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Very nice! Can you talk a bit about your circulation pump. is it a gear pump design or? Looks like 2 stacked together, one serving each engine side of cylinders?

I read Ben Flemming's EDM book. I could sure envision the advantages of having one in the shop, but its above my pay grade at present. My friend is building his the next generation model & he has prior EDM industry experience. So hoping to see that in action one day soon. But regarding the...

Progressive cavity pumps have been around oil field service for a long time, both surface & downhole. Downhole sand cuts can be ~35% within oil/water fluid emulsion. But I don't think anywhere near those target discharge pressures. I believe as the solids content & particle size reduces, higher...

Can you elaborate - what are the dimensions of current draw in this formula? And are these reference RPMs on a single cylinder basis, so a 5 cylinder would be 30K/5=6K max crankshaft RPM for example?

So presumably you selected the magnum model? Is it from prior inventory you sourced from the new supplier/builder? Any thoughts on how tolerant the nominal 6v input voltage would be to say... a 2S lithium battery ~7.4v. I'm sure it would handle the current requirements, but that's a moot point...

@cwelkie I didn't realize you had a channel showing your runners. Very nice! Hope you don't mind if I post it for others to see your nice work. https://www.youtube.com/@charleswelkie265

These examples are quite encouraging. I assume this (link) is the alloy of your crankcase? Have you printed test pieces or progressed on actual engines to see how certain typical model engine features might be more challenging, or at least 'different'? I'm thinking our typical fine threaded...

I think I understand now. Yours does not have a variable speed knob integrated in the control box like the 2 examples I showed? Have you run the motor & if so, does it seem like its up to the task?

Here is another. I think similar motor but different output shaft style & controller.

Your motor looks similar to one I'm considering from AliExpress for a different purpose. It comes many power level flavors but all with matched variable speed units. Does yours have something similar?

You might be right Jason. I'm going to work on this some more. I want to make the cam & template as sketch blocks, rotate them phased together with a belt mate. Then make the follower ride tangent on the template only constrained by the lever/pivot point & see how the grind wheel OD line...

Very nice builds! And also thanks for including link to your channel, I just subscribed. That Arduino Prony brake dyno is just so cool.

Yes & no, requires explanation. I inserted the wrong screen grab. I have a couple versions of these defining some parameters & leaving others to float, meaning they become determined to an exact value when drawing is fully defined. In this version the dimension going towards the pivot point (now...

Can you elaborate on piston / bore clearance? Is the main seal the (longish) piston or the O-ring itself? I got kind of lost in online calculators, but do you have a ballpark figure of what kind of pressure an O-ring can withstand in this size? I cant wait to see it run!

Can you elaborate on fabrication of the crankshaft. Are the webs dowel pinned to the main crankshaft rod? If so, how did you orientate them? Did you feed the rod completely through all web elements & cut away the middle where required? How are crank pins. held into position?

That's really cool. So you mean you are will be making little feet like sketch with a ball socket on one side & flat on the other once your ball end mill arrives? Are the ball ends sourced from RC car/heli/plane application? Reason I ask is I seem to recall some/most? are turned from a native...

I suspect the simple 1:1 example works because certain variables have been nulled by definition. A 1:1 replicator might be a perfectly good grinder for the intended purposes. But when you try to scale it up to a 2X or 3X lever mechanism because template enlargement offers some desirable...

I completely agree, my description was not clear. If the fixed offset amount is perpendicular to the tangent of the cam (which is what the cad program does), then the extending the normal line inward demonstrates it will only be coincident to the cam rotation center at particular points as you...

I think what the CAD offset function is doing behind the scenes might be visualized like this. I'm using same cam but different offset values to the Bell example just to make the screen grabs more compact. Here I define offset amount = 0.500" represented by circle at 12:00 position. Then I make...

Tuning in now because a while back I was struggling with this same geometry. I read the same SIC Don Bell article but it confused me. Oh well, I often confuse myself. I'll throw out some screen grabs using his specific cam example. Maybe it will clarify matters or maybe will add to confusion. I...