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Author Topic: A Baltimore Clipper schooner  (Read 12630 times)

JerryTodd

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Re: A Baltimore Clipper schooner
« Reply #25 on: May 24, 2019, 04:36:30 pm »

Took all three models to a Model Expo at the Chesapeake Bay Maritime Museum on the 18thPride actually free-sailed for the first time!


JerryTodd

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Re: A Baltimore Clipper schooner
« Reply #26 on: June 23, 2022, 06:12:54 am »

  My friend Mark sailed his 46 inch schooner Cliodhna (Clee-na) for the first time in the pool at National Maritime Day (May 2022).

He controls the sails with a sort of clothes-line system driven by a winch.  A common system in RC sailing models, especially schooners, and what I originally intended to use in Pride.
The winch drives a closed loop and the sails' sheets are attached at points so the loop's travel pulls the sheets the requisite length for each sail.  Mark used one loop to control the over-lapping jibs, and the other loop controls all the rest of the sails (the ones with booms basically).
 Watching this work so well in the pool, especially with the over-lapping jib, I started rethinking Pride's set-up - again.
 cliodhna.png.5b0f925dc0338c35021ad5a4b41b874f.png  cliodhna_sheets.png.2827518bdd6f063b60e55bbeb7b5cb96.png
 I could finish this model if I could work out the controls, and what I was working on I don't think was going to work.  Sometimes the first idea winds up being the best idea, with some adjustment,
 First off; I already plan to remove the motor.  There's no way that that 1 inch prop is going to move all that sail in even against the slightest breeze.  The motor will go to the upgrade of my rope-walk.
 With the motor gone, the Rudder servo can be moved aft to where the motor was, closer to the rudder and the receiver, so I won't need an extension cable.
 Two winch servos with be re-mounted just forward of the rudder servo, and the other end of their loops with be at the forward end of the main hatch, just behind the foremast. This should get me enough length to control everything, even, I hope, the square tops'l.
 pri20220622newplan.thumb.png.d67f1078f6d3acb537229d5978252889.png
 Another step towards getting this girl in the water is the arrival of 50 pounds of lead shot.  Now to gather the materials and courage to cast a lead bulb.
 

JerryTodd

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Re: A Baltimore Clipper schooner
« Reply #27 on: June 26, 2022, 08:47:10 am »

Everything but the prop shaft's been pulled out, and some changes were made in the plan...
The rudder servo gets moved a little further aft so I can access the screw that hold the arm through the cabin hatch, and putting it in or out, if the need arises, will be easier.
The winches will be mounted opposing each other; one aft where the motor used to be accessible via the Engine Room hatch with it's loop running to the foremast.  The other winch just aft of the foremast, accessible via the main hatch with it's loop running around the aft winch.  The makes the system narrower and easier to deal with though the hatches.
I printed a test gun for Macedonian a little while back, and sat it on Pride, just to see.  It looks perfect, or darn close.
I thought I had a pair of winch servos around here somewhere, but I haven't turned them up yet.  I have to mount the rudder servo and work up fairleads for the steering lines.  Then make up servo trays for the winches that include a pair of sheaves for turning the opposing loop, which means 3D modeling and printing some sheaves for all that.  I also need to determine the size and shape of the lead bulb.

I'm starting to think Pride may actually sail this summer.

JerryTodd

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Re: A Baltimore Clipper schooner
« Reply #28 on: June 28, 2022, 02:34:43 am »

I pulled out the prop shaft and cut back the stuffing box tube, plugging it with epoxy.
I fit two beams for where the rudder servo would be put, and assembled them into a frame that was epoxied in as a single piece.
Next come the turning blocks for the steering lines, and making mounts for the winches.

PICKETBOAT

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Re: A Baltimore Clipper schooner
« Reply #29 on: July 02, 2022, 03:16:38 pm »

Looks very good and you seem to have all the potential problems covered.


If the control loop for the rudder will be running though eye rings (and there is nothing wrong with this) I found with my models that using light weight fishing line worked better than cord. It creates less friction, its less visible (therefore smaller eye rings can be used) and does not wear and fray. Running the line through very small lengths of copper tube where it ends at the servo arm meant that when adjusted to length the copper tube could be crimped flat with pliers securing the nylon without having to tie knots in it.


I have assorted sailing models that have been working for years with this method and all have been maintenance free.


Keep up the good work

JerryTodd

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Re: A Baltimore Clipper schooner
« Reply #30 on: July 02, 2022, 11:12:49 pm »

(FYI: I can't get the attached images into the body of the post, and they don't open full-size when you click on them.  In Firefox, I right-click the image and "open in a new tab" to see them full size without leaving the post)Constellation's steering lines run through screw eyes and have given me no problems at all.  Pride, on the other hand, is a bit more complicated.  The lines run to the sides, turn to s-shaped tube fairleads that direct them 90 and up through the deck so they come out on either side of the lazarette hatch.  On deck they will run through functional blocks in the waterways.  I'll be using Dacron line I walked from 3 strands of sail-tread (I used off-the-shelf Nylon line in Constellation).   That bit of tubing at the lazarette is the big friction machine, so to reduce it as much as possible I'll be putting functional blocks in the hull where the line makes it's first turn from the arm to the lazarette.
When testing the braces on Constellation, I hadn't walked any of the aforementioned Dacron line I was going to use, and used some cotton cord I had on hand instead.  There's a few eyes under Constellation's deck to guide the braces from the winches to where they come through the deck.  There was so much friction the system wouldn't function, the winches wouldn't budge at all!  In a panic, I hurriedly walked out some 12 foot lengths of Dacron and rigged it up.  It ran flawlessly and has since.
Mean-while, back at the ranch...

I pulled out the old servo-tray that was on the trunk for the fin, and reseated the main-mast step.  Made a pair of trays for the winches from 3/16" luan plywood and painted them yellow, because I had a can of red and a can of yellow spray paint, and I can't paint everything red.  ;)
The old motor bulkhead was extended up to carry the aft winch tray, the blocks I put in when the rudder servo was forward were repurposed to carry the forward winch.
I 3D printed four copies of a pulley wheel I found on Thingiverse and re-scaled to 1 inch (25mm) to be the idlers for the loops.  They're mounted on the little blocks you see on the trays with #8x1" wood screws with a brass washer under each.

I rigged up the loops for testing, but I need to sort out the radio gear I haven't touched in a while, and charge everything up.  I measured that I have roughly 20 inches (50+cm) of travel on the loop which is much better than I was getting the first try (see: http://todd.mainecav.org/model/pride/model09.html )

The picture looking down at the model shows what access will look like with the deck on and the hatches open.
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