ETX TECHNICAL TIPS Last updated: 11 March 2004

Flexible Focuser Parts List

Date: 3/9/04, 06:18
From: terence farrell (Terence.Farrell@unilever.com)
I just wanted to share with everyone a parts list for constructing a
flexible focuser with off the shelf parts. No drilling/tapping required.
I have even included 2 part numbers for different size cables; both
colored fluorescent red. Everything listed plus tons more can be found
on www.mcmaster.com

1 Each  6412K11 Steel One-Piece Set-Screw Coupling 1/4" Bore, 1/2" OD, 3/4"
Length, W/O Keyway          $4.44
2 Ft.   9018T31 Fluorescent Vinyl-Coated Wire Rope Galv, 7X7, 1/8"-3/16", 1700 lb
Break Strength, Red $0.36 Ft.   $0.72  
2 Ft.   9018T11 Fluorescent Vinyl-Coated Wire Rope Galv, 7X7, 1/16"-1/8", 480 lb
Break Strength, Red $0.21 Ft.   $0.42  
1 Each  6332K32 Aluminum Control Knob 0.50"Dia X 0.63"H, Knurled Rim, Fits
1/8"Shaft Dia               $3.28  

                                        Merchandise Total:              $8.86  

Including shipping charges anyone can manufacture a flexible focuser for
about $13 that will take a matter of minutes to assemble. My order was
placed today so i'll let you know by Friday how it works.

Regards

T Farrell

The parts arrived yesterday. The hardest part of the assembly was
cutting through the braided wire. Even including that I had a flexible
focuser in a matter of 3 minutes or so. I purchased the ropes in 2
thicknesses but I prefer the 1/8" o.d. myself. For this wire I also used
a small piece of Tygon tubing as a "bushing/reducer" (1/4" o.d.-1/8"
i.d.) to make the fit in the coupling better. The knob works great
because the opening for the wire is already 1/8" and the set screw keeps
it snug. I haven't used a commercially available flexible focuser but I
can't imagine it works any better than this. Even if you want to use the
stock focuser knob you can cut 3 bucks off the cost.

The best part of the McMaster-Carr website is that you have a huge array
of cables and knobs to choose from and you can also get the coupling in
aluminum and stainless also. Shipping was $3.50 so as you can see the
math works in anyones favor plus you can customize the focuser to fit
your particular needs.

Would love to hear from people if they go this route and I can also
provides pics if you like. I'm at work so I can't attach them now.

Thanks,

Terence F

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