Aaron Sliski's Blog

The Telescope Lives!

Posted on October,27 2017



October 20th 2017, its dark, why is it so dark……. Oh right its 6:30am, who even wakes up at this time, I mean nature is telling me to go back to bed; but we are on a mission. Out the door at seven o’clock am eastern standard time, we get to Dennis’s house, he hops in, we exchange the whole long time no see thing even though we saw each other days previously. Off to the Framingham Bus station, oh? Whats this? There are cones in the middle of the entrance to the bus terminal….. no parking it says. Well shyte (btw that’s pronounced like sheet and shit combined, stress that E sound), plan B, drive to Logan and park there. We come up to the Central parking at Logan and there is a man opening trunks to check for oh, I don’t know, stuff…. We come up to the guy and he basically in one motion opens and closes the trunk, simply because the sign says so.



The past week I had found this super sexy Halliburton ZERO aluminum case at the dump. The guy who dropped it off said it was the pianist of the Cars travel case. Many of the band members of The Cars lived in Lincoln. Anyways this thing was loaded to the gills with can you guess? Shtye…. My arm calculation told me it was atleast 70lbs, 20lbs overweight for checked bags. The other boss thing about this case was that it had rolley wheels. I had never seen a case like this of this age with rolley wheels, my guess is they were custom. Well this puppy was HEAVY, so I take it out of the car at the garage at the airport and smash, one wheel explodes and makes lots of noises. Smash again, and again, three out of the four wheels smashed within the first 45 seconds of using the blasted thing. Ugh, I was not going to carry this heavy case all the way down to the checked bag area, so naturally I just rolled it and pretended it wasn’t making any noises. It was making a lot of noise…… like a lot. So we get down to the checked bag kiosk, and Dennis has a American Airlines credit card that gives him one free checked bag per flight. All is going well, until I roll it over to the scale and the lady starts to take Dennis’s information and she looks at the weight…… it was 86lbs….. She just kinda looked at us and was like uhhh that’s going to be a two hundred dollar charge. So naturally, us cheapskates weren’t going to pay two hundred smackers just to check this bag. I took out all the fragile things and all the metal plates and put them into my backpack. Great I got the bag down to 65lbs, which was only a one hundred dollar charge. We needed the equipment inside the case so we ponied up the money. Ok that drama is over, now to security. I don’t think there has been a single time that we have passed through security without having them open atleast one bag. They pulled both my Dad’s bag and Dennis’s bag, why you ask? Because they were both carrying large hunks of aluminum and they wanted to know what they were. They opened up Dennis’s bag and swabbed the whole thing and found nothing. They get to my dads bag and there is a 12’’ by 6’’ anodized inch thick plate with a bunch of holes in it, he looks at it and asks what its for then just puts it back In the bag.



We get all the way through and sit down for some breakfast, I go to Dunkin with Dennis and get my Birthday Coffee which I hadn’t redeemed yet, if you remember from the last post I got this bad nitro coffee I won’t talk about again but I decided a free Dunkies coffee was the way to go. It was aight ( that’s pronounced “ah” “ite” btw). But I did go back to the same place for a delicious steak egg and cheese and pesto bagel, not one but two. Oh man was that a mistake. It was soooo good at the time but looking back what a mistake. They were large bagels, it was tough to get through the second one….. Dennis was even surprised when he found out that I ate two not one.


We get to Houston, we eat at your typical Crapplebees, Ruby Thursdays, T.G.I Mondays, whatever ribs and burger place for lunch. Since I was still pretty full from the two bagels with steak, and eggs, and cheese, and pesto. I only got some onion rings and buffalo chicken bite things. The question is always…. To beer or not to beer. See I put a value on ordering a beer, is it a fair price, is it what I want, is it the correct size. When you order a draft Guinness its 20oz, so you would think if you get a bottle that is 12oz or 14oz it would be cheaper right? Yea no….. So when looking at the menu at Buffalo Crazy Dangs that’s my joke name for Buffalo Wild wings…. Just bear with me ok… None of the drinks on their menu had prices, so I asked how much a beer was and it took her a minute to give me an answer and after she said it was seven bucks I said Coke please. Ok Lunch is over next is plane to El Passo.


We arrive at El Passo, and I see my amazing Halliburton case come out of the baggage claim and it seems to have more scratches than it did before. I can imagine the bag handlers “oh shit boys we got a heavy one *throws bag* man they don’t make them like the used to”. Nonetheless, the case survived. Then the walk of shame. We had to walk about 250ft to the rental car area, the airport was quiet, right up until the point where I started down the hallway with my case. I would say it’s a mix of an air raid siren and turbine. Not really but it’s really loud and kinda embarrassing. I drag the case up the stairs to the rental car area where we are like lost sheep in a field, which car was ours? About thirty seconds go by looking for our car, this girl appears out of nowhere, and she says can I help you? Then she looks at our reservation looks around then disappears. Then she comes speeding around in this white SUV, she gets out and says sorry it took so long, I grabbed a car with less mileage because you guys had to wait.



Great we are on the road, headed to Alamagordo then to Mayhill to the telescope, but first I was thirsty. So we stop by a gas station 7-12 knock off store and I grab some drinks. Now I didn’t realize that going into a gas station would have such a culture shock but wow. Just WOW. Nintey-Nine Cents gets you this ten gallon hat of a drink, slushy, fountain drink, coffee, whatever you wanted. This thing had to have been over a million ounces. I got my Dad a root beer and myself a Dr Pepper. I walk over towards the register and in the middle of the gas station store is a 8ft cooler with bud lights and similar light beers, in the 24oz cans. I scratched my chin a little, then I look and there is a rack of Male enhancement pills, wake up pills, I shit you not. This place had Budweiser ice cold next to male enhancement wakeup pills, can you imagine if gas stations in Mass had that stuff? It would be, oh you cant do that the kids would steal it, or you can’t sell liquor in a gas station, or they have to charge ten cents for a plastic bag, or you can’t do this or that. It truly is a different world in Texas, but you know somehow everything works down there. But I wondered how they can sell Bud in a gas station, and it was cheap too three 24oz cans was five bucks. Even though bud light is piss water 72oz would get you properly unable to operate a motor vehicle, but who am I to judge. Sadly I don’t have pictures of this event but I hope I painted a good picture for ya.



We finally get to Alamogordo and our ceremonial Walmart run was next. See last time I tried making ribs they were well ummm, the word to describe them would just be, bad. They were just plain bad ok? Gosh not everything I cook is amazing, I will admit it was a hot mess of a meal. But this time I was going to fix that, so we got the usual pizza, burgers, wine, beer, ribs, ham, cheese, eggs, coffee supplies. We also got a couple keeper items like sugar, dry rub for ribs, burgers etc, coffee. Don’t forget the nutty Buddies, I love nutty buddies, see reeses used to sell these things called reese’s sticks, omg they were heaven crunchy, peanutbuttery, flakey goodness. They seemed to have disappeared but nutty buddies are a close second. We also got some fruit and biscuits.


Down to the meat of the story, there is a old game called Fable, everytime you started the game a mysterious voice would say “and so our story begins”. So here we go...



We wasted no time getting started up, breakfast the meal of champions, 9am sharp, we woke up from our slumber of travel confusion. I made raspberry pancakes and bacon with orange juice and coffee. After breakfast we headed to the observatory to tackle installing the mirror and balancing the telescope. THE leading cause of broken telescope mirrors, lenses, optics is dropping them, funny right? Well not so funny, if you are the one doing the dropping. There are many many stories about how mirrors get taken out of scopes and on their way back in they drop something or drop something on them or they get broken somehow.



Observatories often have a coating chamber and lots of equipment to ensure the mirror is unharmed in transit. The telescope even came with this really nice hydraulic table to take the mirror in and out. The problem is the previous observatory is a completely different configuration than what we have. The old observatory had an elevating floor for a old refractor, so you could bring the floor to the mirror instead of using a forklift like we had to use. Anyways the hand powered forklift or Aaron powered forklift was rated for the job and it worked just as planned.



The mirror cell came out with a little encouragement, with a little tappity tap tap of a hammer. In order to make sure the forklift was up to the task we loosened the bolts holding the cell about half an inch, then picked up the weight of the cell to make sure all was dandy. We were comfy with how it looked so we went for it, it worked like a charm.



Once the Cell was lowered, the mirror was picked up put into the cell. The mirror was built before the telescope, when the telescope was ordered it was specified that it was going to use this pre-existing mirror. Now this mirror is kinda funky in that it is hollow, or at least mostly hollow. The other thing that is super duper important is, you want to hold the mirror in such a way that you aren’t applying a pressure to any one point. The load of the mirror has to be uniformly distributed so that to astigmatisms in the mirror. Remember the mirror is ground and polished to a fraction of a wavelength light across the mirror. So imagine if you hold the mirror in a way that it “warps” the glass. So in order to distribute the load uniformly across the whole mirror, there are special pressurized mercury bands around the edges.


And for the bottom mating surface of the mirror there are these pads that are in a triangle formation so that you can tip and tilt the mirror. The mirror was a tight fit into the cell, we had to basically squeeze the mercury bands uniformly in order to get just the right fit. Then the real nail biter raising the mirror back into the telescope. Every pump of the Aaron forklift raised it about two inches or so, and I had to go about seven feet, yea I was there for a while. I felt like Captain Morgan, I was using the foot pump rather than the arm pump, hence the Captain Morgan thing…. Never mind, We also had to roll the forklift about an inch back from where we dropped the cell from. The forklift basically flexed about an inch, so we moved back and inch. After many, many, many, pumps It was pushed up against the telescope. We put all the bolts in and tightened them up, DONE, but it wasn’t over yet. We had another mirror to Install.



The secondary mirror had to be installed, it was much, much easier than the primary mirror, but still a little tense. The secondary, not only expensive, it has some super duper coatings on it, and perfectly clean. Dennis helped me slide the secondary into place and tighten everything down. WhOo *wipes forehead* we were done! Success! Everyone had their fingers and toes, nothing was broken. Nutty buddies were consumed drinks were drunk and huge weight was taken off of our shoulders. The most critical part of the project was done, the fundamental telescope was together. What do you do with telescopes again? Oh right, you look through them.





Now remember the front ring on this telescope has never been used on this telescope before, this is basically half a new optical system. There was one last nail biter we had to find out, was the telescope going to FOCUS! All the solidworks models and tests and reports and documentation we had seems to say that the telescope would come to a focus. I don’t need to remind you about Hubble, but basically the same problem. No matter how much planning you do there could always be one overlooked detail. Well we didn’t do that. We slewed the telescope with a drill so that it was just pointing right over the south wall. We popped in a eyepiece, and Dennis yells “GUYS! Guess what I see?” I was hoping for aliens but sadly no aliens. The bloody thing focuses, all of our hard work all of our preparation came right to that point quite literally. If you think about it this whole 20,000lb monster of a device is just so that you can point a thin film of aluminum around the sky, that’s it. The whole point of a telescope is to point a couple atom thick piece of aluminum around the sky accurately, kind weird right?



First light is such an uplifting momentous event. It marks the beginning of something great, something quite literally as gazing into the heavens. There is a feeling of butterflies in my stomach as I climbed up the 12ft ladder to have my picture taken at first light. This was just the start of an amazing project; I would argue this was the easy part. I may not be a religious man, but there is something inscribed on the pink clubhouse at Stellafane, the birthplace of telescope making. It reads “ The heavens declare the glory of god” every time I read that on the clubhouse I get this goose bump feeling, this feeling that something someone created this heaven, to me the night sky is my heaven. It has driven man for thousands of years, thousands of years or asking the same question why…..


I slept well that night, but it wasn’t over, not even close. The next day 9am sharp breakfast again, this time eggs with ham and cheese. Oh and bacon lots of bacon, I mean you cant go wrong with bacon. The one thing I have learned about these trips, if you put the bacon on the table before the rest of the breakfast is ready; Dennis will eat it all and lose his appetite. You gotta watch the bacon like a hawk. Anywho, It was balance day, now that the mirrors are installed, we need to balance the scope. The problem with the balance is we took a couple hundred pound off the front with our new ring.



We had to attach the blue iron weights to the telescope as well as lead weights that fit into the cell. Seeing, as I am the young one, I get the picking thigs up and putting them down kind of jobs. I had to put those blue weights onto the telescope over my head on a ladder while Dennis screwed them into the telescope. It was not easy but we got the job done. After we had those in, we had to put the lead weights into the cell. But our problem was that the telescope was balanced In the DEC direction basically the tube balance, but the RA Right Ascension, was wayyyy off. So we had to change the RA balance as much as possible and not change the DEC as much as possible.



If you have gotten this far, please stand up and click the video above for further instructions.



Ok now that you have stretched a little, lets back to it. After moving weights around we came to the conclusion it was balanced enough to take the crutch out. The crutch is this giant metal pole that you install when you take the mirror out so you don’t hurt the gears by putting a lot of strain on the system because it will be very very out of balance. After the crutch was off it was time to get things balanced better, we kept shifting weights around until we were happy. Now we could move the telescope around in both RA and DEC, exciting I know. The other critical thing that we spent a lot of time on is meshing the worm gear onto the worm wheel. These gears are super duper duper duper precise, in order to make them that way they have to mesh perfectlyyyy, a little loose? No, I mean perfectly. One of the main reasons why the whole motor plate is so big is because it controls the preload on the worm gear. What you cant see is underneath that whole assembly there is what appears to be something that looks like a triple beam balance. There is a sliding weight that controls a pivot that pushes on a pin, that in turn sets the preload on the worm to the worm wheel. Complicated but pretty simple, but the ratio in which this balance moves the pin is about 100:1. The amount you have to move the arm so that the gear meshes properly vs. improperly is probably thousandths of an inch. This took a while to test and try and fiddle with.



Next up was the motors, we installed the new Dec motor with ease, almost too easy. It was almost like we planned it out. Then we plugged all the motors in and began to configure them. I probably already told you they are three phase motors, but what I haven’t told you is that 3 phase motors take lots of tuning to get them happy. Rather than relying on a physical connection to commutate the direction of the motor we rely on an encoder reading. Let me try to put this simply, a brush type motor has a little section of the motor, where there are, you guessed it, brushes. Those brushes brush up against contacts on the motor, which energize certain coils in the motor in order to make it move in the direction you so choose. In a Brushless motor, there are no brushes, duh…. It relys more on math and a signal from the encoder to pick direction speed and torque. This is not an easy thing to do, so in the software we have to tweak lots of settings so we can get the motor to behave properly. After getting Dan Gray on the phone ( the guy who made the motor controller) he helped us with the initial setup so we could run the telescope around with the hand paddle. And would ya know it all worked! Well kinda…. It mostly worked ok, we had some hiccups but nothing too bad. Everything is hooked up and it just needs more fiddling.



We got a lot done on this trip, we installed the mirrors, got first light, balanced the telescope, installed the second motor, ate nutty buddies. But there Is much much more to do. A home switch location has been picked out and a design has been started. The home switch is a switch that the telescope will home to, hence the name home switch. When the telescope gets lost or loses power or something you can simply home the telescope and then you can figure out where it is because you know where the home switch is. There more work to do on the plates that hold the encoders as well as new bushing made to make the encoder to the motor. The limit switches need to be hooked up and configured, we need to define the “limits” of the telescope, basically where it can go and where it can’t. It is actually a very complicated thing that will have to wait for the next blog post.



Oh and my ribs this time came out pretty well I thought, picture as evidence.



I also took these really nice pictures of these beautiful desert flowers, the bug things, were loving them.



The next morning, I found out that the bugs weren’t the only ones enjoying the flowers…..



Here is the stuff they wont tell you in regular blog posts. This is some bonus content. So In New Mexico there are forest fires, well they must sell like uber sensitive smoke alarms for homes so you don’t die in a forest fire. EVERY SINGLE MEAL, we set off the fire alarm, so one of us has to be a Punkahwallah. Dennis said this word to me and I was perplexed so I asked what it meant. He replied a Punkahwalla is a man who operated this giant fan from a pulley system to fan the king. We had a good chuckle but oh how true it is. I am not kidding, every meal we had to do this. Pizza? Punkahwalla….. Eggs? Punkahwalla……. Burgers? Punkahwalla…… Open the fridge? Punkahwalla…… lol jk. Thanks for reading, this was a long one, so please excuse me grammar and spelling, my eat, shoots and leaves may be a little off.