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Daniel Holman

Member Since 28 Dec 2009
Offline Last Active May 04 2016 08:51 PM
*****

Posts I've Made

In Topic: Downsides of Spectra Standing rigging

04 May 2016 - 07:38 PM

Ive used it (SK78 max) on the forestay and caps of i14. I kept wire shrouds so I had one constant in rake / rig tension measurement. My observations would be that it is relatively light, cheap, durable and easy to use/inspect.

Downsides would be that you probably have about 100mm per stay (~7m length) of constructional creep on the first couple uses before it settles down, i.e. the splices and weaving settling down.

After that its pretty stable, and viscoelastic creep is a function of % of BL, and time under tension. You won't be using more than ~ 30% of ultimate capability really and also for a few hrs at a time, so its quite negligible. if you take rig down and coil it up you regain some of that so it'll feel tight on same numbers for the first sail or two off the trailer.

Apart from that it hums like hell. Mournful at low wind in dinghy park, feral banshee like at high apparent winds, that energy must be subtracted from your boat's kinetic I reckon.

You can rub those sticky gloves up and down it to play a tune like on a harp if you are bored.

I could see myself using it again.


In Topic: Boat Balance - Moving Forward

30 April 2016 - 05:40 PM

Transom immersion is a big big deal in mimimising drag at any particular speed. At upwind RS100 equiv speeds, i.e. laser speeds < 4.5kts, the transom isn't runnin dry so you need to have the transom just kissing. Where the stem is depends on what the designers view is on semi displacement resistance vs ease and tolerance of sailing i.e, how much "rocker" there is.

The stealth I guess would be designed with a somewhat higher modal speed than a una rig boat so it may be straighter, so you may need a fair bit of stem engaged.

at > 15kts boatspeed you pretty much can't have too much transom in the water.

In between those extremes you gradually trim aft. Most boats communicate when they are happy quite clearly!
 


In Topic: Laser /Sunfish Rumors

24 April 2016 - 03:43 PM

Militant capitalism.


In Topic: Unstayed carbon mast rig

24 April 2016 - 03:29 PM

Canoe has about double the RM of the D One so d one mast would feel whippy sideways.


In Topic: Laser /Sunfish Rumors

24 April 2016 - 02:09 PM

 

 

 And Sunfish are going to be "injection molded"?


No, he used the wrong words, he meant infused. (As in resin infused)

 

They could well be using injection molding. Infusion is done under vacuum with a main mould and a bag and the resin "infuses" because of the vacuum while injection uses the same materials, but with an inner and outer mould, with or without vacuum but with pressure injection of the resin. Where you are using old school CSM laminates which require a high resin ratio, this ensures enough resin, whereas the vacuum bag can over consolidate CSM leaving the laminate too dry and thin.

 

Ive never seen an infused part that has been too dry from oveconsolidation (rather than dry spots caused by poor routing of the outlets etc) they are usually swimming in resin!