http://www.ebay.com/itm/Inline-Fuel-...pVuezG&vxp=mtr
I wanted to use this (fuel) filter in my stuff but it is too big, probably good for this size model. Oil filter/fuel filter, they both are trapping particles of a certain size, 5~500 microns,,, the ones I use are very small disposable I get from McMaster. I have to drill out ends and thread for m5 fittings. I'm sure they are way too small for this. My opinion on hydro volumes is about same as above, double the system volume and you'll be good. On an hydro guys side, as big of a tank as weight/size/practicality allows. More oil is just better all way around. Temp, contaminants, lifespan of oil, ect. But on 1:1 machines, lifespan, cost of replacing, and available size is what restrictions are. One thing to try is to have tank suction on bottom and tank return line on top (baffle or just opposite side) allows air in oil to migrate to top and not back into pump. That's the frothing of agitated oil, a lot of oil has additives to lessen foaming. I've never had temp come into issue in any of my models. Excavator cylinders get warm after a hour use in summertime, but never hot. (At least that I am aware of
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And that school you talk about, one of the best I've ever attended!!!