The "Little Pearl" Single Cylinder Marine Engine

[b.lindsey]

Thanks Bent. So far that has been the case and they are machining well also. I found one very small void in the flywheel, but there was plenty of stock there to machine past it with no problem. Other than that very minor place I haven't seen any voids at all.

Bill

[Tennessee Whiskey]

Hey Professor, my thoughts. I have used the carbide on pretty much everything with good results. However, as with any carbide, there is more tool pressure, which makes it harder to sneak up on a dimension and to achieve a great cut, you need to take a DOC equal to or greater than the nose radius. So, I tend to use it for roughing and then leave about the final.010" to be finished with a sharply honed HSS tool. Now the Warner ones won't take the .200" DOC that some of my CNMG or WNMG ones will, but, I can easily take from .010" to .100" off diameter with no problem. Actually, you can go lower than the .010" , just have to make more spring passes due to tool pressure.

Cletus

[b.lindsey]

Thanks Cletus, I mainly want them for the first   few roughing cuts on castings to get through the crust the better machining heart of the casting. Doing that with HSS tends to wear them down fast from my experience depending on the material. I understand what you are saying about the pressure though.

Bill

[b.lindsey]

Today I got a start on the cylinder head casting. The raw casting is shown in photo 1. I was able to chuck it neatly and relatively concentrically in the 4 jaw chuck to clean up the runner and outer diameter and the bottom side just enough to true them up and fit them into the 3 jaw chuck (photo 2). Once in the 3 jaw, I was able to work on the top end (photo 3), taking the two "ears" down to the finished height above the top surface of the casting (photo 4) and to drill and ream the through hole. With that done the center section was parted off first, the machined to the lower height called for (photo 5). Finally I bored out the center in preparation for tapping 1/2"-20 to match the threads of the steam piston stuffing box packing nut which will fit into it (photo 6). This will be left untapped for now so as to keep a smooth ID to center on for drilling the holes for the crosshead guide rods. That will be done on the mill later. That's the progress for today.

Bill

[crueby]

Nicely done.  Does the section of the center parted off get used for something else? Or was it cast tall for reasons of casting?

[b.lindsey]

Chris, no it isn't used for anything else. I suspect it was cast that long to act as a chucking hub maybe, thought I didn't use it as such. As it turned out, chucking deeper in the 4 jaw as shown in the second photo above was far more rigid.

Bill

[Ye-Ole Steam Dude]

So far all the castings look to be of the highest quality and free of defects.

Thomas

[Jo]

So far all the castings look to be of the highest quality and free of defects.

  I still think they should have been sent over to me for the initial inspection, with the drawings 

Jo

[Ye-Ole Steam Dude]

So far all the castings look to be of the highest quality and free of defects.

  I still think they should have been sent over to me for the initial inspection, with the drawings 

Jo

Jo I don't think it is too late, just tell Bill to box all that stuff up and ship it to you....

[b.lindsey]

Thomas, yes the quality has been good so far. A few inclusions but there has been enough material in all cases to machine down below any minor porosity issues.

Jo...as if you don't have enough castings to fondle already??     You had mentioned earlier something about having seen these castings at least in print. Were they from the same supplier or were you talking about the full size version?

Bill

[Jo]

Jo...as if you don't have enough castings to fondle already??    

  That is not possible 

I think they were the full sized one but by the time I looked at shipping and import costs they were very expensive 

Jo

[b.lindsey]

Indeed, the full size ones are expensive over here as well, though if one was going to make a full sized steam launch, I suppose the cost of the engine castings would be a relatively small part of the total cost. Quite a different matter when it's just for a static model.

Bill

[Tennessee Whiskey]

Boy, you don't fondle them long; do you Professor?  Great looking work as always Bill. The Warner tools love the cast bronze

Cletus

[b.lindsey]

Thanks Cletus. Seems like I am going pretty slow but not a lot of extra time at the moment,  mostly weekend work for now. Progress is still progress though!!

Bill

[b.lindsey]

Had some time yesterday and today to finish up the cylinder head. First up was to center drill, drill and counterbore the two holes that the crosshead guide rods will screw into (photos 1-3). Then it was back to the lathe to finish up the OD and height of the head above the cylinder (photos 4-5). Then back to the RT in the mill again to add the flats on each side of the head and the .750" radius scallop (all are for clearance to other parts later on). The finished underside is shown in photo 6 and the top  side in photo 7.

Bill