Minnich A-1-24, Operators & Service Manual

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15
Dowel Drill Manual
USAGE CALCULATION
Usage Calculation
The calculations below are nominal and could vary depending on the hardness of the concrete,
aggregates used and the possibility of bits hitting steel reinforcement.
Whirly Bit, Taper Bit and “H” Thread Bit
(B)Bit=180 holes x 9” (22.86cm)
B=1620” (4114.8cm)
Number of bits needed = (number of holes x hole depth)/1620”
Taper Steel and “H” Thread Steel
(S)Steel=600 holes x 9” (22.86cm)
S=5400” (13716cm)
Number of steels needed = (number of holes x hole depth)/5400”
Example:
Need 50,000 Holes 12” (30.48cm) Deep for the job.
(50,000 x 12)/1620 = 371 Bits
(50,000 x 12)/5400 = 112 Steels
Drill Bit Installation
1. Check to see that the hole through the center of the drill steel is not blocked, if so remove the
object.
2. Clean the tapered end of the drill steel and the inside of the drill bit with a non-oily cleaner,
making sure not to leave any oily residue.
3. Make sure a brass shim is in the drill bit. If not, carefully roll a new one and slide it into the bit
making sure that the ends do not overlap.
4. Put the drill bit on the tapered end of the drill steel and tap it on a firm surface to seat the bit.
Drill Bit Removal
1. Swing latch so that drill steel can be removed
from drill.
2. Pull drill steel out of drill.
3. Using two hammers, place one hammer on
bottom side of bit. Using other hammer, strike
the bit on the topside. Rotate drill steel 1/4 turn
and strike top of bit again. Repeat procedure
until bit comes off.
Bit may pop off of drill steel with some force.