What is the reason why we may lock y axis on Sherline mill?

Hi Guys,

I have been known to touch the wrong hand wheel when using the mill throwing the geometry out and needing to recalibrate. I have now learned Sherline have a X and y axis locking screws. X works fine, the Y is crap as the lubrication stops it creating enough friction on the gib. There is an improvement video i have found which may be better (but still looks poor) but before I do anything is the main benefit of locking the y axis to stop an idiot like me from accidentally touching it or is it to stop vibration moving the axis , or obviously both. If it is primarily to stop hands touching it there is an easy fix of making an obstruction to stop this happening.

Chris

Both reasons apply. Operator error always possible; on Tuesday I found myself turning the rotary table rather than shifting it with the mill table. Most embarrassing.

The main reason for locks is to stiffen up the machine. In general, anything done to make jobs more rigid makes cutting more reliable. In principle I always lock unused axes and snug up the moving one; in practice I forget.

My Chinese lathe allows me to apply considerable force to it's beefy gibs with an Allan Key. I don't know about the Sherline but simply increasing the pressure on the gib may not be smart if there's any risk of breaking the gib (cast-iron?) or stripping threads. (Aluminium).

All machines have limitations. If the Sherline can't be improved on this point, then it's OK to support the gib lock by holding the hand wheel in place. Just don't forget and start spinning it mid-cut!

Dave

It's good machining practice to lock any unused axis when cutting to eliminate unwanted movements, unfortunately you also need to remember to unlock them as this can also cause issues.

Tony

Hi Dave,

I may go for a simple guard combined with a grip on the wheel. still thinking....

Chris

Chris you will do better to find an alternative means to lock the actual ways, by their very nature some clearance is needed so that the table can move and this will also make the set up less rigid so lock it down at source. Locking the handwheel will not eliminate the gap needed for free movement and will not eliminate movement due to backlash in the screw/nut but may only stop accidental movement of the handwheel..

Jason, it is difficult to stop absolutely any movement (I think that's what your saying), yes i agree. But if the hand wheel is moved clock wise and locked at that point by some means and the hand wheel is obstructed from accidental touching it should suffice. If the operator accidentally moves the hand wheel on the Sherline Mill it exerts a fair degree of force and any friction stop is likely to hamper movement but fail.

Chris

Chris, the three of us have said the main reason to lock an axis is to stiffen up the machine, your handwheel lock won't do that only prevent user error so you won't be getting the best out of the mill.

I've never seen a mill or lathe with a locking handwheel but have seen many with locking or clamping to the actual ways which must say something.

Yes I totally get that. The existing Y axis locking screw does tighten the mill. It stops according to some users movement from another machinists forum vibration but still makes turning the hand wheel too easy. So my thinking is if the existing hand wheel takes care off the vibration movement then the barrier to operator error is touching a wrong wheel may well be enough. My initial thinking was as you suggest of clamping the table but there still is likely to be a degree of take up of  movement so I wonder if that was going a tad too far.

Chris

Edited By Chris TickTock on 10/09/2020 18:19:15

Chris, the first thing I did when I got my Sherline mill was to make brass locks with nice handles for x and y axis.

I made x,y, tailstock and depth-stop locks for the lathe when I got that a few years before.

They work so much better than the original set up and really improve work flow.

I also made brass handles for all dials etc. Not really necessary but look and feel superior to plastic.

I'll take some photos when I get a chance if you're interested.

Steve

Would really appreciate some photos Steve..thanks.

Chris