Review on Sliding Positioning Bearing Platform 90mmx90mm: Smooth Motion for Precision Adjustments by Jose Mcdaniel

This item is well made and reliable and would have received 5 stars. However, it was damaged in two places upon arrival. If I needed all four degrees of freedom that this device is supposed to offer, I would have to give it 1 star. The 2-1/4" long rotation stop screw was bent so it couldn't be rotated any further where the bend occurred. Otherwise the block rotation works fine and for me the blocking probably never would have been used. A more serious problem was with one of the linear micrometer. Each micrometer device is mounted in a small aluminum block that locks it in place. The micrometers are cantilevered out of the block as seen in the product images. This makes them susceptible to side force damage to the outer end. In my case, they were the screws holding one of the micrometer holders partially extracted from the baseplate until the opposite end of the micrometer itself touched the side of the device.Thus the affected micrometer is at a horizontal angle with respect to the side of the device and not parallel.It is also tilted at a significant vertical angle. That doesn't work. Luckily I don't need any special degrees of freedom for my application. The device arrived packaged in a box within a box, with thick bubble wrap around the device in the first box and also between boxes. Everything would be fine except that the cantilever mounts for the micrometers (and locking screw) were not rated for the stresses they were subjected to during shipping. This block is strong and heavy, but the micrometric mounts, while not flimsy, are not designed to take large side loads at their open ends. In packaged form, the heaviest loads fall on the weakest spots during transport. There are 2 simple ways to prevent this: 1. Pack the device so that the protruding micrometers and screws do not come into contact with anything during transport.2. Ship the main unit with microns removed and all long protruding screws and boxed separately. And provide a drawing to show where the items need to be installed by customer. I have photos of the damage.