"DragonStein" US1M conversion - RC Groups
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Sep 28, 2017, 12:57 AM
Kevin Gault
poltergeist's Avatar
Build Log

"DragonStein" US1M conversion


I'm sure the Dragon Flite guys will put me on their hit list.

To try and make an easier entry into our local US1M fleet, I decided to try and mod a Dragon Flite 95 into a decent "club level" US1M. We've had a few guys sail stock DF95's in our fleet, and (at least in light air) they are a bit off the pace. Thinking that a max height US1M rig, and a heavier bulb to make the boat less "tippy" might just do the trick. I'm using a heavier lead US1M bulb on the stock (and very nice I must say) DF C/F keel fin, along with a 5cm balsa/CF veneer transom "scoop".

Built a lighter C/F servo "tray" and will switch the boat over to a Hitec digital arm servo. Still need to finalize the rudder servo layout.

Next up a full height 60" US1M sailplan.

Worst case (thanks to Dragon Sailing's amazing stock of replacement parts) I'll get a replacement bare hull and put her back to stock.

Kevin
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Sep 28, 2017, 04:24 AM
Registered User
BAJAN SAIL 51's Avatar
Hi Keven you might be able to go a little deeper with the keel and keep the origanal weight i think it will work
Sep 28, 2017, 07:17 AM
Registered User
Sep 28, 2017, 08:23 AM
Modeler/ Historian
Stephen Vick's Avatar
The spoon stern bumps you up to an even 1 meter I'm guessing? I love it! Very innovative.
Sep 28, 2017, 10:11 AM
Kevin Gault
poltergeist's Avatar
Stephen,

It's fairly common (or at least used to be) on full sized race boats as a way to increase waterline length. I just needed to bring the hull length into compliance with the US1M Class rules (and the free waterline length can't hurt).

Bajan,

The stock zinc keel bulb it quite big for it's weight. The lead one I'm using has less surface area and is quite a bit heavier. I'm within about 12mm of the max allowed "draft" in the US1M rules. I may look at extending the fin farther out of the keel trunk to get to max, but I think I'll try sailing the boat first.

Kevin
Sep 28, 2017, 10:57 AM
The wind is free, go sailing!
Scratchy101's Avatar
It's commonly referred to as a "sugar scoop".
Sep 28, 2017, 11:14 AM
Registered User
Quote:
Originally Posted by poltergeist
Stephen,

It's fairly common (or at least used to be) on full sized race boats as a way to increase waterline length. I just needed to bring the hull length into compliance with the US1M Class rules (and the free waterline length can't hurt).

Bajan,

The stock zinc keel bulb it quite big for it's weight. The lead one I'm using has less surface area and is quite a bit heavier. I'm within about 12mm of the max allowed "draft" in the US1M rules. I may look at extending the fin farther out of the keel trunk to get to max, but I think I'll try sailing the boat first.

Kevin
Yeah .... true you increase the waterline length but also also displacement and you are changing the boat quite significantly .....

It would be easier to build a "new" US1M hull or convert (i.e. build ) a moro hull to a US1M ..... in both cases the boat will be performing better than the modified DF95
Sep 28, 2017, 03:42 PM
Modeler/ Historian
Stephen Vick's Avatar
I think its brilliant. Kevin, is she getting a yellow paint job?
Sep 28, 2017, 11:03 PM
If it floats....sail it!
FoamCrusher's Avatar
Displacement will be the big issue. With a taller and heavier rig and a heavier bulb you may find the hull will sit so deep in the water that the increased drag will make the boat slower than a purpose made US1M.

But you won't know until you actually try. At least it will be be easy to reverse. Good experiment. That's what is so much fun about the US1M class.
Sep 28, 2017, 11:55 PM
Kevin Gault
poltergeist's Avatar
Stephen,

Thanks for the encouragement! Not sure what color she'll end up being, but yellow is up there on the list!

F.C.,

I trimmed your bulb down to about 1700Grams before I mounted it to the fin, Total keel weight is a bit over 1800Grams I floated the boat in a swimming pool with the heavier keel, while trying to get the fore/aft positioning of the bulb nailed down. She floats with the bow knuckle just at the waterline, and the tip of the "scoop" on the stern is about 1/4" or so above the static waterline. By nature I think the DFlite hull has pretty low freeboard aft. I should've floated the hull with the stock bulb as a comparison, but I didn't think to at the time.

Gio,

I guess it depends on your definition of "easier". To me, this is easier than building a hull from scratch. If it can be turned into a halfway competitive "club level" US1M and maybe draw some guys in our club over from the Soling One Meter group, then it will be a success. If it sucks, I'll look into stealing the US1M parts off of it and "stick" them to a different hull.

I weighed this hull in comparison to my Desatoff Mark 2, and the Dragon hull is about 40Grams heavier. All up weight of my Mark 2 is 2610Grams, so I think I should be able to keep the Dragon below 2700Grams

Kevin
Sep 29, 2017, 12:39 AM
If it floats....sail it!
FoamCrusher's Avatar
It has always been a challenge to lure non-builders to the class, particularly since there's no one building US1Ms commercially right now.

I enjoy building and when testing a new design, I build a balsa planked plug, laying glass over the plug for the test hull. If the boat works out well and others would like to buy one, I make a mold from the plug and can crank out hulls rather quickly and inexpensively. Right now, several club members want a Zipper like the one I made by using an existing hull as the plug. Since I a going to make at least three, I'll make a new plug, from that make the mold and then the hulls.

Sails, masts keels and rudders are the expensive parts.

Below in gray is my latest test hull along side a blue ODOM hull for comparison. I will lay up the hull on Sunday and go from there.

I'm not sure which way is cheaper ( which is a consideration for what you are doing) but a purpose built boat probably has better resale value.
Oct 11, 2017, 12:00 AM
Kevin Gault
poltergeist's Avatar
Finally got some time to work on my "project". Got a rudder servo (a Hitec HS-65) installed and the linkage finalized. Used the stock D/F linkage with an offset bend to match the rudder servo location.

Also got a nice treat in the mail today. A set of A-rig sails from Ken Bauser.

Kevin
Oct 11, 2017, 06:26 AM
Registered User
Kevin, this is an awesome project your doing you might want to check out the winches at Dragon Sailing if the stock winch doesn't hold out with a tall rig

Bill
Oct 11, 2017, 10:41 AM
Registered User
Quote:
Originally Posted by FoamCrusher
...... Right now, several club members want a Zipper like the one I made by using an existing hull as the plug. .......
Off topic, but original skinny zipper or III?
Oct 11, 2017, 12:11 PM
If it floats....sail it!
FoamCrusher's Avatar
The one I made was a Z1. It seems to be better in the light conditions we have here than the Z3, which due to the ridge along the keelline, does not tack as easily. The new one will be a Z2+ (my destination), not the Z3.

Steve Andre only made about 5 of the Z2's. There were never any plans for it since they were made by extending the Z1 mold to increase the freeboard. I am going to increase the freeboard like on his Z2, but only from just ahead of the mast to the bow, add a peaked foredeck and add some "secret sauce" ideas of my own.

The mold I am going make will be able to produce either the 2+, or a Z1 by cutting the freeboard back to the original location. I'll scribe a line in the mold at that location so it will be easy to trim.

With modern lighter weight servos and a film deck rather than a G10 deck, it should come in at about the designed displacement.

Now back to Kevin's "monster build" 8-0


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