Chris's Build of Steering Engine

[crueby]

Michael, another set of questions for you!

I was looking at the photos of your engine at how the connecting rods and crossheads are made, as well as the eccentrics.

The eccentric arms appear to be bronze throughout, with pinned pivot rods at the top for where they go through the bottom ends of the valve rods.  Is therea bronze bushing inside the bottom of the valve rod?

On the con-rods, it appears that the upper section is all steel with the blocks around the crank pins bronze, with a steel cap on the bottom. Again, does the pin at the bottom of the piston rod have a bronze bushing around it at the center? Looks like those pivot rods are pinned through the con-rods?

On the crosshead guides that hold the bottom of the piston rod and slide on the flat plate on the vertical wall, are there bronze flat plates on that slider as well? On both sides, against both the flat plate and against the covers that are bolted on?

Thanks yet again! If you have any pictures of those parts before they were assembled that would be great to see (please dont take it apart!)
  Chris

[Michael S.]

Hello Chris,
I have a picture of the valve rod on my mobile phone, you can see bronze bushings and also on the piston rod.
I'm not sure about the crosshead slideway.
Unfortunately I'm in Berlin until Thursday and can't access my photo collection on the computer.

Michael

[crueby]

Great pictures on the bushings, thanks!  That last one does look like it has a bronze plate inside the crosshead guides. Thanks!!

[crueby]

So, the elves and I have it back together again!

Elfric wants to try steering with it, but he needs a ladder to stand on...

I told them that I would make them a catwalk to stand on, but they screamed "CAT!" , and ran off under the cabinets.   

[Michael S.]

Oh, are they so shy of cats?
It all looks great and when it moves by itself for the first time you can be proud of your work.


 

[crueby]

Oh, are they so shy of cats?
It all looks great and when it moves by itself for the first time you can be proud of your work.


 

They know that cats LOVE shop elves. Especially with a little salt... 

[crueby]

Decided to start in on the eccentric arms. Picked through the bronze stock, and found a bar I could saw out and mill the blanks from. Here is the eccentric arm 'casting kit' (well, the raw bar is continuous 'cast') that I wound up with:

Next time I'll start in on the actual shaping. The two smaller bars are for the bottom caps, they will be bolted to the ends of the larger bars for boring out the holes around the eccentrics.

[cnr6400]

 

With the cat / elf relationship as it is, it might be useful to do a side project like a D-9 CAT dozer or 797 CAT quarry truck, just so CAT could be mentioned periodically to keep the elves in line. 

Speaking of dump trucks, how are the popcorn supplies holding up? I could send another load of premium white popcorn with the screamin jimmy dump truck if stocks are low - let me know! I got the ether ready. 

[crueby]

With the cat / elf relationship as it is, it might be useful to do a side project like a D-9 CAT dozer or 797 CAT quarry truck, just so CAT could be mentioned periodically to keep the elves in line. 

Speaking of dump trucks, how are the popcorn supplies holding up? I could send another load of premium white popcorn with the screamin jimmy dump truck if stocks are low - let me know! I got the ether ready. 

I'll have to get out the little Cat-apult that I made years ago...  Maybe paint their little ATV Caterpillar yellow...




Got a decent supply of popcorn, but drive that truck down here, want to see it!

[crueby]

Got a good start on the eccentric arms today. Started out drilling for the side bolt holes so I can have the bottom caps attached during shaping. The cap holes were drilled/tapped 2-56, the upper holes clearance - I have learned (finally) to do them this way to make assembly a whole lot easier when the caps won't be accesible from underneath the frame. The screws will stay threaded into the caps, and the nuts can be run in from the top. All the parts were marked to keep them in matched pairs, and the parts were all set in the vise with mating faces on the back of the vise, just in case I didn't have the holes perfectly centered.


The sides of the upper arms were milled back to form the top of the section that will surround the eccentric, and also expose the face where the nuts will go in.

The shoulders on the caps were also milled in at this point, mainly since without doing this the blocks were too thick to through-tap them.

Here are the blocks bolted together, ready for the next step, boring the hole for the eccentric. The holes will be stepped to fit over the shoulders on the eccentrics and keep the arms from sliding off the sides.

[crueby]

After a great lunch session out with friends, came back into the shop to get the eccentric holes bored out. I first tried holding it in the 4-jaw, but that was not feasible due to the length of the arm, so I got it centered up on the faceplate, clamped in place, and drilled/tapped some holes to bolt them in place to drill/bore out the holes to the size of the shoulders on the cam. I was able to use the normal boring tool to cut most of the recess, it would go up to the shoulder on the far side, but the near side of the tool has a shallow angle.


Then switched to this little internal-threading bit to turn in the recess on the inside up to the near side of the part. Still a slight angle, but close enough for some lapping compound to even it out since its a shallow shoulder.

Here is one of them unbolted to hopefully better show the recess on the inside with the shoulders at the edges. And yes, I marked all the parts first to keep them together and oriented!

With the cam set in place - its a slightly tight fit, will need to lap it to get a smooth sliding fit. I didn't want to take off too much with the boring tools and have to start over.


one set in place to show the assembly:

So, next time I'll get the cams lapped, then start in on shaping the outsides of the pieces and get the holes drilled in the top ends.

[cnr6400]

 

The eccentric followers / arms look great!

Re the screamin jimmy dump truck visit  - will start collecting the 9000 gallons of McDonalds used fryer oil for a return trip with popcorn when needed. Also will start typing the noise apology letters for annoyed bystanders along the way....

[crueby]

Got a bit sidetracked when playing on the computer, I stumbled across the collection of Herreshoff plans online at the MIT museum:
https://collections.mitmuseum.org
They have original plans from the Herreshoff company for ships, engines, all sorts of fittings, including several versions of their steam steering engines

and steam windlasses

as well as a bunch of their compound ships engines... Well worth a look if you are looking for a project!

[cnr6400]

Nice compact engine designs! On the windlass though - double cone clutches on the sheave, without friction material, worry me a bit. If you have seen the YT vids of runaway anchors / anchor winches, they are usually a result of clutch / brake fails, and they make me real nervous.

[crueby]

Nice compact engine designs! On the windlass though - double cone clutches on the sheave, without friction material, worry me a bit. If you have seen the YT vids of runaway anchors / anchor winches, they are usually a result of clutch / brake fails, and they make me real nervous.

That is just the general arrangement drawing that does not show the details of brake bands and pawls that it also has. The drawings there show plans for several different designs and ships, ranging from small yachts to medium size torpedo boats that they built for the Navy. I just picked one drawing to show whats available on the museum site, they have a LOT more.