how exactly was the filament sensor improved in 3.2.0? How about the new hardware?
 
Notifications
Clear all

how exactly was the filament sensor improved in 3.2.0? How about the new hardware?  

  RSS
Eric
 Eric
(@eric-12)
Active Member
how exactly was the filament sensor improved in 3.2.0? How about the new hardware?

I've still been able to foil it with glossy black PETG (which I've, in a separate hilarious incident, damaged and is unreliable...could really use a reliable filament sensor to tell me when it's busted).

Any info on what the actual improvements are?

Does the new part detect glossy black PETG filament?

Thanks!
Eric

Posted : 20/05/2018 2:12 am
motocoder
(@motocoder)
Trusted Member
Re: how exactly was the filament sensor improved in 3.2.0? How about the new hardware?

You can see the difference by looking at the schematics for Rev .02 versus Rev .02e. They are both up on Github:

Rev .02: https://github.com/prusa3d/PRUSA_Laser_filament_sensor/blob/master/rev.02/laser-sensor.pdf
Rev .02e: https://github.com/prusa3d/PRUSA_Laser_filament_sensor/blob/master/rev.02e/laser-sensor.pdf

I only see two differences:

1) A 50ma fuse was added on the +5V supply coming in from the cable. I am sure this is to prevent the scenario that has been posted about here, where a short circuit develops in the sensor board and shorts out the +5V supply, causing things to heat up badly.

2) A 200K resistor was added between the connection from the +5V supply to the Vref for the B-side inputs on the LSF0102 level converter. The 200K resistor is on the datasheet for this part from TI. They should have also included a small capacitor to ground. The two of them are supposed to filter voltage transients out of the reference voltage, which should help reduce jitter for any signals going through the converter.

Posted : 21/05/2018 11:08 pm
motocoder
(@motocoder)
Trusted Member
Re: how exactly was the filament sensor improved in 3.2.0? How about the new hardware?

The lack of responses from Prusa says it all.

Posted : 23/05/2018 6:39 am
Share: