I am shopping for a larger mill and found a Lagun FTV-4 for sale. It looks fine but it has some side to side quill play. If held the 1" bar stock hanging out of the collet and pulled on it while leaning back with my full body weight (175), I got a little less than .001 deflection...if I really yanked hard with an all out inertial type yank using my body weight it looked like it moved almost .OO2.
Is it normal or excessive?
Indicator on head or on table? If it's on the table, you're measuring flex in the column through the head. If on the head, just spindle/ quill/collet play and bar deflecytion. Either way, not too bad.
John Martin
Here is the picture on the measuring set up.
Try this link to see the picture
The runout means you can't bore a perfectly cylindrical hole using the quill feed but you may be able to by locking the quill and raising the table, which is what I have to do. Used machines require a little understanding, no big deal. How is the runout with the quill retracted?
jw
Do not confuse runout with deflection. That a quill moves under a given load doesn't mean it won't run a circle. Running a true circle relates to the bearings, not the quill fit.
Harold
On my 50-year-old mill the lateral deflection increases as the quill extends and its upper and lower supports approach each other. The clamp can remove play from only the lower support.
When I bore a hole with the quill feed the hole tapers slightly inward with depth as the quill deflects away from the cut, and a shaft that fits the mouth of the bore jams a short ways down. If I bore with the quill retracted and tightly clamped, by raising the knee, the shaft fits equally all the way down.
The taper is probably no more than 0.001" / 1" but I wanted that hydraulic gear pump bearing to fit as well as I could get it.
jw
That actually sounds pretty good.
Gunner
deflection...if I really
You got .002 by yanking hard on that setup?
The mill is just fine.
Gunner
You're checking for flex in the structure. Checking for side play only requires a moderate touch.
Bob
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