Chris's Build of Steering Engine

[cnr6400]

 

Major progress! Base is looking great. Plywood under base - not so much!  Dab some paint on it and sell it on ebay as Modern Art. Start bids at $3000 or so.....

[Admiral_dk]

Great progress Chris 

I wonder - since you spend time shaping the 'Cut Out' before removing it - will it be used elsewhere .... like the 'Upright' ...?   

Per

[crueby]

Great progress Chris 

I wonder - since you spend time shaping the 'Cut Out' before removing it - will it be used elsewhere .... like the 'Upright' ...?   

Per

Yeah, the top cuts on the cut out section were wasted, I didn't think that one through enough and I should have left that section full thickness. Its still plenty thick to use for something else, on some model. Its not large enough for the vertical walls though.

[crueby]

Hi Michael,


Apparently the emails I sent in reply to you did not make it through - I don't know why, but both the direct emails to your 'simon' address and the notes I try sending through the forum to your user never make it to you, same was happening a couple weeks ago. Emails from you to me appear to work fine, but ones going back to you don't.

      

So, I did get the two emails with pictures, first one with four pictures, second one just now with 5 more pictures - thanks very much for those!
Chris
 

[Michael S.]

Whenever I see the pictures, I think gold bars are being milled there.
Everything shines.
And once it's done, it's like gold.
Very good work Chris 👍

Michael

[Michael S.]

I have no idea why that is either. I could try again with a different address.

Michael

[crueby]

I have no idea why that is either. I could try again with a different address.

Michael

Its worth a try, I'm sure we'll be trading files again.

[crueby]

I have no idea why that is either. I could try again with a different address.

Michael

Its worth a try, I'm sure we'll be trading files again.

Got your email, replied from both accounts I have, hopefully at least one makes it there!

[crueby]

Getting down to the last milling operations on the base. Formed the cussets on the curved sections first, taking a stop cut either side of each one. The middle ones are along the long axis of the base, the other two on each end are 45 degrees either side of that.

Then came back and cut away the material between each gusset, using the rotary table to cut along the arcs.

Also cut the gussets on the back corners, which are 45 degrees from each side.

That finished off all the gussets,


so the next step was to angle back the gussets to go from the outer edge of the lower flange up to the outer edge of the top of the side walls. To do that, the rotary table was moved to the tilting table, and took some time to figure out which way to orient things and how to clamp it to the table without the mill column interfering with the movements needed. Once that was sorted out, and the angle set, I went around taking off the upper corners of all the gussets, first doing the ones down the sides

then the ones on the rounded ends

When those were all done, the table was set back down horizontal, and the trays in the rounded ends were milled out just like the other trays were.

Final milling was to drill out the starter holes for the square blocks that act as nuts for the vertical engine posts. These need to be squared off holes, so they were started with a drill, they will be finished off with a fine dental bur in the high speed air handpiece - other alternative would be to make a small square broach and press that in. The rotary air tool is quicker than making a special cutter.
So, here is where the base is now. Just needs those holes squared off, a bunch of smoothing with sander and maybe sandblaster, and tapping the holes for the vertical wall bolts. The inserts for the bearing blocks will come later, those blocks will bolt in from underneath, the bottoms of those holes were countersunk so the screw heads will sit flush with the bottom of the base.

While that finishing work goes on, this is probably a good place to break and go back to the Ransome saw, and try out the valve link connections that some of you suggested!
 

[Jo]

Who needs a CNC mill when you have a Chris around   

Jo

[crueby]

Who needs a CNC mill when you have a Chris around   

Jo

   


When making one part, Count Number Cranks works great. I wouldn't want to go into daily production this way though!
 

[Kim]

That's just awesome, Chris!  An incredible job of carving out a complex base from a block of brass.  Simply amazing!   

I didn't see the square holes for the nuts.  Er, the holes that WILL be squared off for the nuts.  While you haven't squared them off yet, I thought you made slots with the mill already?  Did I just miss them?  Inquiring minds need to know!   

Kim

[crueby]

Kim, you didn't see square holes since I had not squared them up yet, in the last photo of the previous post it showed the holes drilled round. I just finished up with the dental burs, squaring off the holes to take the bar stock. Here is where they are on the front vertical edge:

A hole will be drilled/tapped through the top of that square bar to make the nuts. The vertical posts that hold up the front of the cylinders go down through the holes and screw into the nuts. This is how it was done on the original engine so they could remove the posts without having to unbolt the base from the deck of the ship and lift it to get at nuts underneath. The rest of the parts all will have studs sticking up, with buts screwing down from the top.
This drawing shows the four vertical posts coming down from the cylinders, and the square nuts visible in the holes underneath:

[Michael S.]

I cannot understand exactly why this variant was used back in 1897.
Basically, a threaded hole in the base would have sufficed. The rods are always screwed in from above. Or the forces of the cylinder (it should be around 4 hp) The rods can be torn out of the thread and the square nut has more surface. Back then, they didn't trust cast iron to be as durable.

Michael

[Kim]

Ah... I gotcha!  Thanks Chris.  Now I see the square holes!   

Kim