Double Tich Locomotive

Gallery, Projects and General > Project Logs

<< < (3/4) > >>

Bogstandard:
GWR,

Even though I come from what used to be one of the main railway towns in the UK, I have never had an interest in building a loco, I think due to the massive amount of time that, as you have shown, is required to go into even a small loco project.

But that doesn't stop me from admiring the work involved in getting one from the basics to a running machine.

I will be following your postings, but because I basically have very little knowledge of the workings and processes, I doubt very much I could help someone with your experience, but even though I won't be sticking my nose in, I will definitely be following along.

Plus I do like your method of 'hands on' metal working, a man after my own heart.

Good luck with your massive project.

Bogs

GWRdriver:

--- Quote from: bogstandard on February 07, 2011, 02:49:34 PM ---Good luck with your massive project. - Bogs
--- End quote ---
Hello John,
Actually I'm going against the local grain in a couple of ways, first, because I'm building a British loco, and then because it's small (relatively speaking, for 7+ga) and the trend over here these days is toward big, Big, BIG! I tend to prefer quality over quantity. Sometimes things don't evolve exactly as you intend and as I say above, I've added time and labor to the project in an number of areas. One thing is certain however, I am getting an education. The project includes a number of processes, techniques, materials I've read about and discussed, and generally prepared myself to use, but when I did actually get round to doing them I realized how much there is yet to learn. For instance, I learned that a short length of steel pipe which has been turned and finished all over, and to closely match other mating parts, does not stay round when anything more than a drilled hole is cut through it. The adventure continues.

I think there was a popular railway book entiled "From Inverness to Crewe"

Bogstandard:
Both Stew and myself spent our childhood not far from the main railway works, and we both remember and talk about what it was like. In fact my father was stone deaf by the age of 40, because he worked all his life (except for the war years) in the wheel shop, very close to the main forge hammers. But anyway, that is besides the point.

I did help Stew get the techniques right for building his copper boiler, but after seeing what time he has put into the rest of his small loco build, I just knew it would never be for me.

I will leave that for you people that have a lot more patience.

John

GWRdriver:
Page 3
For me working on one task for too long can get tedious so I always have several things going on at any one time so when I tire of one, or just want a change, I can move to another job and still make progress on the overall project. Sometimes when I hit a snag, such as when I've ruined a part, or if waiting on materials, or puzzling over a problem, I find it often helps if I just walk away and do something else for a while. With the frames under way the first alternative chore I switched to was spiffing up the driver castings. These were old and a bit rough, but very well seasoned, so they got a thorough once-over with files and die grinder and with the bumps and grain smoothed out they were sand-blasted. The two bottom drivers [Photo 4] are after dressing but before sand-blasting, and the upper two are after sand-blasting. The finish was good enough that no casting filler was required and the wheels were red-oxide prime-painted and set aside. Note the Cad drawing of the frame (with tons of red marks) behind the wheels.

I began the buffer beam assemblies simultaneously with the frames, first because they gave me an alternative to work on, but also the opportunity to get into some "detail" work (which I like to do) right away. They would also be the first thing I needed in order to erect the frames and actually see something "in the air" rather than on a sheet of paper.

The front and rear main frame stretchers (seen in Photo 8) were made up from 3"x 5"x 3/8" steel angle with 1/4" steel gusset plates arc-welded into each end. What should have been a dead simple task turned out to be an ordeal as I am the world's worst arc-welder and a lot of grinding and rewelding was required, but they survived and were milled square on outside (front) face, tops, and ends, and were drilled and tapped to receive screws through the frames. For structural assembly of the frame I used mostly socket head alloy cap screws, which look SO out of place on a model, BUT the frame screws are cleverly hidden from view so unless you have a flashlight and an inspection mirror you won't see them.

The buffer beams [Photo 5] were planks of 1/4" CRS milled square on the ends and drilled for threaded steel rivets which are not cosmetic but actually hold the beam in place and offer a connection point for platework to be added later. I made up a simple chuck to hold the rivets by their head ends while they were threaded in the lathe. The coupling hooks [Photo 7] which are yet to be finished profiled, were sawn and milled from an alloy steel and the rectangular shanks extend through the buffer beam and connect to a sprung drawbar pocket inside the main frame stretcher. The coupling links and screws are yet to be made.

The buffer stocks (or bases) and heads [Photo 6] were turned from steel and the stocks were a straightforward bit of turning and boring. The diamond tread step detail was done by first milling a rectangular recess in the tops of the stocks. Next an insert, also recessed, was milled from CRS to fit the recess in the stocks and held in by a screw which you can just see in the photo. Finally the raised diamond tread material was made by cutting diagonal slots in 16ga brass sheet using a slotting saw in the mill. Slots were cut at intervals in one direction, then the brass was turned 60° and crossing slots were cut in the other direction. The diamond tread blanks were then milled and filed to fit the recesses in the step blocks.

The buffer heads (the thin round part) presented a challenge . . . how to turn the buffer faces to a true radius by mechanical means, rather resort to the step-turn & file approximation of a radius. The solution was to connect the cross slide (and therefore the tool point) to a fixed point on the bed with a pivoting radius arm, so that as the cross slide is moved in the Y direction the carriage is pulled (or pushed) in the X direction by the radius arm. The result is that as the cross slide is moved, in either direction, the tool tip will trace a true arc, equal in radius to the length of the radius arm, across the face of the work. Once this was done I went to work with some emery cloth to remove the minor tool marks and they were done.

Once the buffer beams, frame stretchers, and main frames were completed the contraption was bolted together [Photo 8] to see how it fit. So far, so good. Next time I'll post a few more buffer details and get to the axleboxes and horns.

GWRdriver:
Lads,
I'm sorry not to have continued to post on my TICH project but Springtime always brings demands on my time which I don't have at other times of year and this year is no different. One of the distractions is when time becomes available I would rather WORK on it than WRITE about it, but I shall return in due time and the compliments are greatly appreciated.

Navigation

 Message Index

Go to full version