Purchased this from “Micro-Mark” the other day using my “Bachmann” HO 4-6-0 Ten Wheeler as the puller.
As you can see the meter is reading out as 2.4 oz. pull, but what I can not figure out is how do you figure just how many cars that will pull on level ground?
Another shot of the pull meter.
Here is copy of the meters instructions. You will probably have to copy and paste, then expand to read correctly.
Maybe one of you can answer the question by reading the instructions ( or maybe you may have this meter? ) as I am a little dim on the subject. [:$]
The last paragraph of the instructions tells how to determine the amount of pull required per car for a typical cut of cars. You can try several groups of cars and come up with a ballpark figure per car. Divide the number obtained for the loco’s pull by the per car figure and that will give you an idea of the number of cars you can pull. Of course, cars differ in weight and resistance to pulling so this will be a trial and error exercise but it should be interesting. Let us know how it goes.
Seems to me that “gizmo” would have to be mounted on an extremely easy rolling truck, how much does it take to “drag” it down the tracks??? You could also use it for weighing very small fish as well!
It doesn’t get pulled down the tracks. It is held stationary and the locomotive powered up to the point where the wheels slip. (unless you connect it to a 1 to 1 scale loco, in which case both you and the gizmo will be pulled down the tracks)
Gizmo?? Not sure if that was a remark or you really do not know what it is used for?
You do not drag it down the track. You hold it with your fingers steady on the track so as it not to move, slowly turn up the throttle till the engines wheels just start to slip, then the meter records the pull at the slip. When I took the pic I had already turned up the throttle and the oz. setting on the meter is what the 4-6-0 pulled in force which was 2.4 Oz. Since my top post I have been busy with other things and also just read joeinPA’s post as a way to figure out the math which I will do sometime this evening.
Fourty Niner have you ever read any of MR “Product Reviews” where they measured the engines Drawbar Pull? That’s what I’m trying to do.
Might be fishy to you but I didn’t buy the meter to weigh fish with.
Well I’ve tried this pull meter in a lot of different ways and I guess the best answer is just to line up the cars behind the engine until it slips and can not pull another. But it looked like an interesting gaget ( Gizmo as Fourty Niner calls it. [:D] ) but it was not worth the $20.
There was a thread in Aug. 2009 here on MR that talked about the “Tractive Force” and more sense was told on that thread about “Tractive Force” than anywhere I had googled. One person figured out that in HO a tractive force of one ounce equals approximately 10 cars. Then again this varies with the different weights of the cars, wheel arrangements, etc.
rockislandnut,
Why isn’t the digital pull scale worth $20? Where’s the problem? If it’s dependible results, well, that’s an issue with your rolling stock and layout. Wide variations on car wheel friction and car weight can drastically effect engine ratings, not to mention uneveness of track and how clean it is.
What do you expect the meter and the results to tell you? Right now, the meter will tell you how much each engine you have pulls to approx. 0.1 oz (which is pretty good). These numbers alone will tell you which engine you have is the most powerful or the least powerful without having to get out strings of cars on the layout.
If you want to convert these drawbar pulls into usable car ratings, you have two options. Base it on rolling resistance or car weight. If based on rolling resistance, mount the scale on a truck or a small flat car with good free rolling wheels. Couple the flat car or meter to the rear of the locomotive(s), then couple the meter to a string of cars, preferably of uniform weight and rolling resistance. As for the number of cars, it’s up to you, but I would start at 5, then 10, 15, 20, 25, etc. Now run the train over your worst place on the layout (maximum grade, maximum curvature…wherever your locos tend to slip and/or stall). Examine the meter when testing to determine the max. load for 5, 10, 15, etc. cars. This result will be in ounces just like the drawbar pull. Put this info on graph paper or in Excel.
Now you have your ruling tonnage rating chart. Look at your engine drawbar results and compare it to the tonnage rating chart, and one should be able to easily extrapolate approx. how many cars each engine can pull on the worst part of your layout.
The other option is to base it on car weight. Weigh every car you have. Do the same test as above, but instead of using number of cars, do ounces of weight (10 oz, 20 oz., 30 oz., etc.). Get th
I have copied and pasted your post. Some things in life I find getting harder to understand as I age ( 75 now ). I used to be an electrician and could rough out a new home by myself with no probs at all. Calculations I loved even in school, but about seven or eight years ago the old noggin started slipping. ( didn’t need any digital pull meter either. [:-^] )
OK so in the morning sometime I’ve a lot of engines and rolling stock to check out. Each engine and rolling stock that I own is already logged for the weights as I do that right out of the box.
