MARK 2 Headstock Parts.
Posted: Sun Oct 03, 2021 6:36 pm
I recently acquired some MARK 2 internal headstock parts.
I post this for those curious or have a real need.
First the Quill. The quill shaft is 6 spline.
The bearing is a Fafnir 202KDD5 (5/8" x 35mm x 11mm)
The rubber bumper ring is the same as all SS quills.
The knurled collar appears to be the same as all SS single bearing quills.
The bearing/shaft retention is the same as all SS single bearing quills.
The quill body is shorter (about 6").
The quill stop ring is the same as all SS quills.
The quill stop ring is the same distance from the quill body end as all SS quills(5/8").
The quill shaft length is about 10 3/4".
The quill shaft has the dual tapered flats like all SS quills.(one for collar, one for arbors.
The quill body od is the same as all SS quills (1 3/4").
Then the Drive Sleeve.
The nylon coupler attaches to the quill drive shaft by two screws. I have not yet verified, but I think the screws go into threaded inserts in the nylon body AND into threads in the actual drive shaft.
Only the nylon coupler has the splines(the drive shaft has a larger id that clears the splines).
Although it looks similar to a greenie dust cap, it is a real coupler.
The long shaft is 5/8" od and is long to accommodate both the SPT hub and also the drive pulley.
The bearings are Fafnir 205KDD and 205KDDG(25mm x 52mm x 15mm). One is grooved for an external stop ring.
I assume the cupped set screw mark on the 25mm portion of the end of the shaft is for a 1"(25.4mm) id pulley.
I do not know what the other set screw marks are from, but the inner one appears to be a flat end set screw and the outer one appears to be from a serrated cup(but that part of the shaft is hardened.
I assume the darker section is that exposed over time(slight rust).
Next the quill feed shaft.
A major difference from other SS is the feed shaft lever exists only on the back side(right side in drill press mode).
The shaft has the three indentations like all other SS.
The shaft is 5/8" od on both ends.
I assume the end with the short shaft goes into a bore in the inside of the headstock.
I assume the groove in the pinion gear provides for retention.
The return spring is the same as all other SS.
The depth stop provides a major difference. The scale stops at 3"! So the shorter quill only allows for a shorter feed range.
The depth stop is also very different from other SS.
The stop ring has the stop tab integrated. I assume the tab stops against a tab on the outside of the headstock.
The depth adjustment is also very different. The stop collar is loosened(5/32 flat ended set screw) and is rotated on the shaft. the shaft has a smaller od portion that the set screw bears against when retightened.
Next post - Someone else 'discovered' how to eliminate the dreaded return spring pin jumped out of keyed hole. Clue is in the last pix.
Later some unique to Mark 2 parts.
I post this for those curious or have a real need.
First the Quill. The quill shaft is 6 spline.
The bearing is a Fafnir 202KDD5 (5/8" x 35mm x 11mm)
The rubber bumper ring is the same as all SS quills.
The knurled collar appears to be the same as all SS single bearing quills.
The bearing/shaft retention is the same as all SS single bearing quills.
The quill body is shorter (about 6").
The quill stop ring is the same as all SS quills.
The quill stop ring is the same distance from the quill body end as all SS quills(5/8").
The quill shaft length is about 10 3/4".
The quill shaft has the dual tapered flats like all SS quills.(one for collar, one for arbors.
The quill body od is the same as all SS quills (1 3/4").
Then the Drive Sleeve.
The nylon coupler attaches to the quill drive shaft by two screws. I have not yet verified, but I think the screws go into threaded inserts in the nylon body AND into threads in the actual drive shaft.
Only the nylon coupler has the splines(the drive shaft has a larger id that clears the splines).
Although it looks similar to a greenie dust cap, it is a real coupler.
The long shaft is 5/8" od and is long to accommodate both the SPT hub and also the drive pulley.
The bearings are Fafnir 205KDD and 205KDDG(25mm x 52mm x 15mm). One is grooved for an external stop ring.
I assume the cupped set screw mark on the 25mm portion of the end of the shaft is for a 1"(25.4mm) id pulley.
I do not know what the other set screw marks are from, but the inner one appears to be a flat end set screw and the outer one appears to be from a serrated cup(but that part of the shaft is hardened.
I assume the darker section is that exposed over time(slight rust).
Next the quill feed shaft.
A major difference from other SS is the feed shaft lever exists only on the back side(right side in drill press mode).
The shaft has the three indentations like all other SS.
The shaft is 5/8" od on both ends.
I assume the end with the short shaft goes into a bore in the inside of the headstock.
I assume the groove in the pinion gear provides for retention.
The return spring is the same as all other SS.
The depth stop provides a major difference. The scale stops at 3"! So the shorter quill only allows for a shorter feed range.
The depth stop is also very different from other SS.
The stop ring has the stop tab integrated. I assume the tab stops against a tab on the outside of the headstock.
The depth adjustment is also very different. The stop collar is loosened(5/32 flat ended set screw) and is rotated on the shaft. the shaft has a smaller od portion that the set screw bears against when retightened.
Next post - Someone else 'discovered' how to eliminate the dreaded return spring pin jumped out of keyed hole. Clue is in the last pix.
Later some unique to Mark 2 parts.