I Made A $30 Tracker, Is It Any Good?

25 degrees per minute so if we look at these two boards what we really need to do is move one away from the other at a rate of 0. 25 degrees per minute and that will keep up with the stars now a very common piece of hardware that you can buy is a quarter inch 20 bolt meaning it’s quarter inch in diameter and it has a thread spacing of 20 threads per inch and so that’s we’re going to use to drive our mounts we’re gonna because we can drive that at one revolution per minute it’ll travel one inch every 20 minutes or 0.

05 inches per one minute so we know now okay we have to move 0. 05 inches per minute and we want the boards to move apart from each other at 0. 25 degrees so all we need now is to solve this equation and if you remember some trigonometry you might already know what’s coming here what we do is we use a simple formula and what we need is the hypotenuse and the hypotenuse is going to equal the opposite side of the angle so we know that’s 0. 05 we know the angle is 0.

25 so we can do is divide by sine times the angle so 0. 05 divided by sine times 0. 25 and we get 11. 4 inches or 290 millimeters for those metric folks and so we want the hole for the bolt to be 290 millimeters away from the hinge and then if we uh track at one rotation per minute we’re gonna get perfect stars and yes for this to work we also need to be polar aligned and so that’s the hard part keeping this build on the cheap and so what i did is i’m just using a metal drinking straw on here taped right by the hinge to site polaris but really this is the first thing that i want to improve in my next revision of this mount as the straw to cite polaris is really a bit of a pain to use it’s not that accurate um and it won’t work for the southern hemisphere so i’m on the lookout for for a used finder scope i mean a used polar scope would be even better but something a laser i don’t know but um let me know in the comments if you have any kinds of ideas for an accurate way to polar align this kind of mount a diy mount as cheaply as possible okay anyways now that we know how it works let’s go through the steps of building it and i made a pdf guide you can download from the link in the description for building it i’m going to go through the steps fairly quickly so the guide will be a helpful reference if you if you want to look at that while you’re building one yourself step 1 measure and cut two pieces of 1 by 6 lumber to 12 and 11 16 inches long that’s 322 millimeters for the metric folks if you don’t have a saw home depot or other kind of home improvement hardware stores might uh cut the lumber for you in the store step two put your hinge or hinges if you’re using two along the edges of the boards to mark out where the holes are going to go and then drill some small holes to attach the hinges and then you’re going to screw on the hinge with some small wood screws i’ll just note here i was able to find a six inch long hinge and i’ll put a link in the description of of one online that i found if you can’t find that though two smaller hinges like two three inch hinges would work just as well it should now look like this with two boards connected by the hinge step three now you want to measure out a spot on the bottom board exactly 11.

42 inches or 290 millimeters from the hinge and make it centered uh in terms of top to bottom on the board and mark this and then drill a quarter inch hole there you’re then going to glue and hammer in a quarter inch t-nut into the top of the bottom board and when you glue it or epoxy it be careful not to get any of the glue into the threads of the t-nut it’s just to secure the t-nut to the board a little bit better than you could by just hammering it step four repeat step three except this time put the t-nut in the exact middle of your bottom board so that that would be six and five-sixteenths of an inch or 161 millimeters this is where you will attach the tracker to your tripod step five um i’ve lost the sunlight so i’m indoors now this is how your tracker should look and you can go ahead and screw in the long quarter inch 20 carriage bolt with the round head into the t-nut that is 290 millimeters away from the hinge this is going to be your drive bolt for the tracker and you can test it out if you want step six print out the pattern i’m providing to make your clock wheel you can just print it out on regular printer paper and glue it onto a cd but if you happen to have avery cd labels like i did laying around you can use those makes it even easier step seven we’re now going to secure the clock wheel and a handle which is i’m just using a sort of a little metal brace here i found to the bottom of the drive bolt and i’d recommend using some nuts washers and epoxy and then tighten it all up with some pliers so that it’s all secured very well to the bottom of the bolt and very permanent and once you have all that done you should be able to easily turn the bolt up and down with the handle like this and the clock wheel will rotate around now go ahead and decide where to attach your ball head to the top board and drill a hole so you can attach it with a shorter quarter inch 20 bolt i put my ball head in the center uh lengthwise but towards the top widthwise um i’m putting it towards the top of what will be the north end of the board because i’m going to be mostly using my tracker for milky way which will always be to the south here so i was thinking for balance with lenses that the weight would be more distributed equally this way if the lens is coming out uh towards the south i’m not sure if this really makes any difference but that was the the thought behind it step nine measure the center point of your boards at the end of it where the clock wheel is and drill out two little holes for the screw eyes and you can screw those in by hand and then you can attach a rubber band around these to give a little tension to the system and turn the screw eyes this way so you can look down and see your how your clock wheel is pointed right through the center of those and step 10 attach your polar alignment device and align it with the hinge of the tracker as i said earlier the drinking straw works okay for very wide angle lenses like i’m using i’m going to be doing 24 millimeters but to use this at 50 or 70 millimeters i think i’d need to find a better polar alignment device and that’s it let’s go test it okay it’s 3 20 am i’m in a portal 4 this will be my first milky way of the season i’m really excited i’m ready to actually try this thing out and the first step is we need to pull or align it and i’m just going to try to cite polaris with this metal drinking straw just try to center it in the straw polaris of course is the the last star in the little handle of the little dipper um and this is just going to be a good enough polar alignment not a great polar alignment but since polaris is actually about a half a degree off from the pole um but hopefully for a wide angle lens like this 24 millimeter this will work well enough so here we go all right the second step now that polar aligned is we have to find our target um by moving the camera around on the ball head until we’re pointing at it so i want to be pointing at the row of yuki area which is pretty easy to find because there’s a bright visible redistart called antares which is right in the middle and it’s part of again the easy to spot scorpius constellation so here we go i’m just gonna go find it the third step now is i want to focus on the stars using the live view i’ll just zoom in to 10 times and try to make the stars as small as possible on the screen the fourth step is i’m going to put the camera into bulb mode and just connect this simple bulb timer or shutter release um so i can take two minute long exposures this has a little lock so i’ll basically just start an exposure lock it and then at the end of two minutes unlock it so now we’re all ready to start tracking let’s see how it goes okay my first few tests were not successful i was still getting sort of trailed stars i found through a lot of trial and error though that with this camera and lens i’m using here which again are the rebel t7 or 1500d and the rokinon 24 millimeter lens at 2.

8 that i need to move the clock wheel or the the bolt at a rate of every 2. 5 seconds um i thought maybe i could get away with every five seconds but i’m getting trails still i’m getting much rounder stars by moving it 15 degrees every two and a half seconds rather than 30 degrees every five seconds so it’s not too bad it’s just a little bit tough on my neck to keep looking down at it but i can adjust the tripod height to sort of fix that i’m just using the stopwatch on my phone to to watch the seconds go by and i’ve just done some short tests so far but let’s go ahead and take a full two minute exposure now that i think i have it working and we’ll see what we get wow will you look at that i’m amazed at how good this looks this is just again a single two minute exposure with this barn door tracker let me zoom in on it so you can see what i’m seeing here just really good detail stars are nice and sharp and round i think this is going to be a keeper i’m going to try to take as many as i can before sunrise here so i’m going to get right back into it so i’ve taken 10 two-minute exposures they’re all looking good but i’m getting close to the bottom of the bolt so i’m going to go ahead and rewind it by turning it clockwise now this way okay i’m done rewinding it i’m not going to have to re-point the camera on my object because uh by rewinding it i probably threw off the pointing a little bit and then i’ll take 10 more two-minute exposures uh and probably by then the sun will be rising and off to stop so we’ll have 20 two-minute exposures for 40 minutes total well it’s the next day i’ve gone ahead and processed what i shot last night and i gotta say i’m pretty impressed by this barn door tracker i wasn’t so sure if a manual tracker was gonna be able to keep up with a modern dslr with small pixels but as long as you rotate the bolt frequently enough to avoid trailing i found it works really well that took a little trial and error of course the big advantage of using this tracker over just shooting on a fixed tripod is to get 40 minutes total time on my target like i did last night i only had to shoot 20 photos at 2 minutes each if i was shooting without a tracker to get to 40 minutes i would have had to do 600 photos at four seconds each so taking hundreds of photos will wear out your camera’s shutter faster and take a lot longer to stack on your computer of course there are some cons to this tracker too the manual nature of it made it a bit uncomfortable on my neck to be looking down at it for 40 minutes just slowly moving that wheel and i suppose some people would also find it pretty boring to just manually track that long so keep those things in mind what’s next for this project well i want to buy a used finder device like i mentioned with maybe a crosshair eyepiece so i can better polar align and that will allow me to try longer focal lengths because i’ve only really tried it seriously at 24 millimeters i did try a little bit longer focal lengths but i wasn’t getting good results i think it was because of polar alignment error so once i’ve done like a version two of this i also want to test it against some of the cheaper commercial options um like this omegon um lx2 windup tracker and the moveshoot move which is a little bit motorized tracker but it’s very small and so you can look forward to a part two eventually where i will show you my improvements and try it against uh these options uh you know 30 tracker versus a little bit more expensive ones well the only thing left now is the image reveal so let’s start with the single unprocessed two minute exposure here it is cropped in a bit to fill the screen and we can zoom in on some stars here just to show you that they are indeed round okay and here is after and all i did in the processing was really uh you know stack with i think i did 12 darks i didn’t have time to do flats or bias so it’s just uh 20 20 lights and 12 darks matched temperature darks and i i just stacked those in deep sky stacker brought this into photoshop and did my usual sort of playing around with curves and saturation and stuff i also just want to mention here again at the end that i have a patreon and another perk of my patreon is i now have an exclusive video just for people who support me on patreon and that the topic of that video is choosing different types of deep sky objects and what kind of gear filters and sky conditions you might need for different types like if you want to shoot a star cluster do you need a filter do you need a dark sky that kind of thing if you want to shoot a constellation what’s the best focal length for that so i go through some different types of deep sky objects so if you’re interested check out my Patreon it starts at just one dollar a month until next time this has been Nico Carver from nebulaphotos.

com Clear Skies.