ETX TECHNICAL TIPS Last updated: 31 December 2001

Saga of an ETX-125EC

Sent:	Sunday, December 30, 2001 3:45:30
From:	sherrodc@ipa.net (Clay Sherrod)
To:	kyoung@usinternet.com (Keen Young)
The problem with that back accessory flange is becoming increasingly
common. You CAN fix this by applying several tiny drops of Locktite
along the seam between the flange and the rear plastic cell.  You must
be very careful to not overapply the glue as this will seep possibly
into the rear cell and could cause damage to the flip mirror or the
mirror's turning mechanism.

Unfortunately there is no other fix for this other than gluing, because
you are correct:  it is only a press fit and lately a very poor one at
that.

I think you are making a huge mistake by NOT painting the chips; the
idea is to minimize scattered light that is reflecting from the broken
part of the glass and thus reduce inherent glare (which you WILL have
from chips on the mirror unless they are painted flat black).  You are
greatly reducing the contrast and resolution of the telescope by leaving
them bare.

Glad you got the repairs done!

----------------------------------------
P. Clay Sherrod
sherrodc@ipa.net
Arkansas Sky Observatory
www.arksky.org


----- Original Message -----
From: "Keen Young" (kyoung@usinternet.com)
> Dear Clay and Mike,
>   Well, I've done the initial repairs to my 125. I didn't paint the chips,
> but I repaired some more serious damage that I wasn't aware of when I bought
> the scope. Initial hand aimed tests on the moon and Jupiter were very
> promising. If you'd like to see some pictures of my repair, they're on my
> web site at:
> www.usinternet.com/users/kyoung/scope/
>
> One more question: The screw mounting at the rear of the scope (the one to
> attatch a T-adapter) is loose. It looks to me like this is just press fit
> into the plastic, with a flange inside bent back to secure it. Have you seen
> this before? What should I do, glue it? Try to tighten up the flange?
>
> Thanks again for your time and suggestions,
> Keen
>
>
>
>
> >Best of luck!  Hopefully all will go well to give you at least some
> >immediate service for a while to come.  Please keep us posted on the
> >results!
> >
> >Clay
> >
> >----- Original Message -----
>
>
> > Dear Clay and Mike,
> >    Thanks for the input. I'll try the flat black paint first, and
> > possibly one of the self collimation procedures on the web site before
> > calling Meade for the bad news. I'll let you know how it comes out.
> >
> > Thanks for the speedy replies,
> > Keen
> >
> >
> > >
> > > Hi Keen...
> > > My first reaction is "OUCH!"
> > >
> > > That is a pretty serious injury.  The problem you have is that when ANY one
> > > of the three (primary, secondary or corrector lens) is damaged or replaced,
> > > you must replace all three in a Maksutov telescope since they are all made
> > > as a matching set....just a new primary will not help you.
> > >
> > > Here is what I would suggest....if the largest chip is only 1/2" (I know,
> > > that is STILL large) you can still use the scope fine;  just unscrew the
> > > entire tube from the back end (the black rear cell is attached to the fork
> > > arms and will remain if you firmly grasp the tube and unscrew it carefully).
> > > Carefully slide off the tube making sure you do not bump the long baffle
> > > tube and/or mirror.
> > >
> > > Now once off, merely PAINT the chips FLAT BLACK with a model airplane
> > > paintbrush very carefully.....just the broken/chipped part.  This will allow
> > > reflection of light ONLY from the proper part of the mirror that is not
> > > damaged and your light loss will be absolutely minimum.
> > >
> > > Meade WILL replace all the optics for you at one set price, but I believe it
> > > is fairly costly.  So try this quick fix first....or you can send in here
> > > and I will get it running for you....it is very likely your collimation is
> > > severely off as well if the impact was hard enough to damage the primary.
> > >
> > > I am truly sorry about the damage.....scopes tend to get away from us inthe
> > > dark of night.  Let me know if I can help.
> > >
> > > Clay Sherrod
> > > Dr. P. Clay Sherrod - sherrodc@ipa.net
> > > Arkansas Sky Observatory
> > > www.arksky.org
> > >
> > > ----- Original Message -----
> > >
> > > > Dear Mr. Sherrod,
> > > >
> > > >    I found your service on the Mighty ETX website.
> > > >
> > > >    I have a Meade ETX-125EC that was dropped. The only damage appears
> > > > to be the primary mirror, which sustained 1/4"-1/2" chips all around
> > > > the central hole.
> > > > Is this repairable? Is a new primary mirror even available? At what
> > > > cost?
> > > >
> > > > Thank you for your time,
> > > > Keen Young

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