A new idea on engine alignment (At least I've not seen it in my research)

Discussion in 'Fiberglass and Composite Boat Building' started by missinginaction, Apr 27, 2012.

  1. missinginaction
    Joined: Aug 2007
    Posts: 640
    Likes: 36, Points: 28, Legacy Rep: 512
    Location: new york

    missinginaction Senior Member

    Hi Folks,

    OK, it's almost time to line up my driveline and reinstall the running gear in my Silverton restoration. When I pulled the engine I found the old nylon stuffing box was just a hair from being destroyed by misalignment. The good news was that the shaft log was not damaged. As many probably know with a v-drive there is so little room under the engine that it's damn near impossible to service a conventional packing gland. I ordered a PSS Shaft Seal as it seemed the only reasonable solution.

    I understand how to align the shaft but in all the reading I've done it seems that one difficult part of the job is betting the shaft centered in the log. My old shaft is serviceable but since it's bronze it's pretty hefty. I see some people block the shaft up and attempt to get it centered and there are other methods.

    I thought of a different technique and thought I'd run it by you all here.

    I have a 1 1/4" bronze shaft.
    The shaft log is 1 3/4" outside diameter.

    Take a chunk of hardwood say 2" thick and clamp it into a drill press. Now, using a Forstner bit bore a 1 1/4" hole.

    Repeat the process using a 1 3/4" Forstner bit and another chunk of scrap.

    Now I have a hardwood block that slides over my prop shaft and a block that slides over my shaft log.

    I line up the two blocks so that the small hole is exactly centered in the large hole. Glue the blocks together with epoxy or some other strong adhesive. Install the block on the shaft log, slide the shaft through the strut and the wooden block. Now provided the glue that I use doesn't fail I have a perfectly centered shaft.

    Seems easier than blocking or hanging..........Once the engine is aligned remove the shaft and wooden "alignment tool" and reinstall the shaft and PSS Shaft Seal.

    I'll post some photos below......

    Regards,

    MIA
     

    Attached Files:

  2. tunnels

    tunnels Previous Member

    Away from your origanal question!! who did the glassing ?? all those white patchs are pockets of air ! bubbles where its never been rolled out properly and is not sticking to what ever is under it so 20% of the glass ,give or take a bit is doing almost nothing !! :eek:
     
  3. missinginaction
    Joined: Aug 2007
    Posts: 640
    Likes: 36, Points: 28, Legacy Rep: 512
    Location: new york

    missinginaction Senior Member

    You know there might be some voids in there but that laminate is over built anyway. What you're looking at is five layers of 1708 Biaxle stitch mat. PAR has told me that I would have been better off using fiberglass cloth but what's done is done. That 1708 soaked up better than a gallon of resin. This was my first attempt at laying up heavy fiberglass. It may not be perfect but I know it's much stronger than what was in there originally.

    With all due respect though, critiquing my fiberglass layup, which has been in the boat for a couple of years now isn't adding too much to the discussion regarding engine alignment. ;)

    Regards,

    MIA
     
  4. tunnels

    tunnels Previous Member

    Cant pull the wool over my eyes !!

    They are pockets of air and theres lots of them !! i been doing my job for to many years to not be able to recognise what i see !!:mad:
     
  5. tunnels

    tunnels Previous Member

    Bubbles !! :(
     

    Attached Files:

  6. troy2000
    Joined: Nov 2009
    Posts: 1,709
    Likes: 163, Points: 63, Legacy Rep: 2078
    Location: California

    troy2000 Senior Member

    What you're proposing sounds reasonable to me. It's kind of a reverse of the stepped piece of wood used for alignment when you're replacing the clutch on a car or pickup.

    But instead of trying to align and glue two pieces, I think it might be easier to take one block, drill a small pilot hole, and then drill your two final sizes from either end.
     
  7. troy2000
    Joined: Nov 2009
    Posts: 1,709
    Likes: 163, Points: 63, Legacy Rep: 2078
    Location: California

    troy2000 Senior Member

    I can feel your distress as a craftsman. But if I understand his response properly, he's saying his layup was such overkill that the bubbles don't really matter.
     
    1 person likes this.
  8. masalai
    Joined: Oct 2007
    Posts: 6,836
    Likes: 119, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    Then remove the excess weight of USELESS GRP.... It is only hiding other defects that could lead to an unforeseen disaster...

    When s41t happens on a boat at sea you DO NOT GET A SECOND CHANCE... If you sell the boat and disaster strikes, you as builder are LIABLE... What evils are you hiding in a shoddy patch up job?
     
  9. missinginaction
    Joined: Aug 2007
    Posts: 640
    Likes: 36, Points: 28, Legacy Rep: 512
    Location: new york

    missinginaction Senior Member

    Thanks for the response Troy and the pilot hole idea, I see what you mean, it would be easier to make a proper tool that way. Thanks.

    Regarding the fiberglass, what's done is done. When I looked back I realized that this part of the job was done in 2008. Keep in mind that this is a restoration of a 1973 Silverton sedan. The boat had been knocking around successfully for 30+ years before I took her on. I just did the best job that I could. I posted here and took advise from trusted suppliers that I know personally. I used System Three resins, and epoxy friendly 1708 on the advise of my supplier. Some here suggested that fiberglass cloth would have been a better choice (and over the years I've come to the conclusion that they were right) but by the time I discovered this the job had been completed.

    I felt it necessary to replace the engine stringers and the floor that supports the rear of the cabin. This was quite an experience. Much cleaning and grinding and solvents and the old polyester was still stained dark. Take a look at the original construction and what I did. You'll understand why I'm not worried. I used Gerr's Elements of Boat Strength to determine the depth of the layup.

    I just did the best job that I could with the skill and knowledge that I had at that time. Perfect, of course not. But shoddy? A vast improvement over what was there though. Thanks for the concern guys.
     

    Attached Files:

  10. SamSam
    Joined: Feb 2005
    Posts: 3,561
    Likes: 110, Points: 63, Legacy Rep: 971
    Location: Coastal Georgia

    SamSam Senior Member

    A pretty clever solution for the shaft. That sort of thinking keeps one healthy.

    It seems kind of cheesy for people to jump all over other things. There seems to be an assumption that any imperfection in a boat is a recipe for instant, inevitable disaster. Folks have no idea of the crap that is turned out by big name boatbuilders.
     
  11. gonzo
    Joined: Aug 2002
    Posts: 12,259
    Likes: 188, Points: 63, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    That is way overengineered. I use a couple of small wedges and sometimes a piece of rope to keep the shaft centered. It's all you need.
     
  12. troy2000
    Joined: Nov 2009
    Posts: 1,709
    Likes: 163, Points: 63, Legacy Rep: 2078
    Location: California

    troy2000 Senior Member

    Can we say "melodramatic over-reacting,' boys and girls?

    I knew you could....;)
     

  13. missinginaction
    Joined: Aug 2007
    Posts: 640
    Likes: 36, Points: 28, Legacy Rep: 512
    Location: new york

    missinginaction Senior Member

    Sam,

    Troy perfected my idea. I hadn't pondered it enough to come up with his pilot hole idea. So thanks Troy.

    My relatively small 27' Silverton won't be blue crab fishing on the Bearing Sea with the Hillstrand boys. Regardless we should all want to do the best job we can.

    It's funny Troy, my brother in law lives out near you in Simi. He used to do Personal Injury Law. I asked him one time about the liability issues that so often come up on these forums. He just looked at me like I was nuts.

    His comment was something like "Look, if you're completely incompetent, do a really bad job and then sell the boat and it sinks or something....Well, maybe someone could come back at you, but probably not and even if he could only for the sale price or some fraction. You see there is this concept called Caveat Emptor...." He then went on to talk about fraud and deliberate concealment of defects. That might be different.

    As far as I'm concerned as long as I do the best job I can and am honest I don't need to be perfect.

    That's that.
     
Loading...
Similar Threads
  1. mtumut
    Replies:
    4
    Views:
    675
  2. swade
    Replies:
    3
    Views:
    631
  3. jamie1965
    Replies:
    3
    Views:
    832
  4. angryfish
    Replies:
    6
    Views:
    979
  5. CatBuilder
    Replies:
    4
    Views:
    1,270
  6. darchitzel
    Replies:
    20
    Views:
    7,642
  7. shizlenut
    Replies:
    9
    Views:
    2,914
  8. CDK
    Replies:
    5
    Views:
    1,681
  9. bajapaul
    Replies:
    4
    Views:
    3,620
  10. milljfred
    Replies:
    0
    Views:
    1,048
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.