Proper Use of Sleeve Bushings
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Almost all of this stuff is the KISS method. I know I have everything done to be at the lowest resistance I can. The rest is set up and propping.
Just think if you can lower driveline resistance, less friction at the strut from metal to metal, run thrust bearing at the motor and what would be the benefit....how about more prop, or less amp draw so your peak power stays longer in the 4th lap?
All depends how anal you want to be....I'm anal. Nothing hard about understanding friction and resistance or prop torque and cable whip.
It really is a about set up in certain water conditions.... but driving is the key!
I can be faster than any boat out there but ending upside down will never prove it.Comment
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The only thing I will add is this is just one set up style you are seeing on some boats....started with nitro/gassers. It works and that is simple enough. Nothing real hard about how or why they do it this way.
Although...almost EVERY FE set up run for years ran Fuller/fine or Octura struts and teflon. The SV and UL1 and Vegas were the first I had ever seen from the factory this way and it was simply carried over from their nitro versions....why re-invent the wheel when it all fits easy enough for the FE versions.
I simply use one of these that slides in the strut and can be used for any of the struts on SV/vegas or any of those but not using the stuffing tube all the way thru the strut.
They begin life as 1/4" KS and then end up with 3/16" ID with slots.
I guess why not get rid of the teflon from these factories? Just makes the tube larger under the hull for drag.Comment
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This thread helped me learn a lot IMO. Thanks for starting it Jay, and for all the other's input. Bottom line, I have some fixin' to do to a few boats. Final thought : I'm way happy with Jeff's wire drive with ball bearing strut on my latest hydro build
and would recommend it without reservation to anyone.2008 NAMBA P-Mono & P-Offshore Nat'l 2-Lap Record Holder; '15 P-Cat, P-Ltd Cat 2-Lap
2009/2010 NAMBA P-Sport Hydro Nat'l 2-Lap Record Holder, '13 SCSTA P-Ltd Cat High Points
'11 NAMBA [P-Ltd] : Mono, Offshore, OPC, Sport Hydro; '06 LSO, '12,'13,'14 P Ltd Cat /MonoComment
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I know this thread seems like it's on it's way out, but I figured it was worth taking a picture. See attached. This is the problem that I (and apparently a few others) are having. The bushing rides down towards the dog when the gap is set properly. There is a larger diameter or flange on the end of the bushing. When the flange pops out, the bushing has a ton of slop within the strut. This creates "point contact" between the bushing OD and strut ID due to the misalignment or concentricity. I think everyone would agree that "point contact" is not good if the bushing is suppose to rotate. Seems it would only wear out the strut ID.
I just purchased a new bushing for WAY too much money and it fits tighter. All my experience tells me that this bushing for the UL-1 is NOT supposed to spin or slide freely down the strut axis. Spinning bushings??? might work great for other set-ups, but not with the stock UL-1 IMHO (unless the flange on the end of the bushing is made longer).Attached FilesComment
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I had the exact opposite, it slid all the way in and made the prop shaft wobble about 1/16th of an inch. This was my fix, cut a small piece of 6mm shrink tubing and shrink it over the end of the bushing and then jam it back in the strut. That strut has way too much play in it and allows the bushing to move in or out too far.Comment
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Thanks 6S! That sounds like it would work to hold the UL-1 bushing granted that the gap is large enough. Typically, my gap has been very small. Not sure that it matters, but one thing we might lose out on if we shrink the entire thing is the bushings ability to store lube between the OD of the bushing and ID of the strut. The bushing (besides the flange diameter) is a smaller diameter for the rest of the length in order to slip into the stuffing tube. This smaller diameter creates a space between the bushing OD and the strut ID that makes an excellent storage for lube. Again, not sure that that matters much.Comment
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Prop thrust transfer to hull?
OK, I've read this whole thread twice, and I can't find anything being said about how the thrust from the prop is transferred to the hull? Surely the electric motor bearing is not designed for thrust loading of this type? If the strut bushing is free to slide in and out, and rotate, then is the prop thrust transferred to the rear of the aluminum strut or up the flex shaft to the motor?
I posted a question about this matter in the Blackjack Q&A area, but no one has responded.
MikeComment
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yes unless you run a thrust bearing between the coupler and motor mount all the pressure is placed on the rear bearing.
it is usally advised to run a thrust bearing if the rear plate on the motor isnt pinned some howComment
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i have never run a thrust bearing on my boats with just feigao motors and i have never had a failureComment
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I will have one more go at it.
Basically all it is doing is making the stuffing tube the bushing housing and can make the part a but stronger using the stuffing tube. BUT....it will wear out the stuffing tube if rotating in there and then you will have slop...more than you need and then you may not be able to do anything except put in a new stuffing tube.
Here is my fix.
Cut your stuffing tube so that it fits maybe a 1/4" in the nose of the strut.
Then build a new bushing ( or buy one) I can make them to fit tight....take your solder and put a few drops of solder on 4 points on the lower end and 4 spots around the bushing at the top end. such as 12,3,6 and 9 positions. Or just solder a ring around the top end of the busihng and the bottom part...this is used to take up slop for an improper fit as the strut is a bit lose. it is slightly more than .250 id.
Now try to fit it in the strut and just file the solder points down so you have a good snug fit as you slide it in the strut. If not take a file and just slightly file the solder points down until you get a tight fit.
SS and brass make a great bearing surface....brass and brass does not and can lead to gauling and wear.
Simple fix and you will be able to put new bushing in as needed.
Fix it once like this and go have fun with it.Comment
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Ozzie, many motors (cheaper ones) have shims between the bearing and the rotor to take up slop to keep the rotor centered...front to back....if you don't damage the bearing you will end up eating those shims up and then you will have more shaft play in your motor...may not kill it but not good on it either. Well... unless those fragments now get in the motor and kaboom....eat your mags or rotor surface. Dead short if they used a thin metal shim.Comment
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