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Sabydent builds a mini

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Created by sabydent > 9 months ago, 10 Feb 2011
sabydent
360 posts
20 Jun 2011 6:14AM
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I have changed the rigging on my mini. I would appreciate your help in letting me know if this looks right.

I am considering placing some rivets on the boom rather than using the knots for the two pulleys. Good idea or bad idea? I will tidy up the knots if I am keeping them.

Should I use a larger line for the downhaul?

Thanks for your help.


Brian





Nikrum
TAS, 1972 posts
20 Jun 2011 10:43AM
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Mr S Dent
Bad Idea!!! Though using Rivets may not be a threat directly to life and limb they can threaten an otherwise happy weekends sailing. We found that their use in Hang gliders was extremely dangerous when used in "A under Tension" mode as after a little use they Will break free. This scenario did happen to a Home Builder in the Auckland Hang Glider Assn when I was a member luckily the pilot was at very low altitude and survived to tell the tail. No I would stick to the ropes but go for a thinner (Probably 300lb) around 3/16 Dyneema. Swivels aren't necessary.
And, please be careful of my Mini, you have scratched the boom.
Ron]

PS; I would also move the 2 Boom Sheet Blocks forward to nearly directly over the Hull anchored Block

Gizmo
SA, 2865 posts
20 Jun 2011 10:35AM
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Pop rivets are fine on a land yacht.......... Your not going to fall out the sky
The reason people often use cord to attach pulleys is they can change them easily to adjust the setup.
My suggestion is use stainless steel rivets rather than aluminium as they corrode badly with high levels of salt, sand, mud etc.
You can only use rivets on metal tubing as other materials won't hold them.

Hiko
1229 posts
20 Jun 2011 9:46AM
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Another alternative is the set up I use on one of my minis
You could adapt your existing blocks to something like this by removing the swivel
and putting the blocks in a f/ glass saddle
It can be moved along the boom by adjusting the centre bolt
Just a suggestion I find it good as the boom can be brought down low when I want


sabydent
360 posts
20 Jun 2011 12:42PM
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Nikrum said...
And, please be careful of my Mini, you have scratched the boom.
Ron]




I will get right on the paint job repair, sorry.

sabydent
360 posts
20 Jun 2011 12:44PM
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Hiko said...

Another alternative is the set up I use on one of my minis
You could adapt your existing blocks to something like this by removing the swivel
and putting the blocks in a f/ glass saddle
It can be moved along the boom by adjusting the centre bolt
Just a suggestion I find it good as the boom can be brought down low when I want




I like this idea. I am going to figure out something in aluminum. I have some problem with the ropes slipping on the smooth boom. As it turns out, I will not be able to put rivets there anyway as this is the same area where I screwed up my boom construction. I cut the boom according to the plans....before I measured my sail. Opps. I had to add the piece of aluminum back to the boom, if I had not cut it it would have been the perfect lenght. To add the peice back on, I had to place another aluminum pipe inside, drill some larger holes in the boom then weld everything back up. Now I have a pretty thick boom (inside) at the area where I need to attach my blocks.

thanks.

Brian

Hiko
1229 posts
20 Jun 2011 3:43PM
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Aluiminium would be fine We must use what we have

sabydent
360 posts
23 Jun 2011 9:45PM
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Hiko said...

Aluiminium would be fine We must use what we have


Bending the aluminum did not work out so well. Hiko how many layers of glass do you use? Other than the washers and the middle strap is there any need to use metal reinforcement?

Hiko
1229 posts
24 Jun 2011 6:28AM
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sabydent said...

Hiko said...

Aluiminium would be fine We must use what we have


Bending the aluminum did not work out so well. Hiko how many layers of glass do you use? Other than the washers and the middle strap is there any need to use metal reinforcement?


I taped a piece of wood of the right size to suit the sheaves to the boom and covered it in plastic food wrap then laid two layers of glass cloth with a layer of carbon cloth between All wet out with resin
All was then covered with more plastic food wrap [We call it Gladwrap over here] and the wooden stick part was squeezed in my bench vice [with packers]and left to cure
I used the carbon cloth because I had some but I think four layers of normal
sheathing fibreglass cloth [ 12 ounce is it ? ] would be fine There is no metal reinforcement The aluminium you see is just to prevent the lower block becoming jammed between the other two when hauled down tight
The centre bolt clamps the set up to the boom in the selected place
I just use plastic sheaves from a boat shop with tube spacers in their centres and have done three like this now
They work pretty well Fit my cheapskate budget too

Nikrum
TAS, 1972 posts
24 Jun 2011 10:52AM
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Brian,
I have been cruising the pages and noted something you may be interested in.. In the photo's your Boom Rowlock appears to be naked against the boom and you have the mast sitting in plastic in the Mast Step.
You could always use some Black Poly Pipe up to and slightly above where the Rowlock is contacting the Mast..
Just a thought
Ron
PS. The Plastic doesn't look so neat,

sabydent
360 posts
24 Jun 2011 1:40PM
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Thanks Hiko, I will give that a try.

Nikrum:

I wanted a neat boom end so here is what I did. I took a polyvinyl silicon impression of the boom end. (I have an old dental impression mixing machine with lots of old impression material in my shop...handy little guy) I poured the impression in dental plaster to get an exact duplicate of the boom end. I then used the machine we use for making dental mouthguards to vacuum form a plastic cover using 3mm clear plastic. I then cut the excess off with a hot knife. The resulting plastic piece snaped onto the boom end. For added security, I glued it on with Gorilla glue.

sn
WA, 2775 posts
24 Jun 2011 3:11PM
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10 out of 10 for inventivness!!

you could probably claim a refund from your health insurance company too!

Nikrum
TAS, 1972 posts
24 Jun 2011 7:02PM
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Damn! That is a bleedin' nice job. LAst I heard it was plain old Ali..
Tell me why is Dentists can use their Melons doing jobs like that but when you need them to be inventive medicly it is No Go??
Ron

PS; I told you you northerners were Anal about finish

sabydent
360 posts
27 Jun 2011 4:45AM
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Nikrum said...

Damn! That is a bleedin' nice job. LAst I heard it was plain old Ali..
Tell me why is Dentists can use their Melons doing jobs like that but when you need them to be inventive medicly it is No Go??
Ron


Actually, we need to be inventive all the time. To see examples of what I am talking about go to www.saby.com/

Brian

Nikrum
TAS, 1972 posts
27 Jun 2011 3:26PM
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Sorry Brian but I gotta pick this up BS in Medical Science?? So that is what Medical Science is all about[}:)] Mind you it is good to see Professionals keeping up with the chosen careers. Congratulations.
I spoke to a dental Prostheses t (Thet done look right) but anyway I asked about a Specialty Mouth Guard I wanted made. The isdea was a silicone seal affair that would fit mainly between Lips and Teeth as well as clamping in my teeth this would have been to seal against Air Pressure blowing out of my mouth when asleep as I use a CPAP machine. The answere was one of disinterest and No such thing. No thought of experimentation etc. Hence my doubts about inventiveness.

Ron

desertyank
1262 posts
27 Jun 2011 9:14PM
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sabydent said...

Actually, we need to be inventive all the time. To see examples of what I am talking about go to www.saby.com/

Brian


Time to update your profile on the website.. You now have to add landsailing



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"Sabydent builds a mini" started by sabydent