Making a Modified SASS - Page 2
Now start on the SASS housing, cut a backplate. In this case,
3/16" ABS ripple surface. Cut with a miter saw, final sizing with
milling machine and a file. I use Stainless Steel 10-24 5/8" Oval
Head Phillips machine screws to attach the backplate. The Holes in
the housing for attaching it will thread nicely with a 10-24
tap.
After tapping the holes, screw the bolts from the inside, place
the backplate in place and mark it by turning the screws. Drill and
countersink the backplate - backplate attached.
Remove the backplate. Measure and mark the mic centers on the
SASS housing front faces. The measurements shown will insure that the
support holes end up entirely in the backplate. Because the MKH-20's
are long enough to cross in the back, the centers have to be offset.
Drill a small hole at each mark. Both faces shown below.
In these next steps, use care, the housing is fairly thin plastic
and will flex if you try to go too fast or try to remove too much per
pass. I feed the step drills by hand, and the boring bar with the
power feed, slowly with thin cuts. Assemble the housing support on
the lathe. This consists of a steady rest casting mounted on the
carriage and a 1/2" thick PVC plate bolted to that. The small step
drill shown. Next, using the small hole in the housing face to align
the housing to the drill, clamp the housing to the support using 2
small bar clamps. On the inside of the housing two strips of 1/2" PVC
spread the stress of the clamping and minimize housing flex when
cutting. Make sure the housing is solidly clamped, but use care, the
housing is relatively thin plastic. 2nd picture shows the boring
tower in place in the chuck and the positioning of the housing.
Using the small step drill, from the back, start the front face
hole. Switch to the 2nd step drill, who's largest step is 1".
Carefully adjust the runout of this drill so it will cut a true 1"
hole. Then finish the front hole. Verify the fit with the MKH-20.
There should be only a very slight gap around the mic.
Now, without changing the alignment of the housing, attach the
backplate. The surface you will be cutting is very slanted, use care.
First start the hole in the backplate with the step drills. Don't
allow the largest step to slip into the backplate or it's likely to
catch. Now chuck up the boring tower and boring bar, the tower allows
you to adjust hole diameter. Taking thin cuts, enlarge the back hole
to fit one of the mic supports. The support should just slip through
the backplate.
Verifying the fit of the support and mic. Now repeat the process
with the other side. Be sure and mark each support for which side it
goes on, I scratch a mark near the front end where it will be hidden
when the SASS is together. I also make sure that mark is pointing
toward the center when I finally assemble the SASS.
To assemble, slip a mic into the support, put the combo in
place, slip a spare o-ring over the mic to show where the o-ring is
inside. I use 1-72 x 3/4" oval head screws, these can be obtained
from http://www.smallparts.com . Mark, drill and countersink the
holes in the face. Again with mic and support in place, mark the
support for the three holes, drill, & tap the three holes. My tap
is shorter than the screws, so the screws have to cut their own
thread at the bottom of the hole, I use a spare screw for this before
mounting the support. Mount the support, again with the mic in place
to know alignment.
Completed Modified SASS with foam insert and mics in place.
Handle is the one crown has for the mic, several metal pieces that
adapt to lots of things. I prefer a lighter plastic handle I salvaged
from a Sennheiser suspension which can be seen on my main SASS page.
Note the supports are attached only at the front face, when inserting
the mics, hold the support, not the housing. Insert the mics from the
rear or the two screws on the MKH will cut the o-rings and scratch
inside the tube. The front edge of the mic housing should be adjusted
even with the front face. Make sure support tubes are clean before
inserting mics. Shown is my fabric covered Y cable to Stereo 5 pin
XLR, and short 5 pin cable. What I use for hand held.
