This page will tell you what type of mechanism drives your National Cash Register machine. It is a nice bit of info to know and it can show what an expert you are becoming!

Here is a quick list of the main National Cash Register mechanisms of the brass era.

Detail adders:

Models include 0, 1, 2-14, 17, 29 216 300, 301 and many others.

Detail Adders are the first type of NCR register. They are very easy to spot in that the have thicker keyarms (cast not stamped metal) with large round keychecks and when you lift up the lid you will see two rows of numbered wheels. Each time a key is pressed the lower wheel indexes one notch if it goes all the way around the upper wheel moves one click.

A storeowner, at the end of the day, would have to look at each wheel and write down the numbers in the top and bottom rows and then add them all up to see the daily sales. Then the proprietor would use the special NCR wrench to reset the wheels to zero by turning the rod at the side of the detail adder mechanism. This must have taken a huge amount of time!! It was sure a great thing when they invented total adders!

These machines usually had an additional Customer Counter which counted the number of times the drawer was opened.

33 principle total adders:

Models includes 30, 31, 33

These machines were the first to add the amounts up of each keypress onto one Dollars and Cents counter. The mechanism is very complex and hard to repair and restore. They are harder to describe; they have the same cast keys with large round keychecks as the detail adders. When you lift up the lid you see one large counter in the middle for Dollars and a smaller counter for Cents and possibly 2 others on the edges for the No Sale and customers.

These machines in working order with all the parts under the lid will command a premium for their rarity.

35 principle total adders:

This is the most common type, models include 34, 35 36-49, 50, 52, 58 (cast iron case Bohemian) 63, 64 311, 312, 313, 314, 315, 316, 317 and the very common 332, 333, 336 and many many others….

The is the big hit of the NCR brass era, this the very common principle. These machines mostly had stamped metal keys with oval keyrings. Although they were sometimes round. Lift up the lid and you will find a combined dollars and cents counter (the total adder!) and a No Sale counter. On 300 class models you may also find counters for Received Paid on Account and Charge. There will be a keyslot to reset the to Total Adder.

135 principle NCR:

Models include the Narrow (128, 129,130) and wide versions (135, 137, 138, 144, 147)
Only 2 case styles Cast Iron Bohemian and Bronze or Ni Art Nouveau pattern.

This was a mechanism design that NCR got in an acquisition. It is a little hard to work on and not all that uncommon, but they are cute machines. They have stamped metal keyarms and Small round keychecks. Lift up the lid and you will find a total adder like the 35 principle and a No Sale counter. Also there will be a reset knob on the outside of the case on the right and under the lid will be a bell stop lever and a drawer release push in the upper left corner.

Lever machines (171 principle):

Models include 171 to 188

These are unmistakable to spot they have levers down the front for selecting the sales amount and a crank on the side.

400 class crank machines (79 principle):

Early models start with 79-101, later renumbered to 400’s. Most common are 442, 452.
Early scroll pattern and Empire case patterns only.

These are the crank machines they have 4 or 5 rows of keys 1-9 down the front for selecting the amount and they have a crank on the side (later had electric motor on back.) These machines usually had a printer on the left side.

These machines had lots of different features and drawer combinations.
See my page on special features.

500 class crank machines:

Models numbered in the 500’s and beyond into plain metal machines. Empire case style only.

These are the big boys! These things are huge, they look exactly like 400 class machines except they have a hug hump on the left side which holds a rotating set of total adders one for each clerk. When these machines had a motor they were mounted on back in a square box.

These machines have lots of different options that can add or decrease value.

Well this is the basics on the mechanisms in early National Cash Registers.
Hope you have found it interesting. It you want to know more get the book
The Incorruptible Cashier Vol. II by Richard L. Crandall and Sam Robins.
Or contact me for an appraisal.

Move on to the next topic (5)….. Topsigns

or back to Step 3(pattern) or back to overview page