The Home Machinist!

Hello My Friends
I have been enjoying all the posts concerning 3/4" scale tonight. The Hudson history, ( thanks Carrdo ) and this thread about couplers. And I must say I have not been the least bit put out by the differences of opinions. One of my favorite photos from last years visit to Waushakum is of two cars coupled together with a screen door hook. Now that's cool! Simple, effective, inexpensive, and replacement parts are easily obtainable. Go with the materials and techniques you are comfortable with. My bronze investment cast couplers look good, and work fine, but they are delicate, just fine for the scale freight train that is planned. Perhaps a run of investment cast steel couplers is in the future. But between my engine and riding cars will be draw bars. A simple length of cold rolled with two holes drilled in it. The little couplers are just too fragile, very cool, but fragile. And when the engine is on display, and not on the track there will be a coupler on the back end of the tender. The sand cast couplers are a lot of work, ( experience speaking here ) machining, silver soldering and broaching and such. The investment cast ones go together with a little clean up in about ten minutes. The knuckle pivot pins are the only real machining needed. So go with what you got. The important thing is that you get out in the shop and JUST DO IT. Too much fun.
See you in the funny pages..
Jack

I am really a traction engine fellow who plays with railway locos because there are so few interested and involved in my world. From my, admittedly rather limited experience, scale couplers, especially cast ones would seem to be a dangerous liability.Live passenger loads behind 3/4" and 1" scale engines, rough tracks,heavy passenger cars with brakes which can virtually lock them solid and passengers who lean over/ fall off/ drag their feet "just for fun" put well overscale loads on wheels ,axles ,trucks and couplers. The Leggett style of couplers are virtually unbreakable, provided you leave enough material around the pin holes. They also have the major advantage that if the engine alone should derail it will be prevented from taking a nose dive by the, by then, very twisted , but unbroken coupler. Prototypical couplers would seem likely to release or break in such circumstances. I went double heading with another fellow this last summer and removed my near scale front coupler and fitted a drawbar with pin holes instead. We had no problems despite being what we thought would be a total mismatch. I really go ooh and ah over scale models but if you want to run in the serious and real world of a club track pulling the public I doubt scale couplers are the best answer. regards David Powell.

To Dale
I forgot to mention that coming soon will be Andrews trucks in 3/4" scale. They will utilize the wheels, journal boxes, half brasses, journal box lids and backs from the arch bar trucks. Also a model of a one piece cast steel bolster will be made to replace the built up twin I beam bolster of the arch bars. These trucks will be a lot simpler than the arch bar trucks, eliminating 15 castings 50 rivets and 24 drilled and tapped holes and bolts per truck. They will also be considerably less expensive The brake rigging from the arch bars will also fit. These trucks will be scale models and will not be suitable for riding cars. The goal is to eventually have everything to build a scale freight train. All the investment cast hardware for a box car, reefer, steel mill gondola, and caboose. Also real wood, scale tongue and groove siding. No shortage of things to do, just finding the time is the trick. Too much fun!
Oh yes, a tank car would be fun too.
Jack

Jack,
Andrews tender trucks as used under the U.S.R.A. tenders would nice too. I believe they were 70 ton with leaf springs.

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Scott K

Here's a thought. Most 3/4" scale stuff rides on an elevated track. There really are no sidings or yards to switch cars like they do on ground level. Why then do you need 3/4" sclae couplers that open. Why not cast them as a complete and closed knuckle. To unhook the cars, just lift the car like you used to do with the cheaper Lionel cars. This would be as safe as you could make them for riding car use without requiring a safety chain. I don't really see the need to be able to "pull the pin". You are probably only going to unhook the cars when you go into the steaming bay anyway.

Steve....about 30+ years ago there was a chap that sold "solid" knuckle couplers. I can't now remember who it was, and I sold the riding cars on which I used them, but they did work just as you described and I wish they were available now....
Keith

Hi Keith,
I have a coulpe of couplers like that and they look pretty good. They are made of cast iron and if I could have gotten a bunch, I would have probably used them for my freight cars. Between the engine and riding car, the O-O type of coupler that Jim Leggett uses is the simplist, has no design issues and is really the best for that situation.

Hello My Friends
That is a great idea about the one piece cast couplers. I will get right on it.
Jack

A photo of the knuckle head parts as they are formed in stages from raw bar stock to a finished knuckle head.

I had a few disasters along the way with deep drilling using small diameter drills but for every disaster there is (are) always (a) way(s) around it. One just has to keep focused and not let frustration/impatience get the better of you.

I guess the object of this exercise is to finally get to the bottom of this project.

The purpose of all of the little plug and other gauges is to allow one to keep everything the same as parts are made over and over again and as well to have each machining step be as simple as possible.

Richard always tells me, the thinking part before any metal is touched is always the most important first step.

Some machining operations on the knuckle release and locking pin.

The 1/32" dia. shackle rivet on the end of the lifting pin uses a #67 drilled hole. Had to make up a special 7/64" wide by 1-1/16" high spacer or parallel for the lifting pin to sit on for the cross drilling operation.

Still chugging along making more and more fixtures.

Have now decided to make every part right down to the last detail. On this project, as it is going to be a marketing adventure, nearly every operation has to be fixtured to assure interchangeability of parts should spare parts ever be needed.

The photo shows some of the new fixtures made and some partially made components.

A little further on with the finishing operations on some knuckle heads.