[PROJECT] Bar Stock Steam Engine

[Cross Slide]

Highpower. That’s a nice design

Trevor

[Highpower]

I think so too. The only thing I would do differently is eliminate the lower set screw and not cut the keyway all the way to the bottom of the threaded first stage. I know he added the lower set screw as an after thought and it does work, but my OCD would have forced me to make a new part instead without the added screw.  

All in all I think he did a great job.

Something else you should consider making for yourself that you will find extremely useful:

[Cross Slide]

I have the next two parts of the steam engine build complete. The Cylinder and Cylinder Head. They are machined out of 12L14. The material I was starting out with was 1-5/8” OD and would not fit through the bore of my chuck. So this caused me to have a lot of material sticking out of my chuck. Also gave me the opportunity to use my steady rest for the first time.
   

I started off by facing the end then drilling the centre of the bore. The I reamed that hole to 1/4”. This hole is the hole the piston rod will slide threw. 
   
   

After that was done I drilled for the piston bore. Once I had the hole large enough I switch to a boring bar. 
   
   

Once I had that done I had to turn down the OD to 1-1/2”. I took TomG’s advice and machined a plug that fit into the bore to accept my live centre. That way I able to remove the steady rest. 
   
   
   
   
   

At this point I was able to put the part in my mill and drill the bolt circle for the cylinder head to attach. 
   

I then made the cylinder head. Once it was made it was bolted onto the cylinder. It was also bigger OD then the cylinder itself. Since I turned the OD of the cylinder down it was able to fit into the bore of my chuck. I used some aluminum stock to protect the finish on the cylinder from my chuck jaws and turned the OD of the head down to match the cylinder.
   
   
   
   

Trevor

[Cross Slide]

   

Once I had the cylinder head turned down I put the cylinder in the mill vice to remove the excess material on the back side to create the rails for the slide to fit onto. I was also able to use the machinist jack that I made!! To protect the surface finish on the cylinder from my vice jaws a cut a pop can apart and wrapped it around the cylinder. Worked great!!
   
   
   

You can just see the 1/4” hole starting to appear once I got this side down to spec.
   

Flipped the cylinder over and did the same procedure on the second side leaving a .250 rails dead centre off the back of the cylinder. 
   
   

I then drilled the 8 mounting holes along the rails
   

Once that was done I had to cut a .500 slot down the centre of the rails. I also left more material at the end to help hold them straight that will be removed later. 
   
   

I used the tang to set the cylinder up vertical so I could drill the air passage holes that will connect with the valve body.
   
   
   

Trevor

[Cross Slide]

After the rails where complete I machined a block to fit in the slot (again TomG’s advice) and clamped the rails in the vice. Again using a cut up pop can to protect it. I then removed the extra material off the end creating two rails. A bit of filing and the cylinder is done.
   
   
   
   
   
   

Trevor

[TomG]

You are making good progress, Trevor. Another method of filling the slot would be to use an adjustable parallel, which would save you the time and trouble of machining a spacer. A set of them is a pretty useful tool in your arsenal.

Tom

[EdK]

Nice work Trevor!

Ed

[rleete]

Nice work, great pictures.

[Cross Slide]

The next part completed on my Bar Stock Steam Engine build is the Connecting Rod. This part is a small piece overall with a large amount of machining on the sides and ends to give it the shape. Pretty well impossible to hold in the vice and do this. So I started off by machining a small Fixture Plate to hold the material and secure it. I pressed in two .250 precious ground rods into the plate with the same spacing as the wrist pins on the connecting rod. This made it possible to hold the material, while being able to remove it, flip it, and know it was in the exact same location every time. Plus I now have a small fixture plate to use in the future!

   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

Trevor

[TomG]

Excellent!

This project is helping you learn the value of fixturing in machining.

Tom