Read an engineering textbook. ■

Prakash, I can do this for you. Would you like my consultancy rates? ■

Grabber.

LOL ■

Dear Mr. Prakash,

You are referring to design of hollow shaft and right now you have designed it as solid shaft. If you want to design it as a hollow shaft, you have to take the values applicable to the hollow shaft and make the design. Shaft design procedure will not change whether it is a hollow shaft or solid shaft. While designing as a hollow shaft you will require the modulus of section and section moment of inertia as input. Use these values considering hollow shaft and you will get the size for the hollow shaft.

No one opts for a conversion factor for converting solid shaft diameter into hollow shaft diameters, etc.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

I'm a child of the '60's so ...

The best things in life are free

But you can keep them for the birds and bees

Now give me money

That's what I want

That's what I want, yeah

That's what I want

I'm also a child of a closed pension scheme so ...

You're lovin' gives me a thrill

But you're lovin' don't pay my bills

Now give me money

That's what I want

That's what I want, yeah

That's what I want

.... ;-)

Oh, and in preparation for my engineering exams (old fashioned 'sudden death' type) I read books, some I bought, some I borrowed from collegues, some on loan from libraries. No internet forums in those days! ■

Dear Mr. Prakash,

The most important thing in shaft design is the deflection

Rulmeca advises 1/3000 of the bearing length to be the deflection limit

if you calculate all the parameters of the shaft you will find that the deflection based calculations gives the most safe results ■

Deflection has no meaning by itself. Its an old wife's tale. If all pulley designs were of the same type, maybe. Since they are not, we resort to engineering the contact stress mechanics of locking devices to study fatigue limits which include the mean and alternating stress levels, stress on bolts, stress on hub, yield limits and plastic flow, and oscillating strain on bolts, et al. ■

No modern pulley designer would use a deflection criteria due to the complexity of analyzing for shaft to the hub and after the hub, hub contribution to stiffnes, locking device stiffness, end disk and shell stiffness contributions. Shaft deflection is no longer a simple beam analysis. Its use was primitive and like the dinosaur its day has passed. ■