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Looking at the design, I'm guessing the cross channel leaks are coming from the boundary layer between the body and the crankshaft. I don't it's actually happening, but possibly there's a bit of seal misalignment with the porting that's causing issues. Therefore I went ahead and added some...

Me too. I'm an industrial machine designer. I've designed machines for the trucking industry, automotive, medical, aerospace, and currently I do electronics assembly. I have five patents with my name on them and I've been doing this for over 25 years. A design, particularly a custom one-off...

Certainly a possibility. A quick calculation shows that the oil pressure against the piston o-ring is 77psi @ 1725 rpm. That's easily within the range of a buna-n oring. But yeah, there's going to be blowby. How much? I dunno. Perhaps a bit of leakage will help lubricate the crankshaft...

The thinking was twofold: As the piston went to bottom dead center, the oil on the back end of piston would get pushed out of the cylinder and then work its way into other areas. When the pump stopped, the oil would then fall onto the center bearings. As for the other comments following my...

I got all the pa;rts finished, bolted the pump to the motor and ran some tests. The results are pathetic. The pump only generates about 10 psi. Obviously there's a large amount of internal leakage. My barb hose fittings were discards from a work project. I wonder if they're sized for metric...

A quick of a primer on sound pressure and the decibel scale. The dB scale is a logarithmic scale. Therefore every decade number change is ten times the level of the previous whole number. Assume you have something at 50 dB and another at 60db and another at 61db. Going from 60 to 61dB is the...

I found the source of the binding. The rear shaft bearing wasn't perfectly centered on the rotational axis. I bored the housing out a little, and the binding went away. Now the bearing fits a bit too loose. I'll compensate with some Loctite 638. I then hooked up the pump to my lathe for a...

I have a rotational interference that I need to figure out. Along the rotation, it binds a bit at one point. It can be several things, the worst being the crankshaft slightly bent (perhaps stress relief from the machining operation). At this point I don't know, but it's certainly something I...

A bit more analysis. I wanted to work out the actual motion of the piston. As the piston rotates around the central axis, it also moves towards and away from that center axis. Doing a bit of math in a spreadsheet shows the piston moves in an ellipse: The X position relative to rotation...

Progress continues to be had. The pump, when pressurized backwards will work as an air motor. Today I fit the pistons and initially put the pump together (albeit without the cover plate). For a test, I indeed pressurized the thing and ran it as a motor. It runs and I found some leakage. But...

Very Cool! The chain appears to make quite a racket. Is it very loud in real life? ...Ved.

Th actual CAC model is made in China anyways. I wonder if they're made in the same factoey.

It's been over month since I've made any posts concerning this project. As you can see in the following photo, I have been making some progress. In the manufacturing stage, I've noticed a couple of design errors and/or manufacturability improvements. The crankshaft really took some planning...

Simple response to your comment: If you have issues with existing plans, don't use them and design your own. I put up my designs here on HMEM for free. I dimension them .xxx. That's not because the part really needs it, but it gives me the dimensions I should shoot for. Any critical fit...

Intentionally ugly can sometimes be something cool to look at.

For me depends on a few of factors: ○ What's the purpose? Am I building something for looks (e.g. my Dancer's Engine) or am I trying something that's never been done before (e.g. Camgine! or my Four Square Engine) ○ How visible is the mistake and how distracting is the error? Can I hide it or...

David, I just found this thread. From what I've seen in the pictures, it appears that nearly all the parts can be made on the lathe with some rotary table work for details like the top of the castle. The only one that appears very unfriendly is the knight. As long as it's design isn't too...

I went ahead and made the drawings for this design. Usually, I don't publish until I make the first one, but being that I'm sharing the entire design process, I'm posting draft drawing set. I'll re-post the design files after I make the prototype, but the attached .zip file is what it looks...

With the pump essentially figured out, it was time to mount it. I want to use a 56C frame motor which is an industrial standard for face mounting of motor accessories. I can direct drive the pump off the motor shaft and then support the crankshaft fast with some bracketry:

I worked a few more hours on the pump design. The pistons are fairly simple, but being that the internals will be oiled via splash lubrication, I added some weep holes in the side of the piston so oil the cylinder walls between the piston. I had to play around with the geometry to keep...