Its metric. I bought it off Ebay a while back because the price was right, but I can't find the descriptive number anywhere now. I would like to get some more the same size, but longer for an application, but for the life of me I can't recall the screw number to look for. Its 6mm diameter and the pitch is about 1mm.
Yikes, looks like it is a very fine pitch. Well, the only thing that matters is the diameter and pitch. Your 6x1 makes me think
6 mm dia and 1 mm pitch. I have actually seen some like that listed on eBay, so you ought to just search there and see what comes up. The real problem is they are rarely made very long as whip and stiffness become problems.
The seller on this one said it was C3, but after measuring its travel a couple times it can't be any better than C7. Probably closer to C9. THK does make one but, "Perforated poop masked crusader!!!" those things are expensive. I think I'll just keep an open search on Ebay and see if any pop up. In the mean time I think I'll explore other options for this application. Wish I had room for 16mm. There are tons of those out there at a reasonable price.
Which is a finer pitch than that used on the Compact-5/CNC, and which is otherwise a similar length. I think that the Compact-5 uses one of 8mm diameter, but I've never actually needed to measure it.
Agreed. Bridgeport, in their BOSS-3 through BOSS-6 machines, even with a ball screw larger than one inch, and with the speed limitations of their original stepper motor setup, did a trick to minimize whip. The Y-axis is normally driven by rotating the screw, but the X-axis has the screw rigidly mounted to the right end of the table, and rotated the ball nut (in a pair of opposed bearings) instead. A very good way around the whip problem, but perhaps not enough for stiffness on a 6mm ball screw.
I am in the process of fitting this screw as a lead on the Z axis of a mini mill. (Smaller than my Taig). I was hoping to finding something similar for the X&Y, but I either can't find them or the price of a single lead assembly is more than the whole machine. I had retrofit that machine from V groove to Acme a while back, but the anti-backlash nuts I found for that size are just to puny. Under light aluminum cutting loads the nuts give constantly. Can't really use anything bigger in the space available. I suppose I might be able to use 8mm, but that would be it, and I would have to drill out the table and cross slide for clearance.
P.S. That nut is freaking hard. I tried to drill it out slightly so 6/32 mounting screws would go through easily, and I had to do it one drill size at a time, and I still cooked two bits even while pouring oil on them while cutting. If I find more of these they will get 4/40 screws for mounting. LOL.
Ouch! Even smaller than a Taig, that leadscrew sounds too small for the task.
And expect that small a ball screw to flex under similar loads.
Note that Bridgeport had an interesting approach for the ball screw for the Z-axis (spindle quill, not the knee jackscrew, which was not motorized). This was in the old BOSS-3, and probably the same up through the BOSS-8 (which had servo motors instead of the BOSS-3's stepper motors.
The quill bearing cartridge was built within a cylinder whose outside was the ball screw, and the corresponding ball nut ran around it in bearings and was turned by a timing belt. This meant that the force applied by the ball nut was truly on axis.
It *should* be hard, given that the surface forms the ball race in the ball nut.
I think that you will find that all the drills which you used need at least resharpening, if not replacement.