I have used pei sheet for about 3 years. Then I started printing petg. At times petg would destroy the pei sheet by sticking too good. So I gave up on it and went back to printing on glass. Used gluestick on glass but hairspray works so much better. Also hairspray is easy to clean up with water and paper towel or wash in the sink.

You mention that the belt seems bend as it moves. I had a problem like that and it was the cheap belts had bends in them in one spot that made it move up and down in a way that could be seen near the pulley. Changed belts and the problem went away. Still cheap belts and pulley's are just that. Cheap. I am now going to upgrade my printer to gates belts and pulleys and see if that helps. Cheap belts also can go bad and make lots of black dust around the pulleys.

All that said you most likely only need to adjust your steps per mm to get it to move the right distance if belt tension isn't way off. That is normal printer calibration. Print a 20mm cube and seeing how big it is and adjusting steps per mm until your printer prints 20mm.

BMG just works. I had problems with the titan too. BMG is a much better design with the gears and drive pushing the filament. Some people seem to get lucky with the titan, but after switching to the BMG I'd never use anything else.

Ok, I'll check that out.

Is there a way to change the speed (mms) that the panel due shows for default extrusion speeds? 5mms is as slow as it goes. On the computer it goes down to 1mms. I'd like to change the defaults to what I like.

Thank you for all the answers.

So if I don't have any reference to pressure advance in config.g, it can be turned on with the m code at anytime.

I think I saw something about Kepler pressure advance that said they had to turn it on in firmware to activate it, so that made me wonder if reprap worked the same way.

I wonder if you have to first turn on pressure advance in config.g before you can use it in say start gcode in a slicer?

I would like to change pressure advance settings for different filaments and not have to change config.g each time. But wonder if it will work if not setup in config.g first.

I just print two outlines around the part to prime and make sure level looks good for every print. The brush idea could be useful for petg and tpu because I find they make a mess of the nozzle. A brass brush with some kind of servo to move it out of the way when not cleaning would be what I may do one day.

Even with calibrate my big fingers sometimes push the wrong buttons on the touch screen. I have used a touch stylus at times to make it easier.