Chemical milling

[brendan riceParticipant @brendanrice44889]

[brendan riceParticipant @brendanrice44889]

Hi All

Does anyone work for a company that has this facility or have access to it? I need to get a couple of small encoder wheels made 2″ diameter in .25 – .3 mm steel or copper. The cut outs are too small for me to do on the mill and the companies i’ve been asking are just not interested in doing a couple for me unless i pay silly money.
Cheers
Brendan

[Les Jones 1Participant @lesjones1]

Hi Brendan,

Have you considered using photographic film supported on a metal hub instead of metal with slots in it. If you could find someone with 21/4″ square format camera you could create a large master on paper and photograph it at at calculated distance to produce the size you require on the negative. If it is just a simple quadrature encoder you want I may still have a copy of a program to print out an encoder.

Les

[Keith LongParticipant @keithlong89920]

Hi Brendon

Suggest you do a bit of “Googling”, depending on what you’re looking for there are ready made wheel encoders for robots from around 3 or 4 euro each. It may be possible to adapt them to your design or your design to them. Also its worth looking for laser cutting services, they can cut those materials for you and should only need a master drawing from you, which could be done with a simple cad (free) program or even the drawing facilities in MS Word or Openoffice for example. It’s a long time since I had some encoder discs etched, but then on a one off basis they seemed expensive but I could get a complete A4 size sheet etched for the same price with as many on it as I could fit in, which brought the unit cost down. I supplied the art work for those as that was quite expensive if you had the etchers produce that as well.

Keith

ps if you make them in copper or brass you can etch them yourself using printed circuit board chemicals. Everything you need is readily available.

Edited By Keith Long on 15/08/2011 23:14:45

[Lawrie Alush-JaggsParticipant @lawriealush-jaggs50843]

Hi Brendan

 

You will find encoders of that diameter made of mylar in dead inkjet printers. You can use one as a positive to etch your copper

[John McNamaraParticipant @johnmcnamara74883]

Hi Brendon
US digital have the wheels and sensors, quite inexpensive.
I have no connection with this company, however they are often mentioned and well regarded on CNC forums.

Encoder wheels and sensors here ….

 

Cheers

John

[brendan riceParticipant @brendanrice44889]

Hi Guys

 

Thankyou very much for the posts and information.

 

I really did think that the process would be fairly inexpensive hence the reason I was asking, i did indeed google and sent out requests to half a dozen companies asking for quotes which came back and were very high.the best quote was180 quid for a sheet of 40.

 

It is a US digital encoder and I currently use thier mylar discs but the AC motor is used in our electric race motorcycle where motor temps can get pretty high and the mylar starts to get a bit too flexible at 150 deg and 8000rpm!

 

Not wanting to waste anyone else’s time and spurred on by my own ignorance of the costs I now realise it is going to be much easier and cheaper to mill them on my starmill.

 

Thanksfor the replies though guys.

 

Brendan

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