Welcome to ModelEngineMaker !If you have problems registering or logging in, please use the contact menu option to request assistance.
Large Face mills seem to work well as they're rigid. I've just got a fly cutter which is ok for a lot of stuff and probably a damn site cheaper. Face mill might be better at taking hard skin off castings. That 3mm port looks a lot bigger to me, probably a just the photo playing tricks with my eyes. Looking good.
A little time on a flat surface with some 320-400 grit paper will get rid of the swirl marks, just takes a little elbow grease. Will make for better sealing mating surfaces later on too. though I still use thin gaskets even so.Looking good though...still following along here.Bill
Definitely beneficial to lap the mating surface with the valve chest to get it to seal properly. If you're looking at surface finish I would have thought about N4 + is required there and if you milled the ends they could probably do with lapping too.
Then realised my mistake. I was going to have to use the mill at some point for my bolt circle and I'd turned away all my waste material! Oh well.. on we go.
Quote from: Heffalump on May 26, 2015, 03:58:09 PMThen realised my mistake. I was going to have to use the mill at some point for my bolt circle and I'd turned away all my waste material! Oh well.. on we go.I drilled for the bolts after making the cover, too. I doubt if the waste material would have helped much if you left it on. I simply put the cylinder in the mill vise, centered using the piston (you haven't made this yet, so a suitable rod representing the piston rod would have worked), and then drilled the 4 holes without an RT. My holes were well placed, but not terribly accurate. I'm not sure what went wrong...maybe I didn't account for backlash. As it is, I need to rotate my cylinder covers until the holes align and then bolt them down. But to the human eye you can't see this.Looks like great progress today!Todd