Slot Car Corner - Making a Controller Adapter

Slot Car Corner

Making a Controller Adapter - XLR to Alligator Clips

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Introduction

This is the third article in a three part series about XLR connectors. The first article, entitled "Adding An XLR Connector to Your Controller", began by discussing the many advantages an XLR connector offers when used with 1/32 slot car controllers. The article then went on to provide detailed step-by-step instructions to replace your existing controller connector(s) with an XLR connector. The second article, entitled "Adding An XLR Connector to Your Driver Stations", provides illustrated step-by step instructions which show you how to add an XLR jack to your driver stations. This article, the third in the series, will show you how to fabricate an adapter like the one shown which will quickly and easily convert an XLR controller connector to 3 alligator clips which can be connected to any driver's station with traditional 3 post hookups.

Before Starting - What Is Your Standard?

Before proceeding with step-by-step instructions, there is one prerequisite to cover off. If you belong to a club planning to use XLR connectors or race at other tracks which offer XLR connections, you will need to wire the 3 connectors according to an agreed upon standard. The Shoreline Model Raceways club I belong to adopted a standard which was already in use by the HSARC club in the greater Houston, TX area. The accompanying picture shows which adapter wire will be connected (soldered) to which XLR connector "pin". If you look very closely, you will see the pin numbers embossed in the plastic next to each solder pot.

Step-by-Step Instructions

The picture to the right shows the basic components needed to fabricate the controller adapter. To assemble the adapter, you'll need the following tools and materials - a soldering iron (with stand and cleaning sponge), rosin core solder, rosin flux, a wire cutter/stripper, and a small clamp or vise. Always wear safety glasses and follow all manufacturer's instructions and safety guidelines when using tools.

Note: The components shown are available in kit form in the Online Store. If you prefer, pre-assembled adapters are also available for purchase.

Start by stripping about 1/4" of sheathing from one end of all 3 wires as shown.

Now use your soldering iron to "tin" the end of each wire. Apply some liquid flux to the end of each wire. Make sure your soldering iron tip is clean and apply a small drop of solder to the tip. Touch the tip to the bare wire - the solder should "flow" from the soldering iron tip to the wire as shown.

Soldering the wires to the solder pots will be MUCH easier if you have both hands free. A quick release clamp like the one shown will hold the plastic fitting which houses the solder pots securely while you position and solder each wire.

Before soldering each wire, apply some liquid flux to the solder pot (see picture) and the tinned end of the wire.

Recall the pinout configuration our club uses is 1 - black; 2 - white and 3 - red. You can solder the wires to the corresponding solder pots in any order - I started with the red wire (pot #3). The tinned end of the red wire was inserted into the solder pot labeled "3" and soldered as shown in the accompanying picture. If desired, you can then reposition the fitting in the clamp to facilitate soldering the next wire.

Once the solder joint for the red wire has cooled, apply some liquid flux to the next solder pot (#2 in the picture) and the tinned end of the white wire. Insert the tinned end of the white wire into the solder pot labeled "2" and solder the joint.

Just one more wire to go (the black one in my case)! Follow the procedure described above for the red and white wires to solder the black wire to solder pot #1 as shown.

After soldering the 3 wires to the XLR connector solder pots, it should look something like this.

Use a pair of wire cutters to trim the other ends of the 3 wires to the same length as shown.

Now insert the 3 wires through the plastic XLR cover as shown. Make sure to insert the wires in the proper direction and use care when working the wires through the small opening in the narrow end of the cover.

Place the sleeve over the 3 wires and slide it up to the plastic fitting as shown. Be sure the "U" shaped cutout in the sleeve is aligned with the tab on the fitting as shown (see arrow). The sleeve will prevent the wires from shifting and serves as a strain relief once the XLR connector is fully assembled.

Now slide the plastic fitting and sleeve inside the metal XLR connector housing. The inside of the metal housing has an alignment keyway which prevents the fitting/sleeve from being inserted incorrectly. Note the relationship of the "U" shaped cutout and tab with the release lever on the metal housing. You may have to wiggle the fitting/sleeve slightly to align it properly with the keyway inside the housing.

Once aligned, push the fitting/sleeve as far up into the metal housing as it will go.

Thread the plastic cover onto the metal housing taking care not to over-tighten it (hand tighten only...).

The completed XLR connector should look like the picture to the right. Depending on the wire gauge you are using, it may not be possible to thread the plastic cover all the way onto the metal housing. This is OK - again, hand tighten only!

Next, use a pair of wire strippers to remove about 1/2" of sheathing from the end of each wire as shown.

Slide the protective boots for the alligator clips over the corresponding wires AND make sure they are oriented as shown.

*** IMPORTANT *** Don't forget this step - once you solder the alligator clips to the wire, there's no easy way to get them on!!

Insert one of the wires into an alligator clip. Try to ensure some of the wire strands pass through the indented tab as shown. This will make is easier to solder the clip to the wire. Turn the clip over and spread/flatten remaining strands to make as much contact with the inside of the alligator clip as possible.

*** Reminder *** Before proceeding, make sure the protective boots for the alligator clips have not slipped of the wires and they are oriented properly (refer to preceding picture)!

Apply liquid flux inside and outside the alligator clip where the wire strands make contact - make sure to flux the bare wire strands as well. Use a clamp or set of "helping hands" to hold the wire and clip in place. Make sure the soldering iron tip is clean. Solder the wire to the alligator clip - note the clip and wire are very effective "heat sinks" (they draw heat away from where you are trying to solder) so it may take a while before the solder will flow depending on the output of your soldering iron. Repeat the previous step and this step for the remaining wires.

Once the alligator clips have cooled, slide the protective boots up over the them as shown (you did remember to put the boots over the wires during an earlier step, right???).

Your controller adapter is now complete and ready for use!!

Summary

There you have it!! This is a relatively easy project (about 20 - 30 minutes) and the finished adapter is a great addition to your track or slot box.

Remember to check out the other XLR-related articles in this series listed below:

"Adding An XLR Connector to Your Controller"
"Adding An XLR Connector to Your Driver Stations"