I came up with this one at work today. It arrived suddenly, like a cleansing bolt of inspiration from the realm of the divine. You know what I'm talking about.
Q: What did the alien trout say to the fly fisherman?
A: Take me from your leader.
Genius? I leave it to you, dear reader...but I think you do well to consider the alleged source.
2012-01-31
2012-01-09
Inexpensive Meade 4.5" 114mm F=1000mm F/8.8 DS-2000 Reflector - Disassembly and Focuser
This is a telescope someone gave me as a gift many years ago, purchased from a chain photography store. It's part of the DS-2000 starter kit, which comes in both refractor and reflector form, and has a computerized drive system. But I never got it collimated - or rather, I screwed up the collimation so badly that it saw poorly.
I have decided to clean it up and get it working, if possible. To do that, I'm going to have to take it apart.
There it all is, taken apart. Just do it. Three sheet metal screws hold the plastic end rings to the ends of the tube. Three machine screws hold the focuser to its port in the side of the tube. Three thumbscrews hold the three tines of the diagonal to their slots in the tube.
I read that the focuser is "lubricated" with something that is practically tar, and that this gunk will eventually cause the stripping of the cheap plastic gears. And I don't doubt it - that stuff was like...like...I can't explain it. Tar is a good word. First take the screws out of the square lid covering the gears.
Then you'll see a thin spring metal device that I believe is intended to push the shaft gear into the linear gear of the focuser tube.
Then under that, the gears.
This is about as complicated as the interface between two dirt particles, but there's one thing to watch out for, which is this side-play tensioner or what-have-you. It's a screw pushing a rubber nub into the smooth side of the focuser tube directly opposite the gear drive. You can see the nub just sticking out in the inside. If I lost mine, I'd make one out of a couple layers of bicycle inner tube glued together or something.
Here's the mirror! It's kinda ratty looking, but it makes your face look really big and is therefore fun to play with for a few moments.
I wanted to put a center mark on it. I'd free-styled a red sharpie dot on it when I first wrestled with it, years ago, but I did it when it was still in the tube and - whatever. It was ridiculous. Took me ten minutes to get rid of it with isopropyl alcohol and a series of cotton swabs. So I tried various techniques of marking the center, including this one. Thales theorem rocks, but actually I wanted a ring around the center so a laser collimator would still work later. Some people use those binder reinforcement rings, but WTF - I can do the same thing forty times harder, without spending $1.29. Right? Am I right? So I wanted to mark a circlish thing around the center and hit upon a genius method.
It's metal ruler with a stop, in the form of some vice grip pliers, attached so as to place the end of the ruler, when the stop is at the edge of the mirror, a fixed distance from the center.
In the center of the mirror you can see the faint lines of Pigma Micron 005 I used to delineate a square with chopped corners - an octagon. Then I stuck tape up to the lines and cleaned up the mirror.
Not very clean yet. It's amazing, after getting a nice camera and cleaning some old lenses, how difficult it is to clean optical glass. Some of the flecks are little grease spots that smear around but never want to leave - you almost have to nudge them off the edge of the mirror. Some of them are pits from either bad manufacturing or awful storage conditions (my bad). Some of them are scratches I put there. Some of them either change every time I look at them or are permanent. After about ten minutes of struggling, I got it as clean as I could and reassembled the scope.
I'll try collimating it next.
I have decided to clean it up and get it working, if possible. To do that, I'm going to have to take it apart.
There it all is, taken apart. Just do it. Three sheet metal screws hold the plastic end rings to the ends of the tube. Three machine screws hold the focuser to its port in the side of the tube. Three thumbscrews hold the three tines of the diagonal to their slots in the tube.
I read that the focuser is "lubricated" with something that is practically tar, and that this gunk will eventually cause the stripping of the cheap plastic gears. And I don't doubt it - that stuff was like...like...I can't explain it. Tar is a good word. First take the screws out of the square lid covering the gears.
Then you'll see a thin spring metal device that I believe is intended to push the shaft gear into the linear gear of the focuser tube.
Then under that, the gears.
This is about as complicated as the interface between two dirt particles, but there's one thing to watch out for, which is this side-play tensioner or what-have-you. It's a screw pushing a rubber nub into the smooth side of the focuser tube directly opposite the gear drive. You can see the nub just sticking out in the inside. If I lost mine, I'd make one out of a couple layers of bicycle inner tube glued together or something.
Here's the mirror! It's kinda ratty looking, but it makes your face look really big and is therefore fun to play with for a few moments.
I wanted to put a center mark on it. I'd free-styled a red sharpie dot on it when I first wrestled with it, years ago, but I did it when it was still in the tube and - whatever. It was ridiculous. Took me ten minutes to get rid of it with isopropyl alcohol and a series of cotton swabs. So I tried various techniques of marking the center, including this one. Thales theorem rocks, but actually I wanted a ring around the center so a laser collimator would still work later. Some people use those binder reinforcement rings, but WTF - I can do the same thing forty times harder, without spending $1.29. Right? Am I right? So I wanted to mark a circlish thing around the center and hit upon a genius method.
It's metal ruler with a stop, in the form of some vice grip pliers, attached so as to place the end of the ruler, when the stop is at the edge of the mirror, a fixed distance from the center.
In the center of the mirror you can see the faint lines of Pigma Micron 005 I used to delineate a square with chopped corners - an octagon. Then I stuck tape up to the lines and cleaned up the mirror.
Not very clean yet. It's amazing, after getting a nice camera and cleaning some old lenses, how difficult it is to clean optical glass. Some of the flecks are little grease spots that smear around but never want to leave - you almost have to nudge them off the edge of the mirror. Some of them are pits from either bad manufacturing or awful storage conditions (my bad). Some of them are scratches I put there. Some of them either change every time I look at them or are permanent. After about ten minutes of struggling, I got it as clean as I could and reassembled the scope.
I'll try collimating it next.
2012-01-07
Installing an Acoustic Strap Button
I'm doing this partly to take pictures with my new camera, and partly because I haven't blogged much lately. The one people who read my blog will be pleased, I know - you're intensely welcome and you know I like you alright. But also my project acoustic refret straight-pull conversion needed a strap button, and I don't like the idea of the thing that loops around the headstock. Why? Because I have strong opinions about things I know nothing about.
For guidance, I consulted this article on frets.com - frets.com seems to have stringed instrument mojo about stuff. Pointless aside: I also like the articles at Fret Not Guitar Repair, which has a wonderful name and great information, but the stuff she works on is way out of my class (search for "acoustic" on this blog to see an example of my class of work on my class of instrument). I pretty much drill holes in things and hack them up with cheese graters.
This is where I plan to drill a hole. Somewhere...on there. Too much toward the back and the guitar will want to flip forward, maybe, and too much toward the front and there could be a flying monkey attack. I'm feeling whimsical.
The button will go in the middle. But I've got to check that I won't hit any metal. Does this thing have a bolt on neck? I have to check, I cannot recall.
Then I screwed in the button, taking care lest I drilled the pilot too small and began to strain the wood.
That's ten minutes of work and I feel like a genius, plus my guitar doesn't fall on the floor when I get up, anymore.
For guidance, I consulted this article on frets.com - frets.com seems to have stringed instrument mojo about stuff. Pointless aside: I also like the articles at Fret Not Guitar Repair, which has a wonderful name and great information, but the stuff she works on is way out of my class (search for "acoustic" on this blog to see an example of my class of work on my class of instrument). I pretty much drill holes in things and hack them up with cheese graters.
This is where I plan to drill a hole. Somewhere...on there. Too much toward the back and the guitar will want to flip forward, maybe, and too much toward the front and there could be a flying monkey attack. I'm feeling whimsical.
The button will go in the middle. But I've got to check that I won't hit any metal. Does this thing have a bolt on neck? I have to check, I cannot recall.
I'm no expert but I don't see any bolts here. Let's drill with abandon. I selected a bit that was about the size of the screw core and taped a stop to it so I didn't go shallow or through:
That's ten minutes of work and I feel like a genius, plus my guitar doesn't fall on the floor when I get up, anymore.
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