NexStar 127 SLT
Posted 01 February 2013 - 09:38 PM
Posted 02 February 2013 - 10:23 AM
Unfortunately, the price you pay for portability is a lack of stability. I don't own an SLT, but I've heard from many here on the forums that this is an issue.
Moving to a CG-5 would be a HUGE improvement ... BUT it is a LOT heavier and, being an equatorial mount, comes along with all the complications of setup, polar alignment, awkward eyepiece position, etc. If you were going to spend $700 on a CG-5, you would be better off to move to something like a Nexstar SE5 or SE6. You would gain stability without losing the portability and ease of use that you have in the SLT.
But before going to that extreme, there are some things you can do to improve your current mount. First is to go over it and make sure all the bolts are properly tightened. Hanging a weight from the spreader can indeed improve stability. If you use a power tank for 12v power, that is a good thing to hang from it. But a weight in the vicinity of 10-20 pounds is about right. A small cinder block can fill this role too.
When you're observing, use the legs in as short a configuration as is practical. Use a chair or stool to sit on so you can lower the tripod as much as possible.
Anti-vibration pads ( http://tinyurl.com/cd7268d ) definitely work and should reduce vibration settling time by about 50%. At $60, they are not cheap, but compared to the expense and hassle of a heavier mount, they don't seem so bad! And even if you decide to move to another mount, the pads will be useful there too. I employ them all the time regardless of what mount I'm using.
In the end though, the SLT is a very lightweight mount that will never be as stable as a heavier one. You can certainly make some improvements and hopefully make it perform adequately for you. But you'll have to decide at what point you want to trade off stability for portability.
Posted 03 February 2013 - 01:07 PM
Cut a large blunt triangle of plywood to fit the legs as a spreader.Drill the center and put a long eyebolt through the hole with washers and nuts on both sides.The upper washer and nut just to keep the eyebolt from falling out. Now from the loop of the eyebolt run three small chains up to the mount ears where the top of the tripod legs fasten. Loop the chains around the ears or back out the tripod leg bolts ( replace with longer?)and pass the bolt through a loop .
Then by tightening the eyebolt on the bottom of the triangle it should draw the chains taut and hold the triangle's ends firmly against the tripod legs. This should stiffen the tripod .It is as similar to the method used with the larger Nexstar as I can think of given the problem of the "cup" mount of the SLT.
Posted 04 February 2013 - 11:38 AM