paper: Working with Wires ( striping, crimping, and soldering)

Thread created automatically to discuss a document in CD-Media.

Working with Wires ( striping, crimping, and soldering)
by: dricks

This Is a presentation on the Basics of stripping, crimping and soldering wires.

This is the presentation used at the 2010 FIRST Texas workshop in Dallas. It is a very basic presentation on how to work with wires

Working with Wire.pdf (1.26 MB)

Page 28: Many of the wires on your robot will connect to the power Distribution block. These wires should be tinned and will be connected with a guillotine connector.

This statement is incorrect. Do not tin the wires that are going into the large WAGO connectors on the PD. This increases resistance and decreases pull out force.

Also, page 25: Step 11-

Step 11- Slide the heat shrink tubbing over the joint. Heat the center of the tubbing with the the iron part of the heating element (not the tip) of the soldering iron

You can also use a heat gun to get a more even distribution around the heat-shrink.
(You also mis-spelled “tubing”)

And on page 29,

The Motors in your robot will connect to your speed controller using spade connectors like the one shown

You can also use these kind of connectors-

And on the last page, page 34, you might want to mention that for connecting wires to the Spike Relay, use spade connectors-

It also potentially makes them brittle and more prone to breaking under vibration or tension.

I’m having a hard time coming up with a reason ever to apply solder to wires if they’re not actually being “soldered to” a circuit board trace or another wire or component lead.

I usually tin small wires that are going into screw type binding posts like the red and black ones on power supplies and such. I find it helps keep the wire from frazzling (sp?) and makes them easier to stick in and out of the little holes sometimes. Other than that I tend to agree.

The reason why you’re not supposed to tin the wires going into a WAGO power distribution board is because the connector literally pinches the wire and the strands are spread evenly against the contact area in the terminal. If you solder the end of the wire, the individual strands won’t be able to spread out against the terminal and will cause a poor and brittle connection.

As discussed in another thread, fully removing the screws can get metal shavings in the motor controller.

While that does seem to be the right part number, it is important to note the picture show a male connector instead of the female version that should be used. Be sure to get the right size for the wire being used.

Only for the older Jags. The newer (Black) Jags have removable screws.

But your point is well taken. It would be helpful to explain that in the paper.


In addition to fork or ring terminals, we may cut a slot in a ring terminal to make it into a hook.

But as pointed out, the Black Jaguars have non-captive screws, so they may be removed without leaving debris. However, I recommend only removing one at a time to avoid replacing the screws to the wrong posts.

A couple of comments I would make to this presentation:

  1. Wire cutters (especially when new) can be sharp. Watch your fingers.
  2. I encourage our team (and others) to use ratcheting crimpers. The yellow handled tool shown in the slides is pure evil. Yeah, I know they’re affordable, but they don’t do as good a job at creating a secure connection.
  3. No mention of wire gauge to the color of the terminal insulation. I.e. Using an incorrectly sized terminal for the wire may result in a crimp that will fail.
  4. Maybe mention using non-insulated terminals, then crimp, solder, then insulate.
  5. No mention of flux for soldering. The flux pens can be useful.
  6. When soldering, I usually clean the tip first, then apply a small amount of solder to the tip of the iron (also having applied flux to the wires/components that I will be soldering). Having some molten solder on the tip aids the process. This is sort of shown in step 9 of the presented process.
  7. Desoldering? Solder wick, etc.
  8. Wow, a picture of a very early PD board… with SLA’d enclosure and everything.
  9. The digital breakout (DSC) can use a ribbon cable as an alternative to the cable provided in the KoP. Many teams use a ribbon cable because a) they can make it smaller (and lighter), and b) there is less stress on the connectors with a ribbon cable.

When stripping wire, the flat side of the strippers should face the end of the wire. When the beveled side faces the end, pulling the tool will compress the insulation you are trying to remove. Also, after you have firmly squeezed the stripper (manual type) release the pressure a little and pull the insulation off. Rotating the stripper, increases the chance that you will cutoff a few strands, thereby reducing the wire size. Another trick I use is to grab the insulation beyond the strip point with the stripper jaws and use that to pull the insulation off the wire. These prevents the breaking of any strands as the sharp edge of the tool pulls across the strands. I like the automatic type you show. These are available at most home stores and Radio Shack. They are all the same tool but the price varies widely ($10-$25).
As discussed, never, ever tin wires for use in the WAGO connectors. They are designed to compress stranded wire for maximum current (highest contact area=lowest series resistance.) and when stripped the proper length (5/8") will achieve the greatest pullout force. WAGO does make a terminal for solid wire, the PD does not use that type.
Alan, we use non-insulated crimp connectors and solder each one, covering the terminal with heatshrink. It is just extra insurance.
I find that slightly tinning the wires to be spliced actually aids in the process. The wire becomes a little more stiff and some solder is already on the joint before you start the soldering process. This also prevents strands from sticking out and puncturing the heatshrink later. Remember that if solder does not start to melt, it may mean you do not have enough heat transfer. Add a little more solder to the tip of the iron and heat the joint again. A good solder joint will have a nice shiny appearance. If you add too much solder, the solder will wick up under the wire insulation making the wire very stiff up to an inch or more from the joint.
No matter the connection (solder, crimp, screw down, or WAGO), always perform a tug test. If you can pull it apart, you need to start over.

On the German Wago web site, the info shows for typew 745 connectors indicated that they can handle both solid and stranded wire.
I completely agree that it is poor practice to tin wires going into a PDB Wago connector**; indeed, I agree with Alan Anderson’s comments about tinning in general (within the boundaries of FRC at least).

Can anyone show me a Wago document that advises against solid wire for the 745-85X connectors used in the PDB?

As you probably have found the WAGO website is nearly impossible to navigate through when looking for information. What you will find is that there are terminations that are designed specifically for solid wire or stranded wire terminated in WAGO pin connections. These types are known as push termination and are specifically recommended for use with non-stranded wire. Brochure 2 on the website shows the advantages of Cage Clamp for wire connections using primarily stranded wire. Other documents on the WAGO website actually outline the testing performed with this series and stranded conductors.

Heh. You should try it in German. :ahh: The US site doesn’t have any hits when I search for “745”, but the German site does. While the exact connector wasn’t found by me, the ones I did find look about right. In the specs, they show the wire sizes for both solid and stranded wire.

I was only asking as a point of information - I’m confident that we know how to use these connectors properly and are unlikely to change our methods.

OK, back on track: I like the presentation, and would enjoy seeing it expanded. Maybe after this season I’ll have some time at work and can do a nice job on it.