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May 15, 2017, 01:20 AM
Registered User
coolmobility's Avatar
Quote:
Originally Posted by Emintaka
Just for the record, the design Dirk mentions is the Frigate Mark 2, which is proving quite promising. Four hulls have now been built, experimenting with the position of the fin and the rig, moving them further aft from the original drawings for more downwind stability. Seems to work.

I have been unable to sail for the past six months or so, but Scott has been campaigning his version of the design with success and tells me that he is particularly happy with its downwind speed. A mark three version is on the drawing board and following Zac Chan's pioneering example (see International One Metre Sailing on Facebook) we have notions of printing it out rather than going the CNC route.
Glad the collaboration is working out and your Frigate Mk 2 design showing promise. Interesting you're moving keel and rig rearwards as that has been our finding too on the narrow hulls we're building. Sorry you have not been able to sail for six months. Hope only a temporary setback.

Would you be willing to give the measurement from stern to LE of keel you started with and how far you've moved yours back?
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May 15, 2017, 07:25 PM
Registered User
Quote:
Originally Posted by coolmobility
Glad the collaboration is working out and your Frigate Mk 2 design showing promise. Interesting you're moving keel and rig rearwards as that has been our finding too on the narrow hulls we're building. Sorry you have not been able to sail for six months. Hope only a temporary setback.

Would you be willing to give the measurement from stern to LE of keel you started with and how far you've moved yours back?
Started with the LE of the keel 490mm from the transom. I took it back to 470mm (which means I have to use a Marblehead crane to get enough clearance between the backstay and the leech of the main). When he built his boat, Scott compromised at 480mm. His view was that 490 went better to windward and 470 improved downwind performance, so he split the difference.

Twenty millimetres might not seem like much but the longer the lever arm between mast and bow, the less likely the boat will be to nosedive, which could well be the difference between winning and losing a race. My co-designer resisted this strongly, his concern being that shifting the fin back relative to the bulb -- necessary to maintain the balance of the boat -- would then induce horrible twist and drag. Suffice to say that Craig Smith's fins are so good that it doesn't even come close to distorting under twisting load.
May 17, 2017, 10:43 AM
David Cook Victoria, BC Canada
Thanks a bunch for sharing Emintaka! There will hopefully be a PP8 after the home renovation is complete unless I find a higher priority shop project. Just started a lightweight carbon fibre off-road/beach/travel power wheelchair. Stay tuned.
May 21, 2017, 10:37 AM
The wind is free, go sailing!
Scratchy101's Avatar

IOM mast bending jig


Here's a video showing John Ball bending an 11mm French mast for one of the WCMYA members at our sailing venue at Long Lake, Nanaimo BC.
The jig is held with a portable vice clamped to the railing and the mast is sent through the rollers twice, once at the top, and a second time down to 900mm from the top. The final bend is 10mm, with the nominal bend being 14mm. In this case, more prebend can be added later if required.

IOM Mast bending jig (4 min 5 sec)
May 21, 2017, 11:08 AM
Steve Landeau IOM USA 21
Quote:
Originally Posted by Scratchy101
Here's a video showing John Ball bending an 11mm French mast... ]
Nice, thanks.
I'm making mine now, have just gathered up all the parts I need.
How far apart are those outer rollers?
May 21, 2017, 12:03 PM
Registered User
hiljoball's Avatar
Quote:
Originally Posted by ibldrc
Nice, thanks.
I'm making mine now, have just gathered up all the parts I need.
How far apart are those outer rollers?
The outer rollers are 12 inches apart.

John
May 21, 2017, 12:34 PM
The wind is free, go sailing!
Scratchy101's Avatar
Here is John's original post with photos and dimensions:
https://www.rcgroups.com/forums/show...postcount=4297
& photos of another one:
https://www.rcgroups.com/forums/show...postcount=4303
May 21, 2017, 01:31 PM
Registered User
hiljoball's Avatar
On the 'two pass' situation in the video - normally, I do it in one pass - in and out. The owner wanted less mast bend than normal, so I dialed back the tension and came down 750mm. But after looking at the effect, there was only about 5mm of bend, which we felt was not enough, so I did it again, down to 900mm.

John
May 22, 2017, 05:26 PM
Registered User
so i played around making a new boat stand. the never ending persuit of perfection!

meet flat pack! 3 parts, 2 modes.

now where did i put that foam!
May 22, 2017, 07:54 PM
Registered User

stand


really nice idea, easily broken down to have a stand when you fly into a regatta.
Mike

May 23, 2017, 02:14 AM
Registered User
coolmobility's Avatar
Quote:
Originally Posted by Whitaker
so i played around making a new boat stand. the never ending persuit of perfection!

meet flat pack! 3 parts, 2 modes.

now where did i put that foam!
Verry sweet design and so easy to design, build and customise.

USA 59 Whitaker has a really versatile design. You could have two cut outs to fit narrow hulls and other two for wider hulls, OR cutouts to fit an IOM and DF95 in one flat pack set. very cool.
May 23, 2017, 11:40 AM
a.k.a. Bob Parks
Yes!
They look laser cut.
Make the top end IOM and the other end DF95, then start selling them! (with custom Sail numbers for an added fee?)

BP
May 24, 2017, 04:20 PM
"consumerwil"
denisoni1's Avatar

Winches!!


I'm getting so frustrated dealing with winches... I really wish there was something solid state. I've gone through a couple of Titan winches (one I didn't install because I tested it before and had a dud ped). I hear mostly positive things about RMG but they seem to have reliability issues too.

As IOM's get lighter, surely there is a way of building a system like this?
Its Alive!! Vintage 70's RC Sailboat Sail Winch System by Royal RC (3 min 31 sec)
(Meaning to add weight due to battery and equipment).

Anyone try to make their own winch?
May 24, 2017, 06:03 PM
Registered User
hiljoball's Avatar
Really old time stuff - stopped using that in 1974.

It had issues - it is not proportional - it only moves when activated and continues until stopped - we called them 'bang-bang' winches. The other issue is weight - in addition to the servo and switches, it needs its own electric motor and gears and its own battery. And after all that, it is quite slow, compared to an RMG and way slower than an arm winch.

May be ok in a traditional M or 10R or A class, but way outclassed by modern gear in modern weight sensitive classes.

John
May 24, 2017, 06:16 PM
"consumerwil"
denisoni1's Avatar
Thanks for the comments John. I kinda had it in my mind like dissecting a RJX servo like how PDC Winches does it. Except having a control box with end point adjustments in case the radio loses the setting while the winch is hooked up. Then again, I suppose you could just program a fail safe on the receiver too ...


Quote:
Originally Posted by hiljoball
Really old time stuff - stopped using that in 1974.

It had issues - it is not proportional - it only moves when activated and continues until stopped - we called them 'bang-bang' winches. The other issue is weight - in addition to the servo and switches, it needs its own electric motor and gears and its own battery. And after all that, it is quite slow, compared to an RMG and way slower than an arm winch.

May be ok in a traditional M or 10R or A class, but way outclassed by modern gear in modern weight sensitive classes.

John


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