Spindle encoder

Good morning,
I have built a cnc lathe and its working great, apart from the spindle encoder which seems very slow. I am using an optocoupler off ebay and I think it cant read fast enough, so threading is a maximum on 300rpm. Can some show me how to built an encoder from scratch and whats they used. Would like to thread at 550rpm so its cutting the material as opposed to tearing it.
Many thanks

Isn't it better to bite the bullet and buy a proper encoder with A/B/Z channels?

Chipo try:
Try to reduce the current oft the sending diode.
Less saturation can speedup recovery timing....

Hi tecno,
I would love to but as I am a mechanical engineer and have a very very limited electrical knowledge would you mind pointing me in the right direction?

Do a Google search and you will have many sources, these are quality encoders.

omron rotary encoder A/B/Z TTL

russkinch wrote: Good morning,
I have built a cnc lathe and its working great, apart from the spindle encoder which seems very slow. I am using an optocoupler off ebay and I think it cant read fast enough, so threading is a maximum on 300rpm.

Are you sure it is the optocoupler?

What is your base thread rate (from the INI). (This question only makes sense if you are using the parallel port)
What is the PPR of your encoder?

Hi,
I have a home made encoder. So its 45ppr aluminium drilled plate on the spindle. The base thread rate was 45000 the last I checked but can confirm on Monday. The encoder is a Slot Type IR Optocoupler Speed Sensor Module LM393 from ebay. Its pluged into my BOB as an input. The pin on the BOB is 5v and when earthed reads as a signal.

45ppr and 45000 base thread suggests that you should be OK up to 493 revs per second, or 30,000 rpm, so it looks like it isn't a count rate problem in HAL.

Just to check, does 300rpm look like 300 rpm?

it seems a little fast but thought it was just an optical illusion. I have bought a digital tachometer to check actual spindle speed. I will let you know