torqueman2002
Well-known member
Member dogzbody1 kindly sent me his problem pre-Block 1/4-HP, m-115.19500 grinder for the mere cost of shipping. 
I optimistically told him I'd look at it in a day or two. That was over 6 months ago!
Anyway, after doing some pre-spring cleaning in the garage-shop, I could finally see the top of the work bench a couple of nights ago. Feeling good about that no-small task, I headed into the house at about 10:30 PM.
Then it happened. I caught my boot on the corner of the box with the Block in it. Oh well, time to take it out of the box and just look at it. Yea, right.
The next thing I knew, this is how my clean bench top looked.
Sorry, no before pictures owing to the lateness of the hour and laziness of the Blockhead. Suffice it to say, this is a sweet little, if not heavy (CI) pre-Block!
It may just get a good scrubbing with Simple Green, instead of a lick of paint.
Also, I didn't run it because I vaguely recall dogzbody1 posting it may have stalled and smoked on power-up, which can be a fatal sign. I later confirmed this, when I found his original post. https://www.garagejournal.com/forum/showpost.php?p=6737761&postcount=805
Update: I heard from dogz: 'It smoked at start and did spin after I helped it, ...'
Dogz - congratulations! You definitely saved this guy by giving it that spin! That's grinder CPR.
The early Blocks (pre-Blocks, ++ ?) do not use a start-up relay. Rather, they use a mechanical centrifugal-switch (CS).
Levers on the arbor shaft attached to weights press a low-friction, non-conductive sliding collar that presses against a plate with a set of electrical contacts, which is mounted to the RH end frame. At start, the collar is pressing on the CS plate, closing the contacts and connecting the start winding. Full description, here. --> https://en.wikipedia.org/wiki/Centrifugal_switch
Centrifugal-switch (CS), removed from RH end frame. The brown mounting plate is quite fragile and care needs to be taken when disassembling.
If the RH bearing is stuck to the arbor and the arbor is removed with the CS still attached to the RH end frame, the CS can be damaged/destroyed.
In this case the bearing stayed in the RH end frame, so removing the CS first was not necessary. I cut the white wire from the start-up winding to the CS. The other white wire from the CS goes to a splice with the power cord neutral (white) and the run winding (red) wires, under the grinder cover.
After removing the LH end frame, where the bearing stayed on the LH arbor shaft, I was able to maneuver the winding assembly enough to remove the 2 mounting screws holding the CS to the RH end frame, so the CS was free to be removed with arbor & winding assemblies. As mentioned, it turned out the bearing stayed in the RH end frame.
Here is the arbor assembly, RH view, showing the mechanical weights and lever of the CS.
RH end frame with bearing. Dark looking wet spots are Kroil penetrating oil.
LH bearing/arbor.
Detail of LH bearing mounting hole in the end frame.
Detail of RH bearing mounting hole in the end frame.
Note the ridge on the inside of the bore. This keeps the bearing in the RH end frame when the arbor assembly is removed. Greatly simplifying disassembly. This must have been a manufacturing revision, earlier pre-Blocks did not have this, IIRC.
I haven't detailed the LH bearing removal from the arbor shaft. It has been posted previously. I will look for the link and post it here. https://www.garagejournal.com/forum/showthread.php?p=5722705#post5722705
I optimistically told him I'd look at it in a day or two. That was over 6 months ago!
Anyway, after doing some pre-spring cleaning in the garage-shop, I could finally see the top of the work bench a couple of nights ago. Feeling good about that no-small task, I headed into the house at about 10:30 PM.
Then it happened. I caught my boot on the corner of the box with the Block in it. Oh well, time to take it out of the box and just look at it. Yea, right.
The next thing I knew, this is how my clean bench top looked.
Sorry, no before pictures owing to the lateness of the hour and laziness of the Blockhead. Suffice it to say, this is a sweet little, if not heavy (CI) pre-Block!
It may just get a good scrubbing with Simple Green, instead of a lick of paint.
Also, I didn't run it because I vaguely recall dogzbody1 posting it may have stalled and smoked on power-up, which can be a fatal sign. I later confirmed this, when I found his original post. https://www.garagejournal.com/forum/showpost.php?p=6737761&postcount=805
Update: I heard from dogz: 'It smoked at start and did spin after I helped it, ...'
Dogz - congratulations! You definitely saved this guy by giving it that spin! That's grinder CPR.
The early Blocks (pre-Blocks, ++ ?) do not use a start-up relay. Rather, they use a mechanical centrifugal-switch (CS).
Levers on the arbor shaft attached to weights press a low-friction, non-conductive sliding collar that presses against a plate with a set of electrical contacts, which is mounted to the RH end frame. At start, the collar is pressing on the CS plate, closing the contacts and connecting the start winding. Full description, here. --> https://en.wikipedia.org/wiki/Centrifugal_switch
Centrifugal-switch (CS), removed from RH end frame. The brown mounting plate is quite fragile and care needs to be taken when disassembling.
If the RH bearing is stuck to the arbor and the arbor is removed with the CS still attached to the RH end frame, the CS can be damaged/destroyed.
In this case the bearing stayed in the RH end frame, so removing the CS first was not necessary. I cut the white wire from the start-up winding to the CS. The other white wire from the CS goes to a splice with the power cord neutral (white) and the run winding (red) wires, under the grinder cover.
After removing the LH end frame, where the bearing stayed on the LH arbor shaft, I was able to maneuver the winding assembly enough to remove the 2 mounting screws holding the CS to the RH end frame, so the CS was free to be removed with arbor & winding assemblies. As mentioned, it turned out the bearing stayed in the RH end frame.
Here is the arbor assembly, RH view, showing the mechanical weights and lever of the CS.
RH end frame with bearing. Dark looking wet spots are Kroil penetrating oil.
LH bearing/arbor.
Detail of LH bearing mounting hole in the end frame.
Detail of RH bearing mounting hole in the end frame.
Note the ridge on the inside of the bore. This keeps the bearing in the RH end frame when the arbor assembly is removed. Greatly simplifying disassembly. This must have been a manufacturing revision, earlier pre-Blocks did not have this, IIRC.
I haven't detailed the LH bearing removal from the arbor shaft. It has been posted previously. I will look for the link and post it here. https://www.garagejournal.com/forum/showthread.php?p=5722705#post5722705
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