Hi Joe: Balancing a SCT can be tricky because of the very short moments of inertia involved. I really can't post a quick method of balancing - but I can say that most commercial telescopes don't have the ability to be completely balanced in every accessorized situation and SCT's are no exception. Even those weights that slide for-and-aft on a rail only address balance in one dimension, and you have to think about balance as a radial function around each particular axis as well. It's a dynamic balance you're after, under any orientation, not just a static balance in a few orientations. And of course whenever you change an accessory the balance will change. It can be a trying procedure, don't be frustrated into a "good enough" mentality. When your telescope gets back, I'll meet you somewhere and we'll give it a look. --- Joe Bauman <bau@desnews.com> wrote:

I want to try again. I have a balance bar that runs along the bottom, and some weights that can be extended out from the tube on their rods. First, can you give me a quick primer on how to balance in dec (it's fairly obvious how to do it in RA). I'm assuming moving the weights up or down on the bars would do it, but I'm having trouble picturing how. More importantly, I feel certain I would have to set up and align on north first and then balance. There's just no room between the tube and the wedge for anything sticking out while it is going through the motions of aligning. But I am hesitant to loosen the settings in RA and DEC after it's set up in order to balance it -- won't that throw off the tracking? Thanks, Joe

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Hi all, Several different folks have asked me what was wrong with my 12" SCT. So here goes. Remember, the tube alone, without tripod and wedge, weighs about 74 pounds, making it impossible for me to hold it up to the wedge and correctly attach the beast. So I came up with a work-around and it was good -- until I screwed up. So for anyone who's interested, here's an explanation, copied from a note I sent to Rob a while back:

Hi Rob,

Thanks for the sympathy. Actually, this mishap wasn"t directly because of the scope's bulk, but it was indirectly. I have worked out a way around having to lift it all the way onto the wedge. I connect the wedge to the tripod and get it aligned and leveled. Then I tilt the assembly backwards, allowing the north leg to stick up in the air and I rest the wedge on top of a folding stepstool that is exactly the right height. The stepstool and the two tripod legs that are on the ground provide a stable and strong platform. It's not too difficult to lift the telescope from the back of my Jeep and onto the wedge. Then I bolt it on, push the whole thing upright, and it's in place. Of course this usually messes up the leveling a little. So I readjust the legs making sure the setup is level, and I go through the normal process of aligning on the North Star, etc.

What happened this particular night was that I was at the Wedge Overlook with Don and a bunch of others. I had finished observing and was getting the telescope off my wedge. It was back in position with two legs on the ground and the wedge sitting on the stepladder. For some reason the wedge was tilted -- probably I did not take enough care to make sure the stepladder was set up properly. I compounded the error by thoughtlessly taking out the bolts the wrong way. I should have left the rear bolt in, though loose, so that it would keep the telescope connected until I slipped it off the wedge. Instead, I took that bolt out, then one of the two remaining front bolts. When I began working on the third bolt I couldn't understand why it wasn't extending from the bottom of the wedge as I loosened it.

Since it was dark and I didn't have a light on, I couldn't see what was going on. But it wasn't hard to reconstructed my little disaster. I kept trying to get the bolt off and when it wouidn't extend I thought I must have stripped the threads somehow. In reality, the telescope was off-balance. As I turned the bolt, the telescope tipped more and more but the head of the bolt remained flush with the wedge. When I reached the end of the bolt, the telescope was free to fall, and it did.

It smashed the power port into the tripod or wedge on the way down. The "lenscap" was on the front and the telescope hit there, denting the cap but not breaking any of the optics.

It's ridiculous and the accident had some bad, expensive consequences. Now I just hope I can get it fixed and working well. Meanwhile, I put my little Celestron 8" back into shape so at least I'll have it for the lunar eclipse.

Yokwe yuk! -- Joe

Oh yes.