This seems to be an important issue for CNC systems.
I’m exploring accessible solutions for the DIY community (not to mention my own projects).
I have three ideas so far.
1) A combination of ordinary ball bearings (like yoyo and skate bearings) and aluminum angle. This seem to be okay for laser stuff. I suspect it can work for smaller cnc mill applications. There are examples of using it for larger systems that cut soft material. Seems MDF comes into the equation when using ball bearings and aluminum angle (to make up for some of the shortcomings of the properties of aluminum angle).
2) Plastic bearings with rod. It seems the plastic linear bearings are not very expensive. Price goes up if they or not “closed”. So I’m thinking that it’s possible that this can make sense with the plain rod. I’m looking at sources of rod.
3) Traditional linear bearings with rod or supported rod. This obviously works but it’s very expensive. I think it’s a barrier for many DIY CNCers. So I’m biased against it for this project. I just did a quick look at how much it would cost to buy the rods and bearings for my CNC Mill and it comes to more than I paid for the mill. This could be that I’ve not been very successful at finding the parts. Or that it needs to be purchased in bulk.
I contacted a few companies that have various products. So far, they’re bad at getting back. They have all sorts of glossy pictures at their Web site but no prices. So I guess it’s all custom stuff.
One has tried to get back. I sent them an email with questions. He keeps calling me (and of course I’m in meetings). I called him back but of course he was in a meeting. (What the @#$@#W$ is wrong with email for some people). After calling him twice and the timing not working out, I’m now waiting for him to answer my email. It’s been about 3 weeks. These guys must be used to dealing with a bunch of non-email people or something.
The other’s have not gotten back yet. I will make some more attempts to contact some of these companies. I suspect a lot of it is “designer” stuff. I don’t want to buy a hamburger (or a bearing) for 900 bucks.
We’ll see how this pans out.
I have lots of ideas of how to use ball bearings with aluminum angle. That will be the answer unless somebody can enlighten me.