Hey everyone!
I built a router using heavy duty drawer slides and baltic birch ply this past fall. The travel (x, y, z) of the 3 axis is just under 28" x 24" x 10"
I used 4 slides per axis, in the perpendicular configuration mentioned above.
I got the Y axis very stiff this way.
The gantry's center of mass is quite far behind the mounting point on the X axis slides, and as a result, the entire gantry does lean a couple degrees rearward. This was quite a surprise to me, since the gantry isn't more than 25 or so pounds, and each pair of slides is rated at 100 pounds. Oh well. Because of all this, the anti-backlash nut and X acme shaft aren't aligned, so I've had to run the thing with no bearing on the non-drive end of the shaft. Otherwise, the bend in the shaft becomes so great at the ends of travel, the machine binds and loses steps.
The Z axis has a fair bit of deflection to it, as well. I'll be redesigning that at some point.
I would also recommend a fixed gantry that houses the Y and Z directions of travel, and a moving bed for X travel. This keeps the mass of the gantry off the X axis, and will increase precision and stability significantly.
Can drawer slides be used effectively? Definitely! They just have their own limitations that you must account for in your design.  |