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Old Apr 15, 2012, 05:59 AM
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seefest's Avatar
United States, MA, Bristol
Joined Sep 2009
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Balance is acheived by float tests. The A3 should float with the bottom of the transom just kissing the water.
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Old Apr 20, 2012, 11:11 AM
I DS slower than I build!
Cory's Avatar
Idaho Falls
Joined Jul 2006
2,348 Posts
I sprayed down the longer section of the twisted mast with a 50/50 mix of household ammonia and water and clamped it into a steal channel to dry. This should do a good job of taking the twist and warp out of the mast.
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Old May 27, 2012, 06:56 AM
benndave
Ontario, Canada
Joined Jul 2007
82 Posts
Another A3 build here

Hello and thanks for posting your build. I recieved an A3 for a gift and am trying to get it together. Your pictures and discussions are filling in a lot of the blanks I am wondering about. You really are covering all the bases well and don't leave much room for suggested improvements. Victor's Soling kit has gone to a solid rudder shaft as this gets bumped quite often, the tube bends easier. I am soldering the rudder tube with next size down brass until it is solid.
My question is about keel placement. Looking at the side view the keel seems to me to be well behind the center of effort in the sail plan, and as such will have a lot of Lee Helm. I am considering moving the keel forward to where the keel front edge is under the mast. Any thoughts on this? How does it compare to your other 1Meter boat's fin and bulb keel?
My other change was to continue the transon line to the deck and cut off the square step on the back. A sheet of polystryne will cover the transon for a long raked look. I just am not a fan of the way it was done in the kit.
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Old May 27, 2012, 02:12 PM
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Dick L.'s Avatar
Minnesota, USA
Joined Aug 2002
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Cory - dump the mast, and don't spend any time on it. If you (or friend/relative) have access to a table say - buy best quality straight grain pine (1x4) and rip off one edge of length which will give you the 3/4 x whatever size thickness you want x 65 inches in length. If you can find straight grained Sitka spruce up your way, even better.

For the Victor boats I have built, I run a thin plywood table-saw blade to cut a groove on trailing edge of mast. I insert the metal screw eyes and then run some SS wire the length of the mast. The wire sits just inside the groove. Sew on some bra hooks to the luff of the main sail and you will have enough "play" in the wire to allow you to hook the bra hooks onto the wire. Once you release the wire, it will pull the luff (leading edge) of the main into the groove. As far as shaping the mast blank, you can simply round all edges, or you can get fancy with a foil shape.

I would also highly recommend West System Epoxy for all building a gluing needs. Only caution is to add some glass to run down sides of the keel box, and onto the the hull to add stiffness and remove flex from the keel box. With 4-5 lbs. of lead on even an 11 inch keel, there will be a lot of torsional twist when boat heels to one side or the other.

Good luck with the build, Dick
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Old May 27, 2012, 11:42 PM
I DS slower than I build!
Cory's Avatar
Idaho Falls
Joined Jul 2006
2,348 Posts
Good thought about the rudder shaft, benndave. I'll drop a solid rod into the tube and lightly solder it at the top. I can't do more than that since it's already installed in the polystyrene rudder. I don't know about your "lee helm" question. I understand the basics of the issue but do not have any practical experience. Since others such as Seefest didn't mention it I'm assuming that it's not a problem; that the available adjustment in the rake of the mast is enough to trim the boat to neutral helm.

I'd like to see some photos of your modified transom. I'm not changing mine, but throwing in other ideas here for other builders is fine by me.


Dick, I got the mast pretty straight. It's certainly not very stiff. I was going to laminate some carbon tow onto all for sides to stiffen it up. I don't think that will add much weight and I already own it.

As far as glassing the keel trunk to the hull, I probably should have done that, but I did use a fillet of West's G-Flex mixed with milled glass and cabosil. I probably would have gotten the best effect if I made the fillet of slightly larger radius and had used chopped strand glass too. I wonder how hard it will be to prep it for a layer of glass. The G-Flex seems like it would sand like a hockey puck...which I've never sanded but doesn't seem like it would be easy. It just seems to be cured but slightly rubbery as I would expect of something with -Flex in the name.

Dick's point of the possibility of the keel trunk cracking loose brings up something I had forgotten to ask. Since this is a pleasure craft that will not be raced but will be captained by myself and my young daughters, what do you with experience think about flotation? I could easily add pink Owen's Corning foam insulation or I could make an air bladder out of painter's drop cloth using a similar technique to that used to make inflation bladders for fuselage molding here.
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Old May 28, 2012, 01:46 PM
benndave
Ontario, Canada
Joined Jul 2007
82 Posts
Mock-up Transon A3

Mast rake will certainly balance the boat, so I will go with that for now.
I mocked up the transon with paper to get you the photo you requested. I have only gotten ready to build it, but no glue has been stuck down yet.
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Old May 29, 2012, 01:35 PM
benndave
Ontario, Canada
Joined Jul 2007
82 Posts
A3 Mods

Cory, you were wondering about strength arround the keel box. You have your own way, but I will show you how I do it with plywood. It is a lot of work, but is very strong. Two wood strips with blind nuts between the bulkhead and gussets are not shown, you can see the cap screws in the other picture, giving four hold downs for the radio board. At the back you can see the cross brace and gussets at the rudder. For flotation we use the large bubble, bubble wrap. Roll it up and shove it into the bow. This stuff is very light. The aluminum at the right side in the picture is the jib-sheet turn-around. Both sheets anchor at the rear bulkhead.
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Old May 29, 2012, 03:27 PM
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seefest's Avatar
United States, MA, Bristol
Joined Sep 2009
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Quote:
Originally Posted by benndave View Post
Mast rake will certainly balance the boat, so I will go with that for now.
I mocked up the transon with paper to get you the photo you requested. I have only gotten ready to build it, but no glue has been stuck down yet.
That is a HUGE improvement in looks over the stock stepped transom. Nice work, wish I had done that to my A3.
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Old May 29, 2012, 03:40 PM
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United States, MA, Bristol
Joined Sep 2009
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Concerning the reinforcing of the keel trunk in the boat: its really not necessary.

I built my A3 about 10 years ago and the stock keel trunk is still going strong. All I did was put a fillet of thickened West System epoxy around the trunk and it has stayed put.

Since my first build, I have "turboed" my A3 with taller carbon fathead rig supporting about 1000 square inches of sail area, as well as a US1M spec 14 inch carbon keel fin and lead bulb which produces alot more righting moment than the stock fin and bulb.

I had to modify the top of the stock trunk slightly but, it's still only held in with WS. With the increased righting moment I get very little/no flexing of the hull in the trunk area.

I really think flotation is unecessary as well. The A3 is a relatively dry boat and the only way you will sink her is to leave the hatch off on a windy day. Flotation will just trap moisture where you want it the least, in the ends of the boat.
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Old May 30, 2012, 02:06 PM
benndave
Ontario, Canada
Joined Jul 2007
82 Posts
Thanks SEEFEST

Glad you like the raked transon. It is reasuring to know your keel box hasn't moved all these years. As usual I'm overdoing things again. I like your comment about trapping water with flotation stuffed in. I tend to agree with you. By "we" I meant the club members that worry about sinking. I don't use any myself. I should give Cory's thread back to him and start hounding him for more pictures. Have you made any further progress, I'm intently watching to see more.
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Old Jun 03, 2012, 11:30 PM
I DS slower than I build!
Cory's Avatar
Idaho Falls
Joined Jul 2006
2,348 Posts
No, I haven't made any progress. I was hoping to have it in the water in May, but I became a Scoutmaster in late April and that and some family campouts has tied up a very large portion of my free time. Hopefully I can get something done soon.

I'm happy to see the ideas of others. I'm a little unsure on how to rig the boat inside the hull. I was thinking of either doing it like this: http://onemetre.net/Build/Drums/ShtLines.gif,

or like this except for seperate, essentially identical lines coming off each side of the drum: http://onemetre.net/Build/Drums/ShtLoopo.gif
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Old Jul 01, 2012, 11:46 AM
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Joined Jul 2012
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Hey

My dad bought me the America3 kit a couple weeks ago and we've been having some trouble with wrapping our heads around a few things... (this thread has helped a bunch) however.. this thread stopped right where I need help...

we're wondering how/ where to mount the board with the servos/receiver. we're also wondering what servo we should buy.

If someone out there has finished the America3 could take a picture looking down the access hole it would be a massive help!

Please help!
Chris
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Old Jul 01, 2012, 03:50 PM
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Chris I'll send you some pixs when I get home. Mike
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Old Jul 01, 2012, 04:07 PM
I DS slower than I build!
Cory's Avatar
Idaho Falls
Joined Jul 2006
2,348 Posts
The thread isn't really stopped...it's just delayed a bit. I'm usually a slow builder anyway, and then on top of that I became a Scout Master two months ago, so a lot of the free time I did have has gone away. I'll get some photos of my servo tray up soon, likely tonight. I still don't have the line routing from the sail servo figured out exactly, though.
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Old Jul 01, 2012, 04:41 PM
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Joined Jul 2012
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thanks for the quick response!

keeping in mind that we've never built any sort of RC before...
we've been shown a few different possible servos and I was wondering if anyone had any input...

number 1 suggestion: HS 785HB
number 2 suggestion: HS 815BB
number 3 suggestion: HS 805 MG
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