Specifications

Drilling Mounting Holes for the Printed Circuit Board (PCB)
There are two acceptable methods for
determining where to drill the holes for
mounting the circuit board, the template
method (6.1.1) and the positional method
(6.1.2). Choose the method that works best
for you.
6.1.1 Template Method
Step 1 – Locate the template “drilling
template chassis/5E3” in Appendix D2. Verify that the template drill markings correctly align
with the PC board mounting holes.
Step 2 – Once verified, situate the chassis with the large chrome side facing up and the
printed control panel facing toward you. Place the template onto the chassis. Make sure the
template markings line up with the actual chassis edges.
Step 3 – On the template, locate the four concentric circular drill indicators (photo 6.1a).
Step 4 – With a sharp, hardened tool (center punch is great), make a mark at the center of
these drilling indicators, leaving an identifiable indentation / mark on the chassis (photo 6.1b).
Step 5 – Utilizing the printed measurements from the template, verify that these marks are
correctly situated on the chassis.
Step 6 – Once verified, drill four, 5/32” holes, one hole at each of these marked spots.
Step 7 – Remove any burrs around holes. A deburring tool is very
helpful here. Verify results by lining up mounting holes with PC
board.
Proceed to step 6.2
6.1.2 Positional Method
Step 1 – Situate the chassis with the large chrome side facing up
with the printed control panel facing toward you.
Step 2 - Apply a 1” strip of masking tape across chassis, situated
between the hole for the output transformer secondary and the
mounting hole for the output transformer (photo 6.1c).
Step 3 – Divide the distance between the edges of these two
holes (5/8” is middle) and place a mark on the masking tape
NOTE
Use a new drill bit when drilling this chassis. Go slowly through the steel at a low rotational
speed. A little drop of light oil at each drilling point helps too. These practices will allow the
metal to be cut cleanly with minimal formation of burrs.
A sharp, large nail and hammer make a great make-shift center punch. By placing the nail
on the template mark and firmly tapping the head of the nail with the hammer, the resultant
mark in the metal is great for accurately guiding the drill bit into the chassis.
NOTE
6
Chassis Preparation
6.1
photo 6.1b
photo 6.1a
Some printers may automatically reduce the size of the template when printing. Therefore,
prior to use, always physically measure the printed template to insure proper scale is
maintained.
CAUTION
12 TubeDepot.com
photo 6.1c