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The project is to rotate a load using a motor with a varying speed between like 2000-10000 rpm.

I'm using a flange coupling to attach the cylindrical tube to the motor. Since I will rotate it to high speed, I think I need to tightly and safely attach the load to the motor.

Do you have any suggestion on what coupling or what is the best way to attach the cylindrical tube to the motor safely?

NOTE: the shaft and load are the same lines. this machine is about centrifugal electrospinning which is a machine to fabricate a nanofiber.

enter image description here

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  • $\begingroup$ Are there any special concerns for the coupling, such as does it need to be electrically isolated? $\endgroup$
    – Solar Mike
    Sep 10 '18 at 5:01
  • $\begingroup$ @SolarMike there is no special concern about it. but I'm not sure about it. should I insulate the cylindrical tube? $\endgroup$
    – norul
    Sep 10 '18 at 5:07
  • $\begingroup$ Just thought it may be linked to this project of yours : engineering.stackexchange.com/q/23658/10902 $\endgroup$
    – Solar Mike
    Sep 10 '18 at 5:38
  • $\begingroup$ @SolarMike yes it links to the project. just a different type of load. $\endgroup$
    – norul
    Sep 10 '18 at 5:41
  • $\begingroup$ Dont you have a machine shop around? I mean you should be able to build your design with a lathe. 3D Pinting this seems exceedingly unsafe. $\endgroup$
    – joojaa
    Sep 10 '18 at 8:40
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One can use the Flange Coupling with Key feature and Axis Support Fixed Seat.

Like this:

enter image description here

This design includes both. Also, one can find these off the shelf according to dimension requirements, or one can design one of them easily.


For example: JoyceDayton

enter image description here

For example: Ebay

enter image description here


Most importantly, after the calculation of the bolt torques, one can use lock tight in order to make sure rigid connection.

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  • $\begingroup$ thank you for the reply. for now, I'm using a flange coupling too. but I'm scared it will not safe. $\endgroup$
    – norul
    Sep 10 '18 at 9:22
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    $\begingroup$ @norul what can possibly happen ? Flange coupling are suitable for transmitting huge torque, if you tighten the bolt as stated in the manual it is probably not going to fail. $\endgroup$ Sep 10 '18 at 9:49
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    $\begingroup$ what is your main concern about safety? shear stress, buckling, power loss due to coupling, coupling fatigue, thermal limits... a little bit more info about the safety factor of the important component may lead to more detailed answer, I am waiting ! and last but not least, if you are going to fabricate fiber like this rotation, I strongly suggest you to use radial bearingsradial bearings to support the cylinder (shaft). $\endgroup$
    – F.Bek
    Sep 10 '18 at 10:09
  • $\begingroup$ @SamFarjamirad. I just concern it will be detached while high-speed rotation. thank you for all the reply. I really appreciate it and so happy that you know what I'm doing. $\endgroup$
    – norul
    Sep 10 '18 at 11:49
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    $\begingroup$ @F.Bek, i just concern it will be detach while high speed rotation and i will search about the radial bearing in more ddetails .thank you so much for the reply. $\endgroup$
    – norul
    Sep 10 '18 at 11:52
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The safest way to attach a non-symmetrical load (such as that shown in your photo) that spins that fast (up to 10,000rpm) will be to mount it to a solid base, using bearings or similar, such that its weight is supported separately from the motor shaft. This will minimise vibrations/oscillations of the load.

As a result, there will now be a slight misalignment between the vibrating motor, and the constrained load. Using a a semi-flexible coupling (jaw, Oldham, etc) to transfer the rotation will accomodate this misalignment safely without damaging the motor.

Your biggest worry should be wobble from any off-centre mass of the load, rather than the direct strength of the coupling, per se.

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  • $\begingroup$ and with those type of couplings, electrical separation may also be possible. $\endgroup$
    – Solar Mike
    Sep 10 '18 at 5:56
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    $\begingroup$ Jaw coupling is not flexible and Oldham here is not applicable since the shaft and load are centric. $\endgroup$ Sep 10 '18 at 6:27
  • $\begingroup$ @SamFarjamirad where is it stated about the support of the load - have you seen info about external centering bearings the rest of us missed? $\endgroup$
    – Solar Mike
    Sep 10 '18 at 9:02
  • $\begingroup$ @SolarMike Do you know what this machine designed for ? because i know, and i know the shaft and the load are along the same line, so why Oldham coupling ? Do you see any radial deviation in OP's photo ? or that's only me who missed it ? $\endgroup$ Sep 10 '18 at 9:15
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    $\begingroup$ @SolarMike The complete answer is give by you (pervious question) and FBek here, I don't try to kill time, i just pointed it out the answer here above is incorrect. FYI this is called centrifugal electrospinning. $\endgroup$ Sep 10 '18 at 10:17
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Normally, you would use two grub screws at 90 degrees to each other, to secure the load onto the motor shaft. I have done this to attach a stainless steel flywheel on a motor spinning at 6,000 rpm and it's holding just fine.

To give it extra strength, you can also use something like Loctite 638 to glue the flange coupling, or whatever coupling you should choose, to the shaft. This probably means the coupling needs to be metal, not plastic (although I'm sure there'll be other glues to bong plastic to metal). Note that Loctite 638 is pretty much permanent: once you've glued your coupling onto the shaft, it won't be coming off again (easily).

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  • $\begingroup$ thank you for the reply. in my case, I need to attach and detach the load since I will put some polymer solution in the cylindrical tank. $\endgroup$
    – norul
    Sep 10 '18 at 9:19

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