Left And Right Threads On A Minimill?

[joshua43214]

When milling pockets, backlash can give problems especially when the cutter sits in a corner. You are trying to change direction and the cutter can chatter/squeal from lack of movement.

True, but this can be mostly mitigated by ensuring that the lash in the second axis is taken up, and that you will be doing conventional milling when you turn the corner. You will get a sloppy corner if the cutter tries to climb mill the new axis of movement. It does mean you have to know how much lash the machine has in each axis, since you will have to take up the lash in the first axis as you enter the second corner, then turn the lash out of the second axis as you turn the second corner. Over tightening the gibs makes this much easier on a small mill, since the table will resist getting sucked into the lash and it is easier to feel when the lash is taken up.

 

[stupoty]

When milling pockets, backlash can give problems especially when the cutter sits in a corner. You are trying to change direction and the cutter can chatter/squeal from lack of movement.

If i'm making a slot i tend to back away from the corner and plunge the cutter more then move again.

Climb milling can be an issue if i dont snug up the table locks, i always lock the axis that isn't moveing.

In the corner of a pocket i load up the screw against the table lock before i unlock it, that way their is no table thunk(i have some broken cutters from that sort of incidence :0. In this situation their is no way to take up the slack to keep the dials properly counting so i would be using the table stops and/or a dti on the table depending on the required precission. Quite often i slot to lay out marking. (I havnt got a dro that would make life much quicker

Squeeking in the corners is bad get outa their quicky quick

Stuart

 

[Line_Bore]

LMS has 20 pitch screws for the X2 mills. The kit comes with screws, nuts, dials, and hardware. I just put them on mine, much easier to deal with .050/rev than .0625. The price is pretty good, and I would say that after the belt drive, this is a top mod to have (for me, anyway).

Sent from my LG-H345 using Tapatalk

 

[unioncreek]

Line_Bore,

Didn't know that LMS had those. I'll probably go with those for right now and put a power feed on the X axis. I decide later if I want to CNC it.

Bob

 

[hman]

Just a quick thought regarding your original question of "why" the LH-RH threads on the mini-mill ... Note that when cranking the table in X, the crank handle moves along with the item being moved (ie, the table). When moving the Y axis, the crank does not move with the saddle. The leadscrews are of opposite hand so that both motions will "do the same thing" when the crank is turned in the same direction (ie, right-hand rule is preserved).