Keeping the bushing in the strut?

[Boaterguy]

Understood, I did get the wrong stuff. I had a small piece of K&S 1/4" tubing and it was slightly big, with some sanding I'm sure I can get it to fit.

[carlcisneros]

the tubing you need for the Speedmaster strut is 9/32".
Take your shaft bushing down to your hobby shop and take the tubing taht is marked as such and
slide it INTO the tubing. It should be a nice slip/ no slop fit and rotate pretty freely.
also take your strut with you and find a nice piece of tubing that slids into the strut with a good push.

you will still have to do a bit of sanding on the tube, but all the tubing is not exactly the same size
due to manf. tollerances.

I hope this makes sence.

[Fluid]

the tubing you need for the Speedmaster strut is 9/32".

Why on earth would you tell the guy the wrong size tubing when he is already having problems with this?
The correct size tubing is K&S Stock #1149 1/4" x .014" according to the label on a 36" piece I am holding in my hand. This fits into the strut (with some sanding) and the bushing is a perfect slip fit into the tubing.



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[sailr]

The brass bushings DO rotate inside the strut. I've never had one that was a press fit! The teflon bushings do press into the strut.

[longballlumber]

Oh boy.... I give up.... "Too many Cheif's, not enough Indian's"

The correct size tubing is K&S Stock #1149 1/4" x .014" according to the label on a 36" piece I am holding in my hand

Listen to Fluid he is pointing you in the right direction...

Later,
Mike

[sailr]

1/4" is what fits into the strut, NOT 9/32" . I use a short piece of 1/4" into the strut and then run the rest of the way with 9/32 or even smaller, stepping it down with the various size pieces of tubing necessary when runner smaller shafts. I go 1/3s" over the shaft size. With .187 flexshaft I run directly inside the 1/4" stuffing box without teflon. I've had much better luck without the teflon.

[sailr]

FLUID is steering y straight!

[carlcisneros]

ooopppssss sorry sailr you are right guy. I was measuring something else when I did that and wrote down the wrong numbers instead of the 1/4" K&S tubing.

can you say DUH?????????????

[martin]

I agree with Sailr on the strut bushing rotating & floating as thats how ive made my own with this design as it gives less wear on the bush & stub. I have seen it mentioned a few times on this forum that the brass bush should not rotate & should be a firm push in fit. According to Harry at Speedmaster the bush should definataly rotate & float back & forth. Martin.

[Boaterguy]

Wow, I didn't mean to start a riot. I am heading to north bay and I need to find a hobby shop on the way to get some tubing, it's the last I need to get the boat running. I will have the whole boat with me so if I need I can bring it in.
I had a good Idea to sand it down, if I put the tubing LOOSELY into the chuck of A drill and spun it up with a piece of sandpaper would that sand it down well?

[Fluid]

Wow, I didn't mean to start a riot....I had a good Idea to sand it down, if I put the tubing LOOSELY into the chuck of A drill and spun it up with a piece of sandpaper would that sand it down well?

You didn't, we just wanted you do do it right and also not to mislead lurkers who learn from these discussions. I put my 1/4" tubing into my drill press and use 600-grit paper to sand it down. Be careful to do it carefully so as to get the same diameter along the tubing and don't sand too far! Stop and check frequentoly, it can change from just a little snug to too loose pretty fast.


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[Boaterguy]

well, lucky for me I arrived at my grandpas about two hours ago, with a drill press! hopefully he has some 600 or more grit. Anyone in the north by area that can recommend an LHS?

[m4a1usr]

The brass bushings DO rotate inside the strut. I've never had one that was a press fit! The teflon bushings do press into the strut.

Maybe in a Speedmaster 21 strut. I own Fullers, Aeromarine, Top Secret and the stock stuff. The bushing's do not rotate. I'm guessing you never replaced the bushing in your UL-1? How about your SV27? They dont rotate. My Aeromarine Stinger bushing is PIA to pull out to when I have to regrease. Now maybe Speedmaster is the odd ball. What your saying makes no sense from an engineering view.
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I agree with Sailr on the strut bushing rotating & floating as thats how ive made my own with this design as it gives less wear on the bush & stub. I have seen it mentioned a few times on this forum that the brass bush should not rotate & should be a firm push in fit. According to Harry at Speedmaster the bush should definataly rotate & float back & forth. Martin.

Why would you build the "sacrificial" load part to wear all the rest of the components in a minimal friction design? Theres a reason why bearings, bushings ans sleeves are made. They take the load, when out of tolerance you replace it. At least thats how engineers are supposed to think. If engineered correctly you dont create multiple parts for replacement. Just one. The Speedmaster Bushings you buy from Aeromarine laminates are listed as having a "Soldered Flange" Design. Go to their web site. I have a call in to Aeromarine for the answer to this question. The gas guys in my area "solder" the bushing into their stuffing tube. That makes sense. Wears out. You toss it and install another. A floating bushing not only wears itself, but the housing its rotating in. That makes sense? I dont get it. But I'm just an engineer.

John

[lectriglide]

Much more discussion of this topic in this thread, very good reading.

http://forums.offshoreelectrics.com/...light=floating

[Fluid]

..The gas guys in my area "solder" the bushing into their stuffing tube. That makes sense. Wears out. You toss it and install another. A floating bushing not only wears itself, but the housing its rotating in. That makes sense? I dont get it. But I'm just an engineer.

An interesting take on mature technology which has proven to work for hundreds of racers for decades. Some of the fastest gas racers in the world race in my area, including several US-1 holders. Not a single one of them "solders" the floating bushing into the stuffing tube. And after talking to them, they almost never have to replace the bushing - the usual reason is losing it, not wearing it out. The stuffing tube wears out first from not running teflon liners - if that even wears out. Lead/teflon bearings OTOH wear out regularly. Not a surprise, lead is soft and the teflon coating just a few thousandths thick.

I too am an engineer, and the floating bushing is an elegant solution. The relative rotational speeds experienced by the bushing and the stuffing tube are half what a bearing sees, so wear is dramatically reduced. The bushing is cheap and so easy to replace - if it ever needs to be replaced. In my experience using the floating bushings for over a decade, as long as you keep them lubricated with a quality lube the bushing/stuffing tube do not wear out. The wear patterns are surprisingly shallow, bu tthen the load is spread out over several lateral inches, not over less than an inch as with L/T bearings. This makes sense when you consider the properties of the different bearing/bushing materials and the resulting wear from the far differing rpm on the wear surfaces.

You are completely misunderstanding what the term "soldered flange" means. There are two different bushing designs sold, one has the short piece of tubing (which keeps the bushing from receding into the strut) soldered to the bushing tube. The other kind has a flare on the end to perform the same function. "Soldered flange" does not mean you are supposed to solder the bushing onto the stuffing tube. But don't take my word for it, ask the guys who make more of this equipment than anyone - SpeedMaster.

As far as the AquaCraft "bushings" the Chinese blew it on the tolerances. Ask Grim what the bushings are supposed to do in the AQ struts.....



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