Introduction
This page describes a little bit about the Walthers Cornerstone kit #933-3248. This is an N-scale oil pump jack, which has an optional motorization kit that can be installed to make the unit animated. The motorization kit number is 933-1050. I bought both of these when they came out in 2001.

Assembly
I don't have any assembly photos, because that was before I started actively documenting my various projects. I remember that the instructions were good. This kit was very popular, and you can see them on various N-Trak modules everywhere. However, I noticed that a lot of people had problems getting them to animate properly. First, you have to be very careful when assembling them, so as to not get any glue on joints that are supposed be movable. Secondly, the motor kit has to be assembled correctly and carefully to get smooth movement from the gear reduction box. After a period of operations, mine seemed to be working better and better.

Article Purpose
I built the model and installed the motor, but I never placed it on a layout. The purpose of this page is to take this model and further complete it to where it becomes a removable diorama for placement on any layout. I never completed the kit's fencing, and now, years later, the parts are gone or missing.

Following the instructions that came with the kit produced a horrible-looking solution. The photo above shows the kit as far as I made it. The photo on the right shows the motorization kit installed onto the model.

Diorama Base
A simple piece of left-over Masonite hardboard will serve as the base for the diorama. I marked off where the unit will sit on the base, and drilled four small holes to prepare cutting a rectangular hole. Then I used a jeweler's saw to cut out the hole. Next, I lined up where the wellhead hole is to be, and drilled a larger hole in the Masonite board. This is where the metal rod goes "under ground".

I used 5-minute epoxy to glue the model to the diorama base.

Electrical Connections
I have a 12-volt accessories bus under my current layout, so I wanted see what I needed to do to make the jack operate at a reasonable speed. The gear box is quite noisy at the full 12 volts (it recommended maximum power supply). After experimenting, my conclusion was to place four 100-ohm resistors in series to create a total of 400 ohms of resistance. This makes the unit run at what I consider to be a realistic speed, and it also minimized the noise of the gear box.

Since the small diorama needs to be removable from the layout, I decided to install a barrier strip. This makes connecting the diorama to the layout simple, and eliminates the stresses on the thin motor wires.
I have found that the motor runs fine on the lower voltage, however, sometimes when I turn the system on, it won't start. The motor really needs a higher start-up voltage. I installed a pushbutton switch that temporarily shorts out three of the four 100-ohm resistors. This gets the motor started. Once started, it will keep going.
I will have to come up with a way of hiding the pushbutton switch. I decided to make it an integral part of the diorama so that, when I remove the unit from the layout, it will act as a single diorama.

Scenery
I covered the holes in the base of the model and the transition from the Masonite board to the base of the model with some premixed grout. That stuff works great as a filler, hardens in minutes, and can be sanded and painted. I purposely left it a bit rough because my model is supposed to sit on a concrete base, but it has been overgrown with sand, weeds, and bushes. I painted the whole base with Poly Scale's "Dirt", which is a dark brown.

I removed the thread idea that the kit's instructions suggested. It tried a few experiments, but this last one is the one that I am the happiest with. I installed a 0.012" brass wire through the hole. Many years ago I bought "HO-scale" chain link from Clover House. The smallest they offer is usable in N-scale. I glued a small piece of this chain to the top of the jack and to the brass wire. The chain is flexible. I used superglue. The kit's instructions say to hang some weights off of the brass wire, but I found that the gearbox caused the jack head to jerk a lot. I left off all the weights and the unit worked smoothly.

Prototype References
These links provide some reference photos of oil pumps: photo #1, photo #2, and photo #3.