Drill bit geometry

[Mr.Ralf]

Hello everyone, I am working on designing a drill bit as illustrated in the figure below. My approach involves creating a pipe and wrapping two helical curves around it. Following this, I plan to design a profile that will be used to cut the pipe, thereby achieving the desired drill bit geometry. I attempted to utilize the sweep component in Grasshopper for this process, but the outcome hasn’t met my expectations. Can anyone provide guidance on how to refine my Grasshopper file or suggest a more effective method to accomplish this task?

drillbit test.gh (21.7 KB)

[inno]

I think you are on the right path

there’s just one thing I would advice, instead of drawing what you have to subtract, and then subtract it (Boolean operation) I would just draw what you need, and then somehow extrude it

for instance, here the top part draws the drillbit section as a curve

and then the bottom parts creates a vertical array of those curves (array height = pitch)

then rotates them step by step until reaching 360°

and then lofts and caps the results:

even if the number of vertical sections is very high, I believe sweeping the curve on a helix (your approach) would produce a geometrically more accurate result than mine, so take this just as -maybe- inspiration

Drillbit_inspiration.gh (17.4 KB)

[Mr.Ralf]

Thank you so much, @inno, for your amazing work! I truly appreciate all the help you’ve provided. Now, I’m looking to modify the end of my project to achieve either a sharp or ball end. For the ball end, I’m thinking of using a Boolean split with a half-sphere. However, when it comes to the sharp end, while I can define the angle, I’m still unsure about it. Do you have any suggestions or advice on how to approach defining the angle for the sharp end? Thank you again for your assistance.

test for ball end drill bit.3dm (1.8 MB)

[inno]

I think you need to go Solid Boolean for this

What I would do is to draw a 2D section and Revolve it, then use it as solid for boolean subtraction

for instance, if it’s a spherical end I would first draw a quarter circle and offset/connect it to get this:

then use Revolution around the Z axis to make it into a solid (here I’m using Rail Revolution because I’m having some troubles with standard Revolution component, but as I’m providing a Circle as guide Rail, the result is the very same)

this is how it looks after Solid Subtraction:

for a sharp end on custom angle, I guess you can use the very same method but change the Revolved section into something like a rectangle, like this:

you could first rotate the XZ construction plane by an angle, then build the very same rectangle over it, which results in this solid using for subtraction:

the Value List help organizing the flow, so you can chose between sphere and rectangle section

now that I see it, I believe the radius of the spherical-tip is not the very same radius of the tip so with this slider you can change it:

Drillbit_TIP_inspiration.gh (29.7 KB)

[Mr.Ralf]

Dear @inno , I really appreciate it. You have been a huge help to me, and this experience has taught me a lot.

[Mr.Ralf]

Dear @inno,

I’ve been working with your script and am struggling to modify it to achieve a result similar to the pictures below. Is it possible to create a drill geometry like that using Grasshopper or your script, or would it be better to use another software?

Thank you!

#endmill HRC55 2 Flute Ball Nose End Mill For Iron Supplier

[inno]

I think this design is pretty different from the previous one (and also much more complex)

it might be possible to do in GH, probably I would use many (MANY) boolean subtractions from a base pipe with round caps? I think the best way to understand more might be to try to understand the way and order they have CNC-machined it?

the main issue is understanding its shape (if you want to reproduce that exactly as it is) and also introducing some parameters that are actually useful and “connect well” with each other, for which I have absolutely no idea

for instance, this surface looks like it’s a continuous one, and it could be the very first thing that was milled:

then this surface might be the second milling operation, with a slightly more steep angle:

the presence of this edge here:

makes me think that those long milling that moves down to the very end of the tool were done first:

I mean these ones, both of them, for each side

and as very last thing these surfaces here:

this dent that I see here:

makes me think that none of the initial thin surfaces that defines the silhouette of the tool, entirely lie on the very silhouette of a round-capped pipe… but at the same time, it might easily be that those silhouettes just recede a little bit just at their very ends, in such a way to allow for the chips to have space to be thrown away?

long story short, if I had to guess the order of the operations, I would say:

1. turning the external silhouette profile (which is also the residue of surface #1) with a revolve

2. thinning the core with two milling (Solid difference using two lofts along a conical spiral)

3. straight cuts (solid difference)

4. this edge here (I guess solid difference once again?)

how to put that together is not very straightforward… I would start with revolving the profile, the using maybe something like this ( Creating a spiral form - #14 by Birk_Binnard ) to create the conical spirals on which to build the solids for the boolean subtraction at step 2, and see where it goes

[Mr.Ralf]

drill tool modif1.gh (25.2 KB)
drill tool test1.3dm (434.2 KB)

dear @inno

Thank you for your guidance and advice. I followed your suggestion from the previous script, where I designed the closed curves and then extruded them. I completed this manually in Rhino, but the result isn’t quite as I hoped. I’m aiming to achieve a shape closer to the complex drill shape.

I also watched a YouTube video to better understand the fundamentals of closed curves, drew them accordingly, and used your script to extrude them.

Do you have any additional advice or suggestions for improving the shape?

Thank you

Siemens NX - End Mill Modeling