Carbon fiber pulley and machining leftover material

[galp]

Hi!

So I got this Idea to machine pulley from carbon fiber sheet. I'm thinking of using 3mm sheets and cutting 4 of them and then bolting them together to get 12mm in width. Carbon fiber could also work better because I can use 1mm or 0.5mm tool. I machined pulley from 10mm aluminum today but I don't know how will it work since there is some leftover material in each slot.

This is what I'm talking about. The blue stuff:




Circle represents the smallest tool I have for aluminum -> 2mm. The blue stuff from picture above is between circle and 3d model.





The question is could carbon fiber work for a pulley? And also should I worry about that leftover material?

BTW: If someone is interested in cf sheets you can get them on ebay. A4 paper size 200×300×3mm for about 25$.

 

[onloop]

Carbon fiber pulleys sound interesting! I hope you make one I really want to see it. It would look awesome with my carbon fiber motor mounts.

However I'm not sure how cost/time effective if would be.

Regarding your alum pulley, i dont think it is suitable as is. The pulley teeth corner radius need to be very accurate otherwise belt doesn't mesh and slips.



My CNC factory uses wire EDM to cut the pulley teeth profile into aluminium.

Here's a lovely video explaining wire EDM

[youtube]RQmVplQ5bdE[/youtube]

 

[bandaro]

Wouldn't advise carbon for the pulley, it's not the type of material that handles the forces placed on a pulley well. Sure, carbon is lightweight and strong, but it gains its high strength to weight ratio by using the fibres in a particular way, and a pulley will use them in a completely different way. Carbon has a high tensile strength, but very low shear.

Regarding the pulley teeth cutout, enertion missed the main problem here in my view, what tooth profile are you using? By the looks of it, you have a t5 profile or similar. I have played with this profile before and they are far weaker than a HTD or GT style gates belts. Additionally, if you use a HTD profile belt, you have the added advantage of no corners in the tooth profile, so a 5mm pitch can easily be rough cut on a 4.75mm up spiral and then finish cut with a 3mm up cutter. This will ensure an accurate and consistent profile without the uncut corners that you have.

Onloop - Surely the EDM is an unnecessary secondary process and it would be cheaper to do the whole process on a turn mill? And I assume the carbon is water jet cut?

 

[galp]

Hi!

I will definately go with htd belt and pulleys. They will be easy machined. Just few 3mm holes on a circle and then a cutout. Thank you!