GS-1, finishing up the hard way

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GS14403
Posts: 274
Joined: Wed May 11, 2011 8:58 pm

Re: GS-1, finishing up the hard way

Post by GS14403 » Tue Feb 04, 2014 10:00 pm

Good evening,

With the knees screaming their displeasure at my latest activities progress has slowed a bit. With the help of my neighbor at this end and ex co-workers at the other end the cylinder block, smokebox and lead truck frame spent about an hour in the "dishwasher". Basically a large box with multiple nozzles spraying a water and detergent mixture designed to clean automotive parts.

This evening was spent with a die grinder and Roloc 3M Bristle Discs and I cleaned the area on the valve chambers to allow the bosses to be welded on. After sufficient paint was removed the new bosses were welded in place. Since they are for looks only they did not require full perimeter welds, just enough to keep them from falling off. The first section of pipe was bent up and a set of flanges finished off this part of the job. The flanges will be soldered to the pipe at each end and of course attached to the valve with studs and nuts. Next is verifying the pipe clears the brake cylinders and if so mounting brackets will be fabricated.

There are many gaps in my machining education and bending sheet metal and tubing has to rate at the top of my general lack of knowledge. I made a bender shown in one of the attached photographs that was used for the booster piping at the booster. At that time I was not satisfied with the results on pipe so I ended up bending solid rod in its place. This also held true for the pipe coming off the valve. I have attached a picture of the bender and the results on a piece of 1/4" Aluminum pipe. The same results were experienced with steel pipe as well. If anyone has any thoughts on how to improve the tool or designing something that will work with thickwall pipe I would like to hear about it. I have read the article on bending tubing but I don't think any of the commercial tubing benders will handle this size pipe and the sharp bends required.

Donald
Attachments
GS-1 25.jpg
Taking off the paint.
GS-1 26.jpg
The boss welded in place. Looks like I need a lighter lens in my welding helmet. I can barely see the puddle while welding. I do have magnifying lenses which help.
GS-1 28.jpg
Here is the first section of pipe. The drawing calls for 3 brackets, two attached to the cylinder block under the saddle and one through the jacket next to the bend.
GS-1 30.jpg
If this was a piece of electrical conduit the bend would acceptable. Trying to replicate prototype piping this bend leaves a lot to be desired.
GS-1 31.jpg
The bender, made from some blocks of Aluminum that came with a rotary table and tapping heads purchased used recently from Craigslist.

srrl5
Posts: 957
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Location: Oakhurst, CA

Re: GS-1, finishing up the hard way

Post by srrl5 » Wed Feb 05, 2014 3:44 pm

If the pipe is just for looks, you could use solid rod and get a better bend.

David Rohrer
We the willing, led by the unknowing, have been doing so much with so little for so long that we are now qualified to do anything with nothing.

GS14403
Posts: 274
Joined: Wed May 11, 2011 8:58 pm

Re: GS-1, finishing up the hard way

Post by GS14403 » Wed Feb 05, 2014 4:01 pm

srrl5 wrote:If the pipe is just for looks, you could use solid rod and get a better bend.

David Rohrer
Hello David,

That is actually what I ended up doing. I doubt that I will live long enough to make a working booster so all of the parts made so far have been just to fill in the many blank spaces on my locomotive. For me though it is just a shame to waste the amount of brass bar I will eventually need for the all the bent pipes when I have 20 feet each of 1/4" steel and Aluminum pipe.

Looking at making a die to bend the brackets needed to mount the pipe to the cylinder block as soon as the knees come around to my way of thinking. They should look something like the bracket supporting the shop air lines to the blower and atomizer in the accompanying photograph.

Donald
Attachments
_DYB4223-2.jpg
SP 2467 4-6-2 type LH cylinder block area taken in the California State Railroad Museum.

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Fender
Posts: 2720
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Location: Chattanooga TN

Re: GS-1, finishing up the hard way

Post by Fender » Wed Feb 05, 2014 7:11 pm

You could just get some low-temp bismuth alloy and fill the tube before bending. I recently bought some that contains bismuth, tin & lead for about $13/lb. It melts at about 200F.
Dan Watson

GS14403
Posts: 274
Joined: Wed May 11, 2011 8:58 pm

Re: GS-1, finishing up the hard way

Post by GS14403 » Wed Feb 05, 2014 9:03 pm

Fender wrote:You could just get some low-temp bismuth alloy and fill the tube before bending. I recently bought some that contains bismuth, tin & lead for about $13/lb. It melts at about 200F.
I have heard about using a filler with thin wall tubing but haven't given filling the pipe any thought. Something worth looking into.

After a couple of ice pack sessions it was decided that the discomfort in the knees will play second fiddle to progress on the GS. A simple set of dies was whittled out of a block of scrap Aluminum. The female die was about .005" dia larger than 11/16" and the male die about .002" smaller than 9/16" These clearances appeared to be sufficient to bend the .062" thick cold rolled steel flat bar. Once the mounting nuts are tightened there is sufficient holding power from the clamps. A test fit of the cylinder on the frame found the booster pipe interferes with the piping for the brake cylinders. The oversize commercial fittings that are currently attached to the brake cylinders were slated for replacement with scale fittings as it was. This interference will ensure the fitting upgrade will happen.

Donald
Attachments
GS-1 32.jpg
Male and female dies. Although not obvious there is a .032" deep groove perpendicular to the curved groove that allows the blank to be aligned square to the die.
GS-1 34.jpg
The bender machine with 90 degree dies currently in plsce.
GS-1 35.jpg
One of the new brackets mounted to the cylinder block.
2467 braks cylinder.jpg
What SP brake piping to the locomotive brake cylinders looks like. The large pipe on the right is exhaust steam to the feedwater heater.

Bob D.
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Location: Saco, ME. USA

Re: GS-1, finishing up the hard way

Post by Bob D. » Thu Feb 06, 2014 12:13 am

There are quite a few low temp alloys. Cerro have many, one melts at 117F. Hot plate and a pan of water makes it easy to heat and fill a tube. Makes bending sharp radii pretty easy. Plastic tap hammer can persuade the tube around a wood form. Then melt the stuff out and reuse it.
Anneal the brass tube first helps much, and even multiple anneals as you work the bend in.
Tension springs that slip fit over your tube works pretty good also. Keeps the tubing from kinking up. Micromark sells a spring set for different sizes pretty cheap.
Bob
3/4" Juliet II 0-4-0
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3/4" Hall Class 10 wheeler
3/4" Evans Caribou/Buffalo 2-8-0
3/4" Sweet Violet 0-4-0
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3/4" Kozo A3. Delayed construction project

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AnthonyDuarte
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Re: GS-1, finishing up the hard way

Post by AnthonyDuarte » Thu Feb 06, 2014 2:00 pm

I was already drooling over your GS-1 at the SVLS fall meet... I'm going to need to bring a bucket next time!

GS14403
Posts: 274
Joined: Wed May 11, 2011 8:58 pm

Re: GS-1, finishing up the hard way

Post by GS14403 » Fri Feb 07, 2014 8:28 pm

AnthonyDuarte wrote:I was already drooling over your GS-1 at the SVLS fall meet... I'm going to need to bring a bucket next time!
Anthony, thanks for your kind words.

I will forward your comments to the SVLS yardmaster and request another 4 inches of gravel in the steaming bays and a power drain system installed. That way a bucket will not be necessary. These improvements will help with my own drooling over all of the truly remarkable engines and cars that run at our track.

Sorry, nothing to report. Trying to give the knees a much needed break. Tomorrow may see the new fittings take shape for the locomotive brake cylinders. Meanwhile this down time will be put to good use studying the great ideas presented in this forum.

Donald

GS14403
Posts: 274
Joined: Wed May 11, 2011 8:58 pm

Re: GS-1, finishing up the hard way

Post by GS14403 » Sat Feb 08, 2014 6:16 pm

Took a few minutes today to try and make some progress. I had bought some of the PM fitting trees so the first step is cutting the trees apart. After that I turned my attention to trying to make the air line fitting that is used on the pilot beam. A piece of hex was step bored so there was a solid stop to press the fitting against. Once assembled a bit of Silver solder was applied to hold the two halves together.

Donald
Attachments
GS-1 38.jpg
Tree trimming the hard way. I used a small square and aligned each cut by eay.
GS-1 40.jpg
Here is a 45 degree fitting with the hex Silver Soldered to the casting.
2467 pilot piping.jpg
Westinghouse fitting as used on the pilot beam.

GS14403
Posts: 274
Joined: Wed May 11, 2011 8:58 pm

Re: GS-1, finishing up the hard way

Post by GS14403 » Wed Feb 12, 2014 3:52 pm

Not much progress during the last week. Finally was able to get the air lines to the brake cylinders to clear the steam supply pipe mounted to the cylinder block. Photo #42 shows the interference problem. Now all is good in that department and progress should resume.

I had received a PM about how I built the cylinder block. Unfortunately I did not document the process and my memory is unclear on the sequence of events during assembly. I have attached a couple of photographs that may help visualizing the assembly.

Photo #43 shows the exhaust passage made up of 90 degree steel weld fittings, Eight total were required. Photo #44 shows the rest of the exhaust passage on the outside of the plate that aligns the valve spools to the cylinders as well as being a part of the saddle.

Photo #46 shows the three 1" thick plates that form the backbone of the cylinder block. The two vertical pieces were contoured to fit the cylinders which were machined from extra thick wall pipe. Allen bolts and welds hold the entire assembly together. The steam passages if I recall correctly were made up of a flat bar that was welded to the cylinder and valve chamber than the outer channel shaped piece was welded on. There are passages on the inside and outside and I must have welded the inner ones first and then welding the cylinder, valve chamber and inner steam passage assembly to the end plates and to the backbone.

The rear cylinder heads were welded on per Southern Pacific practices on these locomotives. I used bronze for the liners, Teflon rings for the piston and cast iron hook type rings for the valves. The cylinder bore is 3" and the valves are 1.5" dia. I used 3" bore as a compromise of the scale bore which would have been 3.583" and the 2-3/4" many of the 4-8-4's have been built with. My dad's Cab-forward uses 3" pistons as well and this diameter seems to work well.

Donald
Attachments
GS-1 42.jpg
GS-1 43.jpg
GS-1 44.jpg
GS-1 46.jpg

GS14403
Posts: 274
Joined: Wed May 11, 2011 8:58 pm

Re: GS-1, finishing up the hard way

Post by GS14403 » Thu Feb 13, 2014 7:42 pm

Got a chance to measure the Teflon ring. The width is .113" the height is .125" and the o-ring is .093" cross section. Nothing else to report today.

Donald
Attachments
GS-1 54.jpg
GS-1 55.jpg
GS-1 56.jpg
One of the pistons from the GS. Twenty years of running and no real signs of wear. Before I knew better I had machined two ring grooves. Only one ring is recommended.

GS14403
Posts: 274
Joined: Wed May 11, 2011 8:58 pm

Re: GS-1, finishing up the hard way

Post by GS14403 » Sun Feb 16, 2014 10:16 pm

Today I decided to take a break from the cylinders and look at the lead truck. One thing for sure is I am a lousy engine cleaner. I ran the lead truck frame and springs through a dishwasher type parts cleaner and there was still a lot of grunge everywhere. A couple of hours with engine degreaser, wire and tooth brushes and brake cleaner the parts were ready for the glass beader. The wheels and axles were spared the washing machine and were hand cleaned. Then a spin on the lathe using a hand held turning tool similar to wood lathe tool and off came the paint from the wheels and axles.

The axles are an experiment that appears to be working. The material is K60 ( I believe that is what it is called ) case hardened shafting that was bought cut to .030" over the actual length. A carbide tool was able to cut through the hardened surface and the axles were machined to the proper length and center drilled. I used 1" dia. shaft and pressed the wheels directly on the shaft. The bearings are sealed roller bearings. Using a Dremel tool with an abrasive cutoff tool a slot was carefully ground into the bearing outer race where the grease fitting will align with. Once the cut is almost through you can see the material start to flake. At that time the flake can be removed with a pick and there now is an opening for grease to flow through.

Once a suitable spring was found the mounting block for the lead truck was modified. Originally a 2.5" dia. rod was used with a 1" dia. hole bored for the centering pin. The rod also sat just inside the ring on the centering block. I re-drilled the upper bar offsetting it .562" and drilled a 3/8" hole to match one of the cylinder block locating dowels. The bar was shortened .25" and the center bored out to fit a 1.25" dia. spring. The pivot pin on the centering block was shortened so that when assembled the spring was compressed 3/8" and still had an additional 1/4" travel before bottoming out. A new ring was made for the centering block that will be welded to the block once everything checks OK. After assembling the lead truck and putting it back under the engine it became evident that the 9/16" offset was too much. I kind of suspected as much but wanted to try to use the original if at all possible. A new upper mounting rod will be made and offset 1/4" This should be barely enough to keep the forward wheelset on the lead truck from hitting the cylinder covers.

Donald
Attachments
GS-1 58.jpg
On the left is the new tube made to fit on the outside of the mounting rod on the right. Once everything is fitted up the tube will be welded to the center plate. Barely visible is the original centering pin that has been cut down. The coil spring sits on this pin.
GS-1 59.jpg
The parts assembled. The offset mounting hole has been drilled and tapped. 9/16" offset was chosen as that was about the minimum distance from the original mounting bolt hole. As it sits there is about 5/8" travel. once under the locomotive there will be about 1/4" travel. The new mounting rod will have 1/4" offset.
GS-1 64.jpg
The axle looks pretty good after 20 years of service with the bearing running directly on it. Two flat hardened washers and a needle thrust bearing sits between the axle box and the wheel.

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