Skip to content

Wildcard week

This week I decided to make part of one of ongoing projects in our lab. We want to have system that recycles plastic and then makes Filament from it. So i decided to make shredding shaft of that device.

I checked Youtube and found Video which contains mostly what i want.

Here is link to that video.

CAD

Firstly I opened FreeCAD and drawed one tooth of Shaft

Then I tought that it would be better to cut plastic in smaller size, so I made 4 edges

In the middle of tooth there must be hole, to set on hexagonal shaft. I drawed 2 hexagons with 30 degree оffset, because I want teeth to be universal, and it will give me option to put teeth every 30 degree instead of 60.

This is final view of hole.

Then I came to my friend Gevorgs factory to make that details, and after small discussion, he adviced me to change detail a little bit. So I made tooth less sharp

And changed hole type to just one hexagonal.

Also I made Washer detail, that I will put between teeth.

CAM

As I sad, I came to Gevorgs factory and met this BEAST!!

It is laser cutter, that can cut steel sheet like butter.

Gevorg imports my drawing to machine

set all necessary settings, told me all security rules and runs machine.

Firstly we cutted one tooth to see if it fits shaft. The cut was absolutely clear from one side, but from other it looks like this.

So we grinded with an angle grinder.

As shaft we used 10mm Hex key.

After that we cutted all teeth.

So it’s time to grind them

Just a very cool image

Shaft

To make shaft Mkhitar came for help . We cutted Shaft at necessary length

And putted it in Lathe machine to make edges round. We need that to attach bearrings.

It was made of Chrome Vanadium, so it was really hard to work with.

Final Result

After puting all Teetch and washers we got this beatiful Shredder. It is as brutal as place where it was made.

Conclusion

This week was one of weeks that I liked most at FabAcademy. I worked with heavy machines and liked that a lot. I learnt a lot from Gevorg and Mkhitar about Metalworking․

DXF files

Tooth DXF Washer


Last update: June 23, 2025