Homemade Equatorial Wedge for Meade LX200 classic
The old classic Meade LX200 is a fine telescope, but has that one major drawback of any SCT telescope: A fork mount Alt/Az mount. Whilst this is quick and easy for visual observing, it makes decent astrophotography almost impossible. You need some kind of adjustable wedge to allow the scope to be mounted up at a 50 degree (or whatever your latitude) angle.
Because of the mass of the LX200, this needs to be a sturdy bit of engineering. Most commercial SCT telescope wedges fit into two categories. They are either flimsy and floppy and downright dangerous (i.e. useless) or they are well made and prohibitively expensive.
Of course, a homemade wedge can solve both these problems at once, and have some fun. Read the rest of the article to find out more.
We have a ten inch LX200 10" classic, but it doesn't see a lot of use. Part of the reason for this is that it belongs to a friend, and he doesn't have an observatory to put it in. Therefore we've never fully exploited the LX200 for imaging. Many years ago we erected a pier in my garden to take this scope, and had a welding friend make up a strong wedge out of thick plates of mild steel.
However, whilst the friend was very good at welding, he was less understanding about the finer aspects of polar aligning and keeping telescopes steady, so, although it was strong enough, it wasn't really useable.
As part of my recent astrophotography revival, I decided to dig out the old parts of the wedge and see if I could improve it.
The Altitude adjustment was quite easy - by changing the way the nuts and bolts worked to raise and lower the angle of the telescope plate, I was able to do fine adjustment without the wedge going all floppy.
Azimuth adjustment was another story. It didn't have any to start with. Worse still, it was attached to the pier using 4 bolts - so the first thing I did was remove the two bolts on the north side, and replace them with one bolt for the whole thing to pivot around. I also milled out the slots on the two south bolts to get sufficent play to polar align the scope.
Then I attached two bits of tapped aluminium to the underside, so that two stainless steel bolts can be used to adjust the azimuth of the wedge by very fine amounts. Having fine controls for good polar aligning is very important. Perfect polar alignment is one of the secrets of really good astrophotography results.
Above you can see a couple of pictures of my progress. The next step is to actually get the scope on the mount and see if it can be used to reach north. Once we are confident we can polar align it, the next phase will be learning how to guide the LX200 and then actually trying to image something through it. I am particularly interested in putting my Artemis camera at prime focus and doing Hi res imaging of very bright targets such as planetary nebula and other areas like the core of M31.
Because of the mass of the LX200, this needs to be a sturdy bit of engineering. Most commercial SCT telescope wedges fit into two categories. They are either flimsy and floppy and downright dangerous (i.e. useless) or they are well made and prohibitively expensive.
Of course, a homemade wedge can solve both these problems at once, and have some fun. Read the rest of the article to find out more.
We have a ten inch LX200 10" classic, but it doesn't see a lot of use. Part of the reason for this is that it belongs to a friend, and he doesn't have an observatory to put it in. Therefore we've never fully exploited the LX200 for imaging. Many years ago we erected a pier in my garden to take this scope, and had a welding friend make up a strong wedge out of thick plates of mild steel.
However, whilst the friend was very good at welding, he was less understanding about the finer aspects of polar aligning and keeping telescopes steady, so, although it was strong enough, it wasn't really useable.
As part of my recent astrophotography revival, I decided to dig out the old parts of the wedge and see if I could improve it.
The Altitude adjustment was quite easy - by changing the way the nuts and bolts worked to raise and lower the angle of the telescope plate, I was able to do fine adjustment without the wedge going all floppy.
Azimuth adjustment was another story. It didn't have any to start with. Worse still, it was attached to the pier using 4 bolts - so the first thing I did was remove the two bolts on the north side, and replace them with one bolt for the whole thing to pivot around. I also milled out the slots on the two south bolts to get sufficent play to polar align the scope.
Then I attached two bits of tapped aluminium to the underside, so that two stainless steel bolts can be used to adjust the azimuth of the wedge by very fine amounts. Having fine controls for good polar aligning is very important. Perfect polar alignment is one of the secrets of really good astrophotography results.
Above you can see a couple of pictures of my progress. The next step is to actually get the scope on the mount and see if it can be used to reach north. Once we are confident we can polar align it, the next phase will be learning how to guide the LX200 and then actually trying to image something through it. I am particularly interested in putting my Artemis camera at prime focus and doing Hi res imaging of very bright targets such as planetary nebula and other areas like the core of M31.
