As a naturally curious individual, physicist and engineer, part of my enjoyment in model-railroading has been in delving into the hidden technical secrets. Over the years we have accumulated a variety of test equipment for our hobby shop and for me. Some, of course, were used as demonstrations of extra service to the customer to increase sales, while others were strictly for my cohorts and me. One of our major policies has been to evaluate new products before stocking them. This offered an advantage, not enjoyed by many, to try many unusual gizmos.
As the page develops, the secrets behind some of these will be revealed. This section will serve only as an illustrative introduction. More technical discussions will be included in other articles under development.
UNIVERSAL LOCOMOTIVE AND POWERPACK TEST PANEL
The panel shown below was initially purchased as a powerpack-transformer tester from a now defunct powerpack manufacturer and highly modified to enhance its capabilities.
Note: Adjust brightness and contrast for optimum viewing.
Everything to the right is for AC transformers, while to the left for DC powerpacks with the exception of their AC accessory output.
Starting at the top center is a power switch and light. Next is a leakage indicator light which glows when a ground fault is detected in a metal cased unit placed on the metal plate, whose edge is just visible under the power pack on the left. The AC meter indicates the primary current to the unit under test, plugged into the socket below. All working units draw current even without a load and the amount can detect a faulty one.
Each side has a voltmeter and an ammeter capable of handling the ranges of standard units. The DC meters are bipolar center off to avoid polarity switching. Between each pair of meters and slightly below is a TRACK/PANEL switch to exchange the load between a loco on a test track below and the rheostat, whose knob is directly below. The object between the DC meters on the left is a polarity indicator lamp, which became redundant when the meters were changed to bipolar.
On the outside of the knobs are the test leads which are connected to the output terminals of the units under test. Below the knobs are the OURS/YOURS switches to compare a customer's old pack with our test units. The two units shown on the shelf are normally on the work bench below and wired to the panel for testing locomotives . Using both switches in combination permitted the customer to try a loco with his own, our standard no frills units or any new one. Even momentum voltage change rate (acceleration) can be observed on the meters under varied load conditions using the rheostats. The rate does vary at different loads on most packs. Electronic pulse "power" can not be tested or shown on the panel. The jacks on the front edge of the shelf accept test leads to test locos in a cradle or motors etc. A rewired Kadee wheel cleaner can also be plugged in.
The DC power pack is a 25 ++ year old MRC 501N with a 90 ohm rheostat to permit low speed testing of N plus small and can motored HO locos. No frills to cheat the customer.
The MOST IMPORTANT TEST is to determine if there is a working circuit breaker. Every pack should have one, even if it is external. By varying the load with the rheostat , the breaker trip current can be measured and faulty ones detected. For safety's sake, breakers should be checked periodically .
BACK
For more in depth details on testing, see other articles.
Links to come.
TEST TRACKS
The picture says most of it, except the tracks are about 6 and a half feet long, are wired to the panel and are N, HO, American Flyer S, O, and Lionel O Gauge. The spacing was determined for finger and not running clearance.
Both above pictures were shot outdoors to permit better perspective and lighting. My cheap? Kodak DC25 didn't like the dark.
See tips for LOCOMOTIVE TESTING AND BREAK-IN.
ROLLER MILL
I call it this, because it's like a tread mill with rollers. It doesn't quite duplicate Pennsy's Purdue test plant, but it does a great job. Sitting on a shelf in the rear of my building bench (old desk), locos can be tested or "broken" in, without moving an inch. The best part is, with well tuned ears, other projects can be manipulated concurrently. The device was purchased about 25 years ago and although the base is a little crude, the rollers are well made. An attempt to order an N scale version and more of these for stock failed. The maker disappeared.
NOTE: The same or similar unit is reported by SAdministrator@northwestcomputer.com :
Bud,
I ordered from these people last summer.
Precision Manufacturing
4546 Sinclair Road
San Antonio, Tx 78222
(512) 648 3170
I talked with Ed and he was very helpful. hope this helps.
tod
---------------
Thank you Tod!
A more recent search turned up 3 newer suppliers of similar items:
BACHRUS offers rollers from N to G. One HO series, with friction bearings, appears to a close clone to those shown here. The remainder are ball bearing, bar mounted rollers.
POLK/ARISTOCRAFT offers HO-O-G ball bearing, track mounted saddles.
SMT offers a series of very expensive stands in many gauges and arrangements. Speedometer and wheel cleaning accessories are available.
The base is a shaped board with a well milled out for the rollers. Down the center is a key-way to accommodate two pins on the bottom of the roller units, which permit spacing and provide alignment. On either side are brass (ugh) contact strips, which require occasional cleaning with Rail-Zip. To the left is a powered section of track to provide for tenders requiring pickup. More often, the tender is omitted and a test lead is clipped to a wireless drawbar or tender lead.
EMPTY VIEW
LOCOMOTIVE ON ROLLERS
The roller unit frames are U shaped with a step in the base to compensate for a sheet of insulation. Nylon rollers are on one side and chrome plated brass on the other. The units can be reversed to handle non-standard pickup arrangements. There is sufficient play between the guide pins and the key-way to allow movement under wobbly drivers. To keep oil off the drivers, lubrication is done at the axles. However dirt can be and has been transferred from one loco to the next with a little bit of "Halfheimer's" disease. With eight units, a 4-8-8-4, DD40 or a Centipede can be handled.
Pictured is the stationary one under the rear driver of the loco above. Barely visible in the top and bottom views, dead center, is the hole for the base pin which prevents longitudinal motion. Without this, the loco would ride right over the rollers.
Not shown is the wiring groove under the felt base.
Derived from current measurements, the additional load on a locomotive is less than that from hauling a heavy tender.
BACK TO LOCO TESTING
CELLAR DWELLING TEST TRACKS
When the right light source is discovered, pictures our cellar dwelling loop test tracks will be added. The basic setup consists of an 8' x 12' table with a 4' x 4' center cutout. All track is nickel silver, laid directly on plywood as a sounding board to listen for problems. In addition the track is not very carefully laid, to simulate the probabilities of a beginner's layout . Around the center are Atlas snap-track loops of 15", 18" and 22" R, extended with straight sections to surround the opening. Basically these are used to test minimum radii of rolling stock to advise buyers. Often new types of snap turnouts are added to the outside loop for evaluation.
Around the outside a sloppily laid loop of 34" Shinohara snap curves with Atlas flex extenders is used to test and run-in locos. Since my minimum radius is 36" R, this radius was chosen on the premise that if it runs well here it should make it on better laid track of the larger radius. For accuracy almost all speed measurement is done on this loop. Almost completely filled, it will handle about 90 ore cars with a little space between the last car and a loco.
The open spaces are often used to test other brands of track, sometimes with cast roadbed, or other trackwork as turnouts, slip-switches and operating accessories. Provisions are made to evaluate power packs under operating conditions using external meters.
Since our policy is to test and lube all locos before delivery, an innumerable quantity of tests were made since 1969. Due to price and other reasons, brass received special attention, including a run-in. Spread throughout the articles, conclusions are many and varied and often surprising. Of note is that large brass diesel and electric locos had a very large proportion of problems in derailment and trucks shorting to frame. Some were caused by steps and ladders, while others were from excess solder, which had to be removed. Including articulateds , steamers had much fewer problems, attributed to poor truck springing and occasionally shorting side rods. Not all of the culprits were large locos. Some problems arose only during load testing
In general and in spite of weight, brass cars did not perform as well as others in long trains. Rolling quality of trucks was much lower and shorts were not uncommon due to insufficient clearance. Passenger cars were much worse. In one case with five cars, a coupler pad solder joint broke. However problems were not limited to brass. In many cases cars with metal trucks had to be carefully lubricated and run-in for lengthy periods at 140 SMI/HR behind a dual powered Rivarossi GG-1. Some of these were from leading manufacturers and importers.
Quality control is not the greatest among modelrailroad makers. The level may vary from batch to batch, growing worse as dies or machining wear. Even assembly seems to be effected by the Monday morning hangover. On several occasions, we returned almost an entire shipment of defective rolling-stock.
Originally built as a TV top Christmas tree "platform" to satisfy my wife and daughters, a much smaller N scale layout, complete with Atlas 3-ways and double slips, is often used to evaluate new rolling stock. Because very little can be done to repower locos or improve rollingstock, extensive deep testing is not as common. However many items were eliminated from our stock, due to poor performance. Notable were the Bachmann Golden Spike locos that required extensive treatment to allow them to even pull the tender. In general most European and Kato locos performed well, while the Hong Kong specials were marginal, with few exceptions. N scale brass testing was very limited due to low demand.
While the above are for general testing, the following equipment is normally limited to satisfying my own curiosity and not put into general use in testing models for sale. Spurred by our business requirements to dig deeper into evaluating new products and the expansion into a computer service center, other more sophisticated test devises were added over the years. However many new products were run through the mill. The information was invaluable in selection of products as well as adding to the overall knowledge of the field, in order to advise customers. Many of the statements and opinions found elsewhere are founded on deeper evaluations with these devices.
Weight, drawbar pull, speed, gear, motor, driver, wheelbase and other data on over 350 locos has been recorded on Superbase 4 Professional database for easy comparison and compilation . On repowered locos both original and modified data are readily compared. Also a complete description of work proposed or done is recorded.
Other files contain data on several thousand cars including weight, length wheel base, couplers, trucks and test results. Having a continuous flow of models from our store, swelled the base to these dimensions. Of course not all models got the full battery of tests, but the odd and troublesome were tested extensively. This data plus customer feedback provided a sound foundation for advice to the buyer. But it also helped satisfy my own curiosity. To investigate these SPECIALIZED TEST EQUIPMENT is required.
Other test devices are found in the MEASURING INDEX including coupler, clearance and height gauges.
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