Cat 374 Excavator build

[supraman]

G'day people . I have a few questions to ask , but i thought i would share what i am doing . After downloading the closest drawings of a 374 i could find i started to copy it . I use Alibre design to do drawings ( cad ) and realized pretty quickly that to make the track links how i wanted , i would need to get the old cnc running . I had plans to machine it all on the old cnc, but with old controllers having issues , i just managed to get all the track links made , literally in time before the cnc lost all settings and programs due to a memory back up battery failing .
So the track links are made on cnc and took about 4 hour to do both sides and i had 5 links in each piece for a total of 96 links .. They are 90mm wide.
I used m5 grub screws for the track pin. All i did was to machine the thread of them , down to 4mm - leaving 5mm of thread on one end . Screw in and locktite . Nylon washers between the links also .
I do not have the patience or skill of some of you guys but it is my first attempt .
Some photos of the track links , track frame ,and other stuff . I have made my own valve , but fear i may have made the rotary valve faces too big - at 24mm dia and will have problems with pressure pushing them too much and possibly making it impossible to turn ?- we will have to wait and see . Although i am thinking of remaking the valve with thrust bearings behind the rotary disc to combat this . I have 15kg servos , but am still seriously thinking of remaking .
The main reason for the size of the valve is i have all 4 cylinders at 20mm bore , using 4mm id pipe and fittings as i do not want it to be slow because of flow issues ..
Which leads me to my first real question , what size pump to use ..anyone have ideas on what pump to buy or should i make one . I am looking for an idea of pump size others have used with similar size cyls .. Cheers guys .