Hi Damiane :)

First, apologies if you have already done this, or found out how to do it, however I'm sure someone else will find this little tutorial helpful, because making a screw via a helix thread can be one of the most difficult models to make, if you don't know what you are doing.

Okay here goes;

1. Open a new window.

2. Go to splines (wiggly line) and choose 'helix spline'

3. Define your start and end points, beginning at 0,0,0 (at the origin), and ending at wherever the end of you screw will be (i.e. 100mm).

4. Now this is where it gets tricky, as you need to define your pitch, diameter and length (don't worry about 'draft angle'- this is for things like battery terminals etc).

Once you are confident that you know these above parameters;

5. Sketch a circle (using 'center point circle' tool for eg) starting at the beginning of your helix. Place the cursor at the end of the helical entity, and tap the 'C' key to set up the correct drawing direction. Your cursor should automatically snap to the bottom of your helix spline that you have just created.

You now have to create another diameter with the above circle tool, which defines the width of your thread. It sounds complicated, but once you've experimented, you will understand, and it is not that difficult.

6. Select the 'One rail sweep solid' tool, first selecting your circle that you have just created, then selecting you helix spline 'sweep'.

There you go!

You have now created your helical swept solid (which should look something like a spring).

Now, not quite finished yet;

7. Select 'back view' (and back view plane too- if ViaCAD hasn't already done so) and sketch another circle starting from the center again. Allow the cursor to automatically snap to the quadrant of the the helical sweep, extrude your circle....and....

Voila!

You have a screw (or at least something that looks like one!). Experiment further until you are happy with the final result.

I also advise people to bookmark this page, for reference, as this process can be quite intimidating to a beginner at first :D

Hello,
Tom(ttrw) asked me to add to this tutorial on making a thread, so here goes!
I am a rookie so bear with me, not good at technical writing, but I will give it a shot.

We will make a 5/16-18 Hexhead Screw. Our finished screw will look like the included file.

Well scratch that because it wont let me upload the finished file so I will have to do it with JPG's. Look at the 3 pictures to see what it will look like.

Walt

Here's one I did years ago CU2 file imported into SharkFX showing basic thread creation.
Larry

Could not resist the temptaion of drawing the nut to go along with the bolt.

This file shows the "Revolved Surface", don't know why it didn't show in the previous file.

Hi Walt,
Here is the nut with chamfers, in case you want to add them.

Wow! Great stuff. In the end I passed it onto someone else to do.

Thanks for all the advice though.

Damian

Hi,

What problem? If you are referring to the need to calculate the rad from the cord length (the P/4 P/8 distance), then that is not a problem specific to Punch software, just a need to understand maths (or find the info on the web.)

I posted the link to save you having to calculate the rads for other thread types if needed.


- Steve

I fully read the error I was receiving when attempting the Rail Sweep.


After 2 evenings of working through the guide and getting frustrated, I read the error properly when i attempted the Rail Sweep step

Helical sweep results in self intersecting body

Next morning, this made perfect sense, this is what i want it to do, make a solid by the edges touching perfectly (assuming that my pitch profile was accurate).

Then I saw the Rail Sweep Tool had an Options button. And in there was a tick box, 'Allow Self Intersections'

And it worked like a charm.

So thanks for the guide and i hope to use it now to create a file with sample male and female threads so i can copy and paste into each new drawing that requires it, build up a library as it were.

Obviously I am still learning but i hope to use ViaCad to produce drawings to eventually 3D print, so screw threads could be useful.

regards
Anthony