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Author: Subject: Drive shaft uni joint angles?
DANMAN

posted on 11/2/16 at 06:07 AM Reply With Quote
Drive shaft uni joint angles?

So when winter comes around (I'm in Oz) and I'm not driving the Blade as much I intend to do the conversion from a reverse box to electric reverse. I plan on replacing the reverse box with a two piece prop shaft with a center bearing and using a starter motor for the electric reverse side of things.
I have made up a gear that sandwiches between the output shaft and the propshaft:

http://i32.photobucket.com/albums/d13/GURUDAN/58281173-BE98-41F0-805D-5AA6220A8427_zpsbhw5pm5w.jpg


Also made up a bracket to hold the starter motor in place:

http://i32.photobucket.com/albums/d13/GURUDAN/648FC661-C29D-4511-BA9B-1EC243DE41D1_zpsehlup8qd.jpg


It even works: http://vid32.photobucket.com/albums/d13/GURUDAN/Clubbie%20Electric%20Reverse_zpsmkm4h5pf.mp4

So this side of it looks like it will work fine, the dilemma I have now is the angle of the front half of the prop shaft. Currently it is set up like this:

http://i32.photobucket.com/albums/d13/GURUDAN/Reverse%20Box%20Setup_zpsgclqhplg.png

After speaking with the local drive shaft mob and telling them what I wanted to do one of the guys there (quite abruptly) told me that it wouldn't work and that UJ's will not work at any more than 3 degrees (seriously he was quite rude, some people have no idea how to talk to customers). This is a problem as it currently sits at about 10 degrees, it has also done about 5,000kms like this since I've owned it and who knows how many kms before that and seems to work just fine. I thought I would ask the masses and see what they thought? I am thinking for the front half of the shaft I could use CV joints at each end, the center bearing in the middle and then a normal UJ shaft for the rear section between the center bearing and diff (live axle BTW).
Has anyone done this before or can anyone recommend any other options?

[Edited on 11/2/16 by DANMAN]

[Edited on 11/2/16 by DANMAN]






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mark chandler

posted on 11/2/16 at 08:22 AM Reply With Quote
My blade engine runs parallel with the side rail so the UJ is far from straight, maybe 15 degrees and it has not been a problem.
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motorcycle_mayhem

posted on 11/2/16 at 08:30 AM Reply With Quote
Looking at the extreme CV angles of some drive systems, I believe 3 degrees is a too conservative a limit.
Plenty of pictures out there (Z-cars, OMS Hornet, buggies, etc.) showing just how extreme it can get.
Tripode joints (e.g.) mini pot-type or specialist GKN versions thereof seem quite happy at the rear of Jedi's.

Of course, to minimise the angle will minimise stress, strain and heat.

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sprintB+

posted on 11/2/16 at 10:36 AM Reply With Quote
For some forgotten reason, I seem to remember that they should run lightly askew, U/J's that is, 7 degrees is stuck in my head, something to do with letting the needles in the bearings rotate slightly whilst in use.
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gremlin1234

posted on 11/2/16 at 10:59 AM Reply With Quote
there was a detailed discussion of prop angles etc on here recently
I think the answer was props should run at an angle, but the flanges should end up parallel, ie engine not rotated relative to diff

shall do a quick search...

sorry, didn't find the thread, but if you google
" site:www.locostbuilders.co.uk prop angles "
there's lots of info

[Edited on 11/2/16 by gremlin1234]

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mark chandler

posted on 11/2/16 at 12:55 PM Reply With Quote
i guess at the end of the day it's a compromise on longevity, For the miles we do and level of periodic checking I do not see this as an issue.
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coyoteboy

posted on 11/2/16 at 01:47 PM Reply With Quote
Yeah with UJ's it's important to match lobe locations and not go too extreme but shouldn't be too conservative - 10-15 degrees wouldn't scare me at all.






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gremlin1234

posted on 11/2/16 at 11:27 PM Reply With Quote
quote:
Originally posted by mark chandler
i guess at the end of the day it's a compromise on longevity, For the miles we do and level of periodic checking I do not see this as an issue.
no, if there is any significant runout, there's horrible vibrations

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DANMAN

posted on 14/2/16 at 04:39 AM Reply With Quote
Thanks for the help guys, feel a lot less concerned about it now.






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coyoteboy

posted on 16/2/16 at 01:13 PM Reply With Quote
http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml



.






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nick205

posted on 16/2/16 at 03:20 PM Reply With Quote
IIRC there is supposed to be some angular change for CVs to run right. I guess it may be so the bearings rotate and any lubrication moves around. No idea what it should be, but if you think about drive shafts working through suspension travel they cover quite a large movement. Having rebuilt drive shafts I also remember that the shafts themselves are usually spring loaded each end to ensure they stay central and absorb length changes during angular movement.






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greavesy7

posted on 21/2/16 at 07:45 AM Reply With Quote
Have you got any better better pictures Of your gear and starter motor bracket ; )
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