600 PPR encoder as pulse filament monitor.

CNCModeller

Hi All,
I've cobbled together this 600ppr filament encoder and was going to use the little 5v to 3.3v converter board and connect a single encoder output via the 3.3v side to E1Stop, taking a 5v elsewhere from the duet to power the 5v side which is then connected to the encoder.

From my understanding I should get 600 pulses from the single encoder wire as the two are only needed to identify direction. So in my mind this should work, giving about 0.06mm/pulse.

Any constructive thoughts?

Cheers
Barry M

o_lampe

@cncmodeller
It'll work unless you use retraction. If you only want a 'Jam-detector' it doesn't matter. Otherwise you'll need quadrature encoder setup to read direction and sum up the pulses the right way.

CNCModeller

@o_lampe
As I understand it RRF doesn't take in direction anyway. As it only uses a single pin for pulse based filament motion detection.

From memory doesn't it just ignore retraction moves for filament monitoring?

If the Duet2 ethernet will take both encoder inputs I can do that but it didn't read that way to me.

Anyway thanks for the confidence boost

alankilian

THIS guy made his own low-resolution optical filament monitor and it's working great for him after he implemented a Schmitt trigger due to his (original implementation) slowly-changing signal.

I expect your encoder produces sharp edges so you would not need a Schmitt trigger function. (Either by inverter or by using the nice optical interrupter sensors with built-in Schmitt trigger.)

I couldn't tell from the data sheet, but I bet you'll get 150 pulses-per-rev on the "A" or "B" signal. That gets you to 600 when you figure the "Quad" (multiply by four by counting all edges) part of a quadrature encoder.

CNCModeller

@alankilian said in 600 PPR encoder as pulse filament monitor.:

I couldn't tell from the data sheet, but I bet you'll get 150 pulses-per-rev on the "A" or "B" signal. That gets you to 600 when you figure the "Quad" (multiply by four by counting all edges) part of a quadrature encoder.

Hi,
@alankilian I get 2400cpr with these encoders on Arduino, so I'm expecting 600 PPR off of each phase. It's all sorted now just need to connect it to the printer and configure it.

We will see...! I'll post how I get on.