Building the Southern Railway PS-4 Frame

[GlennW]

Drilling them separately would introduce a second opportunity for possible error.

If drilled properly without an excessive amount of downfeed pressure on the drill, the drill should produce a straight hole. Excessive downfeed pressure may cause small drills to wander.

Not sure what size drills you will be dealing with.

Nothing nicer than high quality drills when it comes to straight, on size holes.

[LivingLegend]

To insure consistent alignment of both frames bolted together....

I would drill and ream two holes for dowel pins in the frames.... Where those holes would be used to bolt the front footplate (or cylinders) at one end of the frame, and a crosstie at the other. This will spare you the headache of trying to get the frames back in perfect register should you, for whatever the reason, have to separate them before they are finished. It will also prevent a possible shift in alignment while machining them as well.

Use a .1875 dowel....This size will work out perfect if the bolts used to mount the footplate and crossties are #10 (.190). You will want a clearance fit in both frames for the pin. You can get by with a standard sized(.1875) reamer instead of the proper dowel clearance reamer.... The standard size reamer will cut enough oversize to clear the pin.

The holes for the bolts holding the frames together for machining should be match drilled after clamping them together.... Then match drill the holes for the dowels after you bolt together the frames.

Pick up a datum point on your frames once bolted together and mounted on your mill table. Then dial the table over to where the holes for the crosstie and footplate, or whatever are to located.... then drill for the dowel. Forget layout and center punching. Let the accuracy of the mill do the work for you.

Use a center drill or spotting drill as a start for your drill. You might want to consider the use of a split-point drill with a larger included tip angle instead of using a standard drill when drilling thru the thickness of both frames..

LL

[Pipescs]

Back from the road.

One good thing from the trip I was able to drive up and meet David Bortz and look at his shop. It is always makes it more compfortable to write large checks to order things from people once you have met them. I came a way with a great impression on David and put a check in the mail for a set of his Pullman Trucks to use behind the PS-4.

Also during this period I continued my friendship with Earl Mueller who has now been nice enough to sell me a set of casting for the Commonwealth Trucks I need for may Tender.

They are Iron and I was looking at a large shipping bill from St Petersburg to Lester. Earl finally sweetend the deal with a piece of ten inch pipe for my boiler so I will be driving south around the first of the year to pick up the items. Too much to ship.

[Pipescs]

Now that I am home I am trying to get a few parts cast for the Trailing truck Frame. The patterns and match plates are ready along with the cores for the Journal Boxes. I am going to have to deal with the fact I do not have but one hundred pounds of the petrobond sand to do the molds with. I will only be able make up one journal box mold at a time do to the size of the flask.

The sand comes in hundred pound boxes so after I pay for all the new toys from Earl and David I will need to build up the toy fund and order it.

[kvom]

Earl came up to our track earlier this year; if he plans to do so again perhaps he can bring your goods to Georgia and save you some travel time.

[Pipescs]

I will talk to earl about your offer. I fear the six foot piece of pipe and all the castings he is offering me may be too much for him to haul.

I did manage to get into the shop tonight and after six tries ended up with a mold that I hope to cast this week. It is the first attempt at casting the major assembly for the journal Box on the Hodges Trailing Truck.

the issue was the tear out when I would pull the pattern out. I finally sanded the edges better and used graphite for a parting agent.

Won't know if the core went in without damaging the mold until I break it out after the pour. Will be using silicon bronze for the first time

[Pipescs]

Good Furnace Day. The mold worked but I realize now the first attempt was not rammed well enough. Trouble is that it is too rough. When I sanded the bad areas it improved.

Todays furnace event went well but I was still learning how to turn up the heat gradually without flooding it out.

Took an hour to make my two castings today. First time I used the bronze Poured it at somewhere over 1800 degrees.

This is right out of the sand.

After clean up they looked a little better. Still too rough on the surface. I willcontinue to work on my molding

[Pipescs]

Patterns

First Attempt

Weight was four pounds and five ounces for the two castings. Glad I went with cores

Plan it cast four more over the next few weeks.

[Pipescs]

Back side was cored Round for the bearing block

[Pipescs]

Hodges Trailing Truck I am working towards

[Dick_Morris]

Charlie,

Looking good.

It looks like you plan to use the cast depressions to locate the drill for your holes. You might consider making a simple drilling jig instead. Once attached to the casting, the same jig could be used as a reference surface for some of your other machining operations.

Dick Morris
USAF Retired

[Pipescs]

You are right about the dimples and fixtures

I originally did holes in the pattern (Being Untrained) Filled them with bondo and am no looking at a fixture to clamp it in to turn for the bearing and then clamp to the mill table so I can run the holes as a production line.