RE: Off Topic: NGF-S Focuser
| Subject: | RE: Off Topic: NGF-S Focuser |
| From: | Michael Hart |
| Date: | Tue May 28 14:14:10 1996 |
They say
>>it runs too fast.
>>Regards from Antonio
>>benalmad@lander.es
> I have the JMI unit on order to arrive any day. I was told =
that if
>you use the Meade hand controller as your focus speed control, some =
people
>have complained of the slowest speed being too fast. However if you =
use
>the supplied hadn controller with the focuser there is a very slow =
focusing
>mode.=20
> This info came from Joe at JMI, who evidently hand builds each =
of
>the units (at least the ones with the digital option). Ill let you =
know
>as soon as I get mine.
> Burt =
Whicker
> Tom =
Whicker
Burt, you have concluded correctly, the NGF-S focus speed is NOT too =
fast. In fact, I added altered lithium cells to the JMI control unit =
for -25 F. use at 18 v for FASTER operation. The JMI hand control uses =
a simple circuit that provides braking when you release the button. If =
you plug the NGF-S focus motor into the LX-200, no braking is provided, =
so enertia continues to change focus travel. This is true even if you =
use the Meade electric focuser, so precise focus travel is best done =
with the JMI control unit. Actually, I find any convenience provided by =
having focus control on the Meade hand controller outweighed by the lack =
of precise BRAKING control and having to hold one button while pushing =
another.
I only use the NGF-S along with the Meade electric focus motor for =
projection imaging of planets at f/28 and above where precise focus is =
critical and image shift is annoying. I use the Meade electric focus =
motor along with the JMI hand control unit modified for cold, for =
extreme deep sky work (500,000,000 L.Y.+).
Michael Hart
mhart@netexpress.net
