Braided sleeving is a low-cost way to add a professional look and feel to your electronics project. It can be frustrating to work with, but it’s pretty simple once you have the proper tools and techniques. In this tutorial, I’ll walk through the process of applying braided sleeving to a brushless motor and ESC.
Tools & Supplies
There are two types of braided sleeving: split and non-split. The ‘split’ version has a cut running lengthwise down the entire spool (hence the name). For smaller electronics work like I’m doing here, I strongly recommend the ‘non-split’ type of sleeving. It generally must be applied before any connections are made but it results in a much cleaner look.
The sleeving expands in diameter as it’s compressed and applied. Choose a diameter that’s as close to the diameter of the wires you intend to cover, erring on the side of smaller. I’ve found that 1/8″ (~3.1mm) does the job well for motors/escs (using 20AWG both for motor signal wires and ESC power wires).
I’ve gotten mine from Amazon.com, but Ebay is typically a great source for materials like this within the US.
- [Affiliate] Amazon.com: Eowpower Black Expandable Braided Cable Sleeve Sock 1/8 inch X 100ft
- [Affiliate] Ebay.com: Variety of sizes/colors/lengths – Expandable Cable Sleeving Braided Tubing
A hot knife is the secret weapon of working with braided sleeving. The knife melts the nylon/plastic as it cuts, fusing the loose ends together. When cut with regular scissors, the ends of the sleeving unravel easily and rapidly, making it incredibly difficult to use.
You can get away without a hot knife but I strongly discourage you from wasting your time. Mine only cost $15 USD and I’ve seen an easy return on investment in terms of time/frustration saved.
Heat Shrink & Heat Gun
You’ll need a way to secure the cut ends of the braided sleeving, and heat shrink is the most effective method I’ve found. If you haven’t already, I suggest investing in some heat shrink and a heat gun.
- [Affiliate] Amazon.com: Genesis Dual Temperature Heat Gun
- [Affiliate] Amazon.com: Heat shrink tubing, black 532pcs
Below is the basic procedure for applying braided sleeving to a length of wires. Repeat this process as necessary for your project. In my case, there are two lengths of wires: between the motor and the ESC, and then again between the ESC and the power distribution board.
Step 1: Plan and Prepare
Order of operations matters. For example, the braided sleeving must be applied to the motor leads before soldering to the ESC, and the heat shrink over the ESC must be applied after the sleeving but before making the final connection to the power distribution board — otherwise there’d be no way to get the heat shrink around the ESC! Before getting started, take some time to think through the whole process for your project.
Also, take the time to prepare your wires by cutting to length, stripping, and tinning them. It’s always good practice to tin wires prior to soldering, and even more useful when working with braided sleeving. Once the sleeving is applied, you’ll want to minimize the strain you put on the ends to keep it from unraveling: having pre-tinned wires will help with soldering. Additionally, having tinned wires will prevent loose strands from snagging on the sleeving as it slides past. Finally, braided sleeving is heat sensitive: pre-tinning helps minimize the heat applied to the wire afterward.
Step 2: Cut and Flair
With a pre-heated hot-knife, make the first cut. I suggest using a stand for the hot-knife with the sharp edge of the blade positioned skyward. Hold the sleeving with both hands and move it back and forth over the hot-knife to make the cut.
Braided sleeving expands to fit the wires, but this fused end will not easily expand. Depending on the size of the wires/sleeving you are working with, you may need to flair out the end of the cut sleeving to create some more room to fit the wires inside the end of the tube. Immediately after cutting (while the end of the sleeving is still melted from the hot knife), gently tap the end straight down on a cutting mat or other surface. The end will open up a little bit and create some space. You’ll likely need to experiment with this technique several times to get the end opening just right.
For now, do not make the second cut. As braided sleeving is applied, it expands radially and shortens lengthwise. This makes it difficult to measure the length correctly until it’s actually on the length of wire.
Step 3: Apply the Braided Sleeving
The mechanics of braided sleeving is similar to the famous Chinese Finger Trap. As the tube is compressed along its axis (lengthwise) the diameter of the tube expands. Using this knowledge, the strategy is to compress from one end and release on the other end. In this way, the tube moves itself down the bundle of wires.
More specifically, assuming you’re trying to move the sleeving from right to left along some wires:
- Clamp near the left-hand end of the braided sleeving with your left hand.
- With your right hand, push the sleeving along its axis towards your left hand. It should compress, and expand radially.
- Once compressed/expanded, push far enough over that your right hand can grasp the bundle of wires along with the sleeving.
- Clamp down on the sleeving & wires with your right hand.
- Release your left hand.
- Watch the tubing decompress along its axis and ‘move’ down the wires toward the left.
- Repeat this process until the desired length of wire is covered.
Step 4: Make the Second Cut
Recall that as the sleeving expands, it compresses radially. The length of the tube while on-wire is different from the length off-wire.
Now that the braided sleeving is on the wires, you can measure for the final cut. The best way to do this is to mark the sleeving (with a marker, or make a small snip with scissors to ‘mark’ the spot) and then back the whole length off the wire. Use the hot-knife to make the final cut to minimize any unraveling. You may wish to slightly flair out this new end as well. With both ends cut, re-apply the sleeving to the length of wires.
Step 5: Finish The Connections
After applying the sleeving, use your soldering iron to finish off any necessary connections. Take care not to over-heat: excessive heat will cause the braided sleeving to warp and melt.
Step 6: Apply Heat Shrink
The hot-knife does a good job fusing the ends, but they’re still brittle and not very clean looking. Cut a small section of heat-shrink to apply over each end of the braided sleeving. Use the heat gun to to finish it off and hold the sleeving securely in place. Again, use caution and avoid melting the braided sleeving.
Tips and Tricks
While learning to use braided sleeving, I came up with a few tips and tricks to ease the process.
Tip 1: Heat Shrink Cap
If you’re having trouble getting the first end of your braided sleeving over a group of wires, try making a temporary cap with heat shrink. Slide a piece of heat shrink halfway over the ends of your wires and shrink it down as much as possible. The heat shrink holds the bundle of wires in place and keeps them from snagging on the sleeving as it slides over. The heat shrink cap should pop off without any trouble after applying the sleeving.
Tip 2: Heat Shrink Clamps
As mentioned previously, the fused ends of braided sleeving remain rather brittle and easily torn. Temporary heat shrink clamps are a great way to maintain the integrity of the braided sleeving ends as you work with the exposed wires.
Cut a cross section of heat shrink as thin as you can. Place it at the end of the sleeving and shrink it until it’s just barely snug (don’t over-shrink or it will be harder to remove later). This adds a little bit of reinforcement that helps keep the ends of the tube intact as you work with the exposed wires. Once complete, carefully snip the clamp and remove it before applying the final heat shrink.
Tip 3: Cutting In-Place
Step 4 in the application process suggests backing the braided sleeving off the length of the wire to make the second cut. This makes for the best application, but isn’t always practical. For example, very short sections of sleeving won’t hold together well when applied and removed.
It’s possible, with care, to cut the sleeving in place. Rub the sleeving against the hot knife and rotate the bundle around until the cut is complete. This approach requires a great deal of caution to avoid damaging the wires underneath, especially if they’re plastic coated (the hot knife will melt right through the plastic). I also recommend using a heat shrink clamp (tip #2) because the sleeving ends won’t be very well fused together using this approach.
With some patience, proper tools and adherence to best-practices, braided sleeving is a straightforward way to enhance the look of your project. The guidelines above are what I use in my own projects, and I hope they’ll be useful for you as well.
What tips and tricks have you come across while working with braided sleeving in your own projects? Leave a note in the comments below, and be sure to follow @thejumperwire on Instagram, Twitter, and Facebook for more!