clinometer, finally

Dory-Ling · Posted: Sun Nov 21, 2010 9:35 am Post subject: clinometer, finally

For several years ve have been desiring a clinometer which was up to the standard. THe cheep plastic ones are unsightly and there shape is not condusive with good fit.

Ve have gone down many paths before setting out to make our own! Starting by dissassembling a starrett group 2 dial indicator saving only the face and jeweled movement we fit a pendulum to the needle drive gear. This makes a very accurate "heel measuring device" and allows 60 degree of motion 'each way from zero'!
A case matching our other instruments will be made to contain the movement, a case that will be nitrogen filled for elinenation of moisture from the movement.

in all, ve only expect to spend 6hrs of time in creation. After two years of thinking Sad

Martin

SGIDave · Posted: Sun Nov 21, 2010 10:06 am Post subject: Re: clinometer, finally

hardee · Posted: Sun Nov 21, 2010 12:42 pm Post subject:

I hope you only see that 60 degrees in response to a hard cornering situation, otherwise it may need more than nitrogen to keep it dry Shocked

Harvey
SleepyC Moon

Dory-Ling · Posted: Sun Nov 21, 2010 1:10 pm Post subject: clinometer, finally

don't get to hung up on range of motion, as you are correct about the wetting! a total of 120 deg of range is simple coincidence. once the gear driving the needle was replaced with a pendulum the original 360 deg rotation was reduced to what ever the saphire bearing supports would allow. in this case 60 degrees either way of zero.

realistcly i would be cracken walnuts with my hiney if it ever exceeded 25 deg on any given turn.

maybe we need a poll? how many jeweled movement clinometers exist on C-dory's? Laughing

Martin

Captains Cat · Posted: Sun Nov 21, 2010 1:16 pm Post subject:

Sounds like a neat device and a clever piece of engineering. But....

Why do you need one? If it's not damped considerably, it's going to be bouncing all over the place. If it is, it's going to be very slow in reading. I can see the use on a very large boat (read ship). It was useful on a destroyer, told us when to get concerned about righting moments, etc. And on an aircraft carrier when it told us we had to transfer fuel to remain within safe limits to keep aircraft from rolling around.

Might be useful in very calm water, when sitting still to see if you need to move things around to maintain an "even keel" that is zero degrees of list but I think we can feel and see that without a device like this.

That having been said, I've got lots of neat things that have limited usefulness, I just wanted them so I either made them or bought them! I look forward to seeing your pictures.

Did you ever get your lone garden tree cut down?

Charlie

Dory-Ling · Posted: Sun Nov 21, 2010 2:02 pm Post subject: clinometer, finally

different applications all together.
quite some effort has gone into boat trim and how it relates to efficency. by checking speed over water at various trims, its obvious you can leave performance on the table if you have no concern. To some maybe not knowing, were talking port to starboard trim acomplished thru tabs.
Being kindof geeky, i have concern so I play with it. ve can easily gain or loose 3knts by changing trim, with no throttle movement. Bow to stern trim must be adjusted too for greatest gain. when sweet spot is located, gages are set at zero and repeating all trim angles is very easy the secound time. In and 85 hour summer this is quite some fuel burn difference.
Initially no dampening will be used as the pendulum is made from densealloy which is a tungsten carbide 1 1/2 times heavier than lead and appears very stable when shook. If we find damping necessary I have silicon oil from 5 cs all the way to 60,000 cs available and somewhere in that range is one that's just right.

yes it is a gage of limited usefulness but i have one and no one else does which fills a useful niche to me!

our tree is still there but please don't talk about it. one of the bosses thought ve were making politics and said to take it somewhere.
Martin.

rogerbum · Posted: Sun Nov 21, 2010 2:47 pm Post subject: Re: clinometer, finally

rjmcnabb · Posted: Sun Nov 21, 2010 6:49 pm Post subject:

I agree with Roger, but when I ran out of wine I used a 6 inch bubble level. On the centre dash it lay flat pointed athwartships and was good for side-to-side trim. Pointed fore-and-aft, the dash slopes but I could still get a relative sense of how flat the planing was.
p.s. on edit - We no longer have NoddyBleu (or 'Winkle) but now have a 1976 San Juan 24 sloop. But I still enjoy the C-Brats site. Good stuff and wonderful photos. Cheers.