Dominion 2-HW ,a Self-Righting Foiling RC Keelboat/ One-off Design & Build Project - Page 45 - RC Groups
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Feb 04, 2018, 02:27 PM
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DLord's Avatar

D2 Trapeze Power Ballast System


Got the glass pieces cut out and the carbon end pieces trimmed down. All that's left is some sanding, painting and assembly:








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Feb 06, 2018, 01:06 PM
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DLord's Avatar

D2 Trapeze Power Ballast System


Here is the ultra light D2 TPBS on the boat to illustrate the range it will have. The whole rack moves simultaneously with the cart that slides on the rack(containing lead ballast). "Trapeze" wires support each end of the rack as it moves very quickly outboard.
Another shot showing the comparison of the original D4Z rack with the D2 ultralight rack.
In addition to being the lightest version of this system I've ever built the D2 system is also the first 100% independent Trapeze Power Ballast System with its own battery and receiver with no connection to the boat receiver/battery. Uses the same transmitter as the boat system....






Last edited by DLord; Feb 06, 2018 at 01:19 PM.
Feb 06, 2018, 02:04 PM
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John Xman's Avatar

Got Questions?


Doug,
Looks great! Got a few questions because I am thinking of something similar on the AC-86.

1. How does the Rack attach to the cat?
2. will the Rack hinge along the center line?
3. How much weight in your Pod?
4. What drives the weight Pod and how fast will it move the full length of the Rack?
5. How is this controlled off your Transmitter?

Feel free to grab photos of older installs to answer the questions-
Great work!

John Xman
Feb 06, 2018, 05:08 PM
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DLord's Avatar

Trapeze Power Ballast System


Thanks John! Watch the video of the original D4Z version. On that version the module was wired into the boat system. On this version the PBS is independent with its own receiver and battery. On the original version the whole unit moved fore and aft-on the new one its fixed in a position that can be adjusted on shore. The original carried up to three pounds, the new version two pounds. The new version will have the module slightly off center where it was on the cl on the original. Note how the unit pivots about the fore and aft axis. The D4Z version was about 2-2.5 seconds from center to max out, the new version should be about 1.5-2 seconds center to max out. I use the left stick for side to side movement and put the sheets on a knob.
Sailing with one of these systems is the most fun you can have rc sailing with sailing(racing) with a spinnaker a close second! I couldn't afford a new winch so the one on the new system is the same one on the D4Z (17-18 years old, I think). A new 380 Guyatt winch would probably be 20% faster or more. The drum diameter can be adjusted to allow more line(and therefore speed) per revolution since the max ballast is less on the new system.

D4Z, an AC 4.8RC Class Prototype (3 min 32 sec)


D4Z Very Light Air-First Sail! (1 min 19 sec)
Last edited by DLord; Feb 06, 2018 at 09:00 PM.
Feb 06, 2018, 05:17 PM
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DLord's Avatar

Super Scow #1


This is one of the first versions of the system with the battery in the ballast cart back when all we had were ni-cads.Now the LiFe batteries are so powerful thats not necessary and a completely independent system is possible.



Feb 08, 2018, 02:26 PM
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DLord's Avatar

D2 Trapeze Power Ballast System


I cycled the transmitter battery over the last two days and wired a new connector to the small TPBS LiFe battery and charged all 3 LiFe batteries. Just have to wire up the TPBS winch and finish the module assembly. Lots of little detail including installing the F&A carbon tube on the boat and rigging the system-shoudn't take long if I can stay at it which isn't likely. But getting closer every day......
-----------------

These two shots show the maximum optimum angle of heel of the boat at minimum and maximum foil cant. Cant is the change in the angle of the foil athwartship(side to side).
At zero cant the max optimum angle of heel is 7.5 degrees. At 4.5 degrees cant, the maximum optimum angle of heel of the boat is 15 degrees.
In both images, the foil is adjusted for maximum altitude which is adjustable plus or minus about 2".



Feb 10, 2018, 08:43 PM
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DLord's Avatar

D2 Trapeze Power Ballast System


Lots of detailed work done yesterday and today. Assembled the tubes for the rack and guide wires and the fore and aft module support. The rack tubes and fore and aft tube were ground so that the tubes "snap-in" making the whole thing easily removable and easy to store. Tomorrow, if possible, I'll assemble the fore and aft tube to the boat-it can be done permanently because the module just snaps in place.
Bought some liquid electrical tape to fix a place I messed up by cutting the leads to the new battery connector too short-stuff works great!
Feb 11, 2018, 02:11 PM
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DLord's Avatar

D2 Trapeze Power Ballast System


Here's a shot of all the work done yesterday-tedious detailed stuff! Not a good shot of the module-all four sides are mostly covered with high gloss carbon sheet:

Feb 12, 2018, 08:07 PM
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DLord's Avatar

D2 Trapeze Power Ballast System


I was going to order a second LiFe 1300mah battery but with a "star" connector like the larger LiFe batteries have but so far I can't find one. And I'm still looking but haven't found a "star" connector any place. Any ideas? The 1300mah LiFe battery is about half the weight of the larger batteries and has all the capacity I need for now-and I can afford it now......
Feb 12, 2018, 09:43 PM
The wind is free, go sailing!
Scratchy101's Avatar
Star connector is supposed to be compatible with Deans connectors.
http://www.rcstarplug.com
Feb 13, 2018, 08:05 AM
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DLord's Avatar

Star Plug/Deans


Thanks, Scratchy!
Feb 14, 2018, 07:53 PM
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DLord's Avatar

D2 Trapeze Power Ballast System


Will test fit all the parts to the boat tomorrow, then do final painting of the module, then rig the system and its done. Pictures tomorrow....

UPDATE-----Got the F&A tube installed but no test fit until tomorrow which means no pix today...
Last edited by DLord; Feb 15, 2018 at 07:04 PM.
Feb 16, 2018, 11:35 AM
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D2 Trapeze Power Ballast System-Trial Fit / Pivot Range


You can see from the first two pictures the athwartship pivot range of the TPBS rack. The ends of the rack are supported by "trapeze" wires, the ends of which use line and a spring to allow the rack to pivot when the weight moves outboard. The spring keeps the rack level when the weight is near the center.
This allows the lee end of the rack to stay clear of the water and the weight to move lower as it moves outboard. The range is adjustable-the pictures show the maximum range.
For transport the System simply unclips from the F&A tube and unhooks from the two trapeze wires. No wires between the module and the boat since the TPBS has its own receiver and battery operating from the same transmitter as the rest of the boat.





Last edited by DLord; Feb 16, 2018 at 01:03 PM.
Yesterday, 03:57 PM
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D2 Trapeze Power Ballast System


Weighed the components of the system:
1-Ballast + cart= 16.1 oz(lead 14.75oz-50% capacity)
--
2-Module complete= 11.5oz( 380 winch= 4.8oz, 1300 mah LiFe lithium-iron battery=2.3oz, receiver= .35oz, balsa carbon/epoxy module box=4oz )
--
3-40.25" X 4.25" carbon rack(on which ballast slides) =1.5oz ; rack slides on module and is moved by 380 winch.
--
4-Est. rigging 1 oz
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5-Total weight at 50% capacity=30.1oz(1.9lb). Total weight at 100% capacity=44.85oz.(2.8lb)
==================
Again, the Trapeze Power Ballast System is 100% independent of the onboard rc system but uses the same transmitter.
Last edited by DLord; Yesterday at 04:03 PM.


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