Telescope Reviews: Trapped inside the Eufodome!

Sunday was the first non-rainy day we'd had in awhile. So I went out to my observatory to replace the DDW control board. I was having this really minor problem - the board didn't know when the shutter was closed. The shutter actually closed just fine - but the DDW board couldn't detect it properly.

Anyway, I replaced the board, and tested closure of the shutter. I watch the voltage readings returned from the DDW board on my computer scrren as the shutter closes - they drop as expected, finally dropping to zero as the shutter motor stops - just as it should. It works now! A simple fix - 10 minutes, and I'm done!

And then I look up at the shutter. The right side cable has popped out of the lower pulley, and the shutter cable is loose. I look up at the motor, and the cable is tangled on the windlass.

Oh darn.

Problems with the shutter are really regrettable, especially when you are inside the dome and can't open it again. It appeared that I wasn't going anywhere anytime soon.

So I reconnected the cable onto the lower pulley, and called my son. (Luckily for me he was visiting this week.) He brought out a ladder while I attempted to re-open the shutter enough to allow the dome's door to open.

Fortunately I was able to get the shutter open a bit, and get my son and the ladder inside. If I hadn't been able to do that, I would've had to disconnect all of the cabling from the shutter, and lift it by hand. That would've been unfortunate, because then I'd have had to fix all of the cables, instead of just half of them. The windlass, the source of the problem, was 4' over my head. No way of reaching it without a ladder.

We then close the dome, and proceed to attempt to fix the windlass.

I have to say that this is the problem I've dreaded the most. The cabling system to the shutter is not terribly complex. However, if you are not familiar with how it's supposed to work, it is difficult to figure out from the
dome's assembly manual. (The illustrations of the system just aren't very good.) I've always worried that if I had to re-string the cables and re-wind the windlass, I would spend a good long time working this out. (The reality of this did not disappoint, by the way.)

Anyway, we get inside, loosen the cables at the front of the shutter, and I climb the ladder to the windlass. My first big idea was to try to untangle the steel cable on the windlass and re-thread it on without unwinding it. That really didn't work out so well. The cable immediately re-tangled when we tried to operate the shutter. (I didn't really manage to untangle the cable in the first place.) Although this sounds quick and easy, we spent an hour messing with this. (Stubborn and not altogether bright, were we!)

So we figure that we really need to completely untangle and unwind the cable, and then rewind it onto the windlass, stringing it back up through the pulleys. So my son agrees to get up on the ladder and do this, while I apply tension to the cable at the front of the shutter.

Anyway, we rewind the cable onto the windlass and restring it through the pulley system. This doesn't actually take very long. We only have to move the ladder once (this is a 12' tall ladder, and even in a 15' dome, it's crowded with this inside the dome). Geeze, why didn't we do this in the first place!

So we try it out - the dome opens fine. Yay! Next we close the dome. The opening cable becomes VERY loose while we try to close the dome - so loose it jumps out of it's pulley and drops onto the pulley with the closing cable. Also the close cable continuously wants to jump out of it's track on the windlass, and wrap the next loop of cable.

So we figure there's too much slack on the cable, so we attempt to tighten the cables further. We spend a couple of hours on this, and it's pretty close, but still the cable seems to want to hop out of place on the windlass from time to time. By this point, it's dinner time, we're cold, and fairly frustrated. So we pack it in and close the dome go in for supper. You have to watch the windlass to be sure it doesn't mess up - but hey, at least we can open and close the dome now, if not reliably, then at least before it started raining again...

To be continued!