rke[pler
Diamond
- Joined
- Feb 19, 2002
- Location
- Peralta, NM USA
I'm going to try and document the process of pulling the gearbox (speed & feed) from a K&T Model B Autometric - this is the horizontal jig bore with the kinematic ways. I'm writing this after replacing the speed box today but I think I can explain things.
I started from the operator's side. I pulled the switch panel and disconnected the wires that lead to the rapid traverse switch in the feed hand wheel bracket. Remove the whole stop assembly from the left side of the feed wheel, removing the stop bar. Pull the pin on the traverse direction handle, remove the handle. This should allow removal of the feed wheel bracket - be careful as the manual feed is splined into the gearbox.
Remove the 4 screws holding the spindle drive cover, and lift the drive cover. Inside lift the pinion drive sleeve and hold up above the base casting with a plate (or a wrench if you're lazy like me).
Remove the base cover below the feed hand wheel bracket (about 6" diameter). Look inside and to the left and you'll see a copper line leading to the bottom of the oil tube. There should be a valve below the oil tube - you need to use this to regulate the amount of oil sent to the spindle - remember this when reassembling. Unscrew the nut holding the copper line to the oil tube. This will take a while and lead to much cussing. While you're in there you'll also want to remove the oil pickup assembly.
On the back of the machine you need to disconnect the fine speed adjust coming from the gear box to the motor tilt plate. This is best done by turning the control to the minimum speed and reaching in and removing the cotter holding the arm to the plate from the end of the fine speed adjust rod, then unscrewing the dingus from the adjust rod and finally removing the locking nut. You need the fine speed adjust rod clean to removing the gearbox, so after removing all the hardware run it back into the gearbox by turning the fine speed all the way back up.
On the same side you have the rapid traverse input and the spindle input. The spindle input sheave has a center pulley shaft (31653). This needs to be backed out either with the pulley bracket or separately. On mine I tried backing it out but it was jammed so we had to pull the whole bracket. I suspect that the bracket may protrude in too far but if you can pull the center pulley shaft all the way out it might be worth seeing if the gearbox can be pulled with it in place. On mine the shaft was broken at the gearbox end across/around the keyway and so had to be pressed out after backing it out with the 10-24 backing screws.
The rapid traverse assembly has 3 or 4 parts. On mine the motor was coupled to the middle shaft with a bellows coupler not original to the unit (and had the clamping screw heads conveniently stripped). With mine I needed to remove the SHCS holding the intermediate shaft to the input bracket to the body wall then pull the whole mess out of the way so I could remove the 4 SHCS holding the input bracket to the gearbox body (through the holes in the gear), insert some screws to the jacking holes and pull on them (not sure they'd work as jacking screws?) - this part (31807) is sort of strange - the motor drives the intermediate shaft with a gear on the end, the gear drives the inside of 31807 and that turns the pinion inside the gearbox. 31807 et. al. has to be kind of 'worked' out of the gearbox, there's a flat on one side to clear a gear and it will not turn.
That should have the gearbox clear. Pull the 2 taper pins locating the gearbox. Pull some of the SHCS and replace with long 7/16 bolts (or, better yet, make some long rods with 7/16 threaded ends. Remove the rest of the SHCS and get the gearbox loose. I pulled mine out far enough to get a couple of shackles in the top attached with chain to an engine hoist. Find a way to support the bottom of the gearbox, I used a toe jack. Pull the gearbox out about 6-8", enough that the gap between the face and the oil pump is over the bottom face of the hole. Lower the gearbox and tilt the top out of the body cavity, then hoist out. You kind of have to snake it out a bit.
That should be about it. Putting it back in is real fun as you'll have to get the fine speed rod back into it's low clearance hole just before matching the splined shaft for the longitudinal feed. Matching the key on the spindle input is also fun, I finally had to file little ramps on mine (the replacement I made from 4140 to replace the broken one, the original might be too hard to easily file).
At this point I'm putting mine back together, complicated by a previous owner who deleted the fine speed adjust. I'm putting back everything after removing the 2 sheave pulley they put on the spindle input and replacing it with a single 1 1/4" variable companion pulley and putting a Roto-Cone MS-75 on the main motor.
I started from the operator's side. I pulled the switch panel and disconnected the wires that lead to the rapid traverse switch in the feed hand wheel bracket. Remove the whole stop assembly from the left side of the feed wheel, removing the stop bar. Pull the pin on the traverse direction handle, remove the handle. This should allow removal of the feed wheel bracket - be careful as the manual feed is splined into the gearbox.
Remove the 4 screws holding the spindle drive cover, and lift the drive cover. Inside lift the pinion drive sleeve and hold up above the base casting with a plate (or a wrench if you're lazy like me).
Remove the base cover below the feed hand wheel bracket (about 6" diameter). Look inside and to the left and you'll see a copper line leading to the bottom of the oil tube. There should be a valve below the oil tube - you need to use this to regulate the amount of oil sent to the spindle - remember this when reassembling. Unscrew the nut holding the copper line to the oil tube. This will take a while and lead to much cussing. While you're in there you'll also want to remove the oil pickup assembly.
On the back of the machine you need to disconnect the fine speed adjust coming from the gear box to the motor tilt plate. This is best done by turning the control to the minimum speed and reaching in and removing the cotter holding the arm to the plate from the end of the fine speed adjust rod, then unscrewing the dingus from the adjust rod and finally removing the locking nut. You need the fine speed adjust rod clean to removing the gearbox, so after removing all the hardware run it back into the gearbox by turning the fine speed all the way back up.
On the same side you have the rapid traverse input and the spindle input. The spindle input sheave has a center pulley shaft (31653). This needs to be backed out either with the pulley bracket or separately. On mine I tried backing it out but it was jammed so we had to pull the whole bracket. I suspect that the bracket may protrude in too far but if you can pull the center pulley shaft all the way out it might be worth seeing if the gearbox can be pulled with it in place. On mine the shaft was broken at the gearbox end across/around the keyway and so had to be pressed out after backing it out with the 10-24 backing screws.
The rapid traverse assembly has 3 or 4 parts. On mine the motor was coupled to the middle shaft with a bellows coupler not original to the unit (and had the clamping screw heads conveniently stripped). With mine I needed to remove the SHCS holding the intermediate shaft to the input bracket to the body wall then pull the whole mess out of the way so I could remove the 4 SHCS holding the input bracket to the gearbox body (through the holes in the gear), insert some screws to the jacking holes and pull on them (not sure they'd work as jacking screws?) - this part (31807) is sort of strange - the motor drives the intermediate shaft with a gear on the end, the gear drives the inside of 31807 and that turns the pinion inside the gearbox. 31807 et. al. has to be kind of 'worked' out of the gearbox, there's a flat on one side to clear a gear and it will not turn.
That should have the gearbox clear. Pull the 2 taper pins locating the gearbox. Pull some of the SHCS and replace with long 7/16 bolts (or, better yet, make some long rods with 7/16 threaded ends. Remove the rest of the SHCS and get the gearbox loose. I pulled mine out far enough to get a couple of shackles in the top attached with chain to an engine hoist. Find a way to support the bottom of the gearbox, I used a toe jack. Pull the gearbox out about 6-8", enough that the gap between the face and the oil pump is over the bottom face of the hole. Lower the gearbox and tilt the top out of the body cavity, then hoist out. You kind of have to snake it out a bit.
That should be about it. Putting it back in is real fun as you'll have to get the fine speed rod back into it's low clearance hole just before matching the splined shaft for the longitudinal feed. Matching the key on the spindle input is also fun, I finally had to file little ramps on mine (the replacement I made from 4140 to replace the broken one, the original might be too hard to easily file).
At this point I'm putting mine back together, complicated by a previous owner who deleted the fine speed adjust. I'm putting back everything after removing the 2 sheave pulley they put on the spindle input and replacing it with a single 1 1/4" variable companion pulley and putting a Roto-Cone MS-75 on the main motor.
