It wouldn't be a two-speed design, but if I used a thin enough eyepiece on the ground (or worse, on your primary mirror!) Make sure the shroud can slip on and off of the assembled scope, and that it stretches along the circumference (not lengthwise). I did not glue the bearings to the tube box in case I needed to adjust the position later. The back of the mirror floats on 3 or more support points (this build uses 6) that are calculated usinga software tool called PLOP. All in all it seemed like a pretty robust design, so I gave it Nice looking telescope. Tips If you've got a 1.25 inch focuser, You can also use it for an objective. I placed my telrad, optical finder, and an eyepiece on the focuser end of the tube and, using a broomstick as a balance point, found that the tube balanced 22 inches from the bottom. After cutting the circles for the side bearings, I set up the jig to cut the curved edges of the rocker sides. 1" Rack & Pinion Focuser. This scope was originally made as a travel scope using an eight inch mirror that I ground and polished at the St Pete Astronomy Clubs Mirror Lab. I tried this one first and found it wouldn't work for my application. I knew that I would be returning the mirror cell to them, but just for fun I decided to see how it would fit in the tube. on Step 1, Richards in our local astronomy club. The drawings are only approximately to scale. Helicals are adaptable to both refractors and reflectors, but do not "play nice" with zoom eyepieces because "zooming" becomes a two handed operation to avoid changing focus. on my binocular scope for quite a while now and really like them. As the authors describe the benefits of a truss design, it is hard to dispute their arguments. A bit of a monster! I had nearly completed the base and put things together for the first time. I sourced my own Stepper motor and 1:150 reduction gearbox from RS, who are just up the road. And a couple of upright bearing blocks. Finally, I glued a strip of Ebony Star laminante to the curves edge of each side bearing using contact cement, using a flush edge bit on a router to bring the edge of the laminate even with the edge of the wood after the cement had set. Perfect for visual observations with very heavy mirrors. I suspected that the company was either in trouble or no longer in business. I will have a lot of fun building my homemade 12.5 inch Dobsonian Telescope!!! Electronics and software automate the process of taking pictures. (I didn't have the primary mirror yet). My telescope is the Orion ED80T-CF. Measure twice, drill After another 3 weeks, I was concerned that I had not received the mirror. Make the drawtube longer than you think you'll need, just in I drilled the holes in the center of the ground board and rocker bottom using a 9/16 bit, thinking that I needed the extra 1/16 so that the spacer could move. A project collaboration and documentation platform. When you want to focus, you just open the program and press focus. I also decided to make a separate mounting plate for the stepper motor, since I figured aligning the shafts precisely would be all but impossible. His passion is using CAD design and his homemade CNC router to bring large wood projects to life. This is the first telescope that I have built. i am not trying to win this contest with photos. It had been described by many as the most important recent volume for anyone planning to build a dob, and I have to agree. At this point, the scope was pretty much finished. I was inspired to build telescopes during a trip out to McDonald Observatory in west Texas, where I saw a 36 fork-mounted telescope, tiny in comparison to the huge research telescopes at the site. If not, you may need to design and print your own bracket(s), gears, and so on. the nylon screws going up from the bottom, but I found the knitting Share it with us! Along with some silver bits While round tubing is sturdy, square tubing is easier to work with. I paid the 50% deposit and dreamed of DSOs. Built one of these http://emediadesigns.com/focuser/ working really well only cost less than 40.00. I attached keepers 1 inches wide by 5 inches long, extending above the bottom of the arcs by about 1 inches. I called to express my concern and was told that it had all been packaged a few weeks ago and that it, For complete instructions on building a telescope such as this one, I strongly recommend buying a copy of, After cutting the circles for the side bearings, I set up the jig to cut the curved edges of the rocker sides. Did you make this project? I'd be willing to bet that you could easily grind your own 12.5 inch next time and save some $$. Attach the eye piece to another cardboard piece and pass it through the hole from the inside of the tube. The hole did need to be enlarged slightly by moving the bit within the hole , but in the end, the fit seems right. Fire up focusmax, and shoot some images! until a 2" eyepiece or 1.25" adapter is snug. You simply glue or screw the 'nut' part to your scope OTA, and thread the tube part in/out to focus. Inside the OTA is a ring of tightly fitting flocking paper that prevents any light getting in around the drawtube. 10 inch or 12 inch. They said they would make the brackets extra long to accommodate the mirror and it would take about a week. I don't have the skills to build a focuser using a. We are now ready for some testing. After waiting for the stain to dry for a day, I applied polyurethane in two coats, going over the surface with 0000 steel wool between coats. My first telescope I built was a 10" F8. Here is a simple 3D printed helical focuser that cost just a few cents (assuming you have a 3D printer). control. I have already seen some designs on CN, Stellafane and web but still checking if someone has recently made anything simpler. It turns out that sonotubes are a stock item in 8 inch, 10 inch, 12 inch, and sometimes even 16 inch diameters. In the "ARDUINO FIRMWARE" folder, in it you will find a ZIP file "myFP2-Firmware 312-1.zip". His project is very well documented. The focuser is the part of the telescope that holds the eyepiece or camera, and by moving in or out, closer or farther from the . Thanks for the great comment. but try for a snug fit if you can. Deep space photos like these require HOURS of exposure for each one. It took a lot longer than I expected to receive my mirror and other parts from Discovery. As I read the book I decided that I should build a 12.5 inch truss tube scope. off the bearings. Several functions may not work. var gaJsHost = (("https:" == document.location.protocol) ? Both cameras have fairly small megapixels by todays' standards, and are certainly obsolete, but do the job extremely well! The telescopes size is classified by the size of its mirror. See the images how I plan to assemble it. I only use the OTA. The focuser is very smooth. In the sub-folder "Cases" you will see many variants of the case for the DRV8825 based focusers. If you're not familiar with Arduino, watch some tutorial videos. the bearings, totally eliminating any flex. Staples or finishing nails work fine, but be sure they dont bump up above the surface of the plastic. It's rigid, lightweight, and On that noteWARNING:do not look directly into the sun and never point a telescope into the sun without proper filtration you can damage your telescope and burn your retinas and possibly go blind i am not a astrophotographer so i cant comment on the quality of the pictures since there is so much doubt on the photos i will gladly take them down. Quick demo of my motorized focuser, and I will create a detailed tutorial if enough people are interested. Finally, I attached Keepers to the sides of the rocker at the bottom of the arcs using screws and glue. I used the "LEDandBuzzer" and "TestStepsDRV8825" tests. I The original Crayford Focuser is on display there. Thin 1/16 Kydex plastic should be cut to length to line the inside of the cage as a baffle to block outside light. The only thing on the list that was a bit difficult to find was baltic birch plywood, which had to be special ordered from the lumber yard. The next day, I centered the rocker on the rocker bottom (which had been cut using the same method as the side bearing circles), drawing perpendicular lines through the center of the rocker bottom to use as a guide, and tracing the position on the rocker bottom. I started by trying to drill out a metal gear for the focuser shaft. These will be stored in your browser only with your consent and you have the option to opt-out. There are some test sketches in the "Tests" folder, start with those. The wide square footprint would make it pretty stable when mounted to This means you lose much of the night's images. Download and unzip. More commercial crayford focusers are of a more enclosed form, whereas mine is more "open frame" approach. Or in my case, back to SolidWorks :-). Robert is a super guy and more than willing to help those who choose to follow in his footsteps. I wanted a tight / press fit, so I only added half that, 0.25mm. Once built, line the undersides of the arms with textured ABS plastic as a bearing surface. I feel it is a wonderful thing to free oneself from the "store-bought" world, as Tombaugh did, and to use your imagination and skills to develop your own, personal way of viewing the sky. It's the same in form, but has a perfect, true 13.35mm hole. Next, attach the eyepiece and the focuser to the top part of the telescope tube. Funny how the bigger they are the better for dobs. Primary telescope mirror aftermarket, homemade, or custom-made. Then it was time to stain and finish. A Pocket Sundial From a Broken Pocket Watch! corners of the squares provide nice nooks for the eyepiece and eyepiece My concern turned to alarm when my wife told me that Discovery had charged the balance due on all items to my account a few weeks earlier. This combination has the best resolution (steps/revolution), so I didn't see any reason to build anything else. Because thebasic movement and optics requirements are relatively simple, much of the design is left to the builder. large in diameter (1.6") so that adds to the fine-ness of the focus #2 knitting needle would be just about right. Maker-written books designed to inform and delight! on Step 5. You currently have javascript disabled. The box should be deep enough to allow the mirror box to swing all the way down. It would cost less and they have a very good reputation. I set things up in daylight and collimated the scope. In scaling up the K/B 8 inch design, I made a few changes that, I hope, will improve the design for 12.5 inch aperture. The mirror cell: University Optics (eventually). Drill a hole and attach the ball head using a shorter 1/4" 20 bolt. The pivot bolt consists of a 1 1/8 inch brass spacer with an 11/16 inch outer diameter, a 3/8 inch bolt 2 inches long, a stop nut, and two large washers. The mirror itself must also be able to tilt in three dimensions in order to aim its light at the secondary mirror (a process called collimation). The bigger upvc nut will be attached to focuser plate and longer threaded side will be used on it for the focusing. When they arrived, they were beautifully and carefully packaged with the secondary already installed in its holder. Just as it was about to come into focus, the focuser bottomed out. The arc at the top of the sides needed to have a radius 1/8 inch larger than that of the side bearings to account for the thickness of the teflon pads that would fit between. It was important that the two circles be identical because the edges had to match perfectly when glued together and the two side bearings had to be identical in order for the altitude motion to work well.