G Scale Model Train Forum banner
Cancel
Create thread New Forums

7-1/2" Gauge CP #173 Builder's Log - Part 1

Jump to Latest
341 - 360 of 727 Posts
Discussion starter · #341 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Thanks Bob!
Image
Yeah, everything seems fine! I've already decided I need to move the main water supply lines on the tender "outboard" more towards the front corners, and I want to make a longer throttle lever. One of the advantages of "playing with it" for a while before doing any final finishing is to see where changes are either necessary or simply desirable. Eventually I'd like to do Baldwin "Style 1" pin striping on the tender, domes, and headlight at least, and perhaps on other parts like the cylinders, pilot deck, etc. Vinyl lettering and striping may be the way to go here, and I've heard others use vinyl in this scale with great success. Suggestions?


See Dwight a Old Dog like you can still learn New Tricks.....LOLKinda gives even an old fart like you new hope doesn't it?
Image
 
#342 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Posted By Dwight Ennis on 10 Sep 2010 06:35 PM


Thanks Bob!
Image
Yeah, everything seems fine! I've already decided I need to move the main water supply lines on the tender "outboard" more towards the front corners, and I want to make a longer throttle lever. One of the advantages of "playing with it" for a while before doing any final finishing is to see where changes are either necessary or simply desirable. Eventually I'd like to do Baldwin "Style 1" pin striping on the tender, domes, and headlight at least, and perhaps on other parts like the cylinders, pilot deck, etc. Vinyl lettering and striping may be the way to go here, and I've heard others use vinyl in this scale with great success. Suggestions?


See Dwight a Old Dog like you can still learn New Tricks.....LOLKinda gives even an old fart like you new hope doesn't it?
Image





Good news on the mechanicals. GGLS has a lot of expetise, you'll be getting a lot of ideas as you snoop around the steaming bays.

My buddy over in Pahrump put vinyl letting on some rolling stock about a year ago and he says it holds up very well in the hot/dry climate. It should work just fine in your area. He used some kind of cutter/printer thing attached to the PC, not sure what however.

The way Jesse welded the boiler, it should last a century.
 
Discussion starter · #344 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Tapering the Brake Pads:

The last step in making the brake shoes was to taper the pads. As the taper needs to form a cone, one can't just carve it out with a simple 3-axis CNC million operation such as I have because the shoes themselves needs to rotate. Fortunately, I had purchased Sherline's rotary table some time back which I have never needed until now. While it IS set up for CNC with a stepper motor on it, I haven't yet replaced the stepper controller in the Sherline computer. Luckily, only manual operation was needed for this operation and I used the big machine.

The first step was to make a fixture that would bolt to the rotary table and securely hold two shoes aligned on the correct arc and at the correct radius away from the center. I designed up a little fixture and used the CNC to pop it out. It has holes for bolting to the rotary table, two threaded holes to bolt down the shoes, and pockets to accept the overhang of the brake pads.

Image


Two shoes sitting in the fixture.

Image


The fixture mounted to the rotary table and milling machine. The wheel drawings say the wheels are tapered at 2°-50'. I had originally planned to tilt the milling head, but while buying some mills from Rutland Tool, I happened upon a 3° tapered mill... close enough for government work!

Image


The fixture was centered with respect to the spindle with a center finder (the mounting bolt was center drilled in the lathe)...

Image


And we're all set to taper the brake pads...

Image


The finished pair of shoes, except for drilling and tapping the brake beam mounting holes. I numbered them in sets - 1-2-3-4 - and each set will mount to one brake beam.

Image


Next on the list are the brake beams and hangers.
Image
 
Discussion starter · #346 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Not sure I understand your question Andre, but if you're referring to removable pads, I don't expect to ever wear these out. The two runs I've made (well over a couple of actual miles now minimum just on the first day) have been made with no brakes at all. They aren't used often enough to inflict any great wear on them, and when they are used, it doesn't take much to stop this thing, so again, little wear will result. While I could be wrong, at this point I'll be real surprised if I ever need to replace them.
 
#347 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Those brake shoes will outlast the engine and the engineer. On my 4-4-0, the engine brakes were operated by a lever in the cab, with a 7/1 lever ratio, and could lock the drivers with one finger pulling.

That tapered endmill must be for putting a draft angle on molds/dies? Whatcha think, Gary?

Dwight, you aren't gonna abandon the rest of us with the wee steamers now, are you? I no longer burn the Pocahontas coal in my engines, but do haul a gon full of it, crushed to 1:20.3 scale.

Larry
 
Discussion starter · #349 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Dwight, you aren't gonna abandon the rest of us with the wee steamers now, are you?No Larry, I don't think there's any danger of that. hehehe It is an unfortunate fact that the only steamup I've managed to attend this year was the NSS, but that was due to a variety of reasons, and not because I no longer have any interest.I no longer burn the Pocahontas coal in my enginesAny particular reason for that? After I went through the Pocahontas you sent me, I've been burning Australian Char that I had a buddy bring back for me from Train Mountain last year. It seems to burn a lot hotter and cleaner. I'd like to get some more of it if I can find some.
 
#350 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Dwight...in your statement "I had originally planned to tilt the milling head, but while buying some mills from Rutland Tool, I happened upon a 3° tapered mill... close enough for government work!"

Is this actual Rutland Tool listing with their sometimes criptic descriptions, does the "3 Taper" in their description, "Prestige Plus 3/16" Mill Dia. x 3/8" Shank Dia. x 3-1/8" OAL Uncoated High Speed Steel 3 Taper End Mill , mean 3 degrees? Just wondering?

BTW, clever holding fixture and superb work!! FWIW...I get nearly the same satisfaction in designing and making the fixtures as machining the final product.
 
#351 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Dwight, a few years back, I sold both of my 1 1/2" steamers to friends. After 40-some years in the ride-on scales, my back and joints made moving the engines and rolling stock no fun any more, and the nearest club track is 85 miles away from where I now live. By contrast, I was only 13 miles from NJLS. So, that is why I no longer have a use for the Pocahontas coal.

Never heard of Australian Char. Where does Train Mountain get their supply? How does it smell? Over the years, we experimented with coals from various sources, and some of the smoke would choke you. The Pocahontas has a pleasant sweet smell, part of the fun of coal firing.

Larry
 
Discussion starter · #352 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Howard - I have no idea if the description you posted means a 3 degree taper - it could refer to shank taper. At any rate, I have one of their paper bound catalogs, and on a page are tapered end mills with the taper listed. I prefer to hunt for things in the catalog, then search for a known part number when ordering online. Their online search function ain't the best unless you know the part number.


I agree, designing and making fixtures can be more challenging than making the actual part.
Image



Larry - I have no idea where Train Mountain gets it or where it's from. I got a tip from a friend last year that another friend was up at Train Mountain and they were selling coal, and I should call the guy and have him bring me back a 50 lb bag, so I did. It was Jesse who told me what kind of coal it was. It produces very little smoke and very little ash, and I have yet to see a clinker using it (though in all fairness, I've only fired a few times so far).
 
#353 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Maybe I can help with this. The cutter in the photo is a straight shank cutter. Therefore the taper noted is a 3 degree draft cutter (talking about the cutting angle only). That's what they mean in the catalog. IMHO
 
#354 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Gary, the description I quoted was Rutland Tool's internet site description. The internet descriptions, as I stated earlier, are somewhat criptic. Sounds like you have their catalog in front of you, so if you would please, give me the Part number of a cutter that has the 3 degree taper notation and I'll tie it down it that way.

Thanks
 
Discussion starter · #355 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Howard - Rutland has an online Flash version of their catalog (in addition to their web site). Go to the online catalog and in the navigation bar at top, put in page number 247 and hit Enter. That's the page with the tapered end mills I used. They also continue on pg. 248. You'll need Adobe Flash Player to use this (I'm sure you probably already have it). Holler if you have problems.
 
#356 ·
RE: 7-1/2" Gauge CP #173 Builder's Log

Howard,

Here is the page I'm looking at right now. Pretty easy to find the cutter you may need. You are correct that the catalogue number has absolutrly no relationship to the draft. Hope I can bet this link to show for you.

Rutland Online Catalog - Page 247[/b]

Go to page #247.

Apparently, MLS in it's infinite wisdom wants to shorten the link. If you click this link above and look at the box to the left, click on CUTTERS. Then go to page 247. Good luck. Let me know what you get and if you can make this link work. Its frustrating on here!!
 
341 - 360 of 727 Posts
About this Discussion
726 Replies
84 Participants
Last post:
Dwight Ennis
G Scale Model Train Forum
posts
460K
members
32K
Since
2007
A forum community dedicated to G scale model train owners and enthusiasts. Come join the discussion about collections, displays, models, styles, scales, reviews, accessories, classifieds, and more!
Full Forum Listing
Explore Our Forums
Live Steam General G Scale Discussions Beginner's Forum Model Making Track, Trestles, Bridges and Roadbed