Chris's Build of Steering Engine

[Don1966]

Awesome Dog……. 


 
Don

[crueby]

Okay, partway there. I dug through the metal stocks, and found a nice piece of 1144 stressproof that is 2.35" diameter and long enough to get both cylinders out of. They need to be held with the bottom side out so I can machine the threads for the bottom plates as I described earlier, and be able to bore through the blocks for the pistons and valves. Going back to a trick I've used in the past, the block will be held on the faceplate with two sets of holes, each set centered on one of the bores, and the holes the same distance out from the centerline. This allows the part to be flipped around and re-bolted to the faceplate with the other bore centered, both for boring and for milling the outside of the part concentric to the bores.  Here is a picture showing what I am going to do:


The orange cylinder block (gee, its all done! ... nope, lots to do to get there! ) starts out as a taller version of the blue cylinder. I'll slab off the sides of the blue cylinder and drill the bolt holes, and drill matching bolt holes in the faceplate. In the picture the faceplate is shown in two positions, one red, one purple. Same faceplate, just rotated 180 degrees, all the holes are symmetric. In the red position, the valve bore is centered, in the purple position the cylinder is centered. I checked the overhang on the red position, and the blue cylinder will just clear the lathe bed - I may mill that edge back to increase the clearance, if too small then chips on the lathe bed will jam underneath.

This should let me access all sides of the block for milling the outside, except for the top flange which just needs facing and drilling for the cover bolts. That last thing can be done with the block held on expanding arbors through the bores. For turning the bores I like to use the lathe - obviously this will need counterweights on the empty side of the faceplate to balance it. On the mill, both the horizontal and vertical rotary tables will be used to position it. This is all pretty similar to what I did on the Stanley engine block. SHOULD work here too!

[crueby]

Well, one slight change!

That bar of 2.35" steel just didn't feel or look quite right for 1144 Stressproof, so I did some checking back in my archives. Turns out that is the diameter of bar that I bought about 10 years ago to build the wheels on my Kozo New Shay, and that was the first time I used 12L14 steel. Wonderful stuff to machine, but I don't like how it takes a surface rust so easy.


So, instead of that bar, I am going to use a length of 2.75" diameter 1144 that I also have left over from a more recent project, its a little longer so I can make the bottom section that bolts to the faceplate a little thicker, which will help with clearance to the mill headstock from the faceplate. It means a thicker chunk to slab off the sides of the starting bar, but it all works out fine in the end.

[cnr6400]

As Maxwell Smart would say - "ah, the old two level asymmetrical baseplate fixture trick, eh?"   

[crueby]

As Maxwell Smart would say - "ah, the old two level asymmetrical baseplate fixture trick, eh?" 

Shop elves, please whack him with a cone of silence!  And PUNt him across the street.   Hmmm, and get me a cone with chocolate ice cream!   

[Michael S.]

The lineup of cylinders is great!
This will definitely be a feast for the milling machine and the workshop elves can stuff shavings into their pockets again.

 

[crueby]

Thanks Michael,  hopefully they pick up all the swarf for their collection so I don't have to vacuum it up!   

I've adjusted the CAD version for the different size bar stock and printed out a drawing with the measurements needed, mainly for hole positions and the iniitial bandsaw cuts. Also am doing a 3D print of the part on the base, which I've learned from previous projects comes in handy for keeping track of which side of the part I am doing operations on, especially in cases like this where the two cylinders are mirror images of each other, one with the valve on the left, one on the right.

[crueby]

The 3D print of the cylinder/base finished printing while I was off at lunch with friends, here it is with a small end mill next to it to show the step I added in the side so the cutter can reach in to the edges of the cylinder:

and on top of the round bar they will be cut from:

This printed piece will be very handy in keeping track of which side is which, and help in plotting out what cutter can do which feature, remembering (I hope) along the way that I need to make one like this and one mirrored. First step will be to spend some time with the bandsaw cutting the two pieces and taqking the slabs off the sides to square it up, saving time on the mill.

[cnr6400]

 
Great technique to use a 3D printed mockup to check machining clearances and approaches etc. One of the most useful ways to use a 3D printer yet it's not mentioned much. 

(typing to you from the cone of silence) 

[crueby]

Great technique to use a 3D printed mockup to check machining clearances and approaches etc. One of the most useful ways to use a 3D printer yet it's not mentioned much. 

I started sending the files out back during the Marion build, it was a great help in making sure I was working on the proper side of parts  with complex shapes, its so easy to mix up directions from 2d drawings. Now with my own printer, its really quick to do.

(typing to you from the cone of silence) 

Whats that, can't hear you...   

[cnr6400]

What? 

[Kim]

Very cool use of 3D printing, Chris!  Now that I've got me one of them I may have to try that! 
Kim

[crueby]

Very cool use of 3D printing, Chris!  Now that I've got me one of them I may have to try that! 
Kim

Today I started cutting down the big bar on the bandsaw, and also was doing some pseudo casting fondling, trying to work out how to make some of the shapes on the cylinder by looking at the 3D printed one. Most of it is fairly straightforward, but some features require some more pondering - the printed version is great for working this kind of thing out!

[kvom]

Very cool use of 3D printing, Chris!  Now that I've got me one of them I may have to try that! 
Kim

You could have printed the boiler formers you made from wood 

[crueby]

Very cool use of 3D printing, Chris!  Now that I've got me one of them I may have to try that! 
Kim

You could have printed the boiler formers you made from wood 

They do have wood infused filaments...  Don't know if they would hold up to the hammering or not. Never thought of that one!