Mirror problem

iain_downs

Hi,

I'm trying to design a steam engine.  My cylinder block has symmetrical steam ports going at an angle from the face into the cylinder. see cylinder block here.

I designed one with a plane to follow the angle (3 point) then a normal plane to put a sketch on to generate port shape and an extrusion (removal) up to the port on the face.  It's not that complicated to see, but it's quite hard to describe.

Having done one, I wanted to create a mirror of it for the other port - to save all the messing around with planes.  However, having done this the extruded removal passes through the port and intersects with the face of the block.

My theory on this is that the original extrusion was 'up to face' and that face is not in the path of the mirrored extrusion.  I'd assumed that it would be the actual geometry that was mirrored and not the instructions.

Is this intentional, or is this a bug?


Iain


P.C>  I will leave the part like this until this time tomorrow (at least) in case you want to look at it.  After that I may do things the hard way and recreate the second port with planes and things.

bradley_sauln

My first suggestion would be a face mirror. But upon seeing this (not sure if intentional or not), the fact that its not cutting all the way through may cause some unnecessary hassle because it's not cutting all the way through.


The easiest thing to do is take both Extrude Remove features and use them to create a cutting tool so you can do a Part Mirror > Remove and then boolean subtract the original tool as I did here: https://cad.onshape.com/documents/ceb9486efe1ce94bc7f2768e/w/f7d4e67135f26dc6570d5b16/e/c16534d1b79bb01ba0cc68f7

iain_downs

Thanks for this.  I'm not entirely sure I understand it, but it works fine!