How to design a ball screw?

[max2017]

I need to deswign the following ball screw, some one knows how? i tried with thread tool but i couldn´t., any tips? i am using inventor 2010

 

I attach other file where i did a ball screw in tha last post.

Edited August 31, 2010 by max2017
Add final work.

[kencaz]

The thread feature applies only a bitmap image of a thread. Use the coil feature to cut the threads using a profile the diameter of the ball.

 

 

 

KC

[max2017]

ok... i am goning to try, i will post the result when i finish.. thank you!

[max2017]

how do you calculate the diameter of the ball?, is the same as the leaD and also i need to select the meddle of the ball or the external diameter? sorry but i am new in this area.

[kencaz]

I would assume a .2 diameter ball per your drawing. Your pitch will determine the ball offset center to center.

 

You don't need to select the middle of the ball. when you select the "Coil" feature it will start in the middle of your ball profile.

 

KC

[numberOCD]

Algebraic approximation: With 140 degree concave dip, and the length of single thread (1/threads-per-inch) = x, to get the relative ratio of flat filleted edge to dip depth and width use a circle with diameter 95% of x (0.95x) and set the radius of the coil to the radius of filleted edge plus 18.2% of x (R+0.182x)

[JD Mather]

When you get it done drag the red End of Part marker to the top of the browser, then save and zip. Attach the resulting zip file here and I'll show you a special consideration you need to make to get it right. (KC's image is not technically correct.)

[kencaz]

Attach the resulting zip file here and I'll show you a special consideration you need to make to get it right. (KC's image is not technically correct.)

 

I was merely showing a concept JD. I did not attempt to design it for him.

 

KC

[max2017]

Thank you guys i apressiate it, i will zip my work when i finish JD. I am sorry but i had to do some other designs so when i have a chance i will finish it. Thank you again.

[max2017]

KC i forget, .2" is Lead, Pitch is 5 mm so my ball have to be of 5mm?

[max2017]

Here is the link of my final work: Download Here

 

I dont like how the trhead starts, is there any step to make the beginning of the thread more fine like it starts with a little point?

[JD Mather]

I have just started to take a look at this thing, but I can't figure out what the purpose of WorkAxis1 is? Isn't it just a duplication of the Orign Z Axis?

 

Can't figure out why use used Loft1 rather than a simple Chamfer?

Workplane1 doesn't look like it is needed either?

 

Sketch2 has 2 dimensions when only one is needed? (use = constraint)

 

Sketch6 has 4 dimensions where only one is needed?

 

Sketch10 is unconstrained (and won't result in correct geometry anyhow - but I'll come back to that later).

[max2017]

i will review this at the afternoon and then i will answer-question you about some doubts that i have and i hope you can help me, thank you!