Chuck for rotation axis

[dh9ts]

Hello all,

for my 4th Axis of the K40 laser, I needed a solution to quickly adjust the clamping to different diameters.
Link to forum entry: https://forum.freecadweb.org/viewtopic.php?f=24&t=46818

Furthermore the solution should not use much of the available working area.

So I designed a chuck to clamp the different parts.
The black parts will be 3D printed, the transparent parts will be lasercut from acrylic.
The chucks can also removed when they are completely open and can be exchanged with new ones.

The design is made with the Part Design Workbench and Assembly 4.
Thanks for all of you who contributed to this amazing workbenches and Freecad.

Overview:

spannfutter.png (203.14 KiB) Viewed 2957 times

Mastersketch:
Here the position for the jaws is calculated. The Spiral is designed with the Part Workbench. The Position of the chucks then calculated by
the pitch of the spiral and the current angle.

MasterSketch.jpg (169.52 KiB) Viewed 2957 times

Animation:

Animation_compr.gif (786.73 KiB) Viewed 2957 times

Freecad Version (Ubuntu daily):

OS: Ubuntu 18.04.4 LTS (ubuntu:GNOME/ubuntu)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.
Build type: Release
Branch: unknown
Hash: e1cfaf129866b3482bf8650e8993089a834747f0
Python version: 3.6.9
Qt version: 5.9.5
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: German/Germany (de_DE)


Thorsten

[Gregory son of Carl]

Cool! That animation is hypnotic.
Is there a reason you chose to make your own chuck instead of purchasing a similar design? Without the center piece, it looks pretty close to a regular self-centering 3-jaw chuck with machinable jaws.

[HoWil]

Please report back when you have built it.
Please share your model if it works.

[OficineRobotica]

Wow...beutifull work and screenshots. Can we have a bit more insight of how you managed the animation?

[dh9ts]

Wow...beutifull work and screenshots. Can we have a bit more insight of how you managed the animation?

Sure, I will also attach my model, you can download it here:
https://cloud.thorsten-stoffregen.de/s/JqSrringHSknE84

Animation and Assembly are done with Assembly 4, so you need this workspace to animate it.

To animate it, select the part "Spannfutter", switch to the Assembly 4 Workbench and click on the animate button.
The Variable "winkel" controls the rotation angle in degres. It should be between 0 and 1500 ° (1500 / 360 = 4,2 turns)

animate.png (215.41 KiB) Viewed 2319 times

In the assembly the animation is controlled mostly with the following parts:

• The variable "winkel": Controlls the actual position.
• The sketch "Anordnung" is the basis for the animation. Here the rotation LCS it attached and also the position of the 3 grippers is calculated.
  To each end of the 3 Lines for the gripper a LCS is attached for the position of the grippers (LCS Backe1, BAcke2, BAcke3). These are moved when
  the variable changes.
• The LCS "Achse" is use to attach the not moving parts.
• The LCS "Achse_Rot" is like the LCS "Achse" attached to the sketch, but also takes the angle from the variable "winkel" into accout, so if the variable changes, the LCS rotates.

Sketch "Anordnung" / Master Sketch:

master_sketch.png (223.57 KiB) Viewed 2319 times

Attachment of LCS_Achse_Rot:

lcs_achse_rot.png (85.08 KiB) Viewed 2319 times

All names are in German, I did not expect to share this model. So in the future maybe I should switch to english names

Hopefully this helps you, best regards.

[dh9ts]

Cool! That animation is hypnotic.
Is there a reason you chose to make your own chuck instead of purchasing a similar design? Without the center piece, it looks pretty close to a regular self-centering 3-jaw chuck with machinable jaws.

Hi Gregory,

yes, the design is very similar to conventional designs.

But I needed a chuck which fitted into a very small and defined space, for a K40 Laser:
https://forum.freecadweb.org/viewtopic.php?f=24&t=46818

And also it was fun to play around with the design.

Best regards.

[dh9ts]

I finished building the part today, here are some pictures:

Before assembly:

IMG_20200628_171420k.jpg (829.87 KiB) Viewed 2261 times

Assembled:

IMG_20200628_174418k.jpg (970.2 KiB) Viewed 2261 times

IMG_20200628_174434k.jpg (469.09 KiB) Viewed 2261 times

IMG_20200628_174428k.jpg (410.65 KiB) Viewed 2261 times

Some notes:
- The spiral is glued to a backplate. I could also 3D print the two parts together, but I think the lasercut surfaces will lead to a smother operation.
- The mechanism works better than I anticipated, it runs very smooth and has also a lot of gripping power.
- Printing quality is not so good, 5 year old printer but the parts are working.

[Gregory son of Carl]

That turned out pretty slick looking. Being able to see how the mechanism works through the clear components is a neat feature. Also, thanks for including a link to your model.

But I needed a chuck which fitted into a very small and defined space, for a K40 Laser:
https://forum.freecadweb.org/viewtopic.php?f=24&t=46818

And also it was fun to play around with the design.

Makes sense and I can definitely relate to that.