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26-12-2007, 21:48
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#16
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Registered User
Join Date: Mar 2003
Location: Philippines in the winters
Boat: It’s in French Polynesia now
Posts: 11,368
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Quote:
Originally Posted by Kanani
Balance has nothing to do with it. The surface of the flange must be perfectly square with the shaft. If it isn't you cannot get proper alignment of the prop-shaft.
If you can put the prop-shaft in a lathe and resurface the face of the flange, after getting it off an re-installing it, that would be ideal. Maybe even better than a new flange.
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Yeah! And don't forget the concentricity in relation to the bore, as well as the trueness of the register. After beating the spit out of the thing it would all have to be re-machined in an assembly, if there is enough metal to do so.
And that "perfectly square" is NOT, NEVER and CAN Change in sea conditions. See this article............ Marine Engines : Engine-Shaft Alignmnet - Troubleshooting by David Pascoe, Marine Surveyor
__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
The measure of a man is how he navigates to a proper shore in the midst of a storm!
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26-12-2007, 23:18
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#17
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Registered User
Join Date: Mar 2006
Location: Australia
Boat: Seabird Kayak :)
Posts: 523
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David Pascoe's articles are great, I have read that one several times.
I took the beast to the local auto machine shop and the guy said no worries he could remove it with his hydraulic press. A few hours latter I returned to a sheepish look of defeat and still have the flange on the end. I have tried some hammering but i am not so keen on that, i think a small ribbon of cemtex around the end of the flange might work.
At least i got the new (used) motor working today and it purrrrred along on the garage floor, no smoke, easily strated and no vibration !! So at least i had one victory today.
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26-12-2007, 23:47
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#18
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Registered User
Join Date: May 2007
Location: New Zealand
Boat: Trismus 37
Posts: 763
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Is it possible that it has been welded on and the weld bead machined back so as not to appear welded, I'm clutching at straws here but if the machinist can't move it with a press there has to be more going on than we think?
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27-12-2007, 00:22
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#19
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Registered User
Join Date: Mar 2006
Location: Australia
Boat: Seabird Kayak :)
Posts: 523
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After the phosphoric acid all the raw metal was revealed, no prior welding and no pins, grub screws, etc. i have the original drawing that came from yamaha for the flange (Yamaha part i gather) and it is definitly a tapered shaft with keyway. i can look in both ends to see the key. The nut on the flange end is not the same thread size as the propeller end so the taper may or not be the same as the prop.
Every project has it's challenges, this was one of the unseen ones. It's all an adventure !
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27-12-2007, 02:07
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#20
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Registered User
Join Date: Sep 2007
Location: Colombo
Posts: 1,059
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If the coupling is on a taper then another way to try and move it if not tried already is to get the gear puller on it and tighten it up as much as possible (without bending the flange ) then hit the end of the gear puller screw - the one that centres on the shaft - with some good sharp whacks from as heavy a hammer as you dare (I don't know how big the coupling is but if not small then use a sledge hammer). Often that will break the grip of the taper and it will pop off.
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27-12-2007, 05:38
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#21
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Registered User
Join Date: Jun 2005
Posts: 1,901
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Quote:
Originally Posted by ribbony
After the phosphoric acid all the raw metal was revealed, no prior welding and no pins, grub screws, etc. i have the original drawing that came from yamaha for the flange (Yamaha part i gather) and it is definitly a tapered shaft with keyway. i can look in both ends to see the key. The nut on the flange end is not the same thread size as the propeller end so the taper may or not be the same as the prop.
Every project has it's challenges, this was one of the unseen ones. It's all an adventure !
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I had to do this operation on a Yamaha 33 a few years ago. It's definetly a tapered shaft of 25mm, keyed and a nut on the hub of the trans flange.
Loosen the nut put a gear puller on it but don't bend the flange. If there is a way to put the bottom of the hub against something solid. Like a vice and have the shaft hang down. Then whack it hard with a hammer. It'll come apart every time.
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27-12-2007, 06:15
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#22
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Registered User
Join Date: Mar 2003
Location: Philippines in the winters
Boat: It’s in French Polynesia now
Posts: 11,368
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Quote:
Originally Posted by ribbony
David Pascoe's articles are great, I have read that one several times.
I took the beast to the local auto machine shop and the guy said no worries he could remove it with his hydraulic press. A few hours latter I returned to a sheepish look of defeat and still have the flange on the end. I have tried some hammering but i am not so keen on that, i think a small ribbon of cemtex around the end of the flange might work.
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Not a very good Machinist! Don't bother with hammering, if a press ??? won't get it off, neither will a hammer. Hope he didn't charge you$
I think you're just going to have to bite the bullet before the shaft and threads are ruined. I'd split the thing over the keyway with a part-off wheel or hacksaw and see if it pop's off. If not, then split the opposite side too.
But first I'd try a different Machine Shop! One that works on heavy equipment. The 60 ton press that I have would turn that thing into a pancake.
__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
The measure of a man is how he navigates to a proper shore in the midst of a storm!
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27-12-2007, 13:17
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#23
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Registered User
Join Date: May 2007
Location: New Zealand
Boat: Trismus 37
Posts: 763
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I agree with Delmarry, my 80 ton press would turn that thing inside out, a bit of pressure, a bit of heat, and it should be off. IF NOT I would offer it to NASA as an alien piece of metal for them to study, perhaps from mars??
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27-12-2007, 13:33
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#24
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Registered User
Join Date: Oct 2007
Location: Southern California
Boat: Was - Passport 45 Ketch
Posts: 887
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As steel corodes, it also expands (up to 25%). This will not only seize the flange to the shaft but the size of the keyway in the flange will become smaller and the key will become bigger.
I am not surprised that a press would not force the key down the keyway. You must apply a tremendous amount of heat, particularly in the area of the keyway. It must be done with an acetelene torch so that the flange can be heated quickly without heating the shaft too much. I'd wrap the shaft with wet towels or run cold water on it, to keep it cool. As soon as the the flange is red, it should tap right off.
If you have access to an air hammer/chisel, that is far more effective than a BIG hammer or press.
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27-12-2007, 13:50
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#25
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Registered User
Join Date: Mar 2006
Location: Australia
Boat: Seabird Kayak :)
Posts: 523
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Plenty of ideas there, let me try some before resorting to the cemtex.
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27-12-2007, 14:08
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#26
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Registered User
Join Date: May 2007
Location: New Zealand
Boat: Trismus 37
Posts: 763
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if you still have access to a press put some pressure on the shaft with the coupling held on the bed of the press before you apply the heat, then as the heat expands the coupling it will let go before the temp in the shaft gets too much!
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27-12-2007, 14:28
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#27
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Registered User
Join Date: Jan 2006
Location: North Carolina
Boat: 44 footer
Posts: 953
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Cut off wheel, go most of the way through the metal, grab a big cold chisel and smack it with a big hammer. Use a chisel that the tip won't touch the shaft unless it spreads out a LOT.
If the crack doesnt spread and split down to the shaft... cut the other side and cut down again, almost to the shaft. Now take a grinding wheel and chew out a 1/4 inch of the flange opposite your first cut. The flange is where the strength comes from while trying to split it... thats where the height is.
Now find somewhere to brace the flange and knock the shaft out.
Rinse and repeat, you'll never put a tool mark on the machined surface of the shaft that way.
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27-12-2007, 15:22
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#28
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Registered User
Join Date: Mar 2003
Location: Philippines in the winters
Boat: It’s in French Polynesia now
Posts: 11,368
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Quote:
Originally Posted by Steve Pope
I agree with Delmarry, my 80 ton press would turn that thing inside out, a bit of pressure, a bit of heat, and it should be off. IF NOT I would offer it to NASA as an alien piece of metal for them to study, perhaps from mars??
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Shoot, an 80 ton press would just make it's own hole.
__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
The measure of a man is how he navigates to a proper shore in the midst of a storm!
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27-12-2007, 17:15
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#29
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Registered User
Join Date: Mar 2006
Location: Australia
Boat: Seabird Kayak :)
Posts: 523
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Yeeeeha !
It is off the shaft.
How ?
A combination of suggestions:
1/ cranked up the gear puller
2/ lots of big hits sideways on the flange with it sitting on a block of hardwood
3/ retightened the puller
4/ heated the flange quickly
5/ Some more big hits and POP
Sure was nice to see that off at last.
The flange is a bit bent and someone gave me a good contact for getting a new one made up, looks like they can do a new one at a realistic price and they sell flexible shaft savers as well so I will get one of those to match.
Thanks for all the tips.
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27-12-2007, 18:01
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#30
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Registered User
Join Date: Oct 2007
Location: Southern California
Boat: Was - Passport 45 Ketch
Posts: 887
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Whewwww!!!! I'm tired just thinking about it..
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