Hi internets. If you, like me, have a JVM-840 and need to say, repair or remove the key that keeps the collet from rotating, or need to remove the spindle for some other reason, here's one way to do it. There is probably a better way...
1. take off the nose cap - ideally with a 2-pin spanner but I hear you can tap it out with a drift and a hammer. But don't do that. Get a spanner. NOTE - REVERSE THREADS!
2. remove the bearing lock ring that is threaded in the same threads as the nose cap. No spanner you have in your box will hit those pin holes so you probably need to tap this one out. If you want to make a tool, like I do, check back and I will post a drawing of what you need.
3. Insert the drawbar spacer and drawbar. If you're paranoid like me you can also thread in a collet and hold some sacrificial thing (I used a partially threaded 1/2" bolt) in the odd chance the whole thing plops out before you get a hand on it.
4. Get a big dead blow hammer and start wailing on the drawbar (hitting it down) while holding the spindle from below. It should start to come out.
5. The spindle will be in your hand with the main bearings.
6. Main bearing adjusting nut is on the spindle held in place with a set screw that mushes a little brass pad in to the spindle's reverse threads. You can loosen the set screw and thread this off. I marked where the nut was clocked so I could get close on the bearing preload on re-assembly.
7. invert the spindle over a sturdy piece of wood and repeatedly whack it so the main bearings come off. Note their orientation and position of the inner and outer spacers.
8. you now have access to that damn set screw that keeps the collet from rotating.
9. Assembly is the reverse of disassembly. I hope.
If anyone has bearing pre-load info, improvements, or other disassembly info please share!
The main bearings are a pair of SKS 7207B
Found this...
First, lock bearing 7207 tight with washer and locknut
Second, loose bearing 7207 locknut
Third, lock bearing 7207 tight with washer and locknut again
Fourth, When locknut is tight then force to turn another 1/4 rev. to
preload bearing 7207
1. take off the nose cap - ideally with a 2-pin spanner but I hear you can tap it out with a drift and a hammer. But don't do that. Get a spanner. NOTE - REVERSE THREADS!
2. remove the bearing lock ring that is threaded in the same threads as the nose cap. No spanner you have in your box will hit those pin holes so you probably need to tap this one out. If you want to make a tool, like I do, check back and I will post a drawing of what you need.
3. Insert the drawbar spacer and drawbar. If you're paranoid like me you can also thread in a collet and hold some sacrificial thing (I used a partially threaded 1/2" bolt) in the odd chance the whole thing plops out before you get a hand on it.
4. Get a big dead blow hammer and start wailing on the drawbar (hitting it down) while holding the spindle from below. It should start to come out.
5. The spindle will be in your hand with the main bearings.
6. Main bearing adjusting nut is on the spindle held in place with a set screw that mushes a little brass pad in to the spindle's reverse threads. You can loosen the set screw and thread this off. I marked where the nut was clocked so I could get close on the bearing preload on re-assembly.
7. invert the spindle over a sturdy piece of wood and repeatedly whack it so the main bearings come off. Note their orientation and position of the inner and outer spacers.
8. you now have access to that damn set screw that keeps the collet from rotating.
9. Assembly is the reverse of disassembly. I hope.
If anyone has bearing pre-load info, improvements, or other disassembly info please share!
The main bearings are a pair of SKS 7207B
Found this...
First, lock bearing 7207 tight with washer and locknut
Second, loose bearing 7207 locknut
Third, lock bearing 7207 tight with washer and locknut again
Fourth, When locknut is tight then force to turn another 1/4 rev. to
preload bearing 7207