Meade 1244 focuser for LX90?

[Karls48]

Last Friday my LX90 8” was delivered. Since then I can admire it inside but no chance to actually use it to view the sky. Clouds and rain and more clouds and more rain.
That beside, I’m trying to have complete wireless control of this telescope (using Bluetooth) and recently Meade 1244 electric focusers started appearing on eBay for around US$50, so I ordered one. I know that I will have to make some kind of adapter to fit it to LX90 and I believe it can be plugged in Auxiliary socked of LX90 without need for APM module. The Envisage software got focusing control on the screen once the telescope is connected to the computer via RS232. So hopefully this should give me telescope and focuser control by using just one RS232 to Bluetooth adaptor.
Anyone got any experience with converting 1244 focuser for use with LX90?

[Karls48]

Well, it looks like that no one tried to use this focuser on LX90. So I will be guinea pig. If it works, it is going to be great value to have remote focusing for about $80. If it doesn’t work as remote focusing, it is still good value to have an electric focuser for this price.

[madwayne]

Hi Karl

I have the 1209 Meade focusser on my 8" and I am very happy with it.

Just one word of caution with the focusser, watch out if you are in GoTo mode and the scope is heading toward Zenith in a big hurry. I also have a 2" diagonal on the back mine and it was a pretty big reach around to the on/off switch Saturday night when I sent it spiralling upward and then the sickening clunk as the diagonal smacked into the top of the tripod. I would guess you can do some serious damage to the gears in your mount as it would continue to drive until the GoTo reaches what it thinks it is looking for.

Mine worked fine for the remainder of Saturday night but I will be very cautious in the future. There is a setting in the hand box somewhere where you can dial in settings so it will not go past a certain point and I will be researching that at some stage. Might be worth you looking at it also if the 1244 reaches the top of your tripod.

Good luck with the focusser, and I for one will be keen to hear back as to how you get on with it.

Clear skies!

[citivolus]

I think I lost track of how many camera/eyepiece strikes I had on the LX-90, so I second setting the max altitude. At the time I had mine it was not adjustable, so I just had to watch out during slews.

[Karls48]

Well, I hope that 1244 focuser (it was originally designed for Meade ETX –90) will not extend past 2”diagonal and therefore clear bottom of the forks. The attachments points would be two screws where APM module is supposed to go. I’m sure that I can build the bracket that will accommodate this focuser. My biggest worry is, if it is going to work from auxiliary port of LX90 without using APM module. If three is significant mirror flop while focusing, I will install Petersons focuser kit and hopefully it will reduce it.

[Karls48]

I should add that 1244 focuser drives the focuser knob, unlike 1209 that moves eyepiece in or out ( I believe).

[Karls48]

I have received the Meade 1244 focuser some time ago but because my mini lathe had burned out the motor I have to wait until I fix the lathe to do any modification to the focuser. Replacement motor for lathe finally arrived and I was able to proceed with modification. I had two small-flanged ball bearings that come from some old printer and silver steel shaft to suit. I drilled hole inline with front hole, in the back of the focuser body to fit one of the bearings. Hole in the front of focuser was too big for the bearing I had so I machined bush for bearing to fit. I also machined small aluminium pulley to fit on the shaft and groove for the belt on LX90 focuser knob. Next thing was to cut wedge from some black plastic to be bolted in place of APM module to allow the focuser to be bolted to it, square to the telescope tube axis. Focuser gear that would be normally attached to ETX 105 focuser shaft was bit loose on the shaft I used and I had to pack it up with some aluminium foil. The gear is fixed to the shaft inside focuser body to drive shaft and pulley.
When I put it all together and connected Autostar to the laptop I was quite surprised that it worked. Now I can focus from my computer running Envisage without adding an other cable to the rat’s nest of cables that surround my telescope. Whole focuser and modification cost me $80, not bad for remote electrics focusing.
Two small problems emerged with this modification. At even at highest focusing speed focusing is quite slow as pulley and the belt on focuser knob adds 2.5 : 1 speed reduction.
Bet slips on occasions, I have to find rubber belt that fits better or fit couple of trust bearings on LX90 focuser.