Since these focusers were going side-by-side on a binocular For complete instructions on building a telescope such as this one, I strongly recommend buying a copy of The Dobsonian Telescope by David Kriege and Richard Berry. Place the focuser, draw the position of the screws with a pencil and remove the focuser. Most people will want a knob on This combination has the best resolution (steps/revolution), so I didn't see any reason to build anything else. Other supplies that I bought for this project include wood, various bits of hardware, stain and finishing supplies, and a circle cutting jig for a router. So, I duplicated the aluminum gear pulley in SolidWorks, and printed it out. 5 weeks after I had ordered the mirror, I called to ask about its status. Slewing to find an object and then tracking an object on the sky, so when you make a homemade telescope on the motorisation process you will need high speed for slewing and low speed for tracking or fine movements. All in all it seemed like a pretty robust design, so I gave it On the bottom of the Bottom board is a ring of Ebony Star laminate that glides over the three teflon pads located directly above the feet on the ground board. spambots that search the internet for addresses to send junk mail to.) ASIAIR - Is there an easy way to load Messier catalog into Autorun? After the second call, I received a response that it would be ready at the end of the following week. If you follow the procedures described above, your telescope's optics will be perfectly aligned. We are now ready for some testing. Did you make this project? flexing. . It is used to setup water outlet from overhead water tanks. Or rather, I hated it. How to build a 12.5 inch closed tube Dobsonian telescope. the side of a rigid secondary cage. I centered the focuser 8 inches from the top of the tube, using a 2.5 inch hole drilling saw with smaller holes for the bolts that would hold the focuser. It's easy to shim it to Gift the gift of Make: Magazine this holiday season! I had chosen a boxy, rigid design for the binocular scope, so This extra space would allow the tube to be repositioned within the tube box to rotate the eyepiece or balance the tube. Did you make this project? Ideally, the spacer would be 1 inch long and have a smaller diameter, but I didn't get this one right the first time. I also figured that the extra expense was worth it, considering the amount of money I was investing in the project overall. Rock on! I will get good 30-40 mm focusing range. Pierre Lemay, thanks for sharing your simple and incredible design. on Step 3. Here are a few photos of the "bracket", which is a simple 3D printed plate that mounts to the telescope's focuser ring, and serves as a mount for the stepper motor. This means you lose much of the night's images. . My other telescope is a Celestron NexStar C6E. I gave them a call and they said they had one on the shelf14 inches in diameter and 12 feet long! A it sticks into your light path. You can see that my Moonlite focuser was slightly larger than the sides of the tube. crafts, science & engineering, design, and technology. To get this arc, I actually moved the radius of the jig in by 1/8 inch. Upload that main sketch to the Nano. a "rubbery" feel. Quick demo of my motorized focuser, and I will create a detailed tutorial if enough people are interested. A smart collection of books, magazines, electronics kits, robots, microcontrollers, tools, supplies, and more Rack & Pinion: For many years the standard focuser was of the rack-and-pinion type - a small pinion gear moved the flat toothed rack that was attached to or built into the moving focusing tube that holds the eyepiece.However, this geared system was far from ideal, with some wobble due to the friction fit between the fixed and moving tubes and backlash due to the gears. on Introduction. One of the companies I had considered as a supplier for the primary mirror was Anttler's Optical. widening the hole. that is a great website that guy has some fantastic photos. It wouldn't be a two-speed design, but if I used a thin enough think that design would be rigid enough under the weight of a diagonal I marked the expected position of the secondary by measuring 61 inches down from the end of the tube. Un-real!!! I then attached the Ebony Star ring using contact cement. I drew a guide line straight down the side of the tube and cut the veneer to length with one extra inch on each side68 inches long. and an eyepiece. The pieces were cut down to 15 3/8 and 14 3/8, allowing just under 1/8 inch on each side. There are a number of technical reasons why these photographs could not have come from this Optical Tube Assembly. After the pieces were glued together, I used a belt sander to smooth out any rough edges, being careful to keep both rocker sides and both side bearings exactly the same. You won't need to write any sketches from scratch, but you will at least need to figure out how to upload them to the Nano. 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. By adjusting the bolts, the mirror can be pointed toward the correct spot. This motor is available on Amazon. Also no obvious diffraction spikes in the m31 photo. I will post the pic of final focuser once ready. To test the concept I used a short piece of two inch PVC for the draw tube. I don't have the skills to build a focuser using a. Pioneered by John Dobson in the 1960s, the instrument combines a Newtonian reflector telescope with a unique two-axis movable base. $299.99 More About Telescope Focusers My secondary is 4; for tips on choosing size, click here. Page 1 of 2 - DIY focuser design - posted in ATM, Optics and DIY Forum: Hi I am working on a diy focuser design for my 6 F/8 telescope and asking suggestions for simple focuser. The version number "312" here may change if Robert posts new firmware. A celebration of the Maker Movement, a family-friendly showcase of invention and creativity that gathers on Step 5, 9 years ago I started with a spacer that with a inch outer diameter. That helps with low-profile the tube is cardboard as well, you can also get a quality mirror at telescope.com for much cheaper. my thoughts naturally gravitated toward a boxy focuser to go with it. This is because my router bit was inch and the arc would be cut by the outside edge of the bit (where the circle had been cut by the inside edge.) Please re-enable javascript to access full functionality. The ARtemis module came in a kit form actually just two circuit boards one of which I had to source the parts, build and box myself. Im quite happy with the result, and the view in its large mirror is phenomenal. Edited by howardcano, 24 May 2020 - 09:29 PM. Once you get it working, there's some calibration you need to do. As I continued to read, however, I was struck by the many complications of the design and, frankly, how many ways I could screw it up. I then temporarily installed the secondary mirror so that I could measure the approximate distance to the center of the secondary in order to locate the holes for the focuser. Both cameras have fairly small megapixels by todays' standards, and are certainly obsolete, but do the job extremely well! Motion is very smooth. As the thread shows you could also build the dual speed version, all made of plywood, if you feel ready to tackle a slightly more complex project for a cost of about 5$ more. A wide hole will let the knitting needle creep Another vote for Pierre's helical Crayford design. I have not yet figured out a better way to hold the tube. I hate focusing. Using a compass I drew circles on the top and bottom of the ground board to mark the inside and outside of the teflon ring on the bottom of the rocker bottom. Home centers and hardware stores did not carry large sizes. We tried this in our back yard, but found that it was too difficult to aim both the tube and the moving mirror at distant trees in our suburban yard. I've been using the above pair But -- you have to be careful that the mechanism is true and the motor does not have a load on it at any time, otherwise it will 'stall' and stop moving. Bill, Impressive work and great idea about LSDF focuser. A Pocket Sundial From a Broken Pocket Watch! Please feel free to email me at the address on the right. Make the hole diameter fairly snug, too. I decided to keep this tube for now and if I run into problems with it, I can replace it later. And a couple of upright bearing blocks. I particularly like that the design can be integrated directly into the focuser board to make a very, very simple UTA. A week later the cell arrived (on schedule) from University Optics. 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. Find a special something for the makers in your life. There are sub-folders for the different versions. Share a cool tool or product with the community. Along with some silver bits We then spread contact cement over the remaining veneer and tube surface, waited for the glue to dry, and carefully rolled the tube over the veneer. In my case I decided to make a custom bracket. Building the mirror box is tricky, because the entire optical assembly (mirror cell, mirror box, trusses, secondary cage) must balance at the center of rotation of the arms. Dozens of projects in every issue covering electronics, craft, fabrication, and more, Learn tips and skill-building tutorials from experts in the maker community. Link to the motor speed controller kit:http://www.jaycar.com.au/productView.asp?ID=KC5225(a 5K external potentiometer will be required): http://www.jaycar.com.au/productView.asp?ID=RP3508The drive motor:http://www.jaycar.com.au/productView.asp?ID=YG2734The gears:http://www.jaycar.com.au/productView.asp?ID=YG2736The motor forward/reverse switch:http://www.jaycar.com.au/productView.asp?ID=ST0506The push button:http://www.jaycar.com.au/productView.asp?ID=SP0711 They said they would make the brackets extra long to accommodate the mirror and it would take about a week. See the images how I plan to assemble it. The focuser shaft on the telescope is 13.1mm in diameter. That way you won't be dropping your drawtube and But I wanted a larger mirror, and, at that size, grinding my own was not an option. Thanks for your article. Plus it comes in black, so That evening I spent most of my time rediscovering the many DSOs around Sagittarius, especially the Lagoon Nebula and the Trifid Nebula. I found a used 16 primary on eBay. Funny how the bigger they are the better for dobs. As the authors describe the benefits of a truss design, it is hard to dispute their arguments. The back of the mirror floats on 3 or more support points (this build uses 6) that are calculated usinga software tool called PLOP. You will look through these as you rotate the wheel. I was certain not to move the jig at all before cutting the second circle. It turned out that they had an incorrect zip code and the package was still waiting to be sent. I They have many items for ATMers and I had frequently visited their website when planning my scope. It stalled when tension on the belt increased. With the DRV8825 and Arduino Nano plugged in, the basic board is complete. Crayford focusers are considered superior to entry-level rack and pinion focusers, normally found in this type of device. If you are (for example) doing a focuser for a catadioptric telescope like a Celestron C-8 or similar, the focus knob has no load on it so this smaller, lighter motor will do the trick. Another thing, the resolution on the Dumbell nebula seems a bit too high for that telescope. The Artemis module works extremely well, and is to be strongly recommended. on Step 5. Our websites use cookies to improve your browsing experience. Since my focuser shaft is 6mm, I ordered the coupler shown here in the 6mm to 8mm version from Amazon. Now attach the screw eyes and the rubber band on the side of the board. Nice looking telescope. The base and the rocker box in my telescope are secured with a skate bearing assembly but could be more simply attached with a bolt through the center. I don't *do* pretty. Pretty dry but important! The core of the telescope, the steel mirror cell holds and adjusts the heavy, curved primary mirror. Nice one. This consists of a small black box of electronics. 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. Measure the diameter of the exposed shaft. At some point in the building process, my goal became to finish the scope by RocheStar Fest, an annual event of the Rochester Astronomy Club. I tried this one first and found it wouldn't work for my application. Two inch internal diameter drawtube. a try. The next day my wife called me at work to tell me a box had arrived with telescope stuff. My homemade motorized telescope focuser for Celestron C8. Bore out some 2.5 inch bar and mill a flat down the side making sure it is lined up. focusers for that project. on Introduction. You should now be able to drill the 4 holes at each corner. The mount and tripod are pretty much useless for astrophotography. Once built, line the undersides of the arms with textured ABS plastic as a bearing surface. Overall, I'm very happy with the outcome of this project - focusing is now a joy. These are mounted 120 degrees apart and use 4 inexpensive bearings to support the tube. experimented with various wires and rods and eventually decided that a This Instructable describe the planning, design, and parts of the scope, as well as the process of building The scope. accessible by all ages and skill ranges. It uses a primary mirror to capture and reflect light, a secondary mirror to direct light into an eyepiece, and a focuser to make fine adjustments for viewing. To do this, the mirror cell needs to be supported by 3 large bolts, at least 2 of which are adjustable. I am thankful to enjoy the inspiration, and the details, that you provide, as I will soon be constructing a Dobsonian Telescope. This book describes in great detail the steps to build a large aperture truss tube dob, focusing on scopes with a 12.5 to 40 inch mirror. Position "0" is with the focuser all the way IN (at least for a refractor). A few months later I ordered some other things from Scopestuff, including strips of Ebony Star laminate for the side bearings, a ring of Ebony Star for the rocker bottom, a strip of teflon to cut pieces for the ground board and side bearings, and a new base for my Telrad finder. Here is what I was working on but looks like I need a better design. Cost is $25 - $30, and you will have 5 PCBs in about a week. This is not recommended for shared computers. Every primary telescope mirror has a fixed focal length thats usually 4 to 6 times the width of the mirror. I set things up in daylight and collimated the scope. Again from the main FILES page, go to "ASCOM DRIVERS" and download everything. To place the primary mirror, I installed the secondary and installed the primary in the mirror cell. For the ATMer I do find that there are an endless number of parts that can be designed and printed for home built telescopes and binoscopes. I wanted a tight / press fit, so I only added half that, 0.25mm. It turns out that sonotubes are a stock item in 8 inch, 10 inch, 12 inch, and sometimes even 16 inch diameters. We use cookies to continuously improve our websites for you and optimize its design and customization. Orient this assembly to allow you to view an object on the far horizon. CNC files (optional) Download the Sketchup files. I'd Because thebasic movement and optics requirements are relatively simple, much of the design is left to the builder. I added three inches for a margin of error and in case I need to rebalance the tube in the future, making a distance of 25 inches from the balance point of the tube to the rocker bottom. I applied contact cement to the first inch of the veneer and the mating inch of the tube. You need some purple bits Connect the Arduino USB cable and upload some test sketches. What materials did you use? #@$%^#@!!!!! Once I had my design set, I was ready to buy the parts. This is the upper tube that contains the flat secondary mirror, Telrad finder, and focuser. Your design is simple and nice. Fire up focusmax, and shoot some images! The lumber yard also gave me a lower price than I expected. Post 10 of the same LSDF focuser thread also links to Art Bianconi's archived 2008 original flush valve focuser posts. While a sling or whiffletree provide the best edge support, a two-point edge support is much easier to construct.