I've always liked the Meade ETX series of telescopes but could never justify buying one.
A few years ago
Astronomics had the ETX-90RA (pictured at right) on sale for $150; at that price, I just
had to pick one up. The ETX-90RA is the original version of the ETX, and has a single RA drive motor. Dec motion is via a fine control knob, or by
I'd already read the ETX-90RA comments on Mike Weasner's site, and was well aware of the telescope's limitations. After using the telescope for a few weeks, I decided to convert it to a goto telescope, like its big brother, the ETX-90EC (pictured below left).
Mike Weasner's site again came up with the inspiration. In the TechTips section Ralph Encarnacion wrote in with how he mounted his ETX-90RA onto a modified Meade DS-70 telescope mount. By adding a Meade 497 Autostar, he had the equivalent of an ETX-90EC!
Just about any DS or low-end ETX telescope should make a suitable motor and mount donor. You can even buy the DS motor package from Meade and add it to your own mount. During my research into which telescope to buy as a parts donor, I discovered that Amazon was selling the Meade Saturn DS60EC 60mm refractor for $99.
The DS-60EC uses sub-sized 0.967" eyepieces, and is generally not a great scope, but it does come with the DS motors and an electronic handpad.
The DS-60 has an all aluminum alt-az mount that attaches to the tripod legs.
After unpacking and assembling the DS-60, I gave it a quick checkout, looked through it at a distant building...then proceeded to strip it down.
I thought about making a quick conversion (like Ralph's) by adding an aluminum bracket and attaching the ETX OTA to the altitude forks, but I didn't want to give up the original ETX mount. After some examination of the parts and some thinking time, I had a plan on how to adapt the DS motors onto the ETX-RA's mount.
First, I stripped the DS-60. I removed the refractor's tube from its plastic altitude holders, then removed the holders from the altitude fork arms. One holder was easy to remove. The other (on the "West" fork, if this were an equatorial mount), which includes the altitude drive bolt, was much harder to remove. I eventually managed to get the bolt unscrewed from the nut in the plastic holder; it had been glued to the nut using something like Locktite.
Next, I removed the azimuth drive bolt from the fork base. This bolt also had some glue on the threads, but it was relatively easy to unbolt.
The ETX-90RA was disassembled as well. I removed the OTA and set it aside. I took the base apart completely,
including the fork arms. The "East" fork was left untouched and set aside. The "West" fork, which has the Alt/Dec
clutch and fine motion screw and arm, was completely disassembled.