Southworth Engines Boiler Feed Pump

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sbwhart:
Thanks Jack

I always find it interesting how people who share a common language use words in a different way it can certainly land you in trouble. I often wonder what you Guys think of us limeys when we start chattering away to each other using strange words and with dialect spelling, you must think we've invented an all new language.

On with the job in hand then:-

Piston and piston rod:-the piston rod doubles as the pump rod, this will become clear in time, its made from 1/4" stainless steel. Turn down one end and tap M5 and undercut the thread so that the piston screws down square and cut it off to length.

This it being under cut

The engine calls for a silicone piston ring, to ensure that you fit this ring correctly measure the cylinder bore accurately, and the thickness of the O ring and work out the diameter of the groove to give the ring about 10% compression and the diameter over the un compressed ring.

Grind up a grooving tool the width of the ring.

I used a bit of stainless steel hex as this was the only material I had big enough to get the piston out of, turn it up to the diameter of the uncompressed ring. Then cut the groove to the full depth of the ring.

Then stick the roughed out piston to the rod with stud loc.

Then mount the assembly in a collet and turn the piston down to a nice slide fit in the cylinder.

This way the piston and rod will be concentric.

Fit the O ring

It should be a nice slide fit into the cylinder:-be careful you don,t end up pinching the ring on any sharp edges in the cylinder scrape them off.

Next bit the bottom cylinder cover.

This is the casting

First turn the chucking piece up to get a clean diameter

Turn it round face and drill and bore out the pocket for the sealing ring.

Back face to thickness

Then over to the spin indexer mark out the fancy shape.

and mill it out

Then over to the RT clock the bore central to the mill spindle, rotate RT so that the holes are drilled in the correct orientation.

This sequence of shots shows the advantage of having a tooling system based on one collet system in this case ER32.

Back onto the lathe and part it off.

At this point I realized that there was something wrong with the drawing/design as drawn the pocket for the sealing ring is too deep the closing disc won't compress the ring to give the seal, so Instead of having a plane disc as drawn I made the disc with a small boss that will sit into the pocket and compress the ring.

Her are the bits

And assembled

Stew

saw:
Just wunderfull, tanks for bigger picture. :D :thumbup: :clap:

Stilldrillin:
Stew.
I love the way you work, and the work you produce. :clap: :clap:

Watching/ enjoying, quietly...... :thumbup:

David D

madjackghengis:
Hi Stew, I too enjoy the word interplay with our cousins across the pond, it is interesting, and having spent time in the Marines, and visited a few Brit ships, it is easy to enjoy the close relationship we have. You stated the value of having many tools using the same collet system and I was just going to comment on how handy that must be, it has worked very well in this build, and you've shown some very fine bits and pieces, nicely done. I definitely envy your set of collets :lol:, at some point I will have to invest. Very nice pictures and explanations, fine craftsmanship all the way. :beer: Cheers, Jack

sbwhart:
No problem Saw my pleasure.

Thanks Dave

Cheers Jack:- John first showed me the benefits of having a tooling system and I took full advantage of it.

Top pump cover yet another casting this time it odd shape meant I couldn't grip it to clean up the cucking piece, so this time I grip the chucking piece got things running true as best as I could then cleaned up as much of it as I could using the long reach of a parting tool then parted it off so that a I had a sorter but clean bit to grip onto.

It was then just a mater of dealing with it in the same way as the cylinder bottom cover.

For those who have not seen one of these this is the coaxial indicator I use to centre the job under the mill.

To drill the holes around a pitch circle I use the PCD feature on my DRO it's a lot easier than using the RT to index.

This is the finished part after a tidy up with a file.

Pump Body:-this casting was a bit lean on material so had to be carful with it, bit of an odd shape to deal with.

First clean up the main body diameter and face off just enough to give a clean register to work with.

Mark it out checking that everything will come out in the correct position with enough material around it.

Back onto the lathe face off to the mark clean the other dia up and drill out the pump chamber.

Again in the lathe just clean a whisper off the clack valve extensions, getting them running as true as I can.

Turn up a mandrel to locate on the pump chamber diameter, mount this in the spin-indexer.

Pick up the centre of the mandrel using a wobbler.

Set the casting up level using the height gauge (my indexer has a centre height of 70mm)

And mark it out using the indexer and height gauge.

Then machine the arms to length and drill the valve chamber.

Tap

Finished Job

I then turned up the pillar supports sorry no pics simple turning job.

And this is the assembly so far

Stew

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