Building Kozo's New Shay locomotive

[crueby]

Thanks. I've only turned some 303 stainless on my lathe. That was pretty nice. So, I was curious as to how easily it tapped. I know what you mean with the bronze. It gave me fits while trying to ream a hole to size on my A3 tender's wheel bushings.

Todd

The 303 drills and taps nicely with a little cutting oil. Deep holes can heat up quick without enough oil.

 

[crueby]

With the reverse gear links done, on to the fittings that go on them. First up is the little bronze sliders that ride in the slot. They are curved to match the slot, so the same jig that made the links was adapted to make a strip of the sliders - just had to widen it at the end with another bit of aluminum. Then the bronze was screwed down to it and adjusted to be the correct distance from the pivot point of the rotary table.

With all the adjusting done, a few passes with the mill cut the arc into the bronze.

After that, a set of holes was drilled spaced along the strip - this hole will take the pivot pin into the valve crosshead. The strip was long enough for 4 sliders, so have one spare if I cut wrong later.

Last step on the sliders was to cut them apart and to length.

Next up is a little bracket that bolts into the center of the links, and will hold a pin that connects the actuating lever to move the link between forward and reverse. This started out just like the retaining strips did a few posts back, as a piece of larger stainless rod, milled to size, then a slot milled down the center, and the side sawn off to leave an angle bracket shape. This sawn edge was cleaned up with the mill, and it was ready for the next step.

A set of holes was drilled/countersunk along one edge for the mounting screws, and the other side drilled for the pivot pin.

Last step was to angle the mill vise and angle cut the sides of the brackets.

Last photo shows the links, sliders, and brackets all assembled with each other. There will also be a little spacer piece between the slider and the crosshead, but I am going to wait till assembly time with the eccentrics so I can measure the lengths needed.

Next up will be the eccentric followers and connecting rods...

 

[petertha]

I'm so impressed with the parts you are producing on your equipment & your varied set-ups. Can you elaborate on the 4-jaw. I haven't seen one with a clamping flange like that. Did you modify a stock chuck yourself or is that kind of a dedicated accessory item to that particular RT?

 

[crueby]

I'm so impressed with the parts you are producing on your equipment & your varied set-ups. Can you elaborate on the 4-jaw. I haven't seen one with a clamping flange like that. Did you modify a stock chuck yourself or is that kind of a dedicated accessory item to that particular RT?

That is a stock Sherline 4 jaw, came with that slot around the base. The clamp is one of the ones from the mill vise. The table has a screw adapter from Sherline that screws into the center of the table and has the same outer thread as the headstock for the chuck to screw into. The rotary table is not quite wide enough so I have to turn the clamp sideways, but it keeps the chuck from unscrewing itself from pressure from the end mill. I wish the 3 jaw chuck had the same slot. I am not sure if that slot is on all the Sherline 4 jaws or just that model. They do make them to fit several lathes.

 

[crueby]

Only got a few minutes in the shop today, got the pivot pins for the reverse gear links made. Like all the other engine steel parts they are 303 stainless. Started with a length of rod, turned just the end down to size for 2-56 threads - did not want too much hanging out and getting bent.

After threading the end, went back and took the shank down to size too.

Parted it off,

and reversed it in the chuck to trim the head to thickness.

Then, over to the mill to put the hex shape on the heads with the rotary table.



Last two photos show the completed link pins in place - they go through the sliders in the link and into the valve crosshead.



Probably get more shop time tomorrow, will get a start on the eccentric followers.

 

[SilverSanJuan]

That's some fine work. Can't wait to see it all in motion.

Todd

 

[crueby]

Been a fun day in the shop today - got the eccentric followers mostly done. They started out as blocks of brass, taken down to a stepped shape with the mill. This step will form the bolt hole section of the followers. The bottom half is a shallow step, the top half has a post sticking up that will attach to the connecting rod. The curved part of the followers will be done later.



Once the steps were all done, the two halfs were clamped together, and a series of holes drilled down each side. The holes in the bottom half were opened up to 2-56 clearance size, the holes in the top half were tapped 2-56. The sharp-eyed among you will notice that I drilled 7 holes - the block was long enough for a spare set.

Next up was to round over the bottom of the bottom half. The block was clamped in the 4-jaw, on the rotary table set vertically. The inner edge of the block was centered in the chuck so that the milled surface would be concentric with the hole drilled later. A pass was taken with the mill down the piece, the table turned slightly, and another pass taken. This was repeated till the curve was done. On one side, the mill was offset so that the edge of the mill met up with the step. This whole process is simaler to what Kozo does in the book, except that he used a lathe bit on the late cross slide as a shaper bit, where I used the end mill. Same end result though.

Then, on the other side of the piece, the mill was offset the other way to match up with the step on that side. Then, the piece was turned around in the chuck so that the 1" at the chuck end could be curved like the rest was.

With the bottom half done, the top was bolted back onto it, the jaw against the inner surface moved out, and the block reclamped in the chuck. The same process was done on the upper curve, the only difference being that a smaller mill was used since the space was so narrow.

Next the chuck was switched over to the lathe. I center drilled for the tailstock, then slotted between each piece with the parting tool. It was only taken down though most of the posts. These slots will be guides for cutting off each piece later.

With the slots all done, a starter hole was drilled through the center and a boring bar used to open up the hole to match the eccentric cams. I left the fit a little tight, will let the lapping compound take it to a smooth sliding fit.

Last steps were to hacksaw apart the pieces one at a time, turning the face left on the chucked piece down smooth again and the proper distance from the bolt hole (final pieces are 4mm thick, so took it to 2mm from center of the hole and sawed off the next one).

With the individual parts chucked back up in the lathe, the sawn face was taken down to make the part 4mm thick.

Last photo shows the followers so far. Last step will be to notch them for the connecting rods and drill for the mounting bolts.

 

[barnesrickw]

Nice setup on that last. Never would have though of that.

 

[crueby]

Nice setup on that last. Never would have though of that.

I used a simaler setup on my double beam engine a couple years ago to put recesses in the outside of the cylinder to make it look like a casting.
See post 14 in this thread for pics:

http://www.homemodelenginemachinist.com/showthread.php?t=22713&page=2

A rotary table and tilting table combo can do lots of things (wish it could get this winter to end. Today was first day over freezing point in 5 weeks! Spring might finally be sproinging)

 

[RonGinger]

I can't believe you got away with that long overhang from the chuck in cutting those curves. Did you take really tiny cuts? always cutting in toward the chuck? How did you get all the way to the end of the stock without hitting a chuck jaw?

 

[crueby]

I can't believe you got away with that long overhang from the chuck in cutting those curves. Did you take really tiny cuts? always cutting in toward the chuck? How did you get all the way to the end of the stock without hitting a chuck jaw?

The brass piece was only 2" long, so no flex in it and cut depth was not a problem. I think the camera angle made it look much longer. I took cuts up to near the jaws on the first end, then turned the piece end for end and did the other end, so I did not hit the jaws.

 

[crueby]

Getting close to having the eccentric followers/rods done. Continued on by notching the tops of the followers to take the connecting rod. The brass plate behind it in the first photo was just to keep it from flexing at the top during milling.

Second photo shows the set of followers all notched.

Next parts to make are the valve connecting rods. They are milled down to rectangular size with the fly cutter, then I started notching in the sides. The first side just has a shallow recess.

The second side has a much deeper recess - this has the effect of moving the clevis end out, so that the pairs of rods will line up in the center of the reverse gear link later.

After recessing the sides, the ends will milled for a slot to fit over the link. The cross hole in the ends will be drilled later with a jig, so that they all have the same distance from cam to link.

Last step for now was to drill/tap/countersink the bases of the rods into the followers.

Last photo shows the first pair done. After drilling the end hole, the sides will get tapered in and the ends rounded. Before that, I need to finish up the other two pairs...

 

[len1042]

Hi Crueby,

Thanks for the praise.

The butane burner is my own design based on ideas from Morewood's Raritan propane burner. It is working well and it is convenient. I have a mix of hand sketches and CAD files for the parts. I'll look into pulling the materials together, but not before this weekend - I am prepping for the Chile Fest steamup in Houston. The filler valve is a Ronson lighter repair part that you can find on ebay which uses a tightening tool and a special metric tap.

Hi to all, I just got back to completing my Kozo Shay that I started way too many years ago. I have not done the fire box yet and I'm interested in using propane or butane. Can your share the details of your burner design.
Thanks,
Len (freezing on Long Island)

 

[edhume3]

Hi to all, I just got back to completing my Kozo Shay that I started way too many years ago. I have not done the fire box yet and I'm interested in using propane or butane. Can your share the details of your burner design.
Thanks,
Len (freezing on Long Island)

I have made my crude sketches and CAD DXF files available in the download area - http://www.homemodelenginemachinist...for-gauge-1-kozo-new-shay-by-ed-hume-312.html .

Let's not hijack Crueby's build thread for burner discussion. Keep any followup limited to comments on the download, or create a new thread.

Regards,
Ed

 

[crueby]

I have made my crude sketches and CAD DXF files available in the download area - http://www.homemodelenginemachinist...for-gauge-1-kozo-new-shay-by-ed-hume-312.html .

Let's not hijack Crueby's build thread for burner discussion. Keep any followup limited to comments on the download, or create a new thread.

Regards,
Ed

Thanks for sharing Ed!

 

[crueby]

I got the other two pairs of the valve connecting rods for the followers milled out like the first set, and moved on to finishing them. First up was to drill the hole in the top end for the pin that goes through the tabs on the reverse gear link. To make sure all of the were the same distance from center of the followers, which is critical to make sure that the forward/reverse settings both give same valve movement positions/distances, a little jig was made with a plug to fit in the follower hole and a hole the proper distance out an arm. All six of the rods were drilled with this same jig.



Then it was time to taper the connecting rod arms - took a quick look at what it would take to hold them steady for the milling machine, and decided it was easier and quicker just to take them up to the grinding wheel and taper them that way. Last photo shows them after tapering and rounding the ends, ready for final filing/sanding them pretty.

At this point in the book, Kozo goes on to the linkages for the reverse gear actuator. Naturally, after all this time, I am going to take a side trip and get the followers installed, the valves timed, and make up a test stand and some temporary plugs for the piston drain holes so I can test this puppy on compressed air! Got a bunch of other things that will take up a lot of time the next couple days - league shoots, getting outside now that it is finally warming up and melting all that snow, etc., so it will be a couple days till next post which hopefully has a video of the first air powered run! Stay tuned....

 

[crueby]

I have not been able to get into the shop the last couple days, finally got going on installing the valve gear. Started out by lapping the eccentric followers to the eccentrics on the cranks. That all went well. I did run into one interference issue between the reverse gear pivot bolts and the conn rod tips - had to take off about half a mm from the hex heads on the pivot bolts. Once that was sorted, things started flowing. I started with the center piston, since to get the cover off the valve chest for that one you have to remove the right end cylinder. Below are a few pictures with the center pistons' valve gear all installed and timed. Lots o stuff in a very tight space - tough to get all the parts in and get the bolts started, but it is coming along nicely. Two more pistons to go, and I'll make up some temporary fittings so I can test run it on air (need to retain the reverse links at one side, plug the drain holes, make a block to hold the engine on the bench with the u-joints guided, and hook up the air hose - sounds like a lot but should not take too long. I hope. Maybe. :hDe: )

 

[crueby]

Important news first: IT RUNS!!!!! woohoo1woohoo1

Okay. Ahem. Back to the details.....

Got back into the shop yesterday and today after a bunch of delays for other events, leagues, family stuff, etc (all the usuals when you are anxious to get something done). Got the other two cylinders' valves installed/timed, oiled everything, along with making and installing all the gaskets, temporary plugs for oil feeds, air hose connection, and making a quick test stand (adapted a work support and made a couple little blocks to retain the u-joint ends so they would not whip around too much). With all that done, got out the compressor and started to feed it some air. It ran part way around, then would stop at same spot each time, at number 1 piston TDC. Pulled the valve cover, ran the valve down a turn or so, and buttoned it up again (glad it was not the center piston, that one requires removing the right hand cylinder). More air applied. At about 15 to 25 psi it self starts and runs very nicely, up and down the pressure range. After the obligatory Snoopy happy-dance, got out the camera and recorded an official test run - below.

Major step - I am very happy with the progress on it lately! It sounds like there is a tweak needed in one of the cylinders still, I detect a minor hitch in the sound on each rev. I think I will wait till the reverse gear actuating lever is on before that adjustment, it may just be that the reverse links were not in quite the same spot, affecting the lead on the valves.

Here is the video:

[ame]https://www.youtube.com/watch?v=JzB4O0XvtFY&feature=youtu.be[/ame]

 

[RonGinger]

Fine work, that has to be really satisfying to see it run. I sure hope you decide to come to Cabin Fever with it.

 

[fuzzymuff]

Crueby.
That is so great to see the running of the Engine. Fantastic.