Shoptask 1720 XMTC mill spindle runout?

[Knn]

Hi all, been a while since I visited. I have a Shoptask 1720 XMTC (1991 - 1996) (white) and need to know how to adjust the slop out of the mill spindle lower bearing. There is about .010 on an indicator when pushing one direction. This plays havoc when trying to work close.

Thanks in advance, knn

[Doctor Tsugami]

.010 runout is huge if it doesn't return to zero ,most spindles can be pushed off some,a couple thou at most. To check it I always set up an indicator and push and pull on the spindle make a record of max deflection,with no load against the side of the spindle it should return to zero.after that put your indicator on a serface of the taper and turn the spindle slowly by hand or give it a very slow rpm command 5,10 max and read the run out of the spindle. this should tell you what condition your spindle is in. if everything looks good less then .0005 then maybe you should look at cutting conditions or the table the work sits on

[Knn]

Sorry, I shouldn't have stated "runout". Deflection is what I should have said.
I placed an indicator on the taper, the deflection is .007 each way and does not return. Upon closer inspection I found that there is much more in the upper bearing. I am also a member of the 3-in-1 group and Torch just replaced his spindle and he photo documented the process very well. I just don't know if his machine (new machine) and mine are the same. I believe I was wrong about the age of mine. After more research I believe mine was actually built between '91 and '96.

Thanks again, knn

[smallblock]

Originally Posted by Knn Hi all, been a while since I visited. I have a Shoptask 1720 XMTC (1991 - 1996) (white) and need to know how to adjust the slop out of the mill spindle lower bearing. There is about .010 on an indicator when pushing one direction. This plays havoc when trying to work close. Thanks in advance, knn

Since you are unsure of the year I would guess you bought it used. The mill spindle has 2 tapered roller bearings and they can be adjusted up as long as they are not worn out. You can pry the big drive pulley off with a couple of pry bars or big screwdrivers from below. This will reveal the cap with the pulley roller bearing. On older machines this was unsealed, so it should be cleaned and inspected and then re-packed. By removing the 4 bolts that hold the bearing sleeve on, you can take it off and reveal the spanner nuts that tension the tapered bearings for the spindle. Once you remove the spanner nuts and the chrome seal ring from around the bottom of the quill, you can tap the spindle out of the quill. At that point you can inspect the races and bearings and if they look good, just repack them and put them back in. All these bearings are available from Shoptask, or any bearing supply house.

[Knn]

Thanks for all the help folks, I opened it up this morning. Since I was in it I took it all apart, washed/cleaned everything and repacked with grease. Adjusted out the slack and she runs smooth and quiet. No more deflection. Now if I could only make this two axis chineese vise act like a Kurt.

Thanks again, knn