Last updated: 7 October 2004

#1244 Electric Focuser Mod/Info for ETX-105

Subject:	ETX 105 and focuser #1244 misconception
Sent:	Thursday, April 10, 2003 09:16:42
From: (Jason Durrant)
Many people have reported that the focuser #1244 fits the 105 but does
not work.

It's the other way around. It does not fit at all.

Whilst it may look as though it fits, the reaction arm (The moulded part
that slips over the side of the tube).

Pushes the focuser gears apart by deforming the shape of the focuser

That is why it feels such a tight fit.

There is a way of making the focuser fit.

Using a file you can file down the plastic on the inside of the reaction

Whilst it looks ugly, once fitted no-one can tell because it is on the
Jason Durrant

Subject:	RE: #1244 Focusser on ETX 105
Sent:	Friday, April 30, 2004 05:33:25
From:	"Stephen Bird" (

I saw your article on the ETX pages and wondered if you could offer some
advice before I lose patience with the #1244 focusser fitting to my

Having been bought the focusser as a present, so not wanting to ask for
the receipt and go through the pain of returning it, thus upsetting the
kind intentions of the purchaser, I find it an extremely bad fit.

It would seem that the best advice BC&F can give is:

Focus the scope manually on a distant object so that you have a
reasonable mid focus position set up.

Then the brass gear should be fitted to the focus shaft with the boss
towards the main body of the scope and the grub screw located in the
groove in the focus shaft. This then supposedly gives the correct
position for the focus shaft gear.

Next remove the short fixing screw at the rear of the scope, that will
be replaced by the longer screw that will hold the focusser body in
place. Then the body of the focusser unit should be fitted in place on
the scope, meshing the gears carefully. But because the #1244 was
originally designed for the ETX90, but with the ETX105 and afterthought,
the fit of the focusser body to the scope is tight.

It is therefore necessary to first push the focusser body firmly home
and ensure that it is square to the scope body before tightening the
long fixing screw. If it is not fitted firmly and squarely then problems
can occur.

This worries me somewhat as it is a very tight fit and I wondered if you
had any other tips you could offer to ensure a correct fit and trouble
free operation before I embark on the above strategy, such as gear
lubrication and alignment.

Many thanks and regards 

Stephen Bird
From:	"Niall Saunders" (
Hi Stephen,

I am perhaps not the best person to ask. I never actually fitted Nick's
focuser to my ETX-105, all I did was repair and lubricate it. I have had
the focuser on and off my ETX-125 several times (whilst completing the
repair for Nick, and preparing the pictures for Mike's site).

I know (or at least believe) that Nick has re-fitted his by now, and
(presumably) has not had any problems doing so. That is why I am copying
your original message to him, along with this reply from me (and am also
copying it to Mike, as there may yet be a 'definitive' answer
forthcoming from other ETX users).

I do not see any advantage in the first sentence of advice from BC&F.
There is no 'endstop' inside the focuser mechanism, and so it should not
matter where the focuser of the scope is sitting at the start of things.
You just need to be 'mid-way' in order to be able to release the
original focus knob, and to attach the new drive gear.

I agree with their second step - for the ETX-105, the grub screw on the
driven gear must 'bite' into the groove machined on the ETX-105 focus
shaft (see my pictures), and this means that the 'boss' of the driven
gear must face the OTA.

The 'short fixing screw' is the one that is 'above' the focus shaft
(next to the upper viewport).

Before fitting the focuser, I would be making sure that the gear train
inside the focuser has at least SOME lubrication. There was no evidence
of any in Nick's unit (although he may have cleaned the mechanism prior
to sending it to me for repair) and I would definitely not be happy
running the unit without some grease in there. And, by grease I mean use
something like Vaseline Petroleum Jelly, or an equivalentsilicone
grease. Don't go mad, just make sure that there is enough to lightly
coat the various meshed gear surfaces. And make sure that the 'long'
brass drive gear (along which the driven gear 'slides' as the focus
shaft screws in and out of the OTA housing) has enough grease along its
whole length.

What you need to ensure, as the body of the focuser is screwed home, is
that the long brass gear (which you obviously will not be able to see at
this point) remains parallel to the shaft of the focuser - this is
essential in order to keep the driving and driven gears in a constant
mesh. If, as the long fixing screw is tightened, the body settles in a
position that suggest the gears will end up out of parallel alignment,
then you may need to consider some form of 'packing shim' between the
focuser body and the OTA.

It may be easiest to look at the orientation of the two parts as you
slowly tighten the fixing screw, and see where 'first contact' is made.
If the unit is then going to be driven out of alignment by further
tightening, you could just use double-sided (foam) sticky pads (readily
available from any stationary supplier) to 'build up' a shim to take out
any gaps that you notice. The adhesive pads (with their foam inner) will
also give a more positive support to the focuser, as well as allowing
for some lateral movement. And you would not then have to screw the
fixing screw so tight as to cause the distorted alignment in the first

It may not be correct to get the body of the focuser 'true and square'
to the body of the OTA - rather, it is essential to get the two gears to
be parallel, and this you have to estimate, as you cannot see what is
actually happening. The only way to tell is by 'listening', not to the
higher pitched whine of the main motor/gearbox, but the much lower
pitched 'rumble' of the meshed output gears. This should be steady, and
if it is, it should also result in a 'steady whine' for the remainder of
the geartrain, indicating that there is an even and balanced load being
presented by the output gears.

Hope this is of some help. Perhaps Nick, or others, can also contribute
from their experiences.

Niall Saunders
Thanks for the prompt response.

I think BC&F meant mid way to allow for removal of the focus knob and
fitting of the gear, I was just putting the phone call in to writing so
my vague interpetation to a certain extent causing problems there.

The problem with getting the brass focus shaft gear to mesh with the
final drive long brass gear in the focusser housing is simply that the
focusser body is not a sufficient size match to fit to the telescope
body. If the fixing screw is fully tightened, the body of the focusser
distorts, and this causes misalignment of the two brass gears. The
result is they mesh either too tightly or two loosely during a full
cycle and eventually slip.

There was absolutely no lubrication whatsoever on any of the gears, bone
dry! This is easily rectified, but of course as usual Meades standards
of quality control for accessoriesis shown to be lacking.

If I attach the focusser body,without the gear on the focus shaft, this
shows the extent of the profile mismatch. You begin to feel resistance
as the focusser body and scope body meet, before the focus shaft has
entered the focusser housing. With a 5mm gap between the focusser
housing and the back of the scope, considerable distortion and twisting
of the focusser housing has occurred and this would result, if the focus
shaft gear was fitted, in the misalignment and gear slip I described

To be honest, I missed out the part of the BC&F conversation where they
said the #1244 was designed for the ETX90 and not really suitable for
the ETX105. I questioned this as the Meade website clearly labels it as
for BOTH the 90 and the 105, but BC&Fsaid they had fitted it to a
coupleof 105's none-the-less.

So it looks like that to get it to fit, I need to grind the focusser
body down a little until the profile matches better.

Such is life!


Stephen Bird
And more:
I wish I had actually tried out Nick's focuser on my ETX-105 before I
sent it back to him!!

I have attached two pictures, trying to understand what your problem is.
Am I right is guessing that the interference comes when the
yellow-highlighted area on the focuser body starts to meet the OTA (at
the same time as the locating post on the focuser enters the screw hole
on the OTA)? Moreover, does the problem really start to appear as the
'red' area starts to interfere? Further, is there far less effect due to
the 'green' area?

If that is the case then, yes, it may have to be a case of getting out the Dremel and reshaping the red/yellow areas on the casing of the focuser. But, before you do that, I would be sending a letter to BC(&F (or the Meade UK folks) stating that this is what you are going to have to do, because their advertising is misleading. And that you expect your warranty on the focuser to be UN-AFFECTED by your actions. Put he ball in their court, lack of purchase receipts notwithstanding. I recollect that this IS a known issue regarding these focusers. They should either replace your unit with the CORRECT one (at no cost to yourself), or they should allow you to carry out a modification (at no risk to yourself). Speak to them again. Just explain, politely, that 150-worth of focuser should do the job that Meade advertises, and claims, it can. If BC&F themselves state that they have successfully fitted the focuser to "a couple of 105's", them ask them to look out a focuser that they HAVE successfully fitted to one of their 105's, and to send it to you as replacement/exchange for your problematic one. They should not need your proof of purchase for this, in fact if you agreed to cover postage charges (sending your unit to them with a return, postage-paid, jiffy bag enclosed) it shouldn't cost them ANYTHING, and they end up with a happy Meade customer. Good luck, Niall
Hi, yes, you have it in one. First contact is the yellow highlighted
area which does indeed contact the OTA as the locating post begins to
enter the screw fixing hole. On your pictures the yellow area on the
focusser body contacts the OTA higher up than the red mark shown on your
OTA picture. If you look at the focusser body, the recess (indented
area)between the yellow and green highlighted areas looks to be designed
to contact the OTA at the point where the rounded area meets the
straight flat part of the OTA moulding. It would seem that the diameter
of the focusser body moulding in the yellow and green areas is too small
to clear the slightly larger diameter ETX105 OTA body compared to the
ETX90 OTA body. It looks like I will need to grind away the yellow area,
but maybe not the green area as the OTA changes from the round to flat
profile at this point and clearance looks sufficient.

As to warranty, not much hope there. The focusser was a present from an
overseas friend, and regardless, BC&F would rather refund money than
warrant an altered item.

I also have a sneaking suspicion that the locating post is a tight fit
as well, but until I attend to the focusser body it will be hard to
confirm this.

I will proceed with caution and let you know how I got on.


Stephen Bird
If you can take some decent digital pictures, it may help simplify
things for others who are, doubtless, going to be in the same boat.
(Why, oh why, do Meade have such a propensity for shooting themselves in
the foot all the time!!).

And an update:

I have ground it down and it fits and works perfectly now.

In the end, I had to take it down level with the recess / groove that
you can see in your pictures. It needed to be ground both above and
belowthe groove and more at the leading edge in order to get a good fit.
Once done the locating post fastened all the way in and seated nicely
and there was sufficient play to get some adjustment before tightening
the locating post screw up. The gears now mesh perfectly and you get a
nice even note at each speed as the motor runs. Listening to the note as
the motor runs is the only way to check that you have the gears meshed
straight and true. If they are not adjusted correctly the note changes
pitch up and down as it rotates due to the variation in the tightness of
the meshing gears each revolution.

I'll post some digital shots of the mod over the weekend and write down
the process I used.

BC&F called me just now and said good luck!

Many thanks for the help.


Stephen Bird
Congratulations Stephen,

Just a case of 'mind over matter' - you don't mind, and it doesn't


Subject:	Modifying the #1244 Electric Focusser for the ETX105
Sent:	Sunday, May 2, 2004 11:49:04
From:	"Stephen Bird" (
As promised, the process I used to modify the #1244 electric focusser to
fit an ETX105. Please feel free to amend as necessary and post on the
ETX site.

Modifying the #1244 Electric Focusser to fit the ETX105

Meade sell the #1244 Electric Focusser as capable of fitting both the
ETX90 and the ETX105. In actual fact a number of people have found that
the #1244 fits the ETX90 which it was originally designed for, but it
does not easily fit to the ETX105. If you are lucky enough to have an
ETX105 AND have managed to fit the #1244 to it without modification well
done. I was not so lucky, but with help from the ETX site and Niall
Saunders I was able to do a simple modification and get the #1244 to fit
perfectly and adjusted to give trouble free operation.

The problem is quite simple, the OTA of an ETX105 is of a larger
diameter than the ETX90, which is kind of obvious I guess. The #1244 is
designed to fit to the OTA of the ETX90 and if you look at the picture
below you will see that it has a locating post and a rounded inner edge
with a groove in the centre. These align perfectly with the ETX90, not
so the ETX105.

The locating post and inner rounded edgearemeant to fit to the profile of the ETX105 OTA, which you can see below. You can also see the rounded inner edge of the #1244 highlighted with yellow and green. These are the areas that need to be modified to fit the larger diameter of the ETX105 if you want to avoid the risk of distorting the #1244, and worse still the gears slipping and becoming damaged, since in my case and I suspect others, if you do force the unmodified #1244 in to place the gears will not mate squarely. That groove on the inner rounded edge (BETWEEN THE YELLOW AND GREEN HIGHLIGHTED AREAS BELOW) is supposed to sit on the OTA where the tube goes from the rounded to the flat section. It does on the ETX90, but on the ETX105, the larger OTA diameter means it sits just below and consequently does not allow correct mating of the #1244 with the OTA, pushing the #1244 housing out of shape. AT THIS POINT YOU INVALIDATE THE MEADE WARRANTY ON THE #1244, SO YOU NEED TO DECIDE IF YOU WANT AN ELECTRIC FOCUSSER OR A REFUND! I OPTED FOR THE ELECTRIC FOCUSSER!! As an aside, I noticed that the brass final drive gears were not lubricated. I undid the two screws you can see in the abovepicture and found that the #1244 had not seen any lubricant at all! So I applied the smallest amount of lubricant to the two plastic gears and the two brass gears to ensure smooth running. If you do this take carewhen youdisassemble and reassemble the #1244, one of the two internal plastic gears its shaft and the internal brass gear can easily part company with the housing.
focuser focuser
To get the #1244 to fit now requires a leap of faith. You need to grind the yellow and green areas away until the profile fits the ETX105 OTA. I found that you need to take the surface down to the level of the bottom of the groove. A dremel, file or sandpaper will do the job, but tape over the large gear hole aboveand the two smaller motor ventilation holes on the other side of the #1244 first to pevent dust entering the unit. Then grind away until it looks like this.
Finally fit the modified #1244 to the ETX105, you should find thatthe fixing screwnow seats and fastens firmly without distorting the case, or requiring any brute force. In addition you can rotate the #1244 a few degrees either way from the vertical to get some adjustment to mate the gear teeth correctly. You play this by ear (literally) as it is adjusted correctly when the note from the motor and gears during operation is constant throughout a complete cycle. If the note varies in pitch, then the gears are not mated properly and may slip or bind. Here is how mine looked when finished. Just got to fit a longer cord and route it with the dew heater power lead and LPI lead so it doesn't get caught as the scope moves!
focuser focuser focuser
Hope this helps. Acknowledgements to Niall Saunders for some of the pictures and Mike's ETX site for the confidence to take the leap of faith!! Regards Stephen Bird
From:	"Nick Howes" (
Just to chip in (just got back from a long business trip) that Niall's
focuser mod works so well, Meade should make it as standard this way !!

Subject:	Fwd: story continues: focuser #1244
Sent:	Wednesday, October 6, 2004 12:48:56
From:	Audry Buysschaert (
I think now, it's the end of this story.

As you may read in the 3 mails below, Meade europe finally responded to me.

Thus  according to this representative, the #1244 in Europe and also in
the US now really fits both telescope models...aarrgghhh

I have to admit that the explanation why incompatible models were (are?)
still on the market is a little "short".

Dear Mike > maybe you could bring those mails/info availaible at your
page at

Thanks a lot

Yes, this is true for the US - the latest version #1244 indeed fits
both, the 90 and the 105. It is just that there are still some around
that fit the 90 only.
Mario Costantino

-----Ursprngliche Nachricht-----
Gesendet: Dienstag, 5. Oktober 2004 18:24
Betreff: RE: WG: Question about FOKUSSIERMOTOR #1244

thanks for the response.
But it is strange: some of my contacts living in the US and the UK say
that Meade still claims it sells only 1 model (the wrong one) and that
Meade still responds he is not aware of the existence of a model
specifically for the etx105 (in their catalogue they still mention 1
model and say it's suitable for the 90 and for the 105 ...). How does
this come? Very strange

Audry Buysschaert

Dear Mr. Buysschaert,

thank you for your email. This was never an "error" which we needed to
admit. The fact is just that the ETX-90 was sold a long time before the
ETX-105, and the focus motorwas designed and manufactured before the
ETX-105 was even in the head of the engineers. Thus, when the ETX-105
came out, the focus motor had to be changed, but several "older"
versions still were in the market. Therefore, we created two part
numbers to distinguish them. You simply received the wrong model - if
you did not yet do anything to the focuser, please return it to your
dealer and tell him that he should get you part no. 0460201 - and it
will be the right one!
Best regards,
Mario Costantino
APD Marketing & Sales Director
Meade Instruments Europe
Pasinger Strae 90
D-82166 Grfelfing

Date: don 30 sep 2004  07:56:36 Africa/Tunis
Objet: RE: story continues: focuser #1244

Good news if confirmed for new 105 users, but my angle grinder was
cheaper than the 140 UK pounds they charge for a focusser in the UK, so
I'll stick with what I've got. Still, strange how Meade don't seem to
know about this alternate item that they are making! On the other hand,
maybe not, knowing Meade!!


Stephen Bird

"In theory there is no difference between theory and practice, in practice there is."

-----Original Message-----
From: Audry Buysschaert
Sent: 29 September 2004 21:13
Subject: story continues: focuser #1244

I insisted at our Meade importer for Belgium and Luxemburg (POLLUX). I
contacted them by phone .

See below what they answered me (again). It's in french but the
translation is:

"We already replied you that there are two models of the 1244.  One for
the ETX 90 and one for the ETX 105.  You can buy it in any store while
specifying it's the model for the etx 105.  "

Seems interesting for all the new customers interested in this
Now I'm in search of one meade recognised optic shop  in our little
country that has had both products in hand and that could confirm me
this (in our country we only have 1 Meade dealer who's a real astronomy
shop, the other shops are merely optic glasses shops with little
experience in astronomy)


Dbut du message rexpdi :

Date: woe 29 sep 2004  08:25:31 Africa/Tunis
: "Audry Buysschaert"
Objet: Rp : Mise au point #1244: faute de conception

Nous vous avons dj rpondu qu'il y a deux modles de 1244. Un pour
le ETX
90 et un pour le ETX 105.
Vous pouvez l'acheter dans n'importe quel magasin en spcifiant que
c'est le
modle pour l'ETX 105.


P. Ampe
----- Original Message -----
From: "Audry Buysschaert" 
To: ""
Sent: Tuesday, September 28, 2004 8:19 PM
Subject: Re: Mise au point #1244: faute de conception


Suite  l'entretien tlphonique avec quelqu'un de chez vous, je vous
confirme que les magasins que j'ai pu contacter sont incapables de
rpondre  ma question (chose prvisible > ils me renvoient auprs de
vous). Comme promis, j'attends que vous me recontactiez aprs vous
tes entretenu avec le reprsentant Meade sur ce sujet.

Je vous en remercie  l'avance
Audry Buysschaert

Le vrijdag, 24 sep 2004,  08:08 Africa/Tunis, a
crit :

Il existe un 1244 spcialement conu pour ETX 105.
Vous devriez vous adresser au magasin ou vous avez achet votre

Meilleures salutations,

P. Ampe
----- Original Message -----
Subject: Mise au point #1244: faute de conception


Comme Meade devrait le savoir, plusieurs rapports d'utilisateurs
mentionnent une faute flagrante de conception du moteur de mise au
point optionnel portant la rfrence #1244. Ce kit s'installe
parfaitement sur l'ETX90 mais pas sur l'ETX105, modle pour lequel il
est pourtant conu. (problme somme toute logique vu la diffrence de
diamtre entre ces tubes).

Les utilisateurs de ce produit sont alors obligs de bricoler pour
obtenir un ajustement correct du botier moteur. Sans a, ce produit
est tout bonnement inutilisable ! C'est rellement inadmissible. Voir

Les kits #1244 actuellement produits ont-ils entre-temps t mofidis
afin de pouvoir s'installer parfaitement sur un ETX105 ?

Pourriez-vous faire part de ce problme  Meade ?

Merci de me tenir au courant
Meilleures salutations
Subject:	RE: story continues: focuser #1244
Sent:	Thursday, October 7, 2004 00:53:02
From:	 (
So I guess everyone was right, they still only make one model, it has
now been modified to fit both the ETX90 and the ETX 105 (properly), it
has the same Meade part number as the old model, there are still a few
old models on the shelf just to confuse people.

Now in the UK they put the old stock at the front of the shelf to clear
it first, after all they don't want to be left with old items that no
one wants as it erodes the profit margins.

Chances are until the old stock gets cleared, there will still be people
out there with ETX105's who get home to find they have an old model
#1244 and have to return it or grind it!

Such is life!


Stephen Bird

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