Re: Pointy-tipped screws may help (was: Re:MeadeStarfinderCollimation Woes)

I concur with Pierce's assessment of drop.io, unfortunately.
I received an endless series of redirect dialog boxes from firefox,
such that I had to kill firefox.
Could the OP point me at the original content please?
Thanks!
Mark

Date: Thu, 30 Apr 2009 17:13:22 -0700
From: jhbowen@No-Spam
To: tac@No-Spam
Subject: Re: [TAC] Pointy-tipped screws may help (was: Re:MeadeStarfinderCollimation Woes)

It wasn't earlier but sure is now.
John

On Thu, Apr 30, 2009 at 4:54 PM, Mark Buxbaum <markbuxbaum@No-Spamm> wrote:

http://drop.io/xy_axis_adjuster# -->
"This drop is empty" ?
Thanks,
Mark
(I am not happy with my secondary holder...)

Date: Thu, 30 Apr 2009 17:36:22 -0400
From: palsing@No-Spam
To: tac@No-Spam

Subject: Re: [TAC] Pointy-tipped screws may help (was: Re:MeadeStarfinderCollimation Woes)

Here is what I did for my Obsession secondary;
 
http://drop.io/xy_axis_adjuster#
 
The guy who invented this, Melvin Shaffer, doesn't seem to be
around anymore. His company made precision microscopes and he thought that the
mechanics of the stock secondary adjuster was from the stone age, so he
developed this modification.
 
This works just great. The secret is the silicon washer, which
won't change dimensions or properties in the heat or the cold. We are talking
about 10 seconds to adjust the secondary, every time, with no tools needed, and
just (1) thumbscrew to turn.
 
I'm not sure how this could be adapted to other types of
secondaries, but there are plenty of smart guys here who could figure it
out.
 
Check it out at GSSP in June, if you like.
 
\Paul A

From: tac-bounces@No-Spam
[mailto:tac-bounces@No-Spam] On Behalf Of Greg
LaFlamme
Sent: Thursday, April 30, 2009 2:10 PM
To: 'TAC
mailing list'
Subject: Re: [TAC] Pointy-tipped screws may help (was:
Re:MeadeStarfinderCollimation Woes)

>In the past, I have purchased nylon bolts and
whittled down the tips myself
 
Its a great idea. I just did the same thing on my 22".
I sanded them to points that mate with divots in the mirror adapter plate. Works
sweet. You might need them to be 1.5" long or so. Not sure if you can find nylon
screws that long. I picked neat idea from Albert. I have a Allen set
screw in one of the three screw holes. The two are Nylon 10-24. I have only
two collimation knobs to turn now. The motions are very direct and
positive.
 
GML

From: tac-bounces@No-Spam
[mailto:tac-bounces@No-Spam] On Behalf Of Paul
Sterngold
Sent: Thursday, April 30, 2009 1:54 PM
To: TAC
mailing list
Subject: Re: [TAC] Pointy-tipped screws may help (was:
Re: MeadeStarfinderCollimation Woes)

In the past, I have purchased nylon bolts and whittled down the tips
myself. These will not mar the contact surface, so you can crank them down more
tightly than you might a metal bolt. However, they are not as rigid, which can
be a consideration for flexure.
 
Cheers,
Paul Sterngold

From: Greg LaFlamme
<greg.laflamme@No-Spam>
To: TAC mailing list
<tac@No-Spam>
Sent: Thursday, April 30, 2009 1:46:12
PM
Subject: Re: [TAC]
Pointy-tipped screws may help (was: Re: Meade StarfinderCollimation
Woes)

> (Greg LaFlamme
may have known of a source, IIRC)
 
Bobs Knobs will make them for you. You just need to
provide the thread size (10-24 for Protostar) and the length you want the bolt
shaft to be. Also specify how much threading is needed on the bolts. Ask
for "conical tips" on the screws.. +/- $30.00
 
http://www.bobsknobs.com/Custom/Custom.htm
 
 
GML
 
 
 

From: tac-bounces@No-Spam
[mailto:tac-bounces@No-Spam] On Behalf Of Marek
Cichanski
Sent: Thursday, April 30, 2009 1:24 PM
To:
tac@No-Spam
Subject: [TAC] Pointy-tipped screws may help
(was: Re: Meade StarfinderCollimation Woes)

Hi Sean,

You may want to check the TAC archives over the last
few months for a thread about having pointy tips on the collimation screws for
the secondary. NOT having this has been a pain for a number of us.

I
don't think I'm the only one who's had a problem similar to the one you've
described - when you turn a collimation screw on the secondary, it doesn't so
much `tip/tilt' the secondary as TURN it. Instead of simply pushing on the back
of the secondary holder, the screw is imparting a torque to the secondary
holder, which then turns around the big central bolt. Rargh.

Major pain
the rear end. My Protostar spider, although otherwise nice, is a big pain this
way.

I think there's been some discussion recently about getting/making
collimation screws with pointy tips. (Greg LaFlamme may have known of a source,
IIRC). I'd really like to do that for my Protostar spider. Then the screw could
only push, not impart a torque.

Of course, some secondaries get
`tipped/tilted' by being PULLED by the adjustment screws, in which case the
pointy thing wouldn't help. But I'll bet most secondaries get
`pushed'.

Hope that made
sense,
Marek

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