Shaft coupler woes - Page 2 - SailNet Community
Old 06-30-2008
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it depends on how well machined the shaft and face are to begun with. If they're relatively true, should be able to sneak by without facing and fitting, but will probably end up with more wear and tear on the shaft in the long run.
Quote:
Originally Posted by jr438234606 View Post
Is it possible to get a true fit, or at least an acceptably true fit, without having the coupler machined to the shaft? I realize that would be ideal, but it's not very practicle for me right now.

Sailingdog

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Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

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Old 06-30-2008
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Here is a link to help calculate the interference between shaft and coupling...

http://www.tribology-abc.com/calculators/e3_8.htm

It looks like a typical interference ratio... delta/d... is about 0.001. The units in the article are those silly metric things.

Anyway, a shaft of diameter 1.25" should have an interference delta of about a thousandth of the shaft diameter, or about 1.25 thousandths of an inch, or 1.25 thou" as it is written sometimes.

I am not familiar with the surface finish arguments there, but it looks very much like you have consider them also.

Still, it gives an idea of what the designers have to consider.

Rockter.

Last edited by Rockter; 06-30-2008 at 09:34 PM.
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Old 07-01-2008
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Hal...

I am shocked, stunned, and deeply hurt.

I want a full written apology, carved in 3" letters into a solid granite slab, 3 ft x 4 ft x 24 ft, sent to Scotland by 6 pm today, GMT.

I said 0.43 thou"..... and not 0.43" .......yeeeeaaaarrrrgggghhhhh

That is 0.43 thousandths of an inch, and not 0.43 inch.

Don't miss the thou" bit.

0.43 thou" is an interference fit and won't go in without force but 0.43" won't go in at all, at all.

Rockter.

Last edited by Rockter; 07-01-2008 at 05:53 AM.
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Old 07-01-2008
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There is one hour and 3 minutes left.
Rockter is offline
Old 07-01-2008
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how close is close enough

Following the above instructions would most certainly ensure a proper fit of the coupling to the shaft. My boat has a large rusty chunk of something between the prop shaft and transmission. I know this because I am always saying to myself "that don't look right".
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Old 07-01-2008
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Not anymore.
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Originally Posted by Rockter View Post
There is one hour and 3 minutes left.

Sailingdog

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Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

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Old 07-01-2008
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Saildog...

I guess I just have to sulk.
He though I meant an interference of 0.43" on a 1.25" shaft!!!!!
How do you write thou" anyway?
I mean what can you do but sulk?
I am sulking.
I have been sulking for 4.5 hours.
Rockter is offline
Old 07-01-2008
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A sulking scotsman is not a pretty sight. You wrote it properly, he mis-read it.
Quote:
Originally Posted by Rockter View Post
Saildog...

I guess I just have to sulk.
He though I meant an interference of 0.43" on a 1.25" shaft!!!!!
How do you write thou" anyway?
I mean what can you do but sulk?
I am sulking.
I have been sulking for 4.5 hours.

Sailingdog

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Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

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Old 07-02-2008
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Quote:
Originally Posted by Rockter View Post
Hal...

I am shocked, stunned, and deeply hurt.

I want a full written apology, carved in 3" letters into a solid granite slab, 3 ft x 4 ft x 24 ft, sent to Scotland by 6 pm today, GMT.

I said 0.43 thou"..... and not 0.43" .......yeeeeaaaarrrrgggghhhhh

That is 0.43 thousandths of an inch, and not 0.43 inch.

Don't miss the thou" bit.

0.43 thou" is an interference fit and won't go in without force but 0.43" won't go in at all, at all.

Rockter.
Rock I read it correctly! I was just making a little light fun hence all the smilies and winkies and the lack of me including "thou" in my response... I thought the winkines would be a give away that I was merely ribbing ya...

Your carved granite apology slab is in the mail postage due on receipt..!!

______
-Maine Sail / CS-36T

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Maine Sail is offline
Old 07-02-2008
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Yea, but 0.43".
It's a disgrace!!!
Rockter is offline

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