The Home Machinist!

I decided it was time to stop hijacking other threads and start my own.

Thank you jessebanning for the pictures, that is great work your doing on the NYC Hudson. Thank You to abrams464 for the pictures and the prints. After looking at what you sent, I was missing about 2/3's of the prints. I am also missing castings, but that's easy to overcome with the prints.

The B & M P2c was a common locomotive for the B & M as they used it mostly for the commuter service into and around Boston. There is one surviving P2 engine left, albeit under 60ft of water in the Portsmouth, NH harbor. The engine that I had planned on modeling is the 3688. This engine was used in several of B & M crack passenger trains, and was painted in blue, buff strip and red pin stripping. From what I have been able to find out so far, is that it was only in this paint for a 5 years, then back to black like most other engines. The speed at which the B & M steam engines were scrapped, it is a wonder that even the 3713 at Steamtown survived.

I started this engine in 1985 as a 7 1/4", 1.6sc model. A lot of time has passed between the time that I had stopped working on it and now. The castings are little heavy for the P2c, but they will work. I bought the castings that I have from East Coast Locomotive Works and then some from Klamath Locomotive Works.

I have the frame, drive wheels, pilot truck and some of the spring rigging machined and ready for assembly. The pilot truck which I started working on in December is done, except for paint. I never had bought the pilot truck bolster casting, so here we go from a solid piece of cast iron.

The next two pictures are what it is suppose to look like, and are from abrams464.


I have started machining the bottom side first this past Saturday. I got ready for the 1" ball end mill and discovered that I didn't have an R8 1" collet. That ended the milling machine work for the weekend as I didn't want to disturb the setup. I ordered it on Monday, but it won't be here until Thursday. Damn!

Be cautious about using shanks beyond 3/4" diameter with R8 collets. Even 7/8" shanks aren't a great idea because of the thin wall that remains when opening up the collet. Note that Bridgeport didn't provide anything larger than 3/4" for the R8.

I expect 1", if you can find one, would be dangerously thin, or it would have limited depth capabilities, leaving your ball end mill hanging out quite far. When running large cutters, it's a good idea to keep them as close to the bearing as you can, to limit flexing.

Assuming you manage to make the setup you're pursuing, take light cuts to stay out of trouble, at least until you get a feel for how the machine behaves.

Harold

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Wise people talk because they have something to say. Fools talk because they have to say something.

Oh yes, very light cuts!

If I had spent a little more money, I could have got one with a 7/8" shank, and that's what I should have done. Oh well, hindsight.

I bought a 1" R8 collet. I suspect it is only good for holding a drill bit or plunge cuts. I wouldn't load it sideways with anything tougher than machineable wax and that may be a little iffy.

BTW Wholesale tools was my source. IIRC

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Dennis


Thermal Arc 185-TS
Millermatic Challenger 172
Victor O/A
Atlas Craftsman 12 by 24 Lathe
Esab PCM-875
Wholesale Tool Mill-Drill

Thanks for that bit of information. I have a 7/8" size, and don't have a great deal of confidence in its use. I'm shocked to hear you can actually buy the 1" size.

Harold

_________________
Wise people talk because they have something to say. Fools talk because they have to say something.

I use the 7/8" on a regular basis. I just got the 1" collet, and looking at that I didn't have much faith in it. I tried it anyway and it got scary. I am now setting it up in the lathe. Should have done that in the first place. Oh well.

3/4" R8 collets are as large as I would go with an end mill...unless you go with a weldon type holder...even then..use caution when using end mills larger than 3/4" in a bridgeport type mill.


Pamela

I'm not convinced the use of a holder is the answer, either. Considering the added length, and the forces moved a greater distance from the lower bearing, I don't see much of a gain, if any at all.

I've had good luck with 1" two flute end mills in aluminum (3/4" shank), taking as much as a .600" depth of cut and virtually the full width of the cutter. That's the only time I experienced an end mill pulling out, however. I'm a strong supporter of the use of collets, but you have to use them properly, including not being timid when tightening the drawbar.

I've determined that a 3/4" four flute is a good choice for roughing steel. I've limited the use of larger end mills to machining aluminum only (running a Bridgeport with 2 horse head).

Harold

_________________
Wise people talk because they have something to say. Fools talk because they have to say something.

I ended up doing the bottom side in the lathe, it was also quicker.

The top side I did part of it on the rotary table.

As I said in an earlier post, I routinely use a 7/8" collet. Facing soft metals of which cast iron is a soft metal, I use either a 2" face mill or a 1.5" face mill to bring the block to size.

The last place that I worked, had about 60 Bridgeports when both the high volume machining dept. and the tool & die departments were running. To see what was done on a daily basis with these machines, I am being cautious with my machine. I wound up being the "Bridgeport Guy" and I only changed about 5 spindle bearings in 20 years. These were in the tool & die dept. with the compliant that they were out by .0005". I would carefully take them out and save them for reuse in friends machines.

My machine isn't a Bridgeport, but it is a well built Taiwanese machine.

Now, on to the frame. I thought that the machining was done. Nope, on another print it says to do some more.

Jim

Wholesale tool. The tool actually sits below the spindle. Really only good for a drill bit.

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Dennis


Thermal Arc 185-TS
Millermatic Challenger 172
Victor O/A
Atlas Craftsman 12 by 24 Lathe
Esab PCM-875
Wholesale Tool Mill-Drill

I've used a 6 flute 1" endmill on a Smithy Granite 3 in 1 hogging away material.
Please keep in mind the material was MDF...
Tried it on aluminum once, only once...

That would be a lousy choice for aluminum, due to the lack of chip carrying ability, and, in many cases, poor geometry in regards to relief angles. They're intended for cutting steel, not aluminum.

I'm not suggesting a two flute would work for your particular machine, as I'm not familiar with its characteristics, but a two flute would provide the necessary chip relief. I don't even recommend a four flute for aluminum, let alone a six flute.

Harold

_________________
Wise people talk because they have something to say. Fools talk because they have to say something.