Rotary engraving into rubber

[Michael Arruda]

Hello,

I would like to make a stamp. I have a CNC Router, so would need to use a material that can be mechanically engraved. It seems most rubber I'm finding is for laser engraving. What kind of material should I be looking for?

Thank you,
Michael

[Viktor Voroncov]

Rubber stamp on CNC router - don't know . First of all you need special tools for rubber engraving. Second - you need special (very hard) rubber, which is usually black and not healthy in use.
If you need just one stamp - order from any laser shop. If you have orders for many stamps - buy laser.

[Kathy Madan]

We used to make rubber stamps with our rotary, but it is a multi-step process using other equipment. We used to rotary engrave the rubber stamp information into scrap formica, then place in a rubber stamp press with regular vulcanized rubber. After that you cut and assemble.

[Michael Arruda]

Hmm... Well, if it's not too feasable making stamps on a CNC, what about making molds on the CNC to cast low durometer urethane into stamps? I don't know if it'd work as a stamping material though. Any experience with this?

Kathy- did you have a vulcanizer to cast the stamps? I'm not understanding your method of creation.

Thank you,
Michael

[Chuck Stone]

If you can make a negative on your CNC, it should be no problem to use
a pourable RTV to make the stamp. You don't want the durometer too low,
though. Something in the 50-60 range (Shore A) should work fine for a stamp.
I haven't used urethane for stamps so I'm not sure how well it
would work. I have some 74-30 here.. maybe I shoud try it!

Scrap corian should work well for the negative..

[Kathy Madan]

I guess it was called a vulcanizer. Basically its two metal plates that heat up and you use a car jack to press the plates together with the rubber and mold sandwiched between. This heated the rubber and pressed it into the mold. It wasn't very fancy but did the trick. We have been lasering stamps for almost 12 years now, its much quicker.

[Bill Cunningham]

I guess it was called a vulcanizer. Basically its two metal plates that heat up and you use a car jack to press the plates together with the rubber and mold sandwiched between. This heated the rubber and pressed it into the mold. It wasn't very fancy but did the trick. We have been lasering stamps for almost 12 years now, its much quicker.

Yup! did that route when I first started back in 89.. I used to scavenge all the formica I could find and cut the text on a pantograph. It was pretty hard on the cutters, but it did the job.. Then, I bought a photo polymer machine that would make the hard masters, and you could use the vulcanizer to heat the matrix and press in the master (like a hard rubber stamp) into the surface. then lay the rubber on and 4 minutes later you had a stamp plate.. Waterwash negatives, clear film, and a laser printer, made life easier than the three bath negative processing.. But the laser makes it Soooo much easier for short run or single stamps.. If I have to make a large quantity of a few designs, I will still use the vulcanizer because for quantity production of a single or few designs, it much faster than the laser..