'Other' Constructional and Allied Systems Info & Downloads

Duplex Standard Construction Toy

Little Jim(1)
Steel Tech
Trumodel
Steel Engineering(2)

Duplex Standard Construction Toy was a development of the Erector construction system with alternate large and small holes for sale under stores own brand names. It was made in the USA from 1927 to 1932. It is believed to have been sold under the following brand names:-
Little Jim - by J.C. Penney Department Stores
Steel Tech - by Montgomery Ward & Co.
Trumodel - by Sears Roebuck (The Kelmet Corporation)
Steel Engineering - by an unknown company/store.

Initially, separate manuals were supplied for the various brand names. However later on in 1929 some manuals were issued without the relevant brand names. Presumably to save on costs.


Info from the Metal Constructional Systems Database for DUPLEX STANDARD CONSTRUCTION TOY

Maker
Gilbert Erector
System Type
ERECTOR type
Country
USA
Dates
1929 to 1932
Material
Steel
Thread
8-32
Boss Type
single-tapped
Boss Thread
6-32
Diametrical Pitch of Gears
24
No. of Parts in System
207
Hole Pitch (Spacing) (mm)
12.7 (multiples of value shown, including half.)
Diameter of holes in Strips(mm)
4.4 (see comment *1)
Diameter of the Bore in Bosses(mm)
4.1
Diameter of Axle Rods(mm)
4.0
Types of Nuts and Bolts
Nuts: square
Bolts: round (slotted)
Material/Finish of Nuts and Bolts
Steel with a Nickel plated finish
Size of the Nuts across Flats (mm)
6.4
Bolt diameter (mm)
7.2

Comments
Generic name of modified ERECTOR with alternate large & small holes in Strips, Plates. Sold by stores under brand names, see LITTLE JIM [1], STEEL-TECH, STEEL ENGINEERING [2, TRUMODEL. Data from LITTLE JIM set. *1 & 6.6.

The MCS document for this system is shown below. It can also be downloaded to your computer if desired here

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The report can be zoomed into, made full screen or downloaded as a pdf document by using the controls provided


Below there are manuals/leafets which can be downloaded by clicking on the appropriate image.


A Trumodel branded Duplex Standard Construction Toy manual for set 4 dated 1927.
(Added 20/01/2021)

An unbranded Duplex Standard Construction Toy manual for set 4 dated 1929.
(Added 23/05/2019)

A photo of the box lid of a Little Jim(1) set 1.
(Added 12/12/2020)