Linear Rail Guide Slide Table 100mm with Ball Screw SFU1204 - Enclosed Structure Manual Slide Stage with Ruler for DIY CNC Router Controller | Precision Motion Control for CNC Machines, 3D Printers & Automation Projects

I purchased the "Linear Rail Guide Slide Table 600mm Ball Screw SFU1204 Enclosed Structure Manual Slide Stage with Ruler for DIY CNC Router Controller". It arrived in an Amazon box with bubble-wrap and some pieces of foam. Although the packing seems a little skimpy, the unit arrived fine.I bought this because it is sealed, it has a linear scale and indicator on the side, and an indicator on the rotary handle in "units". The indicators are red metal arrows -- simple and effective.When I first started using it, it was rubbing consistently on one side on each turn of the handle. After a little investigation I discovered that the screw holding the clamp-bracket was too tight (not the clamp-bracket tightening screw, but the screw holding the clamp-bracket to the housing). Once I loosened that, then the operation was very smooth. I suspect that this clamp-bracket slot isn't drilled square or lacks clearance. Regardless, the operation is fine now.The various set screws are metric Allen.The linear scale on the side is in centimeters, with ticks every millimeter. The rotary units are a little strange though. A full turn of the handle is "18". 5 turns (80 units) is 2 cm. 100 turns is 40 cm. So this means that each unit on the handle (e.g. 1,2,3) is 400mm/1800 = 2/9 cm. OK folks, why not just have the handle go to 10 or 20; why 18? The answer is that they wanted to map the units to the degree indicators. So 18 units is 360 degrees. But with a LINEAR slider, degrees are meaningless. This handle is also shown in the Amazon page, so I didn't get the wrong handle. It just seems to be a poor choice. This handle is more indicative of a rotary stage.Also, each "unit" on the handle has 10 ticks. So each tick is 1/10 of 2/9cm = 2/9mm. Thus, 9 ticks is 2 mm.The handle quality is quite good and the numbers are cut into the metal instead of just printed.I'm giving this 4.5 starts and am looking to buy a different handle with more reasonable numbering.In my case, I'm using the handle although this slide also appears to be designed for CNC use.There are 6 threaded mounting holes on the carriage. The Amazon page shows two slides mounted in an XY configuration, although it isn't clear to me how to mount one to the other. There aren't any empty holes on the bottom of my unit.Scott