Machining / carving / milling silicone ?

[Externet]

Hi.  Any methods for milling channels in silicone rubber that you may suggest ?

[Sensei]

In every material I drill in, I start with a smaller radius/size and then increase the bit size when I'm done. Bit by bit. You don't want to mill the whole size at once. That could damage the whole thing.

Edited October 5, 2022 by Sensei

[John Cuthber]

Freeze it until it's not "rubbery" then machine it quickly.

[Sensei]

2 hours ago, John Cuthber said:

Freeze it until it's not "rubbery" then machine it quickly.

This was also my thought, but silicone rubber is resistant to -55 C, which could be a problem in a typical home.

"The embrittlement point of typical organic rubbers is between -20° and -30°C, compared to -60° to -70°C for silicone rubbers."

 

Edited October 6, 2022 by Sensei

[Externet]

Thanks, gentlemen.  Can anyone please translate what is called a 'needle' here ?---> https://vimeo.com/236164661    

Seen rubber stamps made with a pinkish very soft rubber... how are they made?  Casting or carving ?

 

[Sensei]

1 hour ago, Externet said:

Seen rubber stamps made with a pinkish very soft rubber... how are they made?  Casting or carving ?

Complex stuff I am 3D printing but it is TPU.

https://en.wikipedia.org/wiki/Thermoplastic_polyurethane

There are others e.g. FLEX.

 

Edited October 6, 2022 by Sensei

[Externet]

Would this put to spin fast be able to carve silicone in your opinion ?

[ hypodermic - injection needles ]

 

Or a U gouge chisel ?

[Sensei]

You have to experiment by yourself with material at hand.

Like I said earlier, I would drill very small hole e.g. 1mm, then 1.5mm, then 2mm etc. until reaching final size.

There are mini drills for precise operations: https://www.google.com/search?q=mini+drill+machine

I bought mine in an electronics store. They are used by electronic engineers.

 

[Ghideon]

2 hours ago, Externet said:

Would this put to spin fast be able to carve silicone in your opinion ?

EDIT: Language issue; I confused Milling with Drilling. My comments below may not apply at all!

Intuitively* I would do the opposite; very slow motion to slice through rather than try to drill. Success might depend on how much work you plan to do; doing many and/or deep holes could be rather time consuming if going slow. If available a hollow drill** might work better. A pipe with sharpened edge might work if hollow drills are not available. I would try to avoid regular (spiral) drills in soft materials, it could get stuck, tearing the soft material rather than cutting. Fast rotation makes it tricky to stop fast enough, increasing the risk.

Some other possible options depending on the situation:
If the material is reasonably thin and holes are small I would try a Single-hole punch (for leather, cloth, or thin plastic).
Thin material and larger holes: Hollow Punch
If material is soft and does not take damage; compressing it and drilling or cutting through might work
If precision is required it might be an option do do a silicon mold around pins instead of drilling holes 

 

 

*) Note I've never drilled though silicon but have some experience with having to improvise with tools or use them in unorthodox ways, hence I share an opinion even without having an experience from the exact situation.

**)video showing how to sharpen a pipe, using it as a hollow drill to make a hole in rubber: https://www.youtube.com/watch?v=yQ-s0sBMHig

Edited October 6, 2022 by Ghideon
Comment may not apply to OPs questions

[zapatos]

I think I would try a very high speed grinder with a relatively fine edge and a light touch. The idea being you remove very small pieces very quickly before the silicone gets to respond much to the impact of the grit on the grinder. Perhaps a Dremel would work for you.