ToolMaster TM-U3 - Page 22

Twist Drill Grinding Attchment
The twist drill grinding attachment has been designed for grinding twist drills of 3 to 18 mm (1/8” to
9/16”) diameter. The lip angle is always 116° , while the back rake angle is adjustable as required.
TomounttheattachmentK1 (seeFig.2),inserta12mm( 1/2”)springcollet,into the index head.
Insert the drill grinding attachment into the collet making sure that the the retaining pin K2 locates
into the front of the index head.AdjustablestopK5hasaatsurfaceononesideforholdingtwist
drills of 3 to 18mm (1/8” to 11/16”) diameter. The drill is held by hand against stop K5 and the V-
guide K4 attachment swiveled during grinding (Fig.1). After backing off the clamping screw K7, the
stop K6 can be moved forward for small drills (3 to 6mm or 1/8” to 1/4”) by means of clamping
screw K6, sincethatsuchdrillsaredifculttoholdbyhandwhile grinding..
Setup Operations
Release clamps K3 and K4. Hold Index drum T4 against stop by means of the knob and set swivel
arm at 13°. Retighten clamps K3 and K4.
2, Release clamp K2 and set swivel arm at zero on setting scale T2 (resulting In a normally suit-
able rake angle). If larger or smaller rake angles are required, adjust swivel arm accordingly.
Ret-ingten clamp K2.
Release clamp K6 and screw D6. Move index head slide T until its front face roughly coincides
with the front face of cross slide Q. Retighten clamp K6 and screw D6.
3. Only if new grinding wheel should be used :
4. Release clamp K5, move cross slide Q fully to the right using knurled screw S5. Retighten
clamp K5. Release clamp K3(on attachment) and adjust swivel-mounted V-guide K4 until the
scale shows the diameter of the twist drill to be ground. Retighten clamp K3.
Release clamp K1, tighten clamp K2. Move index head bracket on the tubular guide until gauge
plate K8 Is position 6. approx..04”(laterally fo the face of the grining wheel. Align vertical swivel
mount index mark with reference line of tubular guide, then retighten’clamp K1and release clamp
K7
Place test drill on V-guide "K4". Back off clamping screw "K7" and advance stop "K5" until the
cutting face of the drill rests against gauge plate "K8", projecting approx. 0.02”(.5mm) Tighten
clamping screw "K7". When using the adjustable stop in reverse position (for small twist drills of 3
to 6mm (1/8” to 1/4” dia,), tighten clamping screw "K6".