Tuesday, April 12, 2011

The new gear

I haven't had any new photos to show for some days-I've been busy playing telescope mechanic.

When you want to upgrade equipment like I own, any telescope store will simply tell you that you must start over with new shiny (and expensive) equipment, since your inferior junk is simply not worth upgrading, or worse-is totally incompatible with "real" equipment.

This may be true if you aren't sure which end of a drill you're supposed to hold, but there is no reason you can't sigfinicantly improve the stuff yourself.

My tripod was horribly wobbly-the slightest touch to it or the scope (the kind of thing you would do if you tried to use it, for example,) would take 30 or 40 seconds to dampen itself out. Additionally, it was flexible enough that I could watch it deflect from side to side as the scope moved-well over half an inch. I went to some pretty funny lenghts to stabilize it, but a dog is a dog. A new tripod was needed. Well, firstly, it is true that my EQ mount will not bolt directly onto anything out there as is. So I went looking for the type used with many Alt-azimuth mounts, which have a large flat plate on top. New, something of adequate strength was upwards of $300, and that still would require modification. A local store has a back room full of used equipment, and by chance they had four suitable tripods, all alike. They wanted $40. But one of them had a broken clamp for adjusting the length of the leg-I pointed out that they'd only ever sell that one if they had sold virtually every other tripod in the store first. They gave it to me for ten bucks, and I replaced the clamp with one from a speaker stand. Now on to modding it to take my mount-

This was fairly simple...if my old mount and tripod MUST go together, then just pull the top off of the old tripod and bolt it to the new one. The first night I tried this, I found I had to fiddle with my method a bit, but that was easily fixed. (See that freaky streaky thing two posts back...) And walla! as they say in Yurp...the tripod is now replaced, for a total cost of $10, since the speaker stand was already missing other parts anyway. I can sit on this thing and bounce around with no wiggle or wobble at all. I have an ETX-60 that I'll probably mount on the old tripod.



Ages ago, the motor driving the declination axis died, and in this case it WAS true-an exact replacement simply didn't exist. But a motor from a scope sold by Orion turns out to have the same dimensions and motor speed, just a different set of reduction gears. That sells for $59 all over the internet...too high. At this same shop, some of the "used" stuff is actually new replacement parts that they no longer want to stock, and wouldn't you know, there was that Orion motor. That plus several of the clutches that I mentioned earlier were $15. (The clutch is that shaft with the chrome locknut and brass gear at left.) It did take some fiddling and drilling to adapt the gears from my old broken motor to fit, but in the end, it all worked. I hadn't realized how much I missed having this-a motor on this axis is not needed for following objects across the sky, but it makes it MUCH easier to aim and fine-tune. And yes, for you sharp-eyed viewers-the chrome thing on the left is indeed a Ludwig Hi-Hat clutch, now holding the bushings for the worm gear rather than holding cymbals on a drum set. It's getting harder and harder to decide what brand this thing is.

I wish I had though to take a picture of the old electrics-it was a horrorshow. The handset had two telephone lines plus a battery pack hanging from it, which over the years had suffered from various cable wraps and zip ties and tangles. Each cord ran to a different part of the rig, and things were always a mess.

After working all the rust out of the handset, I replaced all the wiring-the handset now connects to a computer monitor cable, which leads to a junction box that lives under the tripod. That has the cords that run to the motors, as well as a plug to use either a battery pack or an AC adapter.

Here's the finished rig-the handset can be stuck to any tripod leg with velcro, while the main electrical guts are on a box that straps inside one tripod leg. All very tidy, and so much less to trip over. I've added a steel rod from the scope mounting rail to the counterweight bar as well, to fight vibration. There is no detectable movement in any part of the mount or tripod as the scope is slewed through its entire range of motion. Which means two things-it's a much better platform for taking photos, and if there are still tracking issues and star trails, I can't blame anyone or anything but myself.

Today I have taken it all apart again to repaint a lot of the metal bits with Hammerite; this is going to be one very pretty kitty once that is done. Then I'll have to ruin that sleek look with some bands of bright yellow duct tape around the legs. Ugly, but I know I'm going to trip on them constantly if they stay black. Or I might add a red LED to the junction box.

Over the next couple of weeks, I should be able to show whether this makes for better pictures or not...

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