I love my speedmaster struts with the floating bushing. They work great, and with minimal wear on any components.
Keeping the bushing in the strut?
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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.
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I cant speak for why Aeromarine or any other manufacturers that use a fixed bush. All i know is after speaking with Harry at Speedmaster on this very subject & they deff use in their design the rotating & floating bush. My take on this & why ive made them this way as well is by rotating it reduces the wear on the bush & the stub because the rpm is effectivelly reduced by both rotating. It also helps with any wear on the bush being in one place. Martin.Comment
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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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I never implied that the soldered flanged bushing was designed to be soldered into the stuffing tube. That’s why I explained that locals do solder them since they can be. And that reason is because they float. These guys don’t like that. I don’t blame them either. It makes no sense to have additional rotating components when the end result will be increased friction and wear. Don’t waste your time trying to explain that that’s not the case. The facts of its operation clearly proves otherwise. Your old mantra of “The Laws of Physics Never Change” is quite appropriate here.
Adding additional clearances, increased friction points (lubrication holes act like cutters) in a struture and simple material compatibility (galling) don’t make for a more efficient design. And that’s what a floating bushing does. The additional clearance just adds to the instability (balanced load) issue. We’re back to friction again.
If it was an accepted building practice it would be prevalent. But its not. For the reasons stated above. Not withstanding, the fact that SpeedMaster does use this design does not imply that its flawed or imperfect. RC stuff often defies decent engineering. It comes down to cost. Now look at common industry. The real world. Nothing like that is used. Matter of fact most bushings, liners or bearings are either captured or contained. Why? Your an engineer. You know why.
JohnChange is the one ConstantComment
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JohnChange is the one ConstantComment
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I just set up a Speedmaster strut for my FE_30. The .250" brass tubing will NOT fit into the strut, and I tried 2 different brand new struts. You either need to ream the strut or sand the tubing. I actually got a piece of tubing stuck and had to drill it out, which made the strut the perfect size to accept the .250" tubing. Which I found a little surprising because repeated drilling beforehand had little effect, since a drill cuts at the end and a reamer on the sides. I guess the presence of the brass tube caused the drill to cut a minute amount of the aluminum, opening the hole when it didn't before. I see where both Fluid and m4a1usr are coming from; I guess, as always, what works is what is right.Fast Electrics Have A Small Carbon Wake
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Just take a peice of sandpaper in one hand and the 1/4" tube in the other...wrap the sandpaper around the brass tubing and just twist the dang tubing till it fits in the strut...Lordy, Lordy!!!!! You are not polishing a diamond!!!!!!Comment
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well, I got the tube today and got to sanding. It seems there is a lip inside the strut, does the tube go all the way through? I can get the first bit of it to go through, but it won't go all the way through, and I sanded it quite a bit.Comment
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BTW - Here's a funny one for all the "e" people around here:
http://forums.offshoreelectrics.com/...8064-EngineersComment
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100% agreed. Some are tight. Some are loose.
BTW - Here's a funny one for all the "e" people around here:
http://forums.offshoreelectrics.com/...8064-Engineers
JohnChange is the one ConstantComment
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