Aaron Sliski's Blog

Telescope Adventures

Posted on August 11, 2017

I just want to start with a semi-professional paragraph. It is an honor to participate in such a group as this one. Not only is this a rare project for someone my age to be a part of it is a rare project in general. Not many people on this planet can take a telescope of such stature, and disassemble it, move it across the country, find a site, stake out an observatory, design buildings, reassemble the telescope, AND upgrade it to the newest state of the art technology drive system. I feel grateful that I am allowed to travel with my father and Dennis and help with the project. That being said here is now my casual blogpost, you have now been warned. If you are a person who can’t take a joke go no further, because we like to have a good time as well as getting things done.

This trip had a lot of work to do, lots of careful thought and work has gone into preparation for this trip. We had some “simple” goals, get the telescope balanced and install the new motors encoders and electronics. Seems simple right? Well yea no….. To balance the telescope there are many things going on. This telescope originally had a steel front ring where the secondary mirror was mounted. For more modern uses and for what we envisioned this project we didn’t want a cassegrain focus. The cassegrain focus gives you a very small field of view, which limits what you can do with the telescope. Therefore, my father designed a new aluminum front ring, which enables us to have a much shorter focal length with effectively gives us a much larger field of view. BUT, the new ring is roughly 500lbs lighter than the original one, which is a good thing right? Well it is and it isn’t, since we are talking about balance since we took roughly 500lbs of crap off the front of the telescope which is about 16’ long its much lighter on the ass end. On the other axis, we have the Right Ascension (RA) there is a counter weight on one side and the telescope on the other. All of these things have to balance.

The plan for this trip was to also install the mirror so we can balance the telescope. Not only is it a very fragile thing it has to be lifted up 10’. In order to install the mirror we have to unbolt the ass end of the telescope or the “mirror cell”. Another thing, when they were making this telescope it’s like ¾’’ steel was on sale or something, the mirror cell weighs about 1200lbs, you know because it totally needs to be that heavy. I figure Boller and Chivens wanted this telescope to withstand a nuclear blast and still be able to open that night for observing. I mean the amount of overkill and just sheer metal in this thing is astounding. In most cases overbuilt is bad thing because it’s heavy and clunky and so on, but for telescopes it’s the opposite. The just pure craftsmanship on this telescope is mind blowing. How everything is made and the tolerances and the care that went into the design of this beast is just unaffordable today. As John Briggs has said this is the Rolls Royce of telescopes, and well damn he is right.

Back to the story, we were unable to install the mirror because of bad weather. Its monsoon season in New Mexico and I did not really know what that meant until now. It is the Florida coast without the insane humidity. One second it can be sunny and beautiful the next minute it is pouring so much so that it was raining In the observatory almost. I mean I could have sworn I saw a couple of cats and dogs coming from the clouds.

My father designed motor mounts for the new motors and encoders we are installing. He and Dennis machined the pieces and had them anodized so they look perdy.

The reason why we need new motors and encoders is because; well things have changed since 1965. Whoever designed this telescope clearly designed battleships because it was turret technology. There were motors for each speed, so there was a slew motor, set, guide, for each axis, plus these thing called selsyn which are kind of like motors but instead of powering them to move things you can take readings from them to basically use them as an encoder. BUT there were about 6 selsyns and in order to make everything work there were, lions and tigers and bears oh my…… Electric clutches and differentials and gearboxes and mechanical interlocks and micro switches and just brute force technology.

Therefore, we can replace all of those motors and selsyn motors all with one motor and an encoder. These are not just any motors, these are what’s called frameless 3-phase motors. Imagine a motor then you just take out all the parts except the coils and the magnets. Why use frameless motors you ask? It is actually simple, since this telescope is so precise and so accurate you really do not want to mess with the drivetrain. The other motors were super carefully pinned and bolted down with unparalleled precision. We however cannot do what they did; we do not have a milling machine with a 3x5ft table. Not only are these plates with the motors on them super precise they are so fucking heavy it’s not funny., and I don’t use that word lightly. One of the motor plates is about 800 lbs? When we were first taking it apart we were all like wow look at that inch thick aluminum plate isn’t that nice. Then we took one piece off and yea….. it was steel. They were not messing around with this stuff. I can just imagine some guy in a meeting, I got a quote on aluminum plate, and the chief engineer spit out his coffee and said aluminum? We cannot use that communist aluminum we have to use cadmium plated steel. *shakes head*, moving on….

These frameless motors are exactly what we need because there are no bearings, no shaft couplers no clutches no differential gearboxes no nadda. We can mount the motor directly to the worm gear and cut out all that crap. Also when adding motors like I said you need it to be super accurate when lining up shafts, and we just can’t do that easily. By using the super duper duper bearings that already exist, we do not add anything that is sub par to the system and everything is much happier.

My Dad and Dennis made all these pieces for the new motors and it was almost a challenge for the two of them who can make the parts with the tightest tolerances, well I think my dad won the award for that one. To attach the motor to the housings they had to be slid in right? Nahhh that’s too loose, so they had to be pounded in very carefully. All the parts were a perfect fit.

Now here is where we add the Sliski Decicco flair to the project. We had assumed that the Declination axis was the same as the Right Acension axis. But *evil laugh* yea no….

The whole worm assembly was slightly different on the RA, why you ask? We still don’t know. So the parts they made for the Dec were just slightly different. We couldn’t add the Dec Motor on this trip but the new parts have been designed and will be made in the weeks to come. I also asked dennis to pose for these pictures he didnt actually do this. He probably isnt going to like this but I think its really funny. Please dont think we are serious haha. Things are just frustrating sometimes.

The other thing we had assumed was that where wanted to put the motor was on one side of the worm, take a part off the place and put our motor there. Well once again the over engineered thing beat us. The thing we wanted to remove was a precision bearing that located the worm gear onto the worm wheel. And as much as we wanted to mess with is we left it alone because it would be near impossible to move it and still have what we wanted to get done to work. *sigh*. Let’s just say through this process of head scratching there was this moment.

Then it came time to actually put the motor plate onto the telescope.

We did it the same way we took it out in Princeton. We positioned the plate with a cool mini manual forklift near where it had to be. Then With two ratchet straps and one big ratchet strap we just slowly winched it up into place. We would winch up the two small straps a couple times, then use the big strap to take the weight off, then reset the small straps, rinse and repeat. The tough thing was positioning the plate and mounting the plate to a pair of precision bearings on one side. The way this plate works is that the worm gear is put in the middle of the plate and this 4’ plate can pivot from one side, the reason for this is so you can “disengage” the worm gear from the worm wheel for balancing purposes. The worm is never fully disengaged but just enough you can play with the balance of the telescope. Now the thing you don’t want to do is mung up either the worm or the worm wheel. The worms on this telescope *child giggle, they aren’t real worms* are accurate to about a half of an arc second average on the whole 60’’ diameter worm wheel. So on average you can point to one part of the sky and then go to another completely different location and be off on average of .5 arc seconds, now an arc second is 1/3600 of a degree so take half of that and its 1/7200, which is about .000138 of a degree. Yea that’s pretty amazing, so the worm is one of the most important things in the telescope. Now we do know that you can install this plate incorrectly, jam the sucker in there and just keep going. Have you ever seen one of those videos of a cruise ship just mowing through a dock, and you can hear the helmsman *YOU’RE GOOD YOU’RE GOOD YOU’RE GOOD*, pretty much the same thing. If you don’t mesh up the gears then you put a 200-pound gorilla on the bolts to tighten up the plate, what’s the principal again two things can’t be in the same space at the same time. Well yea, you just screwed up your most precious gear, but we knew this.

So we were extra careful and took our time, there was swearing and coffee breaks where we would just stare at the thing and plan our next move. Everything went well until we all high fived *not really cause old people don’t high five* but I totally did a mental high five. We noticed we had forgotten a piece, oh so simple right? Yea this is where the swearing came in. @)#(*$@#()*$ son of a (*$(@#*$@ WHYYYYYYYY *screams at sky*. Ugh these people… So in order to disengage the worm like I was talking about they had this beam balance basically under this whole assembly that you pulled a lever and it would move the plate. BUT the pin that moved the plate up and down sat in this little puck, and guess where the puck goes, yup you guessed it underneath the blankety blank plate. Not only is there a puck but the puck has three screws that screw into the plate so even if you get the puck in there which oh by the way you can’t because there isn’t room, you have to screw it in. So we figured out a solution and all is well.

While we had some setbacks with what we were going to do there was still plenty of work to do. *rant incoming*. So cable management is a big thing in telescopes, as you can imagine there is a lot of crap you put on a telescope, cameras, spectrographs, focusers, filter wheels, widgets, phidgets, no im not making that one up, and other stuff. My father and I spend a lot of time thinking about what is the simplest most elegant, easy to fix, easy to use solution. The best thing you can do is to run an Ethernet cord and a power cord up the mount and that’s it. No USB cables, no serial cables, nothing else. As you can imagine the telescope moves a lot and rotates, and twists. Most horror stories are from cables ripping out because the telescope got into a weird position. Anyways we are careful about wires but Boller and Chivens? They take it to another level. Not only did they have custom cables made with 20 conductors and coax, not one, not two, not three, but four of these run through the mount. I am talking like over an inch thick giant cables that are probably 50 feet long. The thought that went into everything, not only is the cable management and dressing something for textbooks with every wire labeled tied wrapped and proper length, but it’s impossible to put the telescope in such a way that they would get damaged.

These giant cables that run though the mount are wrapped about 3 times around near the base of the telescope, then those wrapped up cables to go these 50 pound weights with pulleys on them so that they keep the proper tension so they can’t be wrapped up improperly. These guys just were not messing around. The uber cable management didn’t stop there. Those weights and pulleys were made specifically for these particular wires, there are two tracks where the wires can go, and it’s so tight that if you put the wrong cable on the wrong side while putting it together, you have to start all over again. There isn’t enough clearance for the cables to slip over to the other track. So you have to make sure the orientation is correct, the right cables, and no kinks or twists. THEN if that wasn’t enough there are cable clamps to hold the wires so that the pulley system works. It just doesn’t end people.

So I knew this, and my dad just snarky just said to me go on run the new cables. I simply said there is no room, And there really wasn’t. So Dennis and I did some poking around and took more covers off to see how they did it. Well I can tell you that whoever did this cable management system had his spidey senses tingling.

The main axis of rotation has a nice big hole in it running the whole length of the telescope. So we slipped the wires down that hole and routed them to the electronics package on the inside of the telescope. It isn’t as elegant as the original but it’s the best we can do without harming the original wires.

The mirror for this telescope is very special, it was designed to be flown in balloons, and the project was called Stratoscope. This mirror was for that project but this never flew.

The mirror is very light because it had to be flown. I am unsure of the actual type of glass but its two giant pucks of glass with some cylinders in the middle, then they took that whole thing and put it in an oven and fused it all together.

Anyways the mirror was filthy so we cleaned it! We didn’t want to harm the aluminum coating so all we used was a spray bottle with water and a drop of soap, and some diligence. Dennis took these cotton pads and dragged them across the surface to collect any dirt then throw that pad away and get a new one. The soap breaks the surface tension of the water so you can clean the mirror.

After cleaning the mirror with soapy water, we just splashed on purified water to rinse it off, and boom a clean mirror, or at least a lot cleaner that it was. We weren’t going to go nuts cleaning it because the coating isn’t in great shape.

After cleaning the mirror, we were going to install it but the forecast was very iffy, so we opened up the roof and had things in place then Dennis said close up. There was a good rain coming our way just on the other side of the hills. So we sat and watched the storm blow through and cleaned up and talked about plans for next time as well as a list of things we needed before we came next time.

What’s a blog without food pictures?

So let me start off with a slight ramble. While I was in Vermont for Stellafane we stopped at this ice cream place and I saw for the first time Nitro Coffee. It looked very interesting, me being a brewer, nitro coffee sounds delicious. A nice cold, creamy head coffee sounds amazing to me. Well when we got to the airport, it was breakfast time so I got a tasty egg steak and cheese bagel thing. Moreover, they had nitro coffee. OH BOY!!! I was excited so the nice barista poured me out a large nitro coffee. My mouth salivated with anticipation. I took one sip and wow what an over hyped piece of crap. I have never had more of a hipster drink in my life, *hmm marketing idea, serve nitro coffee in mason jars*. This large, cold brew, nitro coffee, with half and half, and sugar in the raw. It’s like the Lego movie when he walks into the coffee place and gets a coffee and the depressed hipster college kid behind the counter says that will be five dollars sir, then he screams with enjoyment. Fuck yea I am so cool with my nitro coffee, bro have you ever had nitro coffee? Well this is a nitro coffee is so good, you are just drinking regular coffee, what a pleb (plebian). Also Cold brew is over rated, it’s just not right……

When going on these trips with my father and Dennis, let’s just say they aren’t the best meal planners. Dennis could and would eat ham sandwiches forever if he could. Dennis is a good cook but when he’s not home he doesn’t. My father is a good cook buts when given the opportunity of a menu, I’m sure pizza and wine are the only things on it.

I do my best to try to diversify what we eat. Breakfast is easy, eggs with some sort of toast and bacon or sausage, and since I went with bacon last time, I went with sausage this time. I got some Texas toast, cause you know we are close to Texas so we can’t have just regular toast. In addition we have, juice, coffee, bananas, cherries, and raspberries for breakfast.

Then for lunch I am fine with simple things, so ham and cheese sandwiches is it. For dinner, we usually go with pizza, lasagna, chicken fingers. This time rather than pizza, pizza or pizza, I got pizza, BBQ ribs, mac and cheese, and broccoli. I heard my mom yelling in my ear when there was no green, and broccoli is the least evil green thing there is. However, really there isn’t a huge selection of other things at Walmart. I think we did pretty well.

Our first dinner was at the Western Bar and Café in Cloudcroft.

This fine establishment offered wet drinks and warm food, as well as some spicy chips and salsa to start. I knew what to expect so I went on the safe side with Chicken Alfredo, worst case it’s from package. It was actually pretty good, it was nicely grilled chicken with tomatoes and not overcooked pasta. Moreover, just to throw the extra southern flair to the dish lets add a piece of Texas toast.

The highlight of the meal wasn’t the food or the snappy service, it was my beer. I asked what beers were on draft and she names off the proverbial bud this and miller that. Personally I’d rather drink Cambridge water than to drink anything with the word light in it, have you had Cambridge water? Its gross. Anyway, I asked if there was anything dark, to which she replied we have something called Moose Drool. Not even a millisecond passed and I said I’d have one of those. I mean with a with a name like moose drool how can you go wrong, what if she came back with a whole glass of actual moose drool, I wouldn’t even be mad. So after some time had passed we didn’t get our drinks, after about 10 minutes I joked that maybe they had some sort of cruel device in which they hang delicious veggies or fruit in front of a poor moose, and the moose had a funnel below his mouth which went into a glass. Or perhaps they had some sort of press that would squeeze the moose’s mouth to get all the nice moose juices out. The anticipation and the jokes were all good fun. When the glass arrived yea it rather looked like moose drool, now I am not sure what moose drool actually looks like but maybe the moose drool is just like a garnish. How was the beer you ask? It was meh, but the name, the name was brilliant. It’s always in the name.

Thanks for reading, I know this was a long one. Bonus video I made of dennis using a pair of wirecutters and to his surprise, they were really sharp.