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Old Nov 30, 2007, 06:22 PM
Damp and Dizzy member
Brooks's Avatar
Bozeman, Montana, United States
Joined Aug 2003
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Dual purpose iceboat

When life hands you Ice....make an Iceboat :-). This is a simple, dual purpose craft. With wind, power is from a 4' mast and sail. When there's no wind, there's a prop and brushless motor to propel the contraption. Haven't had any wind to speak of since I built it, naturally, so I just have photos of the prop version. The motor pedestal comes off easily and is replaced by the mast and sail. Since it won't fit in my car rigged, the sail mast detaches easily, too :-). The design is based on a scaled down version of Bill Korsgard's K-1; My thanks to Bill for posting photos and description of his craft. I would have ordered Bill's plans, but got in a rush, so just winged it :-). John cut and shaped the runners, and power-planed the splintery lath as smooth as you could want.

Dimensions:
Frame is made from lath. 36" long, 27" wide.
Mast is 48", boom 11", motor pedestal 14".
Runners are 3/4" angle iron, 6" long, sharpened.
Lines are 20# non-stretch fishline, bowsies are my usual buttons.
Sail is Tyvek.
Motor is PJS 550E; it provides more power than needed, I have to throttle back to keep from shaking the boat :-). I tried the PJS 300 but could not get it to run properly (same stuttering/dieing problem as the first one I had, this one was a warrantee replacement). Both motors were purchased several years ago, so I don't know what the present quality of PJS is. Another 550E has run my GWS Tigermoth on floats w/o problems for several years.
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Old Nov 30, 2007, 06:53 PM
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Bozeman, Montana, United States
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Video here:
http://www.rcgroups.com/forums/showt...00#post8648873
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Old Dec 02, 2007, 03:03 PM
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Bozeman, Montana, United States
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Sail Powered

Enough wind to sail, Yay! Very fast in a gust. Pretty stable, only dumped once; skids sideways instead of toppling. Hard to tack, turns into the wind easy enough, but does not keep way on and stops head-to-wind. I only made 1 out of dozen attempts. I'll try more rake to the mast next time. Wears well, but has a tendency to spin out as you head up if you are going fast. Better tiller work should solve that. Seems more sensitive to wind speed, with a smaller acceptable range of speeds than a water boat.

Hint to self: if the mast is removable, be sure to keep shrouds and forestay and sheet tied off, lest they get entangled as you try to re-rig in the breeze :-).

Movie did not come out well enough to post, boat too far away.
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Old Dec 02, 2007, 07:40 PM
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Minnetonka Minnesota
Joined Aug 2007
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Brooks, that's a beaut! One good thing about a wind blown lake in December after all (unless you like to icefish too). I don't know the first thing about iceboats but when I was a kid there was a group that sailed them on White Bear Lake, they went very fast. It seemed a bit of a dangerous sport, they'd tip over and slide on their side once in a while. Cap
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Old Dec 05, 2007, 08:51 PM
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Bozeman, Montana, United States
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Switching to the Castle Creations Phoenix 10 ESC solved the PJS 300 SF stuttering problem. The Jeti 18 could not handle the motor, but the Phoenix 10 could, even with a bigger than recommended prop. All this gear was purchased 4 years ago, so I don't know if present Jeti products might work. The PJS line is not as prevalent among vendors as it was back then, so this esc info may be moot.

After a warm spell, the snow on the pond all melted and then refroze. The pond surface is only smooth where I had been shoveling snow, but it's nice to use more of the pond, even if it is bumpy ice. The main problem is still lack of wind; I sailed for about 1/2 hour today, but had to swap out the mast for the motor due to the combo of soft ice (high drag) and light wind. No luck tacking. I put some Pb weight aboard, but may have to add more to get enough inertia to complete a tack. I think Bill K used 20 oz in one of his iceboats.
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Old Dec 19, 2007, 08:01 PM
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Bozeman, Montana, United States
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A good day sailing at the (frozen) pond. Wind was just about perfect, 5-10 mph. Better yet, John figured out how to tack the iceboat. By not turning too abruptly into the wind, the boat does not scrub off velocity by scraping the leading runner on the ice. You can use your ears: if the runner is making a scraping sound, lighten up the joystick. As the boat slows, you can tighten the turn, again listening for the scraping sound. We each made numerous tacks :-).

After lunch the wind picked up to 15-20mph. That was too much for the sail, the boat would just skid sideways. I made a 1/2 size sail for stronger winds, but it was too small when I tried it last week. I will make a 3/4 size sail for the 15-20 increment. Since the iceboat can't easily heel to spill excess wind, unlike a regular sailboat, it appears that sail selection is more critical to this style of craft.
-----------------
The 15amp brushless motor installed in Bob & John's iceboat really makes it move out (Tower Hobbies/Electrifly 28-30-950 Outrunner with 3 cell LiPo). Sounds cool too, with a almost-radial-engine rasp. With appropriate throttle and steering adjustments, it's possible to make a bootlegger style, 180 skidding turn. Bob (and John) is really good at this :-). I suck....time to review the old Eliot Ness movies, I guess. And I need to upgrade my motor if I am going to keep up with the J&B bootlegger team :-)

Turning in the regular manner requires slowing down, otherwise the lead runner just skids over the ice. We added a "fork brake" to each boat. A common dinner fork is suspended under the cross rail, tines to the stern. By leading a line from the fork's handle to the servo that normally runs the sail sheet, you can pry on the fork, making it dig into the ice. Initially, we tried simply rubberbanding the fork to the cross brace. But, the arc-ing pull from the servo arm would tend to dislodge the fork. John welded a short piece of nail across the fork handle. Then, using rubber bands on the nail, we made a hinge. The fork remains perpendicular to the cross rail, now.

The old way to deliver healing shots of brandy was with a St. Bernard....the new way is via motorized iceboat with New Improved Braking Action! Place your orders at Bob's Place, downstairs, the password is IceCreamSundae.
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Last edited by Brooks; Dec 19, 2007 at 08:09 PM.
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Old Dec 20, 2007, 06:31 AM
jimi hendrix
Joined Apr 2006
1,509 Posts
another ggod optoin is a swamp boat.

im building one at the moment
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Old Dec 20, 2007, 08:56 AM
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Spitfire123 - The swamp boat would be particularly good on this pond as most of the ice is covered in snow; I've only shoveled off a small section, John said he might rent a snow blower to increase our usable patch. I will be interested in your experience turning on ice; ice provides much less resistance than water, will you have a keel or pair of runners on the bottom to dig into the ice? I suppose the air rudder will do the job w/o runners, please film your bootlegger turns for us :-) You still might want a brake of some sort :-).
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Old Dec 23, 2007, 11:52 AM
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Bozeman, Montana, United States
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John's ice boat, while brilliant at zippy 180's, would not perform slow speed turns; the lead runner would just slide across the ice. He ground a rocker in the lead runner, and now the boat turns on a dime, even at slow speeds.

I modified my Tyvek sail to put in draft, cutting it from leach to luff at about the 1/2 way up point and taping it back together. The Tyvek is stiff, so the rejoin along a 1/4" arc (with sailmakers doublestick tape) left it with wrinkles. Not enough wind to really test it this morning. I think the cut-and-rejoin-along-an-arc method might work better with flexible cloth or with thinner non-cloth (mylar). Sailmaking is an art, and I need more practice.
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Last edited by Brooks; Jan 02, 2008 at 04:47 AM.
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Old Dec 24, 2007, 10:45 AM
jimi hendrix
Joined Apr 2006
1,509 Posts
Quote:
Originally Posted by Brooks
Spitfire123 - The swamp boat would be particularly good on this pond as most of the ice is covered in snow; I've only shoveled off a small section, John said he might rent a snow blower to increase our usable patch. I will be interested in your experience turning on ice; ice provides much less resistance than water, will you have a keel or pair of runners on the bottom to dig into the ice? I suppose the air rudder will do the job w/o runners, please film your bootlegger turns for us :-) You still might want a brake of some sort :-).

well its going to have a big engine for a smallish boat,the 2 ruddrds are going to be abouve the deck.

as i will be using on cocerte,grass,snow,water etc....

im doing it as a shool prodject
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Old Jan 01, 2008, 07:56 PM
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Madison, Wisconsin USA
Joined Aug 2006
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Quote:
Originally Posted by Brooks
When life hands you Ice....make an Iceboat :-). .....
Brooks,
I love your attitude! It looks like you're off to a great start, and it just proves how simple these things can be to build. The proportions look fine.

You made some mention of spinning out & skidding, so I thought I'd give you a couple suggestions. John's idea to grind some rocker into the runners is a good one. Use a good straight edge with a light behind to see it better. I usually only have about 2" flat on an 8" runner. The next thing is to have a really sharp edge, cut to an included angle of 90 degrees (not a knife edge). See below pic for the sharpening setup I use. Drag your fingernail across it sideways & it should peel a thin slice. Lengthwise should feel no bumps or gouges.
Finally, don't be afraid to add some ballast . This will enhance the bite, help keep the boat upright & the added momentum will help carry you thru the eye of the wind in a tack.
Hope this helps,
Bill K
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