If you read the post on turning 4140, you now know that I'm screwed and need to take my lathe appart to put on a continiouse belt which I already have. First is to remove the chuck. I am a bit hesitant to put it in back gear with the pin in and try to put a wrench on the chuck because when I got the lathe, the back gear and bull gear had broken teath. My thoughts were that, most likely the previous owner chipped the teath using this method to remove a tight chuck.
Is there a proper prefered way of removing a tight chuck or is the back gear jamb meathod the defacto standard.
Assuming that this is a screw chuck, bumping chuck in reverse with a strategicly placed block of wood placed to have a jaw hit it is how I have always got tight screw chucks off.
Hardwood is better for the block.
I've watched maintenence monkeys with a 6 foot pry bar fail to get a screw chuck off when the hardwood block gets it done every time. If worried, take short runs at it. It will come off.
Actually the meathod you mensioned of bumping the lathe with a wood block is in the text but they dont say to bump it electrically. They state to just turn the spindle in back gear by hand. I was un succesful. I sort do the same proceedure to remove stuborn harmonic balancers on cars. Put a wrench on the bolt. Let the wrench wedge up against something and crank the engine. Good to have the radiator out when you do this because the wrench usually flies. But it flies after it breaks the bolt loose.
The split belts are still available from Logan Actuator but I have a continiouse one in stock. I'm finding it to be not to bad to change to the continious belt. It's just time consuming when you havent done it in years. I got the head stock all back together now. I'm just stuck in need of a brass drift to drive out the back pully shaft. I will see if an auto part store has one tomarrow. I'm going to order a spare belt and it will probably be a continiouse one. I dont think I will have too many problems now since I sort of know what I am doing. I will use the rest of the night to take apart my carrage and find out why my fead clutch wont engadege.
But while I'm on the subject of removing chucks. Another problem I constantly have is removing the tailstock center or chuck adapter. I havent seen this discussed anywher in text. Usually this means running the tailstock all the way out and driving the center out with a long rod and hammer. Seems too crude to be right.
We usually used a long piece of steel. Put the lath in back gear and the steel between the chuck jaws, or even close the jaws down tight on the bar. Pull down medium hard on the bar and whack it with a hammer down near the chuck. Usually don't have to hit it all that hard. The combination of force applied with the bar and a sharp shock usually gets them started.
I'm not sure of the logan geometry but on my hercus lathe putting the spindle back in the bearings is prevented by the oiler wicks being spring loaded and pushing out into the space left by the spindle. the method of correcting this is to remove the brass oilers, push the wicks back down out of the way and then to feed a wire in through the oiler hole to spear the wicks and hold them out of the way as you put the spindle back in. it'll drive you troppo trying to get the spindle past the wicks unless you have them held out of the way.
Usually running the tailstock all the way in with the wheel will cause the screw to knock whatever out of the socket. This works for both tanged and untanged tools on my lathe. If your MT tapers have a drawbar thread this might not work, in which case I'd thread a screw or something in the drawbar thread to give the tailstock screw something to push on.
It is! All the tailstocks I've dealt with have had a feedscrew long enough that they pop the taper out when the barrel is screwed all the way in. Doesn't make any difference if the tapers have tangs or not, they pop right out. Might be your screw has been damaged and shortened, something to check. There's usually a couple of pins inserted to keep tanged shanks from twisting, too, something else to check. If your tailstock taper has pimples or rings inside, get the appropriate finish reamer for cleanup.
When I got my old Logan, the taper in the tailstock slipped very easily. I took a half inch wood dowel, slotted the end to hold a doubled over piece of emery cloth, clamped the dowel in the chuck, inserted the emery cloth end into the tailstock and worked it back and forth while running at fairly high speed, squirting in a little WD-40 now and then. I finished by wiping the tailstock out with a shop towel. It was amazing how much better it worked.
Leave it out of back gear, disconnect the change-gear train, set the drive belt tight (to soak up some of the impact) Chuck up a piece of hex stock in the 3-jaw, then use your air or electric impact wrench to break it loose.
The screws wear every time you drive it against a center or drill.... Some morse are longer than others. I have some short versions that won't just pop out and some longer ones I use on the wood lathe only.
Thank you for all the suggestions. Chuck removal is under control. For the center, I will do some measuring and see if I can get a longer center. I also have a dead canter that I purchased from Logan 20 years ago. I never used it so it will be interesting to see if it is longer than the live center and chuck adapter I am currently struggling to swap back and forth.
John R> The screws wear every time you drive it against a center or drill....
I also have a 922 Logan 11", purchased it used about three years ago. It came with a Jacobs #34, 1/2" chuck, mounted on a M2 taper. Don't know if it came from the factory this way or was modified by a former owner, but the small end of the taper has been squared off and drilled and tapped for a 1/4-20 SHCS which is about 3/4" long. This allows the length of the taper to be adjusted so that the chuck and taper pops out when the ram is drawn all the way into the tail stock.
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