Reply
 
Thread Tools Search this Thread Display Modes
 
Old 03-29-2017, 10:03 PM   #1
Senior Member
 
ak-guy's Avatar
 
City: Gustavus, AK
Country: USA
Vessel Name: Troll Hunter
Vessel Model: Allweather
Join Date: Oct 2016
Posts: 120
R&D Flex Coupling and Split Flange

I have a new 1.25" shaft, a new R&D shaft coupling and new R&D flex coupling and have a few questions about installation. If you have done it before how did you measure the distance at the red bolt head as the limited directions say. The directions say to use feeler gauges but the distanced is such that it would be a stack of many gauges, is this acceptable? Also I do plan on having the flange fitted to the shaft by a shop. The fit of the flange on the shaft now is an easy slide on fit. It is a split coupling so I guess this is all right?
__________________
Advertisement

ak-guy is online now   Reply With Quote
Old 03-29-2017, 10:40 PM   #2
Guru
 
LarryM's Avatar
 
City: League City, TX
Country: USA
Vessel Name: Pelago
Vessel Model: Wellcraft 3300 Coastal
Join Date: Aug 2011
Posts: 922
Quote:
Originally Posted by ak-guy View Post
I have a new 1.25" shaft, a new R&D shaft coupling and new R&D flex coupling and have a few questions about installation. If you have done it before how did you measure the distance at the red bolt head as the limited directions say. The directions say to use feeler gauges but the distanced is such that it would be a stack of many gauges, is this acceptable? Also I do plan on having the flange fitted to the shaft by a shop. The fit of the flange on the shaft now is an easy slide on fit. It is a split coupling so I guess this is all right?
I installed one on my last boat and don't quite understand your concern. The red bolt head is pretty close to the flange face. Here is a pic I found of a typical installation.

Combining or stacking the feeler gauge blades works just fine as you are only looking for the relative difference in gap measured at 90 intervals, not the exact gap. Just vary one blade as required, and leave the other blade(s) in the 'stack' unchanged.

As for the flange fit on the shaft, it should have NO play, but a smooth sliding fit is OK.

__________________

__________________
Larry
M/V Pelago
LarryM is offline   Reply With Quote
Old 03-29-2017, 10:41 PM   #3
Guru
 
AusCan's Avatar
 
City: Adelaide
Country: Australia
Vessel Name: Kokanee
Vessel Model: Cuddles 30 Pilot House Motor Sailer
Join Date: Jul 2012
Posts: 2,889
I've got a similar shaft coupling & flex coupling but not R&D, which I've had on and off a few times.

I had a look at the R&D installation procedure at R and D MARINE : Flexible Shaft Couplings

Yes - the gap will be more than one feeler gauge in thickness, so you'll have to stack them. They are still relatively accurate as long as the feeler gauges aren't old & corroded. Alternatively you can use a hard piece of steel, plastic, or anything of uniform thickness, plus one or two feeler gauges because you are only comparing the difference in measurement at each 90 degree interval. The total measurement is not important.

In regard to the split coupling, they should be a relatively easy slide on by hand, but you shouldn't have any noticeable movement other than lengthwise on the shaft.

edit - looks like Larry has got it covered
AusCan is online now   Reply With Quote
Old 03-29-2017, 10:55 PM   #4
Guru
 
LarryM's Avatar
 
City: League City, TX
Country: USA
Vessel Name: Pelago
Vessel Model: Wellcraft 3300 Coastal
Join Date: Aug 2011
Posts: 922
Quote:
Originally Posted by AusCan View Post
edit - looks like Larry has got it covered
You know what they say about 'Great Minds' . . . . . .
__________________
Larry
M/V Pelago
LarryM is offline   Reply With Quote
Old 03-29-2017, 11:35 PM   #5
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 16,077
I like those flexable couplings.
And I consider the alignment feature a plus.
However there's a great danger in their use.
As the thrust becomes greater the plastic plates bend. Choosing the right sized coupling is very important because if you get one too small there will be enough thrust to move the bolt heads close enough so they hit the opposite shaft flange. This will be similar to taking a jackhammer to the output shaft of the gear and it's thrust bearing. You know when that happens because there will be marks on the bolt heads and the shaft flanges. If this continues over a period of time you'll need to fix your trans thrust bearing at least. It happened to me. My very soft and flexable Yanmar engine mounts may have played a part in my transmission damage. Don't think so though as the max movement is at idle and max thrust is at high power.

But if the coupling is correctly sized there probably will be no trouble. I think they are sized to power rating. Hp ratings vary even w the same engine but thrust varies even more so with lower gears. So if the couplings are for a 120 to 160hp engine and you have a 140hp engine you better get the 160 to 200hp coupling. All these numbers are just as an example.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 10:11 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×