Yesterday I decided to improve my old RepRapPro Mendel, and I found a clever way to easily block a digital calliper on all the three axes, and then I started to carefully calibrate the axes steps.
Now I am printing the first objects after years of dust. They look very nice.
Then I think I will try to recalibrate the objects fitting capabilities.
That printer type brings such fond memories. 
Mine is still running after 4 years duty. The latest cura,2.7 does wonders for printing quality and speed.
I have a tricolour mendel sitting in my office waiting for me to replace the damaged melzi electronics i broke (snapped usb cable on master)
Instead of kapton tape I use hair spray. It is more than wonderful
I have never used the capton tape (allthough i have a roll). For me it’s hairspray for ABS and PLA.
Now I changed to the following configuration:
A - One glass with Blue tape (only on cold plate)
B - One glass with hair spary (only for hot plate)
Now I am printing PLA only.
I am testing the A glass, with very good results. Often I need to remove (unclip) the glass from the bed in order to detach the prints, to avoid to damage the printer due to the force I need to apply to detach the objects.
I still need to test the B configuration and evaluate what is best.
If you print on tape, the bottom of your print won’t be smooth. With hairspray you even get a extra smooth coating. Keep us posted on your findings!
@Mano_Biletsky_Open_M You are right. I have already noticed, that comparing the bottom layer of objects printed on scotch with the bottom layer printed on kapton, there is a significant difference.
I will try also :
- glass+hair spray at cold bed
- glass+mixed glue (3M stick spreaded with water) at cold bed.
@Roberto_Coli both of those don’t work on a cold bed. They won’t dry without the heat of a heated bed.
Without proper drying they won’t stick enough.
My printer look very similar, Metric Mendel Prusa with LMUU bearings, still in daily use