Re: Need Help with 15 degree Primary Support System
HA! I Finally get to *answer* a question! Yea!
Alright, here's what we have.
6" Dia Sec Form inside a 20 turn (15 required) 15Deg primary made from 1/4"
copper tubing with 1/4" spaceing between turns. Almost exactly the same as
you, so I believe we can help.
There are 2 solutions we came up with for ours, we believe both will work,
but have only used one.
Solution 1 (the way we did it)
1 make 8 wedge shaped (roughly) pieces of Lexan (we used 1/4" thick, cut
from a 4X8' sheet) at a 15 deg angle with an extion on top to hold the
strike rail. Our strike rail is exactly 1" above the outer turn (20)
directly above it.
2. Cut the notches as requred (we used a verticall mill) if possible cut
them in as big a group as possible, stacked vertically with each plate
offset a little bit (we used 1/8") to make the spiral easier)
3. Drill some holes (4) on the side of the plates near the bottom.
4. We placed the plates in location on the base and secured them to 1X1X10"
pieces of UHMW with nylon bolts and nuts. That way everything is rigidly
mounted and aligned.
5. Wind the coil (we started at the center, it seemed the easiest way).
6. To secure the coil (if required) place a strip of Lexan over the coil on
the plates and cement it in place with epoxy.
this is the best method we could devise, and has worked wonderfully for us
so far. If you have access to a milling machine you've got it made.
Method 2 (should work, but would be a pain to do)
Same thing as above with wood (like you have done).
we made our first attempt using 1.5X3/4X12" pieces of Oak and Hickory (there
is a wood shop next door and we got the scraps from his dumpster)
We abandon this idea after playing hell trying to cut the notches by hand in
the wood. Wood sucks anyway because it will trap moisture and either be very
lossy, or be prone to arcover, either one is bad. Plus it will warp, dent,
defrm, and generally be bad for a long term design. Lexan (or other similar
polycarbinate resin) is great. We love it, it machines well with excellent
tolerances, and has no problems with heat or moisture. Plus it looks cool
(always a plus).
Good luck and I hope we were of some help.
Christopher A. Boden & the whole herd here at.....
The Geek Group
The Geek Shall Inherit the Earth!
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