The 1990s saw Meade mass produce thousands of fork-mounted Schmidt-Cassegrains on their infamous LX200 fork.
These instruments, known as the ‘Classic’ LX200s, offered the only truly affordable Go-To system at the time.
Many of these old telescopes can now be found for sale at giveaway prices on internet forums and eBay.
The only problem with Meade’s package is that the drives burn out and cease to work over time, so that the scope loses its Go-To capability.
Optically, the scopes are fine.
But the tiny plastic moving gears and glued-on encoder wheels, which monitor motion and position in the mount, suffer from wear and tear.
The heaviest models, with tubes weighing up to 30kg (66lb) and loaded with CCD cameras, piggyback scopes and dew caps, took their toll on the drives.
When slewing at a maximum 5° per second with spin rates up to 14,000rpm, these didn’t last long.
What’s more, the 1992 vintage motherboards have components that have been obsolete for more than a decade.
With the one-year warranty long expired and the drives on the blink, it will set you back £500 to fix the problem, because you’ll need a re-conditioned motherboard and both sets of motors.
However, there’s another way around this, and that is to re-mount the old scope tube on an equatorial mount.
Many people prefer these to fork mounts.
They enable you to view the polar regions and are far less prone to vibration.
What’s more, the telescope can be precisely balanced in right ascension so that there’s less strain on the drive, and the same mount can be used for more than one telescope.
Weight watchers
To rescue your tube in this manner, you’ll need to find a suitable equatorial mount.
Consider the weight issue carefully.
Compared to an 11-inch Celestron 11 tube, you might not think the 12-inch Meade Classic tube would be heavier, but it is.
A modern Celestron 11 tube weighs around 12.5kg (27.5lb), whereas the Meade 12-inch Classic weighs around 18.5kg (40.7lb). It’s a similar story with the 14-inch models.
The Celestron weighs 20.5kg (45lb) while the Meade weighs 31kg (68lb).
You’ll need an equatorial head that is going to be heavy-duty enough to cope with the weight. We opted for a Sky-Watcher EQ6 Pro.
With one of these, you can resurrect a 12-inch scope and getall the advantages of an equatorial mounting for under £1,000. At 18.5kg (40.7lb), the 12-inch LX200 tube is towards the upper weight limit of what this mount can take, but in practice the EQ6’s drive gears and bearings can easily take a balanced 20kg (44lb) payload.
It’s the dovetail bar and tube interface that are the weak points.
With our new mount ordered, we turned our attention to the old one. LX200 systems aren’t designed to be disassembled but, if you’re determined enough, the tube and fork can be separated.
Fortunately, the older Classic models have a black cradle that connects to the fork tine bearings and simply screws to the tube at the mirror end.
Once three vital screws are removed you just need to prise the tines apart and slide the tube out. Modern LX200 AutoStar GPS models are far trickier to remove.
However, a US amateur called David Illig has a website detailing how to do just this with these models.
There’s no dovetail bar on the Classic LX200, and a simple Vixen-style dovetail plate wouldn’t safely hold the weight. So we asked a local machine shop to make a few components, which cost £20.
The first item was a job for their milling machine: a friction-fit dovetail bar that would slide snugly into the EQ6’s mount head.
This should be a milled slab of aluminium that is such an exact fit that it never tilts sideways out of the channel.
The second item we asked them to make was some steel bands to fit tightly around the tube and bolt onto the dovetail bar.
Find out where the centreof gravity of your tube is, because this will affect how long the dovetail bar is and where the bolt positions for the bands will be.
Get the machine shop to make a right-angle bend at each end of the band and drill two holes so you can screw it to the dovetail.
Welcome home
Once you have these items, fitthe bands around your tube, screw them to the new dovetail bar and slot this into the mount head to secure your Classic tube.
Conversions like this can be carried out on many fork-mounted scopes.
If the tube is heavier than the LX200 at 18.5kg (40.7lb), it would be wise to employ thicker steel bands or use a Homeyer Cradleto avoid the tube flexing too much.
This will ensure your views aren’t blurred while you’re enjoying Go-To views with your resurrected scope.