I have a 34" sprintcat. Running 5s2p, feigao 580L 1649 kv. Anyhow, the longest section of the stuffing tube extends from the hull towards the strut. It ends about3/16" before the strut. The strut is a bearing style strut. When bench testing, ( simply blipping the throttle), I notice quite a bit of vibration in this area of the tube. How can I get rid of this, being that there is so much unsupported tube? It is .187 flex, running linerless k@s brass.
flex vibration
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Here is a couple of things you can try:
Check your collet. It may be out of round or balance. To check...simply spin your motor in hand with collet attached. I have two of the Octura .187 collets and only one of them is in balance
OSE recommends using 7/32" brass tubing with .187 cable.
Try a slight S bend on your stuffing tube or crimp your stuffing tube slightly every 2 inches to reduce harmonics.
Use lots of grease.
Read here; http://forums.offshoreelectrics.com/...ad.php?t=11896
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pics
here ya go...Comment
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It's the pic. I'm running linerless. There is no room to go into the strut with teflon or the brass. I like the idea of the S bend but I may have to adjust my motor angle to raise the motor shaft a bit, or just put a much more aggresive type bend in it. My collet runs true and is balanced pretty well it seems.Comment
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It's hard to see in picture, but you should have used the next size larger tubing epoxied to your hull. That way you can remove your stuffing tube from hull without having to cut it away from hull and cured epoxy. I would cut that out and re-do.
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KS brass tubing is telescopic. Meaning the next larger size is a tight slip fit. If using a 1/4" or 7/32" stuffing tube use the next larger size epoxied to hull (short piece). That way your stuffing tube can be easily replaced. A slightly sharp bend or S bend will prevent tube from rotating while cable is spinning.Comment
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Take your flex assy out and put it on a flat surface. Clean it well prior to. Roll it back and forth with your fingers where the rigid shaft is silver soldered to the flex, observe how well it was centered when soldered. You would be amazed at how many folks dont do the one simple check. It was probably misaligned when soldered, more common then you think from name brand sources. It will be appearent right away if its not properly centered. And its a huge source of power robbing friction.
A better method is to chuck up the rigid part in a drill press and spin it up. You can immediately see an out of tolerance solder/ misalignment job.
JohnChange is the one ConstantComment
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Take your flex assy out and put it on a flat surface. Clean it well prior to. Roll it back and forth with your fingers where the rigid shaft is silver soldered to the flex, observe how well it was centered when soldered. You would be amazed at how many folks dont do the one simple check. It was probably misaligned when soldered, more common then you think from name brand sources. It will be appearent right away if its not properly centered. And its a huge source of power robbing friction.
A better method is to chuck up the rigid part in a drill press and spin it up. You can immediately see an out of tolerance solder/ misalignment job.
JohnGovernment Moto:
"Why fix it? Blame someone else for breaking it."Comment
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Sure looks like too small of a stuffing tube but hard to see in the pic.
Is the shaft soldered or loctited in the stub? I had a long flex on a hydro that slapped a bit but when under load in the water it was nothing.Comment
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Most struts have a nose piece on them that your tube slides into, the fact that it is unsupported by the strut will cause many a problem. Any harmonic or balance related flexing will move the tube about instead of the tube limiting them. The tube is to small ID as Jeff stated as well. See if you can get a strut only { no mount=cheaper) with the nose and replace the stuffing tube. If you heat the epoxy with a hair dryer it will peal away easily.Comment
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Most struts have a nose piece on them that your tube slides into, the fact that it is unsupported by the strut will cause many a problem. Any harmonic or balance related flexing will move the tube about instead of the tube limiting them. The tube is to small ID as Jeff stated as well. See if you can get a strut only { no mount=cheaper) with the nose and replace the stuffing tube. If you heat the epoxy with a hair dryer it will peal away easily.Comment
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