Reworked OB1.4 open beam printer

Great design but for 1515 profile I had 2020 profile so amended and resized to use 2020.

Now up and running will be posting any improvements I make as I tune and adjust performance.

I have made printer somewhat larger and intending a 300x300x400 print area up to 500mm height if possible. The printer is fairly large internal frame dimensions are 360x500 external dimensions with protrusions about 500x600mm height will be approx 600mm. Still checking all calculations and printing last pieces