Try google, "drill bit cross section"
cgsociety.org shows how, in general.
Extrude and rotate a cross section (somehow.)

it's not a drill but this tut can gives some ideas ;)
http://moi3d.com/forum/index.php?webtag=MOI&msg=4388.138

Hi Mati - the Extrude with path option is not what you want for this kind of shape because that particular method does not rotate the profile as it travels along the path.

The sweep tool is the one you want to use for making a shape that follows a path and also rotates with the path as the path changes direction.

In the sweep tool there is also an option to control how the profile rotates around the curve tangent as it moves along the path - you will want to set that to Twist: Flat for this kind of shape that you're doing.

See this previous examples of doing screw threads for some more explanation:
http://moi3d.com/forum/index.php?webtag=MOI&msg=767.2

- Michael

Hi bemfarmer,

> Try google, "drill bit cross section"
> cgsociety.org shows how, in general.
> Extrude and rotate a cross section (somehow.)

So probably what you would want to do for a cross-section like that is to think about creating it by cutting a base shape.

So you'll start with just an initial solid tall cylinder for the main body, then build 2 tubes that follow a helix path twisting around it, and then use boolean difference to cut those tubes away from the main body shape.

- Michael

Made a cross section with a circle and conic, mirror, trim.
Having fun trying to extrude twist, but I guess there is no twist command yet. :)
Lunch break is over, will try your suggestions later...

Hi Brian, yup no twist command yet but that is one that I expect to add in the new "Deform" tools section. It will probably be pretty convenient for making things like this once it is in place.

In the meantime the method to use is to basically construct it already twisted from the start by making some construction pieces by sweeping along a helix path.

- Michael

I modeled a drill in MoI a few weeks ago to use as a prop in a larger scene.

Swept cross section of drill down a helix. Revolved a profile of the tip and Boolean Diff with the drill to form the point. Fillet to get cutting edges.

Rendered in KeyShot.

Ed

I have believed that a drill was this :)

Well, without a properly engineered MoI drill bit - the very nice T-Splines-SuperSolidClaim cordless drill body would be useless!

Well I used to know a supervisor who (incorrectly) called a hand drill a "drill motor", and a drill bit a drill. :)

Success with boolean difference of 2 swept helix(s). (Wrong pitch - looks more like a wood auger.)
Be sure to sweep a circle that does not touch the helix.



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Ed's method made me think of another way to do it.

Starting with this bottom profile:



Select it and then run Transform > Array > Circular, and pick the center point as the array rotation origin.

Normally Array circular is used for making a circular pattern of shapes, but all it really does is rotate things around the center point, so you can use it combined with the vertical step option inside of it to make a pattern like this:



That does a rotation and a vertical step for each item.

Then window select all those curves and run Construct > Loft to build a surface through them:



- Michael

Very quick and easy!

Seems almost like a twist command. Take a 3d object, slice it into many cross sections, rotate each cross section and loft???

lol.. Very cool.. We can brush our hair with that!!! :o

Cool Michael
You have shown the great
power loft tool -
al

Yep - It's a twisty machine.

I made a bar of twisted wroght iron using Michael's method. Probably have way to many steps in the array, but it's too late tonight for a do-over :)

Got it red hot with my torch.

Bent it into an arch with Flow command.

I'll finish making it into a gate for the ranch some day. Gotta win the lotto and buy a ranch first.

Ed