SX2.7/LMS 5500 - Y axis sloppy backlash

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harrzack

Harrzack
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Mar 27, 2013
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The mill is ready to make chips - now waiting for the DRO. I notice the X axis feels like it has no backlash at all! However the Y seems pretty sloppy to the feel.

Does anybody have any info on how to adjust the backlash on this mill?
 
Check the nut that holds the Y hand wheel. I have the same machine that had MUCH Y axis backlash. Snugged up this nut and got about .004 backlash on the dial. There was also a binding on the X axis when moving the table left making the hand wheel hard to turn. Discovered the countersink for the thrust bearing was cut too deep. So the dial was acting as the thrust bearing. The fix was to turn the inner race around backwards so now the caged thrust balls run on the flat side instead of in a groove. Works real slick now and also has about .004 backlash. So much for quality control! I haven't had mine very long and only done a few jobs on it but so far it seems like a decent little machine. You just have to consider it's origin and tweek where tweeks need be......
 
Kitch - thanks - that did the trick! I was over-thinking it and missed the simple answer. Mine Y is still a tad rough so may look into that bearing situation.

Does your quill seem inordinately hard to operate? Mine a real knuckle-buster if your hand slips off the spokes. One member mentioned taking some turns out of the "clock spring" that operates the quill. I then found this great YT vid on doing just that (with a Bridgeport): http://bit.ly/2rCPZOa
Will tackle that gingerly - but good to know a solution is available.

Yes - for a Sieg product they DO seem to be getting their act together with this mill. Naturally a few rough spots yet, but overall very happy. Still haven't "made chips" yet - but sure it will be sweet!
 
Let's just say my quill feed is a little "spirited". Seriously, it's stronger than my drills presses but not so strong to be a pain. The fine down feed turns easily enough to be easily adjusted. Maybe your coil spring DID get an extra wrap. BTW...the power tap feature will have you tapping holes that don't need tapping...it's a neat feature.
 
Ok - will test further. I did find the fine feed to be quite stiff and not very conducive to FINE feed... Maybe it needs a bit 'o tuning as well.
For the tapping - can you use common garden-variety taps or do you need the special ones made for power tapping?
 
Have only tapped in aluminum so far. I just used a 4 flute taper tap. It worked great. For tougher metals I would think 2 or 3 flute taps would be more appropriate, as in way stronger. Seems I saw a discussion on this elseware on this forum. Oh....and lots of oil on tap!
 
I got fed up with the fine feed on the Z axis when I was boring some 1" deep holes. A zillion cranks down & back up, using the pretty stiff knob. I did a relatively simple mod to add a much longer crank handle to the knob -- see attached. It's been so handy I just left it attached -- initially I thought it would be too much in the way but au contraire. It's still a zillion turns but at least they're a lot easier. I can cinch down the lock screw a bit to stiffen up the Z axis and still easily set it where I want.
Crank A scaled.JPG
 
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