DIY Linear Rails - Building from scrap on a budget of next to nothing

[Boyan Silyavski]

I have such a machine, with V bearings. Will work OK for wood and plastic. Aluminum-NO.

The good: Cheap and makes money if you are clever.

The bad:
-Man, i hate the V bearings and all their incarnations. Plus people who promise not achievable things with them .

-The biggest pain is to tighten equally all carriages. Though CNCrouterparts solution seems more clever than on my machine. Usually have to over tighten them so there is no play. That means the motors are always on big strain, so you need good high voltage drivers

-You will need on the gantry 3rd or even 4rth way to support the Z from behind. Additional rails i mean, at the back best done with roller bearings

-Dust resistant-Not at all if you don't use aspiration. I don't use and have to clean regularly the rails and bearings, not a big deal though. Though clever design will eliminate the problem.

I learned CNC on my V bearing machine, i paid my machine and earn money for living on it. If i see in person the engineer who made it i will

So how to make it:
-Make sure you buy the biggest V bearings you can afford
-make sure you use NO V bearings on the Z
-support the Z also at the back of the gantry/ 3-4 points of support/ . If not sure, will send you photos of my machine if you need ideas there.
-use belts
-No plastic V bearings
-design it easy to tighten the carriage. And accessable.
-There are by the way 608 roller bearings that are 0 clearance and are good for CNC. Just don't be fooled by ABEC this or that. VXB has them and other sellers at ebay. 2 of them can go in a V casing, then you change only the bearings, not the V. One guy sell these on ebay.


When i bought my V bearing machine there were no cheap Chinese machines, no other options. Also i was very . No MYCNCUK forum, only overexcited Americans at the Zone. Me with cash in the hand and nobody answering correctly or truthfully my questions on the forums.

But honestly, now in 2015- i will rob innocent children of their savings but not buy or make V bearing machine. In fact i would buy 4 supported rails with blocks and make all else around them from scrap if a cheap build is desired.


PS. Honestly-V bearings