Posted: 10/2/14
The hardware fails, but the part is fine. This is the opposite of what we expect to happen. As it happens on full-size vehicles, it also happens in RC. Usually in RC, it’s a small set screw or flat head screw. Both are prone to stripping out if poor quality tools are used or if care isn’t taken. Many people get stumped when this happens, and while the fix is a bit of work, when the worst happens, it is still fixable.
Prevention
Two things prevent stripped hardware—quality tools and proper use of those tools. Axial Racing vehicles include some basic tools to get you started, but lots of wrenching (half the fun in this hobby) requires quality tools. Axial offers hex drivers with comfortable handles that feel like real tools and have replaceable tips. The tips are precision ground so those are a perfect fit. Proper use consists of making sure the tool is fully seated in the hardware. Besides using worn out poor quality soft steel tools, to not have the tip of the driver fully seated in the hex hardware is one the biggest reasons hardware gets stripped out. In addition, to make sure you are inserting the wrench fully, make sure the hardware is free of debris. Use the tip of a hobby knife to clean out any screw heads that may be clogged with dirt.
Gear Puller
Pinion gears are held in by small set screws. These small screws are prone to stripping out when we use Herculean efforts to tighten them down. Great Planes makes a pinion puller (item no. GPMR2410) that can sometimes force a pinion off a motor’s output shaft as the puller is tightened down. These pullers cost about $25 and are not guaranteed to work. Axial pinion gears cost between $5 and $6, so it will most likely eventually pay for itself as other methods of removing a stuck pinion result in a destroyed pinion gear.
Rotary Tool and Cutting Wheel
I wouldn’t even read this section without eye protection. When a set screw is stripped in a pinion gear or in a driveshaft, the most common way to fix the problem is to break out a rotary tool fitted with a cutting wheel. The fiber reinforced cutting wheels are preferred as they are more durable, but regardless of what type of cutting wheel you use, you must use eye protection and keep your head clear of the path of potential flying pieces. Cut off wheels shatter and the flying pieces can blind you permanently. This type of work should only be done by an adult.
To remove the stripped out hardware, you will need to basically grind out the set screw. This is the preferred method over attempting to drill out the set screw. Drilling a set screw on an object that wants to spin can be very difficult and even dangerous. Grinding out the set screw results in a ruining pinion or driveshaft, but cures the problem.
If a flat head screw is stripped (most commonly stripped screw type other than set screws), use the cut off wheel to notch a flat groove across the screw head. If you’re careful, you will only damage the already damaged screw. This notch will allow you to remove the screw with a flat blade screwdriver.
Reliability and customer satisfaction go hand in hand, so Axial is continually improving our products. A great example of this the WB8 HD Wild Boar driveshafts that uses a 2 mm hex drive instead of a 1.5 mm hex, which can be prone to stripping out if the wrong tools are used.
