rudder (starboard, from memory), then a link from that to operate the port rudder.

But most, if not actually all, of the pictures I've found of other people's setups show direct links to each rudder from either side of the servo arm. Which I think is what I would have done instinctively.

I was just wondering what the pros and cons of each approach are?

Nick

[BRYAN ASTONParticipant @bryanaston57723]

Nick

My rudders are linked together and connected to the servo arm by one wire ,unfortunately the wire that links the two rudders together snapped ,why I don't know, Because the rudders are hidden under the rear deck I cannot get my tiny hands far enough under the deck to reconnect a replacement link yet but I will persist

Normally rudders are connected by two separate rods to the servo but that would be too easy.

Have a nice day

Bryan

[Nick LewisParticipant @nicklewis66033]

Bryan,

Yes, that sounds like the arrangement shown on the plan. Something more robust needed by the sound of it.

I don't have small hands by any stretch of the imagination, so I don't want to build in problems!

Nick

[Nick LewisParticipant @nicklewis66033]

Hi All,

Apologies for resurrecting this very old thread, but, as the OP, I felt entitled.

My Calypso build stopped stopped shortly after my last post. First, work intervened, and then serious eyesight problems. Bothe of which have come and gone in the intervening nine years. The eyesight problems in particular have precluded taking on any large and fiddly modelling projects, so I have been dabbling in other things.

But my last op has finally returned my sight to a level where I can think about Calypso again. Fingers firmly crossed when I say that!

So I thought I’d say “hello” again, and perhaps turn this into a build thread.

Right now, I’m grappling with what RC controls to fit. I had grandiose ideas about lighting, sound, bow thruster, etc. etc. But I’m also inclining towards a minimalist throttle and rudder. I want to actually finish this someday and see her sailing!

Nick

[Richard SimpsonParticipant @richardsimpson88330]

Sorry to hear about your challenges Nick, but pleased to hear that things are at least improving.  Looking forward to seeing some progress on the Calypso now.

Just a thought on the above, lighting has to be considered throughout the build as it is almost always integral to the structure.  It is significantly more challenging to add it afterwards, although I have done it a couple of times.  Sound on the other hand is fairly straightforward to add at a later date.  Perhaps the most basic of a lighting installation could be worth considering during the build that could be expanded on at a later date?

[Colin BishopModerator @colinbishop34627]

Good to have you back Nick. I have lost an eye myself in the meantime with two 1:150 scale scratch build liners on the stocks so I can appreciate the way you feel. I put them to one side while I built a couple of other boats to larger scales but am now back on on one of the liners with some success.Takes longer and some new techniques needed though.

Colin

[Nick LewisParticipant @nicklewis66033]

Hi Richard,

I take your point about the lighting. I’ll give it some thought.

I suppose a “basic lighting installation” would be the basic nav lights – port & starboard, stern and steaming?

I’ve more or less dumped the idea of a bow thruster – to be true to scale it would have to be in the observation chamber at the bow and I think that the only way of making the mechanism available for servicing would be to fit the motor through into the main hull bow compartment. Not what I’d prefer to do!

Nick

[Nick LewisParticipant @nicklewis66033]

Hi Colin,

Sorry to hear about your loss of an eye. I’ve not completely lost the sight of an eye at any stage, but there have been a couple of occasions when the sight of one eye or the other was so bad that I had little or no binocular vision in practice. Bad enough in the “real world” but in modelling it was a major, major challenge.

[Nick Lewis]

On Nick Lewis Said:

I suppose a “basic lighting installation” would be the basic nav lights – port & starboard, stern and steaming?

 

That’s the sort of thing I had in mind Nick.  Lights on masts that require wires inside the mast and bridge nav lights are all a bit trickier and easier to install during construction.  Cabin lights and deck lights can be far more easily added at a later date if necessary.

[Nick LewisParticipant @nicklewis66033]

Well, I’ve made a small amount of progress. I’ve refreshed my memory about all teh bits and how I’d filed them, fixed some vacform together, and trimmed the aft of the equipment deck slightly so the prop shafts fit. They didn’t before…

I have also put some lead shot ballast in. Which brings me to a question, referring back to how I started this thread.

I’ve fitted about half of the ballast I calculate I need, divided more or less equally into three locations: two amidships, one each side of the keel, and the bow. All of these locations are going to be difficult to access once the boat is built.

The amidships locations next to impossible.

What would people do now? Part of me is saying “put the rest in, and crack on”, and part is conscious that it’ll be little short of a miracle if doing that results in a properly trimmed boat when all is finished.

How do people approach this?

Nick

P.S. I decide to follow Richard’s advice and fit basic lighting.

 

 

[Colin BishopModerator @colinbishop34627]

Nick, you are right to stop and think at this stage. Calypso is notoriously prone to instability with insufficient ballast and too much topweight so you really do need to be able to some trimming when the model is complete. If you have already got 50% of the projected ballast installed then the fact that the remainder can only go in at the ends won’t make much difference as long is it is centered and low down enough.

Can you modify the model to allow ballast to be added more easily or maybe use flexible ballast in the form of steel shot in plastic bags etc.?

Colin

Edit: I see there is a small hatch on the foredeck. Can this be made removable with part of the hull boxed in underneath so that steel shot could be poured in followed by resin to fix it in place?

[Nick LewisParticipant @nicklewis66033]

Thanks, Colin.

I’ll have a look into the hatch idea. I don’t see why not – I don’t think there’s anything under the foredeck.

I’m sure I saw build pictures where someone had built hatches into the equipment deck, but they are going to be awkward to site without fouling spots where motors and equipment need to go. Not the end of the world, admittedly, but it’d complicate fine trimming.

Nick

 

[Colin BishopModerator @colinbishop34627]

As a last resort, it is possible to add ballast to the bottom of the hull where it will do most good and is effectively invisible. I used self adhesive motorcycle wheel balance weights on my Bilsdale paddler and Ashley has also added under hull ballast on some of his models.

Sometimes there just isn’t enough ‘inside’ to accommodate the required weight!

Colin

[ashley needhamParticipant @ashleyneedham69188]

I can thoughrouly (?) Recommend putting ballast as Colin suggested under the hull. It is not seen, even on the stand, and is in exactly the right place.

As a person who makes unusual models I would NEVER fully ballast a model until I had a try out on the pond. You don’t sometimes know how it is going to trim out under power, even if it’s a kit. By all.means put ballast in, but dont glue it in place until you have tested it!

Ashley

[Nick LewisParticipant @nicklewis66033]

Me again.

Thanks for the advice everyone. I get the message, and it’s rather as I suspected. Have a plan for final ballasting to allow all-up trimming.

I’ve been doing some building – mainly planking the main deck, and will post some pictures as soon as I can get round to it.

Meanwhile, I have another question…Sorry!

I have bought the pieces to construct Double Cardan joints between the motors and prop shafts. I.e. two red plastic UJ’s for each shaft with the appropriate brass inserts and couplers. I gather that is the best way to obtain smooth running. Can anyone advise me/give me a steer as to how much misalignment such an arrangement will tolerate both laterally and angularly? If I simply attach the motors to the equipment deck, there’ll be what I’d guess would be a about a 5mm vertical misalignment and about a 15° angular misalignment. Horizontal alignment should be good.

Do I need to mount the motors on some sort of wedge or will this be taken up?

Nick

[ashley needhamParticipant @ashleyneedham69188]

Nick. A double coupling should cope with that, however if you can get it a bit better that would be good.

Possibly you might get some vibration with the issues as stated at higher revs

My HMS Manchester has double couplings as I have changed the motors several times as the years have gone by, and there is a considerable mis-alignment, but no issues…and they are quite smooth.

Ashley

[Nick LewisParticipant @nicklewis66033]

Thanks, Ashley.

I suppose it shouldn’t come as a big surprise that “doing it properly” is the best course of action…

I’ll look into creating a suitable mount.

Nick

 

[ashley needhamParticipant @ashleyneedham69188]

Alternatively,  I have bought thick- walled silicone tubing…6mm internal diameter, 3mm walls and this is a good tight push fit on the brass splines, to replace the ujs. It’s good when retrofitting mounts and so on as you can cut the tube and make the coupling the length you want it to be rather than being constrained by the standard uj length. I would not make the tube to be as long as a double coupling however as I think that long an unsupported tube may whip a bit and it won’t take up a very large angular difference.

Ashley

[Nick LewisParticipant @nicklewis66033]

It probably would whip  at the length the UJs come to.

I measured the angular difference more accurately at 11º, which was a bit less than I thought but thevertical displacement was quite a lot worse at about 8mm.

I’ll press on with making a mount. I have the UJ bits now anyway.

I’ve just noticed your avatar/pic. Fantastic. I’m assuming you’ve built a Stingray. Pics anywhere?

Nick

 

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