Building the Southern Railway PS-4 Frame

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Trainman4602
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Re: Building the Southern Railway PS-4 Frame

Post by Trainman4602 » Wed Sep 07, 2011 7:30 pm

ALLWAYS OPERATING MY TRAIN IN A SAFE MANNER USING AUTOMATIC AIR BRAKES

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Pennsy fan
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Re: Building the Southern Railway PS-4 Frame

Post by Pennsy fan » Wed Sep 07, 2011 8:22 pm

I guess should explain on the tram comment. When you have weight (i.e.) boiler on the frame you can have the pedestals get wide when you have the caps off for a time. Having tabs is just a simpler way to tap the caps on when you are working on the boxes.
On the pedestal tabs, I like them as if you use vertical pins, if you are off it's bugger to get the caps off and on. Also the pedestal tabs are used on the prototypes, I have worked on enough full size engines to see that first hand. It's just my experience.
The pins in horizontally is a nice idea.
d.

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Pipescs
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Re: Building the Southern Railway PS-4 Frame

Post by Pipescs » Wed Sep 07, 2011 8:51 pm

I have had great success using a dowel pin horizontally. A Dutchman pin if you will. I use the cap screws ¼-20 is plenty. I place a .005 shim between the keeper and the frame and then drill and ream a hole on the joint line. When completed I disassemble the keeper and remove the shim. The .005 smaller holes will “clamp” the dowel and give a tight fit acting like a key.
Ok having had to bend the frame everytime I put my binders on the LE American Frame I can see how the horizontal dowels will help pull a sprung frame back into "Tram". By the way what is the origin of the word Tram? I see we use it when aligning the head of a Milling Machine.

Question on the Dowel Pin. Are you using a .250 Dowel Pin?
Charlie Pipes
USMC Retired

Current Projects:

2.5 Baldwin 2-4-2/2-4-4/0-4-4 Conversion (What ever)
Little Engines American Restoration
Bobber Caboose

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Pipescs
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Re: Building the Southern Railway PS-4 Frame

Post by Pipescs » Wed Sep 07, 2011 9:16 pm

Don't laugh here as this the world I am coming from compared to the new one. The little TAIG Mill has been mine for thirty years and made tons of parts. The Bridgeport is a little intimidating at this point and I have a ton of questions on things I am new to.
DSC_0123.jpg
I believe I may be taking too small a cut with a half inch end mill. When cutting how deep of a cut in mild steel is possible and where is a good place to read up on this? Right now I am doing it by feel and am running the belt speed on the lowest speed.

What is a good cooling fluid to brush or spray bottle onto a part when cutting?

Where does one go to learn the angles to sharpen a tool bit for a flycutter? I mean as to the angles needed.
Charlie Pipes
USMC Retired

Current Projects:

2.5 Baldwin 2-4-2/2-4-4/0-4-4 Conversion (What ever)
Little Engines American Restoration
Bobber Caboose

mjahn
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Re: Building the Southern Railway PS-4 Frame

Post by mjahn » Wed Sep 07, 2011 9:31 pm

Pipescs:

Here's the best I could find online for tram:

http://www.thefreedictionary.com/Tramming

I used .250" dowel pins in .251" reamed holes for my horizontal pins. My pedestal binders had a .001" press fit but it wasn't enough to hold them in place when installing the binders to the frame sides so a tighter press fit into the binders is probably in order unless you want to drive the pins the last bit of the way in after the binder is on. If you use locking groves or pins be sure to put jack screw holes in your pedestal binders so you can get them off easily!

Pennsy fan:

Oh, sag! I follow you now. :) Tapered groves would make it easier to hammer the binders on but I don't know if it would be worth the extra time to do all that machining especially if you've got a Lot of pedestal binders! :D
Mattaniah Jahn

Matt Corps. Railsystems,
operating on the Manatee Central RR
http://www.flickr.com/photos/62441046@N06/sets/

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Pipescs
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Re: Building the Southern Railway PS-4 Frame

Post by Pipescs » Wed Sep 07, 2011 9:52 pm

Going with the horizontal pins (.250) with five sixteenth or qtr twenty cap screws. Will add Trainmans instructions on the .005 shims and drilling procedure to the plan sheet.

Off to bed Morning comes at 0400 around here on week days.
Charlie Pipes
USMC Retired

Current Projects:

2.5 Baldwin 2-4-2/2-4-4/0-4-4 Conversion (What ever)
Little Engines American Restoration
Bobber Caboose

kvom
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Re: Building the Southern Railway PS-4 Frame

Post by kvom » Wed Sep 07, 2011 9:58 pm

You might want to invest in the G-wizard caclulator for feeds and speeds info. The depth of cut you can do with a HSS endmill depends on a number of factors, including:

1) width of the cut (axial engagement)
2) number of flutes
3) Stickout from the collet
4) roughing or finishing pass

For example, G-wizard tells me that for a 100% axial cut (slot) with a 4-flute, 1/2" HSS endmill, I should go no more than .026" deep with a moderate rate would be 819 RPM and 7 ipm feed. This rate will deflect the end mill .0007", which is less than the .001" deflection it regards as the max for a roughing pass.

Using the same endmill at 3/16" engagement (37.5%) it recommends 1161 RPM and 8ipm at a depth of .091". So lots of variables. These values are good starting points, and the mill and the chip color will tell you a lot.

I use a VFD on mine for speed control, and I have a DRO that tells me IPM, which helps too, esp. having a power feed on the X-axis. I keep the belt on the 2nd fastest pulley and allow the VFD to go up to 90Hz. This gives a pretty good speed range with decent torque down to about 600 rpm. Below that I use backgear.

That vise looks awfully big on your mill. Is it a shaper vise?

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Re: Building the Southern Railway PS-4 Frame

Post by mjahn » Wed Sep 07, 2011 10:41 pm

You'll find yourself with a portfolio of coolants for different applications.
I use kool mist on a lot of stuff and it does a pretty good job. Haven't tried it on aluminum yet, used WD-40 on one such part (my trailing truck frame) and I don't know how good it was, especially since I went through $30 and still killed the end mills. I'm experimenting with anchor lube for drilling and it seems to work real nice... I also like that its non-toxic. Lastly I use tap magic for tapping (and drilling sometimes) and I absolutely love the stuff though tapmatic gold seems to be good too.

Also, I started out with squirt bottles and gave up on them pretty quick. Moved to flooding but it was a mess and I didn't use a loc-line. Finally went to misting and its SO much better! Clean, keeps the cutters cool, and you can focus on your operation instead of getting coolant to it.
Mattaniah Jahn

Matt Corps. Railsystems,
operating on the Manatee Central RR
http://www.flickr.com/photos/62441046@N06/sets/

Harold_V
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Re: Building the Southern Railway PS-4 Frame

Post by Harold_V » Wed Sep 07, 2011 11:20 pm

mjahn wrote:My pedestal binders had a .001" press fit but it wasn't enough to hold them in place when installing the binders to the frame sides so a tighter press fit into the binders is probably in order unless you want to drive the pins the last bit of the way in after the binder is on.
A half thou (.0005") is more than adequate as a press fit for a ¼" diameter pin. If you had problems with the pin moving, look elsewhere for the reason. More than a thou is NOT recommended, although there may be some strange circumstance where that may not be the case. Typically, you'll mushroom the dowel pin when you allow too much for a press fit.

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

mjahn
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Re: Building the Southern Railway PS-4 Frame

Post by mjahn » Wed Sep 07, 2011 11:25 pm

Harold, I defer to your greater knowledge on the matter :)
Mattaniah Jahn

Matt Corps. Railsystems,
operating on the Manatee Central RR
http://www.flickr.com/photos/62441046@N06/sets/

Harold_V
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Re: Building the Southern Railway PS-4 Frame

Post by Harold_V » Wed Sep 07, 2011 11:31 pm

To expound a little, often the hole one achieves is not representative of the tool used. If you're reaming your holes, you may discover that your reamer is creating an oversized and tapered hole, which is very common. Best way to determine what's really going on is to measure the hole, then try to determine if it is round and straight. Also, check for bell mouth, which is quite common when reamers of questionable quality (or condition) are used.

If you're establishing diameters with twist drills, you'll have endless problems. I'm not a reamer fan, but they tend to stand heads and shoulders above twist drills in creating reasonably sized holes.

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

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Pipescs
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Re: Building the Southern Railway PS-4 Frame

Post by Pipescs » Thu Sep 08, 2011 4:42 am

Thanks everyone for the input. Will be reworking the drawings for the pins at lunch today.

The vice came with the mill and it looks to be older than me. I am using a small vice I have had for a while for the binders and only have the large one bolted down to check to see how square it is. It would make a great anchor for the Queen Mary.

The vice and a DRO are on my Christmas list.

I am currently looking at the DRO by DRO PRO. Does anyone have one to comment on?
Charlie Pipes
USMC Retired

Current Projects:

2.5 Baldwin 2-4-2/2-4-4/0-4-4 Conversion (What ever)
Little Engines American Restoration
Bobber Caboose

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