The current fit between the main shaft and the holes in the main body was so loose that the tool stand became unusable for me. For such a low price you would have expected something like this. I opened the case and planned an inexpensive upgrade. I found the metal shaft to be about 5/8 inch diameter long but the holes in the case are too big. I added two McMaster-Carr P/N 2705T34, "Light Duty Dry Running Flanged Plain Bearing, Acetal, for 5/8" Shaft Diameter and 3/4" Body Bore, 3/4" Length. These 6, $22 bushings required two modifications: 1) grind the face on the flange to center the bushing on the body bore and keep the bushing from rotating, 2) grind the diagonal face on the unflanged end just enough, to clean the gear teeth.. (I made these modifications by hand with a Dremel tool because I don't have a tool stand yet, lol. For the same reason, I didn't try to put 3/4" diameter holes in the Body to put in bushings (I don't have a big fine boring machine for this.) Both new bushings fit snugly into the body, they hold up somehow, in the photo they're in place with some play, but there's a spot on the body to um to clamp them with screws recommended I I'd say it improved the stability around the center of the Dremel tool by a factor of 10 or better for twelve dollars plus tax. I'll report later on how well this improved tool holder performs in drilling and milling. I doubt my new bushings are exactly parallel to the Z axis because I haven't tried to check that, but we'll see!