Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 25-04-2012, 00:24   #61
Registered User

Join Date: Apr 2012
Posts: 4
Re: Engine Alignment

As is so often the case, reality and theory diverge. I still think the modeling in Sketchup will help, but our first day was spent lifting and lowering the engine, so we could modify the mounting plates between engine mounts and the bearers.
We now have the necessary movement to get the shaft and gearbox output properly aligned.
The problem is that our setup uses a flexible coupling with 4 bolts - 2 on the gearbox and 2 on the shaft. They are at 90 degrees to each other, making it impossible to measure the gap between the faces.
I read here that I need a machined disc in place of the coupling to get it right. The old coupling was made by Metalastik, but they no longer make it. We've found what is promised to be an identical part.
Can anyone add to the method of using a solid disc to obtain accurate alignment. I think I can see (in theory) how to do it, but any further information on technique would be most welcome!
__________________

__________________
Lowestoft Mike is offline   Reply With Quote
Old 25-04-2012, 00:43   #62
Registered User

Join Date: Jan 2011
Location: Fl
Boat: 73 pearson 35
Posts: 142
Re: Engine Alignment

Quote:
Originally Posted by Lowestoft Mike View Post
As is so often the case, reality and theory diverge. I still think the modeling in Sketchup will help, but our first day was spent lifting and lowering the engine, so we could modify the mounting plates between engine mounts and the bearers.
We now have the necessary movement to get the shaft and gearbox output properly aligned.
The problem is that our setup uses a flexible coupling with 4 bolts - 2 on the gearbox and 2 on the shaft. They are at 90 degrees to each other, making it impossible to measure the gap between the faces.
I read here that I need a machined disc in place of the coupling to get it right. The old coupling was made by Metalastik, but they no longer make it. We've found what is promised to be an identical part.
Can anyone add to the method of using a solid disc to obtain accurate alignment. I think I can see (in theory) how to do it, but any further information on technique would be most welcome!
let me get this right.
you currantly have 2 flanges......one on prop shaft and one on trans......with a flex coupling in between...as in soft not steel thingy.

and someone told you you need to put a hard piece of steel permantly in between them to "get it right"........

get a new piece of flex or take the currant SOFT flex to a machine shop and have them squar it up.then take a digital caliper,
rotate till you get all 4 sides to specs the re-cheack in a week.they will change.recheach weekly till they don't

Amazon.com: Neiko 01407A Stanless Steel 6-Inch Digital Caliper with Extra-Large LCD Screen and Instant SAE-Metric Conversion: Home Improvement=

to easy...
Mark
hands him a tub of hand cleaner to take a shower with.
__________________

__________________
travler37 is offline   Reply With Quote
Old 25-04-2012, 00:49   #63
Registered User
 
Capn Morgan's Avatar

Join Date: Jul 2009
Location: South East Asia
Boat: Hans Christian 48T
Posts: 381
Re: Engine Alignment

Mike

I had a copy of the flexible coupling made in steel, machined to a good tolerance in a workshop. Installed this dummy flex coupling to the shaft end and aligned the engine as close as I could with it on, then moved the shaft back again and re-installed the flexible one. While it seemed to work in theory there are caveats. If I use the engine at my preferred cruise setting I could put a glass of water on top of it and not see a ripple. As soon as I open up a bit more the shaft pushes the engine forward because the mountings are soft-ish and the whole thing changes. In my boat there isn't a thrust bearing to take the load so I have to live with this limitation. Unless someone corrects me? Please?
__________________
Capn Morgan
'If you can fill the unforgiving minute with sixty seconds' worth of distance run...'
Capn Morgan is offline   Reply With Quote
Old 25-04-2012, 01:16   #64
Registered User

Join Date: Jan 2011
Location: Fl
Boat: 73 pearson 35
Posts: 142
Re: Engine Alignment

Quote:
Originally Posted by Capn Morgan View Post
Mike

I had a copy of the flexible coupling made in steel, machined to a good tolerance in a workshop. Installed this dummy flex coupling to the shaft end and aligned the engine as close as I could with it on, then moved the shaft back again and re-installed the flexible one. While it seemed to work in theory there are caveats. If I use the engine at my preferred cruise setting I could put a glass of water on top of it and not see a ripple. As soon as I open up a bit more the shaft pushes the engine forward because the mountings are soft-ish and the whole thing changes. In my boat there isn't a thrust bearing to take the load so I have to live with this limitation. Unless someone corrects me? Please?
OK,
Personally am a admitted old fart,broke 50 so i have a excuse......

The flex is there for a reason,if it is old it does not flex as much but if you can not buy a replacement then machine it and go.If you can, put a new one in after it has ben squared off in a machine shop.
Why would you put a piece of steel into the alignment equation?
Moving the shaft looses all you have gained.....did you square the flex or just trust the..........not going there.Did you machine the steel to the flex?as in same tolerence/out of
Mark
__________________
travler37 is offline   Reply With Quote
Old 25-04-2012, 01:50   #65
Registered User

Join Date: Jan 2011
Location: Fl
Boat: 73 pearson 35
Posts: 142
Re: Engine Alignment

Ok,
So someone teach me something here.
Taking a flex piece to square is a easy job in a shop.Shop min is useally a hour but is a 1/2 hour job.
Making a new piece gets to the 2 hour+ shop time.
What am i missing here?
And apoligizes if i sounded sarcastic previously.
Mark
__________________
travler37 is offline   Reply With Quote
Old 25-04-2012, 02:18   #66
Registered User

Join Date: Apr 2012
Posts: 4
Re: Engine Alignment

Quote:
Originally Posted by travler37 View Post
let me get this right.
you currantly have 2 flanges......one on prop shaft and one on trans......with a flex coupling in between...as in soft not steel thingy.

and someone told you you need to put a hard piece of steel permantly in between them to "get it right"........

get a new piece of flex or take the currant SOFT flex to a machine shop and have them squar it up.then take a digital caliper,
rotate till you get all 4 sides to specs the re-cheack in a week.they will change.recheach weekly till they don't

Amazon.com: Neiko 01407A Stanless Steel 6-Inch Digital Caliper with Extra-Large LCD Screen and Instant SAE-Metric Conversion: Home Improvement=

to easy...
Mark
hands him a tub of hand cleaner to take a shower with.
Thanks for your feedback, but not sure what you mean by 'a new piece of flex... and have them square it up'. I have a digital caliper, and understand the basic principle.
Can you clarify, please?
__________________
Lowestoft Mike is offline   Reply With Quote
Old 25-04-2012, 02:32   #67
Registered User
 
Capn Morgan's Avatar

Join Date: Jul 2009
Location: South East Asia
Boat: Hans Christian 48T
Posts: 381
Re: Engine Alignment

The theory is that you have to align the engine and shaft before you install a flexible coupling.

In my setup, the diameter of the flexible coupling is larger than both the shaft and gearbox flanges. It is in a very tight spot and making any measurements with accuracy less than a foot proved too hard. The piece I had machined is a copy of the flexible coupling and it is planed on both sides, but with the diameter of both couplings. This afforded me the space to be able to measure a bit better, then put the flex one back in place. Still, the problem remains that once power is applied beyond certain setting, the engine moves significantly more than the tolerances required. Proof of this is that I can push the engine by hand in nearly all directions at least as much as 3 thou, the mountings will give. I did this a couple of years back when I replaced the mountings.
__________________
Capn Morgan
'If you can fill the unforgiving minute with sixty seconds' worth of distance run...'
Capn Morgan is offline   Reply With Quote
Old 25-04-2012, 02:47   #68
Registered User

Join Date: Jan 2011
Location: Fl
Boat: 73 pearson 35
Posts: 142
Re: Engine Alignment

Quote:
Originally Posted by Capn Morgan View Post
The theory is that you have to align the engine and shaft before you install a flexible coupling.

In my setup, the diameter of the flexible coupling is larger than both the shaft and gearbox flanges. It is in a very tight spot and making any measurements with accuracy less than a foot proved too hard. The piece I had machined is a copy of the flexible coupling and it is planed on both sides, but with the diameter of both couplings. This afforded me the space to be able to measure a bit better, then put the flex one back in place. Still, the problem remains that once power is applied beyond certain setting, the engine moves significantly more than the tolerances required. Proof of this is that I can push the engine by hand in nearly all directions at least as much as 3 thou, the mountings will give. I did this a couple of years back when I replaced the mountings.
thank you for that,
i learned something and is a good day.....grins
but would still do it different..smiles
Mark
__________________
travler37 is offline   Reply With Quote
Old 25-04-2012, 02:57   #69
Registered User

Join Date: Jan 2011
Location: Fl
Boat: 73 pearson 35
Posts: 142
Re: Engine Alignment

and when i get to my/new to me boat next week will look at coupler and see what i have..laughng......never even thought of it.

Standard and Nib Jaws Digital Calipers (Max Range: 0-80 inch/2000mm) - Series:EC11

Buy the tool and shave some off the flex? long jaws might be....
less frustrating But again thanks for the explanation.
Just a thought
Mark
__________________
travler37 is offline   Reply With Quote
Old 25-04-2012, 03:04   #70
Registered User
 
Capn Morgan's Avatar

Join Date: Jul 2009
Location: South East Asia
Boat: Hans Christian 48T
Posts: 381
Re: Engine Alignment

Yeah Mark, a bit too much theory sometimes. The last time I re-adjusted I just did it with the engine running in flat water, loosened bolts, pushed donkey until it vibrated less, tightened and it seems to work. Brutal, I know. I remember an RAF engineer saying to me 'never force it, just use a bigger hammer'.
__________________
Capn Morgan
'If you can fill the unforgiving minute with sixty seconds' worth of distance run...'
Capn Morgan is offline   Reply With Quote
Old 25-04-2012, 03:04   #71
Registered User

Join Date: Jan 2011
Location: Fl
Boat: 73 pearson 35
Posts: 142
Re: Engine Alignment

Quote:
Originally Posted by Lowestoft Mike View Post
Thanks for your feedback, but not sure what you mean by 'a new piece of flex... and have them square it up'. I have a digital caliper, and understand the basic principle.
Can you clarify, please?
new piece of flex,rubbery piece between tran and shaft flanges=can you buy a new piece.if not use old.
Take it to a machine shop and have them square it up.do not trust injection molded pieces or stuff machined from who knows where.
From previous post/educational experence if your calipers will work then your good to go if you have the room to measure.

good luck and let us know how it works for you.milage may vary
Mark
__________________
travler37 is offline   Reply With Quote
Old 25-04-2012, 03:08   #72
Registered User

Join Date: Jan 2011
Location: Fl
Boat: 73 pearson 35
Posts: 142
Re: Engine Alignment

Quote:
Originally Posted by Capn Morgan View Post
Yeah Mark, a bit too much theory sometimes. The last time I re-adjusted I just did it with the engine running in flat water, loosened bolts, pushed donkey until it vibrated less, tightened and it seems to work. Brutal, I know. I remember an RAF engineer saying to me 'never force it, just use a bigger hammer'.
And your not a long lost realtive to me............
My gramps showed me the same thing.
Losen farthests nuts and kick it sideways till it quiets as i recall.......laughng.
Nice that nowdays we have a way to pass that piece of knowlage on.
Thanks again
Mark
__________________
travler37 is offline   Reply With Quote
Old 25-04-2012, 04:31   #73
Registered User

Join Date: Apr 2012
Posts: 4
Re: Engine Alignment

Ok, Mark, and Capn Morgan, thanks for that. I understand what you mean, but my coupling is made of metal, with bushes mounted in rubber, inserted in the metal disk, as per the attached picture. So, thin metal disk with bushes running through, mounted in rubber, and as you correctly say 2 flanges, each with two bolts - yokes, effectively. If there were 4 bolts per flange, life would be a lot easier.

Since starting this post, I've received the replacement part, and as your post suggests, it's made of some sort of flexible material, hmm....
Attached Thumbnails
Click image for larger version

Name:	Screen shot 2012-04-25 at 09.24.10.png
Views:	36
Size:	99.3 KB
ID:	40356  
__________________
Lowestoft Mike is offline   Reply With Quote
Old 25-04-2012, 05:23   #74
Registered User

Join Date: Jan 2011
Location: Fl
Boat: 73 pearson 35
Posts: 142
Re: Engine Alignment

Quote:
Originally Posted by Lowestoft Mike View Post
Ok, Mark, and Capn Morgan, thanks for that. I understand what you mean, but my coupling is made of metal, with bushes mounted in rubber, inserted in the metal disk, as per the attached picture. So, thin metal disk with bushes running through, mounted in rubber, and as you correctly say 2 flanges, each with two bolts - yokes, effectively. If there were 4 bolts per flange, life would be a lot easier.

Since starting this post, I've received the replacement part, and as your post suggests, it's made of some sort of flexible material, hmm....
Bolts do go all the way through opposite flange.right?
Mark
__________________
travler37 is offline   Reply With Quote
Old 25-04-2012, 05:51   #75
Registered User

Join Date: Jan 2011
Location: Fl
Boat: 73 pearson 35
Posts: 142
Re: Engine Alignment

Quote:
Originally Posted by Lowestoft Mike View Post
Ok, Mark, and Capn Morgan, thanks for that. I understand what you mean, but my coupling is made of metal, with bushes mounted in rubber, inserted in the metal disk, as per the attached picture. So, thin metal disk with bushes running through, mounted in rubber, and as you correctly say 2 flanges, each with two bolts - yokes, effectively. If there were 4 bolts per flange, life would be a lot easier.

Since starting this post, I've received the replacement part, and as your post suggests, it's made of some sort of flexible material, hmm....
Brass bushings in rubber should all be the same lenghth.If they are not then..get them machined so they are.
Can asemble with a fealer gauge.Just pick a point.say 12 oclock.and snug them down till they are the same.Move engine,snug to nothing.should be a set nut on the back of bolts or....somewhere.
Mark
__________________

__________________
travler37 is offline   Reply With Quote
Reply

Tags
engine

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
The Right Way to Run a Diesel off-the-grid Engines and Propulsion Systems 80 09-12-2012 19:06
How to Lift an Engine Charlie Engines and Propulsion Systems 38 03-09-2011 02:12
Cruisers Stranded - in Need of Advice Bright Eyes Engines and Propulsion Systems 61 02-08-2011 11:47
Stalling Universal 5424 Engine ryderstk Engines and Propulsion Systems 13 27-07-2011 10:20
Engine Vibrating Violently when Shifting to Neutral Heikki Engines and Propulsion Systems 24 13-07-2011 08:07



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 23:47.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.