The only commercial electronic focuser I can find for my C6 is the JMI MFNEX6
which uses buttons for the adjusting and is pricey ($200). I thought about
getting one and then modifying it to be ASCOM compliant. But $200 seems like a
lot for what you get. And it doesât appear to allow you to manually focus
when itâs installed.
https://optcorp.com/products/jm-mfnex6-motofocus-for-celestron-nexstar-5-6-8se-c6-sgt
<https://optcorp.com/products/jm-mfnex6-motofocus-for-celestron-nexstar-5-6-8se-c6-sgt>
Whether I end up using gears or pulleys, Iâd like the mounting mechanism for
the stepper motor to be such that the motor can be swung out of the way so the
scope can be manually focused. Leaving the knob on does constrain the
mechanical options though.
Mike McDonald
mikemac@xxxxxxxxxxx
On Sep 7, 2018, at 11:31 AM, Paul Lind <pulind@xxxxx> wrote:
My camera gives percentage cooler power in the Maxim-DL program screen. I
haven't really measured the actual current. Inside my shop cooling from 80F
(26C) to -15C -> 41C cooling, the readout says 80 percent. I think I got
good cooling outside on a 50F (C) degree night, cooling to -15C with it
reading 60 percent. That's 25C degrees cooling. It seems to indicate that
your cooler will run at about 50 to 60 percent of max when observing. If
it's quite cold outside it will take less. Also, some people like to cool to
-20C or lower. I've been using -15C for my 5 minute exposures.
As far as using a stepper motor to drive a focuser, an important thing is to
allow manual focus by means of some sort of clutch. There are commercial
add-on units that come as either pushbotton control or USB control from a
focusing program. I recall that Al Stiewing mounted one of those on a short
refractor.
----- Original Message -----
From: Michael McDonald <mikemac@xxxxxxxxxxx>
To: az-observing@xxxxxxxxxxxxx
Sent: Thu, 06 Sep 2018 19:05:22 -0400 (EDT)
Subject: [AZ-Observing] Re: Telescope power
Mike McDonald
mikemac@xxxxxxxxxxx
PS For the ATM meeting on the 18th, start thinking of ideas on how to attach
a stepper motor to my Celestron C6 (SCT) for automating the focuser. Thatâs
going to be my next project. If I can decide between gears or pulleys.
