This sucks as I’m getting invalid attachments.
Given that I really don’t know the specifics here you have basically two choices. One is a drag chain. The other is the use of flexible electrical tubing. It is good that you are concerned about bend radius but not having enough cable works against a robust install. You may very we’ll end up needing a new cable to install these options properly.
Flexible electrical tubing suitable for CNC work generally has a larger bend radius than a drag chain. This requires more thought into how it is installed. More so you really want to stay away from the minimal radius. However if an arraingement can be found the minimizes bends and is of modest travel ( think Z axis here) you can get good long lasting protection for your cables.
Drag chains, especially the “open” ones, have the negative aspect of collecting junk or searching. This junk can accelerate cable wear. However on relatively long axis you don’t have much of a choice. A totally enclosed drag chain adds a bit of cost. The bend radius on drag chains is basically a hard parameter. Thus you need to design around the specific chain you select or get premature wear or breakage.
Unless the drag chains are designed for clean rooms you get a lot of particulate matter coming off the chains and cables as they wear. In some cases I’ve seen designers resort to using large diameter urethane tubing to support cabling in a clean room. The problem is this isn’t self supporting.