[GregoryA]

Building my first CNC router. Going through McMaster I think I have found the acme screw I need, as well as lead screw, and end supports. Reading through the forums I keep running into two terms, and I really have to apologize for my total ignorance here, hack saw and file.

If I understand correctly, I have to hacksaw the lead screw to length, then i Have to file it flat.

First off, how do I select a hack saw and file for this procedure? Secondly, my attempts in past of cutting steel with hacksaw have all resulted in weapon bits rather than machine tools. So I guess my question is, how do I do this?

[mxtras]

OK - no answers - so I will pitch in.

If you are buying a length of threaded stock, you will need to cut it to the length you need - so you need a hacksaw. Go to Sears or your local Home Depot ot Lowes - they will hook you up. Buy a good one - the price usually reflects the quality, but not always - I would not buy the $0.98 special they have in the bargain bin. Get a few 24 tooth or 32 tooth blades for metal cutting and remember that the blade is directional - put it in the frame with the teeth facing away from the handle. It will only cut in the push direction. As you push the blade, apply a bit of downward pressure, then kind of drag it back to help remove the small chips from the teeth. Once it is cut (after you take a break) you will be left with a somewhat ragged edge - hence the need for a file. I would skip the file and buy a 4.5" grinder annd use a flap disc (on the grinder) to flatten the end of the shaft and remove the ragged edges. A flap disc looks like a bunch of pieces of sandpaper glued to a disc (that's pretty much what it is) and they are very controllable and cut smoother and cooler than a grinding disc although they are a bit slower to remove large amounts of material.

Now - there you have a length of threaded shaft that is the length you wanted, but you will need to be able to turn the end down to fit your support bearings, right? This is where you need access to a lathe. Got any buddies that have a lathe?

Is this the kind of answers you were looking for?

Scott

[carlnpa]

I'd cut the rod with a 4/4.5inch grinder and sneak up on the dimension needed. If you don't have a bench grinder you can clamp to or mount the grinder in a vise and rotate the rod for fine control. A basic grinder from Harbor Freight for less than $20 will do the job fine.

[mxtras]

I think the guy's gone. One post, some lurking, and off he went.

Scott

[GregoryA]

Thanks for the help. Guess Ill need to get some cheap v threaded rod and practice a bit before I make the cut in the expensive part. Hmmm, Bench grinder, I saw one of those on sale at Ace hardware for $20, think Ill grab it next time I am there.

Ill have to ask around about a lath. I have access to a wood lath, that would hold the part, but its slowest speed is 600rpm. I am guessing that would be too fast... Also it seems like i would have to divise a way to support the part, to keep it from bending while i turned it.