J-Boat Ranger - Page 3 - RC Groups
Thread Tools
Jan 04, 2014, 09:26 AM
Registered User
200-300 oz/in for a rudder servo?

Heck yeah! Now we're talkin!
Sign up now
to remove ads between posts
Jan 04, 2014, 09:40 AM
Originally Posted by tbarjohn
Schrott, I talked to one of out club members today that has built several "J" boats, he said the you need somewhere from 200 to 300 in/oz toque, he said he would use a Hitec HS-7945TG ( http://www.servocity.com/html/hs-7955tg_servo.html ) and a set screw shaft coupler ( 525134 )
( http://www.servocity.com/html/set_sc..._coupler_.html ) you mount the servo upside down right above the rudder shaft ( no linkage to mess with ) if you go with this set up make sure that the spline is the same on servo as coupler, here's a pic of 1 of his J's
John R.
Thank you for that information. I already had made plans how to rout and what so ever the linkage, because of the very steep angle of the rudder shaft.
Never thought to mount the servo directly to the shaft, that solves a ton of problems..

Please say thank you to your friend for me.
Jan 04, 2014, 09:44 AM
Originally Posted by breakwater
200-300 oz/in for a rudder servo?

Heck yeah! Now we're talkin!
It takes a little to getting used to the dimension of the boat. A friend of mine builts 1:100 WW1 boats, some are as big as the rudder of the J and weigh as much with all rc stuff installed.
Jan 19, 2014, 04:10 PM
I am getting the rc-stuff installed.
Ruderservo came in, Little bastard, for being that strong.

For the RMG ein bent a U out of 3/32 Alu. The U gets bolted to the board in the hull. In the pulling direction I gave a gusset .
Since I have not decieded how many sails I will hand up front, I left myself an option for 2. I built 2 mounts for HS-785 winches. They are in front of the RGM and the room between them will be the place for the bat..
There will be enough room on the board for the receiver and a fusebox.
Jan 19, 2014, 04:12 PM
one more
Jan 23, 2014, 09:09 PM
As a fusebox I will use an automotive aux unit.. It has room for 6 fuses.
Mounting was rather easy, since Hillman Alu threaded post fit nicely through the mounting holes. The posts were slightly to long and I had to trim then down and than rework the threads.
On of switch and I decided to run the wires from the bat and switch through the bottom of the rc unit. Now I just have to built a distributer for the negative.
Than I glued the rc platform into the hull, PC7. makes a bit of a messy look, because of the black color.
Naturally I had to mount the winches, bat and fuse box, just to see how it looks in the hull. The empty mount is for further use.

Next will be the end blogs, wheels, for the winches.

In order to get a feel how much travel I need for the boom, I had to do some moth. That is not really what I like, grrrrrrrrrrrrrrrrrr.
The plan I have, that shows the rigging, is 3/16 = 1foot, yaiks.
First I had to get it all in tenth and than made a simple excel for inches and than to double check made it for mm, my prevered measurement. They checked out very nicely, 1/10 difference.
So for the inchies, the boom will be 48.8 and for the mmies 1240.
Next I have to check, if going scale for the lines makes sence, or if I will cheat.
I decided on 1 cheat, I will run the back stays, from the top of the mast and so far back that the boom and the sail will easily swing past them. No crew on board.
I have to make some preparation for the deck fittings of the stays. I plan to use the pekabe swiffels. They look beautifull and are rocksolid. Idea is to glue into the subdeck threaded studs, inside thread, so I can later screw the hardware, after planking etc, in.
I have to say, this built is a challenge, because every step has to be thought through. No manual.
I need to do the ballast. I might have already screwed up a little by glueing the rc platform in.
Jan 23, 2014, 09:13 PM
couple of snap shots from the rigging plan
Jan 28, 2014, 12:43 AM
Registered User
Originally Posted by Rssailor
What a major bummer. Build quality of the hull sounds like it was not that good. Hope the boat turns out. I have always been interested in J boats, but there are none that live out here in California that I am aware of. Ryan
There are some - the J Nationals in 2009 was in Sacramento that I attended and sailed some races in with the winning boat owned out of Pacifica.
Jan 28, 2014, 02:59 AM
Registered User

An interesting place to eat in Scotland

Maccallums Fish Bar Troon, a few years back I ended up storm bound in Troon Marina Scotland for a week. J Class fans might find a reason to visit for on the walls is some junk apparently cleared out of a local Boat builders drawing Office, a small scottish boatbuilder called Bill Fife?

It is hard to see in the photo but which J had a dented "Whale nose" sheer line?

The resturant is right at the end of the dock, it looks nothing from outside but this is the treasure inside. The food is execellent by the way

Last edited by Robert May; Jan 28, 2014 at 03:02 AM. Reason: bigger verson of photo available on trip advisor
Feb 04, 2014, 03:35 PM
Next I had to figure out how much travel the TMG would give. It turned out to be a healthy 40 inches. Now I could find out were I would go through the deck for the line.
Than I routed a soft alu pipe towards the winch line. I used an awl to oben up the ends trompet style to prevent shaffing.
Feb 04, 2014, 03:45 PM
Naturally I ran into a little problem with one of the supports of the ribs. The pull line of the winch was rubbing on it.
Before I started the cutting, I installed the lines for the jib winch, stroke of genius.
I really like to have a lot of support on that rib, it is part of the mast and stay system. There will be a lot of pressure and pull in that area.
But that support had to go and I replaced it with a set of small beams covered by 1/4 ply.
Feb 05, 2014, 09:44 AM
Registered User
Looks like the build is going very well. Your boat looks great. Ryan
Feb 13, 2014, 06:53 PM
Thanks Ryan.

I got some more work done on the subdeck. I got them all in except for the part around the mast and the ankers vor the stays.
That one has to wait till I got the ballast done. It will be easier to fit it, if I can do that through 2 large openings.
It will be in several parts, for easier removal, but the fiting will be a different thing.

I worked the plug today and it is smooth enough and painted that I can built the casting form tomorrow

One of the problems on the tub was the top edges.
Theu were badly rolled lots of large airbubles in the jell coat and so on.
To get a straight edge, I used a trick from dry walling, for the corners you got a special puty knife it has 2 blades in a 90 degree.
I used an Alu angel, aint a corner. It gave me a very nice edge. Still som spots that need some rework, but now I got a nice start.

Quick Reply

Thread Tools