Increased PINDA sensitivity?  

Re: Increased PINDA sensitivity?

I have the thicker PEI as well, and it is possible to find a PINDA setting that works. Just adjust it VERY SLOWLY down in the mount and try again. It takes some patience but you should be able to find a spot that works.

Re: Increased PINDA sensitivity?

Ok, I'll keep trying.

Have you had any trouble getting PLA to stick? I'm not having much luck, but I'm not sure if that's an independent problem.

Re: Increased PINDA sensitivity?

Is there any way to increase the sensitivity of the PINDA probe so that it triggers a little farther from the black surface of the hotbed? .....
yes there is !
but i can't promise that it will work with all units, because i was only able to test it with two p.i.n.d.a. probes.
read my thread about the printer i build using genuine prusa spare parts. if you read the third post carefully, you'll know what to do.
i even posted a little circuit that might help you to do the proposed alteration.

Re: Increased PINDA sensitivity?

Persistence paid off. I've got the PINDA properly positioned and PLA now sticks just fine. Thanks all.

Re: Increased PINDA sensitivity?

There are some tricks here. On adjusting the PINDA, the setting I would start with is shown in the manual. You want the top of the PINDA sensor just flush with the bottom of the orange cable holder next to it. Then perform the XYZ calibrate. As it says USE A SHEET OF PAPER ON THE BED. If during calibration the nozzle presses on the bed, the calibration will fail. LOWER the PINDA sensor one thread and try again. To lower loosen the two allen screws, pry the plastic apart a bit and gently push it lower until it clicks in place. maybe 1/16"

Now once you pass calibration its on to Z adjustments. My comments are for 3.0.11 firmware which is quite a bit different than 3.0.10.

Here is what I do. It works and its easy. DON'T LOAD ANY FILAMENT, or unload it if you had some in. The clean the bottom of the nozzle so no plastic is sticking out.

Place a piece of blank copy paper on the bed, the "print" the V2Calibration model from the SD card. Once the "printing" starts (remember no filament is in the printer) adjust the Z level to where you feel SOME resistance between the nozzle and bed if you try to slide the paper. For my printer I needed to go to about -0.950 for this to happen. Remember you don't want NO resistance between nozzle and bed, nor do you want the nozzle really pressing hard on the paper.

Thats it. PLA and ABS should stick. For PLA or ABS don't use ANY tape, gluestick, etc. Just clean the bed with 90% isopropyl alcohol. If its not sticking, the Z Level is too high, but it won't be if you follow these instructions.

Re: Increased PINDA sensitivity?

You can try updating to the latest firmware:
http://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/new-firmware-3-0-11-mk2s-mk2-t4478.html#p33275

I did it and my printer calibration got better.
It used to pressed on to the bed during z-calibration, and now it is not.

Re: Increased PINDA sensitivity?

On my setup I tried 1mm and 1.5mm the 1.5mm was better, faster calibration more accurate readings, used feeler gauges and flush with the bed, I may even try 1.75mm.