Chris's Slew-Crowd Engines

[vtsteam]

.....Fortunately the windows are wider than the top of the vise, so I will be able to use the vise base to align the tubes for the second side. So far I've cut the first window in one tube:

Don't quite understand, Chris....

I first cut the window on one side of the Thew tubes. Then needed to roll them over 180 degrees to do the window on the other side. I laid the first flat on the tube onto the vise between the jaws, where my giant elf finger is pointing....   Does that clear up my phrasing from the first post?

Oh okay, the last pic clears it up, not the top of the vise, the top of the bottom of the vise, since the top of the bottom of the vise is narrower than the top of the vise, but that isn't shown in the first pic. There, the milled window looks narrower than the top of the vise, but you can't see the top of the bottom of the vise, so I was wondering, how could it fit? Now I see you meant the top of the bottom of the vise, not the top of the top of the vise. 

[crueby]

.....Fortunately the windows are wider than the top of the vise, so I will be able to use the vise base to align the tubes for the second side. So far I've cut the first window in one tube:

Don't quite understand, Chris....

I first cut the window on one side of the Thew tubes. Then needed to roll them over 180 degrees to do the window on the other side. I laid the first flat on the tube onto the vise between the jaws, where my giant elf finger is pointing....   Does that clear up my phrasing from the first post?

Oh okay, the last pic clears it up, not the top of the vise, the top of the bottom of the vise, since the top of the bottom of the vise is narrower than the top of the vise, but that isn't shown in the first pic. There, the milled window looks narrower than the top of the vise, but you can't see the top of the bottom of the vise, so I was wondering, how could it fit? Now I see you meant the top of the bottom of the vise, not the top of the top of the vise. 

Top o the morning to ya...       


 

[bent]

vt, you made my brain hurt! 

[vtsteam]

Top o the morning to ya...       
 

Wait, I don't understand.... it's 10 PM here, how far west IS Rochester?.....nope, better not start this again......

Top o the morning to ya, too sir! 

[crueby]

Top o the morning to ya...       
 

Wait, I don't understand.... it's 10 PM here, how far west IS Rochester?.....nope, better not start this again......

Top o the morning to ya, too sir! 

Pretty far west. Go around the world westwards 2.1 times and you'll be  here from Vermont!   




Yeah, we better stop trying to Top each other with puns or we'll never get to the Bottom of this conversation...   

[vtsteam]

Chris, real Vermonters have a saying when something is really huge: big as New York.

[crueby]

This morning started in on the pistons - at last some moving parts!  Two of the engines have 1" pistons, two have 0.9" pistons, so I'm making them up in pairs. That lets me sneak up on the depth/width of the grooves for the o-rings on one, then repeat the handwheel movements on the other three. My parting tool is slightly narrower than the Viton o rings I'm using, so it takes pairs of cuts to get the slot just wider than the ring, to give it room to squish a little. Here are the first to pistons with the slots cut...

and drilled for the piston rod in the same chucking:

After making the first four this way, and sawing off each one from the bar, the apprentice shop elf did the QA on them. They still need to have the flat faces trued up, but I'll do the other four pistons first then do the faces as a batch.

[cnr6400]

 

[vtsteam]

Chris what kind of tool do you use to make the ring slots, a parting tool?

[crueby]

Chris what kind of tool do you use to make the ring slots, a parting tool?

Yes, one of the type that is about 1/16"  thick, 3/4" tall, and has a concave top all down the length, rather than being just ground on the end of a square bar. Not sure what this style is called, got it at Little Machine Shop I think, several years ago. Every couple uses I take it to a fine grit grinding wheel to freshen the end, and take off where wear makes the end narrower. Have a holder for the quick change toolpost that lets me set how much overhang it has. I like that style. For each marerial and diameter it takes a little experimenting to  find a good motor and feed speed, a bit slower on my Sherline than normal turning. It has to be set parallel to the  face of the chuck and have the tip ground dead square or it pulls to the side.

[crueby]

This picture from an older post shows the parting tool...

[crueby]

This morning I made up the other four pistons, and got all eight trimmed/trued on the sawn flat faces:

The shop elves keep trying to take them for their Elflympic Curling team...

Next up I'll start making all the piston rods, then move on to the crossheads.

[Michael S.]

If you don't make the piston rod so long, it should work with curling.

[vtsteam]

Thanks Chris, re. parting tool. I hadn't heard of the concave top type before.  That's interesting.

[crueby]

If you don't make the piston rod so long, it should work with curling.

True!  Hmmm, anyone ever build a Zamboni powered by a steam engine?