L.E. American & tractive effort?

[johnpenn74]

Dianne,
Here's another check for you. Take you engine's lead truck off and see how much tilt in the locomotive you get. I'll throw out a number and say the lead truck carries about 25 - 30% of the total engine weight. If you remove the lead truck you should see the journal boxes bottom top out on the front axle and bottom out on the rear axle. This is a good indication that the suspension has enough flexibility from to back. Remember, your driver are equalized, so if you don't see this motion the load is not transfering between axles. This should happen even if the springs are too stiff. The reality is it will probably lift the back axle (lead truck is gone remember) but you should still see this happen with the rear driver in the air.

I encountered this at Nicks last year when i pulled the lead out and low and behold the engine was an 0-4-0 and did not tilt. When you fix the equailization problems you will get equal loading on all wheels which will give you the best possible adhesion from a weight stand point.

JP

[DianneB]

Excellent idea John!

I made a quick stop in the shop yesterday (busy day!) and tried to lift the front axle of pilot truck off the rails - DAMNED heavy! Not a very scientific test but an indication that I might be carrying too much weight on the lead truck. Considering that this engine has been apart and reassembled a couple of times it is quite possible that things weren't put back together exactly the same. With the warning on the L.E. drawing about the length of the pilot pivot pin, it is possible that there is too much weight on the pilot truck.

I like the idea of dropping the pilot off the rails and looking for the shift in the suspension. I may even be able to rig up something to check the weight on the pilot truck. It will also give me the chance to drop the pilot tuck and check the pivot pin.

[Fred_V]

Take a big screw driver and put the tip under each wheel and pry down. You will lift the wheel just bit and will get a feel as to how much weight is on each wheel. Not scientific but I do this all the time and can find a light or extra heavy wheel easily and know where to look for problems.

[Caribou Doug]

Dianne,
I used the design of little engines frame but where they had used spreaders to separate the frame I filled in with as much material as possible. I am a novice machinist and spent a lot of time to add as much weight as possible. I have been told that this particular loco does not pull a lot but I have always liked the look. I also have added a lot of plate brass to it and am in the process of machining out a new 1/4 plate cab as the original looks to be cast aluminum and very light. So far I have added about 23lbs and continue to look at different ways to increase her weight. Some of the comments/suggestions that John P. had made regarding the suspension are excellent things to look at and I will also be looking at those suggestions on my build as well (Thanks John !!). I had the pleasure of meeting John once at my home clubs 45th anniversary meet last year and he certainly seems to have a lot of knowledge as the loco he brought up from Georgia ran like a champ.... I have included a couple of photos that I had with me but can take better ones once I get back from my current tour in the middle east.

Doug

[DianneB]

Nice looking engine Doug!

I moved the American back into the shop this morning and checked the pilot truck - seems to be carrying about 30% of the weight which I am told is correct.

When I ran the pilot truck off the end of the test track, the front of the loco didn't drop very much so I don't think the pivot bolt is overly long (i.e. carrying too much of the engine weight) and when the pilot truck is dangling, the loco rocks back and forth and side to side quite nicely (indicating the equalizers and springs are doing their job. It seems to be setup well and not out of line with what to expect from an American.

I had a look at the drawbar arrangement between the engine and tender and found that by rearranging things a bit, I could transfer some weight from the front of the tender to the frame at the rear of the engine so I did that (in a temporary way). If that helps, I will do a bit of redesign on the drawbar and its mountings and make the changes permanent (and maybe even adjustable!)

I'll let you know how it works out (if the weather here ever gets warm enough to go steaming LOL!)

[cp4449]

If you could find some unobtainium, then it would work really well also. The only problem is finding some.....

This is a great series that I enjoyed reading. Does any one know if the problems mentioned occur with a 1" version of the 4-4-0?

[DianneB]

After 3 or 4 different designs, I came up with one that works very well with minimal modifications to the engine or tender.

REVISED DRAWING:



(http://s163.photobucket.com/user/dianne ... 1.jpg.html)

It uses a spring on a pivot shaft on the tender to transfer weight to the end of a modified drawbar, is quite rigid, and transfers as much weight as you wish (depending on the stiffness of the spring used). The rear of the drawbar is counter-drilled from the bottom to allow some flexibility in the coupling

The modified drawbar is cut from 1/2" plate steel and picks up the pivot on the engine in 2 places to avoid concentrating stress on the pivot pin.

The height of the rear arm of the drawbar needs to be set according to the individual engine, tender, and compressed length of the spring to be used. (The dimensions shown are for my engine.)

I used a stiff spring that just lifts the front wheels of an empty tender off of the rails and causes the rear beam of the engine to sag somewhat when the weight is applied to the tender.

I'll get some pictures (when the paint dries) and give a track report later.

[DianneB]

As promised:





I just noticed a mistake in the drawing! I'll figure out where it is and post an updated drawing.

[Pipescs]

Having an American on the way here to be restored, I am sooo impressed

[FriscoJim]

I have a small 12" gauge 4-4-0 that I rebuilt quite a few years back. My method of transferring weight from the tender to the locomotive was to make a drawbar that spans from the locomotive to the kingpin on the lead truck of the tender. The front of the tender frame has another pin that engages a hole in the drawbar. This way, the weight from the front of the tender is split between the locomotive and the lead truck. It is simple, transfers some of the tender (and engineer) weight to the drivers on the locomotive, and keeps a reasonable amount of weight on the tender's front truck so it doesn't derail. Just another option to increase the traction of your steamer...

[redneckalbertan]

If you are transferring tender weight to the engine, you could add lead to the front of the tender if more traction is needed. It may be easier to hide something in the front of the tender than on the engine.

[DianneB]

.... you could add lead to the front of the tender if more traction is needed.

I ride on the tender so there is LOTS of weight that could be transferred.