1/3rd Scale 5hp Galloway Build

[Jo]

Its bigger than I remember it 

Thanks for bringing it to see me so that I could appreciate it 

Jo

[Jasonb]

Thats because last time I only showed you little bits at a time so you would not get over excited

[Jo]

A man visits my house and brings castings with him, what reaction did he expect 

but then he took them home with him 

Jo

[Jasonb]

The next job on the base was to machine the flange for the water jacket to butt up against. The casting was not disturbed from the machining plate and transfered to the lathe. I know the exact centre height above the cross slide is 3.389" so it was a simple matter to subtract the casting and plate thickness from that to arrive at what packing was needed. The side of the machining plate was clocked true to the lathe axis ensuring the face to be machined is at right angles to the beraing faces.



The flange was then fly cut to the correct distance from the bearing centreline



<a href="https://www.youtube.com/watch?v=NAgF8tAo-YQ" target="_blank">http://www.youtube.com/watch?v=NAgF8tAo-YQ</a>

I then swapped the flycutter for a boring head and machined the socket for the liner. The tool in the boring head is one I use to put a final chamfer on the corners.





<a href="https://www.youtube.com/watch?v=T87tM6RPm5Q" target="_blank">http://www.youtube.com/watch?v=T87tM6RPm5Q</a>

I then put a rough hole through the cam side bearing before returning to the lathe once again to mount the casting on the cross slide but this time the machining plate was clocked at right angles to the lathe axis and a wobbler used to pick up the location for the hole.



The other bearing housing was then drilled out so a between centres boring bar could be used to open out both housings to finished size.



With the lathe work done it was over to the mill to machine the timing gear stud hole and faces for the push rod brackets



J

[Jo]

Looks good Jason 

I see you were making use of an old set of feeler gauges to provide a shim. Its well worth picking those up from car boots for just that purpose 

Jo

[steamer]

That looks great Jason!..  I can see they didn't spare the iron on that casting!....

I love the lathe set ups!..

Dave

[Don1966]

Hi Jason, love the videos you provided. Like Dave has said, I also liked your lathe setup. Gives me different aspects of doing it,  when not being able to machine it in the mill.

Don

[ths]

I'm taken with the lathe set ups as well. I assume that the sub-base is used as a datum to align the casting to the lathe axis for the various drilling/boring/facing operations?

Hugh.

[Jasonb]

Hugh, yes the machining plate gives me nice flat and true surfaces to clock in and also has several 10mm holes to suit my hold down bolts etc.

The next part to be attacked is the cylinder, I spent a while working out where best to place the cuts and put some basic marks onto the casting. The bosses for the rod guide and ignitor can't really be moved so the end faces were marked from the bosses.



The face where the hopper mounts was the best face to use for the initial holding but was not totally parrallel to the cylindrical part so a feeler gauge was used between the casting and the angle plate and a cleaning up cut taken over the head end.



This freshly machined end was then placed against the angleplate and the top face cleaned up but left oversize at this stage.



I then knocked in a temporary plug and marked the centre to make it a bit easier to set things up in the lathe, the machined end of the cylinder was set back against the chuck to keep things square and the end faced.



I then mounted the old 4-way toolpost that came with the lathe and centred up a 16mm indexable boring bar and used that to open out the bore. Its not easy to see but the bore does not go all the way through as the end of the liner needs to butt up against the face you can just see in teh bottom of the hole. The inner diameter is also 0.010" smaller than the outer so the liner can slip most of the way in before the press fit takes hold.



The casting was then rechucked so the other end could have the cored hole clean out to 0.100" undersize and machined to final overall length

J

[Jasonb]

The liner is supplied as a large lump of cast bar about 70mm dia. This was held in the 4-jaw, faced and then opened up first by drilling in stages upto 3/4" and then boring to 0.0100" below finished size.



Approx half the length was then turned down so it was a nice firm fit into the base casting.



Here it is slipped into place, you can also see that I added a taper to help fitting the piston rings before I removed it from the lathe.



Before I forgot to drill it the coolant drain hole was added to the cylinder with an extended drill, this needed to be drilled before the liner is pressed into place.



The liner was then held by the machined end and clocked true before boring the waste out of that end and finally turning the different diameters to press into the cylinder. Not easy to see but there are 3 different dia all only a few thou different from the next.



The cylinder was then pressed onto the liner while still in the chuck using the tailstock to apply pressure and some Loctite for good measure.

After allowing things to dry over night I inserted packing and shims so the assembly could be bolted down to the cross slide. By doing this with things still in the chuck it kept all the bores true.




I then used a 35mm bar between ctrs to bore out the assemble to the required 1.750"



And without disturbing anything ran the sprung hone up and down the bore a few times.



And a quick look down the bore. I was pleased that the butt joint between liner and cylinder did not show so things must have pressed into place as planned.



J

[Jo]

Nice 

Why did you choose to use the 4 jaw independent chuck to hold the CI bar? It looks nice and round would the three jaw not have been as good?

Jo

[Jasonb]

My 6" 4-jaw has longer jaws than my 5" 3-jaw plus there is more jaw still in the chuck so all round a better grip.

J

[Jo]

  Sounds like a good reason to me.

Jo

[Jasonb]

Oh and its a Bison not far eastern

J

[NickG]

I was sure i had posted on this but musn't have. Spot on Jason, definitely want to watch this one.