Bob-Mac Gauge for HO-scale Magnetic Couplers

Does your railroad suffer from phantom uncoupling or derailments due to gladhands set too low and contacting crossing rails?  The Bob-Mac coupler gauge (gage) is the best available gauge for checking HO-scale magnetic couplers.  Benefits of the design include:

"I bought TWO of these gauges about a year ago. Easy to carry in a pocket. Ready to use in a New York minute. I might say a brilliant design.
Recommended and endorsed.
BAKERPOPPET on Ebay" 5/11/14.

Available in HO-scale from Great Decals!, 3306 Parkside Terrace, Fairfax, VA 22031 for $7.99 each, plus $1.71 shipping.  Virginia residents please include sales tax.  See our web site,

The Story of the Bob-Mac Gauge
by Bob Cook

Circa 2000 Bob Miller and I were serving on the “Standards Committee” of  Northern Virginia Model Railroaders (NVMR).  We were using a Kadee coupler gauge, at “eye level”.  However, Bob Miller is somewhat shorter than I am, so “eye level” was different for each of us and I would  “pass” a car for correct coupler height and Bob M. would reject it.  And vice a versa.

Bob Miller, a technical engineer, and Mac Goodwin, then a machinist with the Washington Post, got together to design a “go/no go” gauge based on NMRA standards and the dimensions of the Kadee couplers.  Mac made a batch of “prototype” gauges which were sold to NVMR members.

They thought that the next step to mass production was to find someone who could make the gauges in large numbers and market them.  They found someone who said he could do this. However, after making 2000 +/- gauges he backed down on the marketing aspect. 

Granddads Hobby Shop bought these gauges and sold them for several years.  I do not know how Granddad learned about these gauges but Mac was a regular costumer and might have said something.  Starting with the Kadee gauge, I designed the label and directions for the “Bob-Mac” gauge.


Return to Great Decals! Web Site