theropod

The code is just a revamp of the “Blink Without Delay” example provided in the Arduino IDE package. I lied. There are 19 lines, but 3 of those are just ending statement curly brackets. The end user will have to alter the baseline timing number to fit their final drive gear ratio, but it’s clear where this number is and how altering it effects the stepper motor speed. Code below: const int ledPin = 13; // the number of the LED pin int ledState = LOW; // ledState used to set the LED to off or step pulse to off unsigned long previousMillis = 0; // will store last time LED was updated const long interval = 50; // adjust numerical value to suit your needs larger number equals slower pulses void setup() { // set the digital pin as output: pinMode(ledPin, OUTPUT); } void loop() { unsigned long currentMillis = millis(); if (currentMillis - previousMillis >= interval) { // save the last time you blinked the LED previousMillis = currentMillis; // if the LED is off turn it on and vice-versa: if (ledState == LOW) { //if step pin signal is off ledState = HIGH; // turn it on } else { ledState = LOW; // if the step/LED pin is high then turn it off } // set the LED with the ledState of the variable: digitalWrite(ledPin, ledState); // sends the signal depending on the state of the pin. } }

My Arduino based barn door tracker runs on an Arduino sketch with less than 16 lines of code. Don’t fear the reaper! Seriously, the code for driving a single stepper is super simple, but it is designed for the Easy Driver hat just sends a pulse stream. The “secret” to making an Arduino precisely time those pulses is using the “millis” feature instead of the “delay”.

Old fart story warning: My oldest brother was the crew chief on a top fuel dragster (rail) that contended very well here in the USA back in the late 60’s. We talked about the toothed belt driving those huge supercharged engines more than once. His take on the issue that a little too loose was far better than a little too tight. He also said they put a new supercharger belt on with each rebuild of the engine, which was about 6-10 runs. Granted, your mount isn’t cranking >1500 HP, but I would think the same principles are at work. Your old belt looks like it suffered from cord breakdown. A little too tight and those strings in belts give up.

Idea: Use a multi faceted dome-like structure with dozens of iPhone type cameras overlapping each other’s field of view to capture an all-sky panoramic effect. Feed these images into a powerful system that would automatically stitch the individual images into a projectable planetarium-like view, or VR feed. This multiple camera approach could provide higher resolution capture than using single wide angle lenses and delicate exposure balances.

I had one of those active ice chests running on 12v DC. It did work, but not well. If I filled it with already cold stuff, and filled the voids with ice, the active cooling would keep ice far longer than would otherwise be the case. It would freeze a lump in the immediate area around the cooling plate IF it was being fed slightly higher voltage than a resting battery (when it was attached to my running vehicle). That 14ish volts over 12 volts seemed to make a big difference.

I lightly painted 600 grit black wet/dry sandpaper, cut a long tube out with an exacto and steel rule, curled up and ever-so-carefully slid into the final focal wall tube of my C-90 killed 95% of the bright target side-glare, like Jupiter just off the FOV, and a dead black dew shield helped even more (a combo of self stick flocking with flat black paint). Killing those side light reflections somehow improves contrast, or maybe fools my eye, because even my little scope was markedly improved by blacking out as much stray light as possible. How much is to be gained from opening it up, not going to push it. I see no reason the same effect cannot scale up with overall APO diameter. Make ‘em black holes inside. If it’s not a lens/mirror it’s black! These scopes just need to be a little easier to pop apart and back together, for the very reasons outlined in the OP. Getting back together right is absolutely critical.

Called it! Those are some nice sharp moon photos. Just think if the ancients had a scope like yours.

Good work! I assume the collimation came right back to “right”. I imagine the flocking will really make the mak shine, pardon the pun. Side-glare (now removed), when viewing Jupiter for example, will make contrast superb. If I were you I would be prepared for greatly improved views. Some fuzzies won’t be as fuzzy, and something like the GRS (great red spot) will just seem more pure (depending on the skies of course). If you now made a dew shield/light trap about as long as the OTA, made sure the focal tube was flattened and using a good EP your scope would become the little engine that could. I love maks!

To me, the issue with this fault is the component labels are burned away. Unless a schematic can be had that lists which part is what, or a known working example can be used for reference/comparison, it might be next to impossible to make repairs no matter how the traces are fixed.

One method to “fix” burned out, or otherwise ruined, circuit traces is to replace them with single strands of copper wire following the EXACT path. This can be done by following the trace to the next component/pin, carefully soldering from one source to another. Test that the wire is conducting properly, and then use enamel varnish to secure the wire to the board. “Magnet wire” found in all diameters, works very well for this as it already has an insulated coating, and only requires a thin coat of adhesive to secure it to the board. Of course this wire must be bent to match the trace, and be of the same length. Magnet wire will need to have the tips striped of the insulation, but careful scraping with an exacto will do a fine job. Otherwise the wire will not accept soldering. Sometimes a trace can be exposed with an exacto far enough away from the damaged area to avoid a long run, and the new jumper wire soldered to this “fresh” trace point. Careful work can remove the insulation overcoat on the trace and provide a solid point without lifting it from the substrate. All this being said the real issue becomes the downstream components that may have had the magic smoke released when the fault happened. One failed component could have caused a cascade of failures across the board. I’ve fixed surface mount voltage regulators using this hack, but it requires patience and a magnifying work light is a big help.

I’ve considered pouring a concrete observational pad several times, and I have the space for it. I was thinking that such a slab could “float” on a thick layer of coarse sand. If the sand was drained well so that precipitation wouldn’t “stand” under the slab there should be little, if any, heaving with freezing temperatures. My thinking is that such a “floating” slab would absorb vibrations more fully than if the pad were in direct contact with the packed earth underneath. Am I overthinking the issue? Sorry for the thread hijacking.

Consider the Celestron C-90 mak as it has a lifetime warranty. With a little careful flocking and a long dew/stray light shield it can provide some stupid crisp views. I love mine, but a twin of the Hubble would be practically useless around here as perpetual cloudiness has hung around for months!

Oh my, that’s WAY over the top for this tiny little scope project. I think the focuser cost me $12.50 off eBay, and the 60mm objective was free as the binoculars were given to me before I drove over them with my pickup (they fell off the bed I had laid them on in an absent minded moment). This is just a make work project, and maybe practice of I find a larger objective lens in the future. I’ll probably give this away in the end, but I want to test it on my DIY alt/az stepper driven mount. I expect the finished weight with EP to be under a pound, and on that mount should really shine. The FL of the objective is less than 6”, and whatever I settle on won’t be a bank breaker, so a hunk of carbon fiber tube that short might not be prohibitive. I’ll look into it. I wouldn’t even be bothering with this if the objective was junk, but apparently the majority of the cost of the binoculars was tied up in that front glass. Before removing the lens from its tapered housing I jerry-rigged a PVC adapter to hold my 1 1/4” 12.5mm, and the views were awesome. Getting the prisms out of the path really helped a lot. No CA even on a full moon, and Andromeda just fit in the FOV, and crisp as could be.

OK, that’s impressive. Now the search for AL tube begins!

Hi all, I am thinking of turning a wooden form upon which to lay down fiberglass mat to make the main tube for a small refractor. I have a nice 60mm objective salvaged from a set of hopelessly broken binoculars. I bought an inexpensive 1 1/4” rack and pinion focuser with a 2” tube attachment point. Since I know the focal length of the objective wouldn’t turning down a closed grain hardwood mandrel/form work for laying down multiple layers of fiberglass? If I smooth out the mandrel, with appropriate tapering from 60mm to 2”, shouldn’t that work? I’m also thinking a good layer of car wax would allow the fiberglass to release after curing. I could make the form in 3 pieces. Imagine two main halves divided by a slat that could be removed and allow the form to collapse. If I made extended pieces on the form where I could place automotive radiator hose clamps to hold everything together I cannot see why it wouldn’t work. Should I think about inserts to strengthen the objective cell mount point l, and the focuser’s? Should I just go buy some PVC plumbing parts and make that work?