Crimping

Last update: 01/15/2018.
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Introduction

Connectors consist of the following part: 1) Header pins, 2) Plug, 3) Crimp Connector, 4) Wire.

The header pins are soldered to the circuit board.  There is usually one pin removed.  This is the ‘key’ and it prevents the wrong plug from being used.

The plug is the plastic housing where the wires are inserted.

The crimp connector is the metal connector attached to the wire, then inserted into the plug housing.

The crimp itself is the act of bending part of the connector to wrap around the wire.

Most of the connections on SS Williams/ Bally / Stern / DE / Sega / Gottlieb (Sys 3) are either 0.100 (small) or 0.156 (larger) connections.

Supplies Needed:

  • Plastic plug housing (GPE and search “connector plug 0.156” and “connector plug 0.100”).  Size depending on the number of wires.
  • Header pins (GPE. Either 0.156 Part Number: 26-48-1241, or 0.100 Part Number: CH100-40T-0.318).
  • Crimp connectors. Either 0.156 22-26AWG (Part Number 08-50-0185 at GPE)  and 18-20AWG wires (Part Number 08-52-0113).  Or 0.100 (Part Number: CH100-40T-0.318)
  • Polarity or Keying Plug (for the ‘key’).  Part number 15-04-0297 for 0.156.  Or 15-04-9209 for 0.100.  Search ‘Keying Plug’.  A dab of glue can be used instead, but these plugs are handy.
  • Crimper (see ‘Crimper to Buy’, below).

There is also an extraction tool available from GPE, Part Number: 11-03-0016 for 0.156″.  This tool is handy.  However, it is not too difficult to remove connectors using a small screwdriver.  Also available is a kit containing most of the parts needed, Part Number: 76650-3008.






Replace the Header Pins

Burned connector
Sometimes one may come across a burned connector like this one

SS Pinball machines have connectors on every board.  A sure sign that it is time to replace a connector is when it burns. When replacing these connectors, it is important to replace both the plug and the pins on the circuit board.  If the pins on the board are not replaced, that new plug is likely to burn up again.

Replacing the pins on the board is pretty straightforward: remove the existing pins by desoldering. I find it easy to heat each pin with a soldering iron and pull each individual pin out one at a time with needle nose pliers. Then clear the solder holes with solder suckers. Insert the new pins. All done.

0.156 Header Pins
0.156 Header Pins. Locking pins on the right.
0.100 Header Pins
0.100 Header Pins

A supply of header pins can be purchased from GPE. Most of the time, the pins will be either 0.156 (Part Number: 26-48-1241) or 0.100 (Part Number: CH100-40T-0.318). These pins can also be purchased from the other suppliers listed on this site. Some machines use ‘locking’ header pins.  For home use,  non-locking are sufficient and easier to use.

Note: On most pictures on this page, click for a larger image.






Understanding How A Crimp Connection Works

0.100 connector.
Typical 0.100 connector.

A crimp connection consists of two separate crimps: One to hold the insulation, and a second to hold the wire.  The insulation is held for strength.  The wire is held for the electrical connection.

Molex crimp.
Proper crimp connection.

When the crimp is made, the connector is wrapped or folded on these two parts of the wire.  For the connection to be right, there must be enough wire stripped to just work under the inner crimp.  This is important so that wire does not insert into the connection too far.  Or that insulation will not be under the outer crimp.  If too little wire is exposed, then the electrical connection will be poor.

For more information, visit the Molex website.

Crimper To Buy

Crimper back
Hanlong Ratchet Crimper HT-225D.
Crimper
Hanlong Ratchet Crimper HT-225D.

Great Plains Electronics has a larger number of excellent crimpers to select from.

For my money, the best for the light user is the Hanlong Tools HT-225D.  This has a ratchet system that is found usually only on the more expensive tools.

Other Supplies Needed

0.100 Plug Housing
0.100 Plug Housing

Prior to starting, obtain the following supplies: plug housing, crimp connectors,  (GPE and search “connector plug 0.156” and “connector plug 0.100”). It is not necessary to get a connector with the exact number of wires / pins as ones too large can can be cut with fine wire cutters, so I usually get 20 pin or larger plug. Since these are cheap, I get a supply of them. Part Number: CS156-20-LR works for 20 pin 0.156. Part Number: CP100-20-LR works for 20 pin 0.100. Or get the smaller or larger sized ones that are exact for your application.

0.156 Plug Housing
0.156 Plug Housing

Note that there are other size connectors in your pinball machine, but these .0100 and 0.156  are the most common ones in Bally, Stern, Data East / Sega and Williams games.
Gottlieb uses edge connectors in System 1 and System 80 games.  Replacing those connectors is not covered here.

Trifurcon connectors
0.156 Trifurcon connectors for #18 – 20 AWG wire.

You will also need to purchase the crimp connectors themselves.  Like the housing, there are two sizes commonly used: 0.100 and 0.156.   When purchasing the 0.156, be sure to purchase the Trifurcon connections as they make superior contact with the header pins.  For the larger 0.156 connectors, it is generally wise to get those that accommodate different size wires. The two common size are 22-26AWG (Part Number 08-50-0185 at Great Plains Electronics)  and 18-20AWG wires (Part Number 08-52-0113).  The smaller number is a larger wire.






Crimping

New plug with markings.
The new plug with wire markings. This helps to insure that I don’t put the wire in the wrong hole. Long line is for the ‘key’. ‘X’ means do not insert a wire.

Select the proper size (0.100 or 0.156) housing with the correct number of holes in it.  If there are too many holes, cut off the extra ones with fine wire cutters. Next, hold the new one next to the old one and mark up the new one.  I place an ‘X’ on the spots that do not get a wire, a line for where the key is located. This helps to insure that I don’t put the wire in the wrong hole.  Note that the ‘key’ is where there has been a header pin removed on the circuit board.  That makes it impossible to insert the wrong connector. I also like to mark the first and last position.

Next, remove one wire from the existing plug. Most plugs used by pinball manufacturers were not crimped in place, but pushed into a pin. These are easy to remove: just pull on the wire. If a standard crimp connection, cut the wire at the plug.

Cut off a small section that is damaged. Remove the right amount of insulation to expose the proper length of bare wire (see ‘Understanding A Crimp’, above). The amount of bare wire needed is to insert far enough to reach the inside crimp. The second crimp should catch the insulation.

Grab you crimper and insert the crimp connector into the proper slot.  The crimper listed above has only two slots.  The smaller is for the 0.100 connector and the larger for the 0.156.  Note that there is a correct direction for the connector to point.  On this crimper, the wire comes in from the left.

Crimp connector in the crimper, ready for the wire.

On this ratcheting crimper, close the handle one click.  This will hold the metal connector in place (on non-ratchet crimpers, it will be necessary to hold the handle closed partially to hold the metal connector in the tool).

Wire and crimper
Wire inserted into crimper.

Next, insert the wire into the crimper. Insert the wire so that the stripped portion goes into the inside crimper, while the outside crimp holds the insulation (see photo ‘Anatomy of a Terminal’ above). Then squeeze the crimper. A ratchet crimper will then release.  Non-ratchet crimpers will be necessary to judge the right amount of force.

Inspect the connection.  If not done properly, remove and start over.  Expect a high failure rate at first, but don’t get discouraged.  It takes practice, especially with less expensive crimpers.

Crimp tab
The tab that holds the connector in the housing.

The crimp has a small tab. That keeps the connection inside the plug.  Grab the new plug, carefully identify where the wire should go, and insert the wire with the crimp into the plug.  Make certain that the side with the tab is facing the side of the plug with the small slots.

Once the wire and crimp is inside the plug, it should not come back out.  If it does, carefully use your fingernail or small screwdriver to bend this tab further out.

New plug with markings.
The new plug with wire markings. This helps to insure that I don’t put the wire in the wrong hole. Long line is for the ‘key’. ‘X’ means do not insert a wire.

At some point, you may find that what looks like a perfectly good crimp is not.  After inserting the crimp into the plug, the wire comes right out.  To remove the failed crimp from the plug, use a small screwdriver and, showing no mercy, smash down that tab on the plug.  With some small amount of violence, it will be possible to remove the connector and try again.

Repeat one by one with each of the next wires.  Be sure to follow your marking and skip the positions on the plug where there should not be a wire.   By doing one at a time, you are going to make a perfect copy of the original plug and you are now an expert.






For comments, suggestions and corrections, please email:

Additional Resources:
Molex Good Crimps
Clay’s Guide to Crimping