How to model an ACME thread for lead screw?

[AfricanDan]

Hi,

How would i go about modeling an acme thread for a lead screw on a milling machine?

thanks

[Bishop]

1. Get the specifications for the thread.

2. Model a rod that's your desired length, with the OD of the rod being the minor diameter of the thread.

3. Model the cross-section of the thread against the edge of the rod. Model only the cross-section of 1 thread.

4. Coil feature using the rod as the axis, set up the options to match your needs and the thread specs.

[JD Mather]

What reference (textbook?) are you using?
Can you post the file of what you have attempted so far?
This is a pretty easy part to create, but I would like to see what you have attempted before providing step-by-step solution.

[AfricanDan]

Hi
thanks for replys, ill have a go at that bishop and see how i get on, g/f just had baby so not got round to it yet, but need to crack on soon

Hi JDMather, im not working off any textbook im just trying to model a lead screw for a small cnc machine which will be say inch DIA 10TPI 1000mm in length.
Ive not managed to successfully create anything, i had a play about and had a look on the net for a tutorial but with no luck.
im very new to inventor and CAD in general and have learnt inventor off my own back step by step designing this machine so can get it up and running but i have Level 1 2 and 3 courses to get on with so can get bit more experience which i will get on with soon, so if i seem a little in-experienced and feel like im asking questions i mabye should already know i appologise as ive only just done a year in autocad 2d, but inventor has opened my eyes to do more.

i know i could get away with just doing a round bar for the screw but i would rather find how to do things properly and learn.

thanks again

[JD Mather]

You should go to the library and pick up a reference book or search the internet and find a reference for ACME thread dimensions.
Once you have real information on the dimensions I can help you model this thread.
An ACME thread has a 29° included angle to the teeth.
The profile of the tooth will be created and then the Coil command used to cut it from shaft.

[Dadgad]

I've done it with Autocad, but it was quite tedious and a challenge coaxing it to sweep the helix.

[JD Mather]

http://www.unionmillwright.com/2884.pdf
http://en.wikipedia.org/wiki/Trapezoidal_thread_forms
http://www.atimetals.com/products/Do...hreadforms.pdf

[JD Mather]

You will have to attach a file here if you are having trouble.
I did a simple Revolve of a rectangle for the rod
and a Coil to cut the thread.
Just like turning the diameter on a lathe and cutting the thread on a lathe.
Acme Sketch.PNGCoil.jpg

[AfricanDan]

managed to do it, think i worked the dimensions out right, i couldnt do it by using formula's like it looked like you did i just worked the dimensions out and entered them in

more learning needed on my part

anyway thanks for your help

heres the file, i understand the will be better and easier ways to do it but i dont know how yet

ACME DIM2.jpg

[Dadgad]

managed to do it, think i worked the dimensions out right, i couldnt do it by using formula's like it looked like you did i just worked the dimensions out and entered them in

more learning needed on my part

anyway thanks for your help



heres the file, i understand the will be better and easier ways to do it but i dont know how yet

Attachment 36063

Congratulations AfricanDan that looks real nice.