After the second call, I received a response that it would be ready at the end of the following week. We use cookies to continuously improve our websites for you and optimize its design and customization. It's easy to shim it to Below are cutting diagrams and diagrams of the rocker and tube box with side bearings. Having an RS trade counter 2 miles away is such a luxury! One of the neat things about the square design is that the a "rubbery" feel. The lumber yard also gave me a lower price than I expected. This is the mirror box for my 16", with Jim doing a bit of cleanup sanding. Read the documentation though, there are a lot of functions and options. Participated in the Celestron Space Challenge. needle so the knitting needle will be snug against the drawtube without I want to make this direct drive system work. 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. Thanks again for the 'ible. If you go to buy all of the components for this project from dealers, you will see that you mostly have to buy at least 5 parts, sometimes bags of 50 parts! You can view and download the full file here. Step 4Attaching the Side Bearings and assembling the Rocker. Not sure if it is available in the USA. Fairly easy to build and could be adapted to suit any SCT focuser. This proved fatal for the stepper motor! Nice looking telescope. It doesn't. A tilted focuser will have no effect on the image quality. 1" Rack & Pinion Focuser. That is dirt cheap compared to the cost of commercially available focusers, which can top $1000 and are much heavier than what we will build. This can be shimmed out with paper wrapped around the A I did not glue the bearings to the tube box in case I needed to adjust the position later. I have already seen some designs on CN, Stellafane and web but still checking if someone has recently made anything simpler. Just drill holes in both ends and mount the lenses. until a 2" eyepiece or 1.25" adapter is snug. Rock Paper Scissors Using Tinkercad Circuits and Arduino, Punchy the MECH & the Autonomous Fight Club, Soft-sensor-saurus | an E-textile Soft Sensor Soft Toy With LED Light. on my binocular scope for quite a while now and really like them. To test the concept I used a short piece of two inch PVC for the draw tube. Just to make sure I liked the stain, I applied some to a piece of scrap wood. Both cameras have fairly small megapixels by todays' standards, and are certainly obsolete, but do the job extremely well! 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. I decided to order an aluminum mirror cell from University Optics instead so that the mirror could be supported at 9 different points. var gaJsHost = (("https:" == document.location.protocol) ? both sides. A 6 in primary mirror does not have enough weight to make the dob stable. Two different construction supply companies told me that sonotubes were not available with a 14 inch diameter, even by special order. While round tubing is sturdy, square tubing is easier to work with. document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); but try for a snug fit if you can. I used a hole saw to cut a wooden plug to fit inside the really stiff and light for their size, and even though a #2 is pretty The last chapter of the book describes a plan for an 8 inch sonotube dob with a few design elements from their truss design, and, as I read that chapter, the simplicity of its construction was very appealing. The pieces were cut down to 15 3/8 and 14 3/8, allowing just under 1/8 inch on each side. This cost around $100 to build and all of the components came from. Position "0" is with the focuser all the way IN (at least for a refractor). Plus it comes in black, so you don't need to paint it (or worry about paint flaking off it). you could probably space the bearings 3/4" apart instead of 1" and mount But who cares, really? that is a great website that guy has some fantastic photos. I really had to, since the underside of my telescope's focuser is all curves, no flat area for attaching the mounting bracket. Obviously an open truss telescope. Once Id built a CNC router, I embarked on my third telescope, featuring a 16 primary mirror with aluminum trusses, wide vertical bearing arcs, a steel front-adjustable mirror cell, and a rotating base. Use mild soap and distilled . This unit takes signals from your computer and drives the stepper motor on the focuser. To interface with the computer, I have used the Artemis Focuser module from Steve, Arthur and Co. Again from the main FILES page, go to "ASCOM DRIVERS" and download everything. Thanks Bob. control. I ground and figured the mirror with little troubles, making my focault tester, etc. This is the first telescope that I have built. As I set of the scope, several club members came over to check things out and it was nice to hear the positive comments on the appearance of the scope. They even offered to send the spider, secondary holder, and secondary mirror immediately so that I could begin working on the tube while I waited for the primary. So, for my telescope I used a 6mm to 5mm coupler available on Amazon. in the tube so they'll hit the knitting needle before your drawtube runs Another vote for Pierre's helical Crayford design. spambots that search the internet for addresses to send junk mail to.) Given that you can make the drawtube any length you 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. accessible by all ages and skill ranges. To get this arc, I actually moved the radius of the jig in by 1/8 inch. Instead of the rack and pinion, they have a smooth spring-loaded shaft which holds the focus tube against four opposing bearing surfaces, and controls its movement. And bolt to scope 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. Best Wishes, Reply Im quite happy with the result, and the view in its large mirror is phenomenal. and hope it doesn't fall off I had some carboy caps that make good knobs. The dimensions of the Tube Box Sides are based on the outer diameter of my tube14 3/16. I've been using the above pair The kit just contains the electronics - it is up to the user to find a stepper motor and attach it to their own telescope focuser. Put it all together The scope including the optics, truss tubes, and eye pieces all stored in a single box making it easy to store and transport by car, but it was a little too big to fit in the overhead compartment or under the seat on most aircraft. The specific hardware used for this is described on the Building page. I laughed, packed up the cell with a long letter describing the series of events that led to the return, and put it in the mail. The length of the Rocker Front also had to be changed so that the outside edge of the Side Bearings matched the outside edge of the Rocker Sides precisely. surfaces to put the bearings in and a vee at the bottom that would hold Parts List (the full story of acquiring the parts), The primary, secondary, spider and secondary holderDiscovery Optics. The version number "312" here may change if Robert posts new firmware. And you can tell it's not a mosaic because the stars at the corners show coma/field curvature artifacts. I would also like to know about how you can take such fantastic pictures without a field rotator and an autoguider system. } catch(err) {}, SH-232 Sharpless sh-232, sh-231, sh-233, sh-235, NGC2174 Monkey Head Nebula, Sharpless 252, Sh2-252, HDW3 Hartl-Dengel-Weinberger 3 PN G149.4-09.2, SH-198 Sharpless 198, Soul Nebula, IC1848, NGC281 IC11, Sharpless Sh2-184, Pacman Nebula, SH2-173 SH2-173 Phantom of the Opera LBN 593, SH2-168 Sharpless HII regions. The day I received the refund, I ordered a mirror cell from University Optics. To view, go here: http://emediadesigns.com/focuser/ Those are the last screws to be tightened. Get hands-on with kits, books, and more from the Maker Shed, Skill builder, project tutorials, and more. (actually, it ended up a smidge more than 2 inches) Lighter than the existing focuser. I waited until dark and pointed the scope at the sky. Inside the OTA is a ring of tightly fitting flocking paper that prevents any light getting in around the drawtube. It stalled when tension on the belt increased. var pageTracker = _gat._getTracker("UA-1008534-4"); 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. Fairly easy to build and could be adapted to suit any SCT focuser. The focuser 'knob' on the Celestron is just a rubber sleeve that usually pulls off easily. You can see that my Moonlite focuser was slightly larger than the sides of the tube. Use the externalMirror Edge Support Calculatorto decide whether to use a two-point, four-point (whiffletree), or sling support. 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. The heaviest piece is 40 lbs, and the total scope weighs about 60 lbs (not counting the baffle). . The original Crayford Focuser is on display there. : "http://www. stronger, but would give me a coarser focus action because of their $299.99 More About Telescope Focusers 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. As the authors describe the benefits of a truss design, it is hard to dispute their arguments. When you figure out Pioneered by John Dobson in the 1960s, the instrument combines a Newtonian reflector telescope with a unique two-axis movable base. This motor is available on Amazon. This is where you will use screws to strongly attach the focuser onto the tube. I tried all of my other eyepieces and found that I could bring the image into focus in the other eyepieces, but it was very near the bottom of the focuser travel. knob, and a drill press to make sure the hole for the knitting needle I applied contact cement to the first inch of the veneer and the mating inch of the tube. But let me see what items I can arrange to make a helical. Lining up this center point with the center of the top of the side bearing, I brought the corner of the side bearing up to the edge of the tube box and attached it with screws. A couple setscrews and you're up & running with an off the shelf solution. Above youll find an interactive 3D rendering of the Sketchup file I used to design and cut all of the parts for my telescope. Crayford-style design with four bearings and one driveshaft. A week later the cell arrived (on schedule) from University Optics. I am using scrap upvc pipe material. on Step 5. on Introduction. Two such companies would not give me a price because the order of a single tube was too small. The 48 inch width of the veneer was close enough to the diameter of the tube that I used it as is. Using a compass, I drew lines for the inside and outside of the Ebony Star ring on the top and bottom of the rocker bottom. Rock on! Before attaching the sides and front to the bottom with wood screws, I wanted to make sure those screws would not interfere with the Ebony Star ring that would be attached to the rocker bottom. I The diameter of the focuser is usually indicated in inches. The curved sides of the Side Bearings are also covered with strips of Ebony Star that glide on the teflon pads on the curved edges of the Rocker Sides (figure 3). he might just have a $3200 camera, they aren't very hard to come by. So, am curious to see what others have designed and built and proud to show off here on the homage to Crayford thread. For a while I decided that 10 inch would be the best size. The focuser is very smooth. The side bearings are each made from 2 identical semicircles of 5/8 inch plywood glued together to make a thickness of 1 inches. 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. While a sling or whiffletree provide the best edge support, a two-point edge support is much easier to construct. 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. Newton, and others including James Gregory and Laurent Cassegrain, believed that a reflecting telescope would not be affected by the chromatic aberration that affected . Un-real!!! Although they don't usually sell these parts, because I had ordered the mirrors from them they offered to sell me the spider and secondary holder that they use in their scopes. To place the primary mirror, I installed the secondary and installed the primary in the mirror cell. The next day, I called back to ask their opinion about the kind of spider and secondary holder to order. Many sources point out that 10 inches is a kind of sweet spot in the balance between power and portability. When the skies were dark enough for observing I found that the scope moves easily into position and holds that position well. A week after they said they would send the secondary and other parts, I called to ask if things had been sent. Pierre's Helical Crayford gets my vote hands-down for elegant simplicity. the bearings right at the edge of the frame, reducing the frame to An Altitude Azimuth mount would also require a field rotator.There's no way these were taken with an Orion GoTo Mount. It interfaces to the computer via USB and comes with an ASCOM driver. Part numbers 351-4574 and 336-422. You can easily, and economically (10$) build a Crayford Helical Focuser like the one pictured above in one evening with simple tools. Quick demo of my motorized focuser, and I will create a detailed tutorial if enough people are interested. When they arrived, they were beautifully and carefully packaged with the secondary already installed in its holder. You should watch (and bookmark) this video. Pioneered by John Dobson in the 1960s, the instrument combines a Newtonian reflector telescope with a unique two-axis movable base. Make the drawtube longer than you think you'll need, just in Please feel free to email me at the address on the right. Contact cement is permanent, so the only solution would be to replace the tube! How to build a 12.5 inch closed tube Dobsonian telescope. A decent machinest will do a far better job, but, there is always a lot more pleasure to be gained per astrophoto when you make bits yourself. Drill a hole and attach the ball head using a shorter 1/4" 20 bolt. Carve out a hole on the top part of the sonotube first. 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. 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. This is my copy of the telescope that Sir Isaac Newton presented to the Royal Society of London in 1671, and is considered to be the first successful reflecting telescope. So I decided to make my own, using my normal "blunder in naively and see what happens" approach to making things. focusers for that project. If you're going for simple, have you considered a helical focuser? To get this arc, I actually moved the radius of the jig, At some point in the building process, my goal became to finish the scope by RocheStar Fest, an annual event of the. Place the focuser, draw the position of the screws with a pencil and remove the focuser. 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. Accordingly, with 1.25 focuser, you can use 1.25 eyepieces, with 2 focuser - both 2 eyepieces and 1.25 (through a special . You currently have javascript disabled. I tried to call, but the voice mail had a recording stating that the customer was unable to receive messages. Here's my 8" f/6 travel scope with a 2" PVC draw tube and the helical Crayford focuser built right in the focuser board. I want to put my 12.5 mirror in a collapsible structure so I can haul it easy, Say a truss tube design, 7 years ago I used my router to "mill" a flat area for better contact with the focus adjustment rod. on Introduction, Very nice build nikon20. This was to allow the circle cutting jig to be attached to the board to cut the arcs from a center point of 25 inches above the ground. Measure twice, drill #@$%^#@!!!!! 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. I will have a lot of fun building my homemade 12.5 inch Dobsonian Telescope!!! I also doubled the thickness of the rocker sides (not the front wall) to provide better support for the heavier tube. This is the upper tube that contains the flat secondary mirror, Telrad finder, and focuser. In addition, we use third-party cookies to help us analyze and understand usage. Interfaced with a computer, so the computer can make the decisions about where the best focus is. I called to express my concern and was told that it had all been packaged a few weeks ago and that it should have been sent. forward and back along with the drawtube when you focus, and you'll get See the images how I plan to assemble it. adapter set screws to slide into. You will look through these as you rotate the wheel. occurred to me that a square turned 45 degrees would give me two flat it sticks into your light path. And, once your telescope is finished, be sure to join a local astronomy club to learn more about the sky and share your hobby with others. The overall project is super cheap, we're building this thing for something like $50 in materials. I marked the expected position of the secondary by measuring 61 inches down from the end of the tube. I had already made a lightweight focuser for This motor is available on Amazon. pageTracker._trackPageview(); This focuser (see pic at bottom) was motorised by me several years ago, but the motorised system didn't give me very fine control, and the motor running at fast speed tended to make the Artemis camera crash. I got no response to phone calls or emails after another week, and decided to wait until the primary would be finished in another two weeks. Connect the Arduino USB cable and upload some test sketches. I had considered a Moonlite or Featherlite focuser, but I knew from my experience with my 6 inch scope that I wanted a 2 speed focuser, and the price tag of their 2 speed focusers scared me away. I started by trying to drill out a metal gear for the focuser shaft. Once I decided to build a scope myself I had to decide on the aperture of the scope. However more than the focuser, I liked your scope. After researching several possible sources for a primary mirror, I decided to order an f/5 12.5 inch mirror from Discovery Optics. needle adds no friction that I can feel to the focus action. The focuser knob had two set screws. (A badly tilted focuser may subtly alter the illumination pattern of the focal plane to a degree that would be impossible to perceive visually but that's about it.) I carefully cut exactly through the center of each side bearing circle to make my semicircles. Someone is pulling someone's leg here. Edited by sunrag, 28 May 2020 - 10:44 PM. But I wanted a larger mirror, and, at that size, grinding my own was not an option. my 12.5" trackball, but I didn't I ordered the focuser, received an immediate email confirming the order, and it arrived two days later. I marked the spot and moved things back inside to install the mirror. It's easy to shim it to exactly 2" with adhesive labels placed one at a time inside the tube until a 2" eyepiece or 1.25" adapter is snug. Brandon Lawler is a hobbyist telescope Maker and an active member of the Central Texas Astronomical Society. We all know the problems with focusing. The silly colours are mainly due to me experimenting with various clothes dyes in the anodising. There are sub-folders for the different versions. Likewise, the side bearings are made of two identical semicircles of 5/8 inch plywood glued together, creating side bearings that are 1 inches thick. Fast forward a few months to the next time I had the tube outside. DO NOT drill out the holes in the board! By adjusting the bolts, the mirror can be pointed toward the correct spot. Your choice here will be recorded for all Make.co Websites. the side of a rigid secondary cage. It took about 3 weeks but, since Anttler's did not even reply to the Paypal dispute, I received a Paypal refund. off the bearings. It turned out that they had an incorrect zip code and the package was still waiting to be sent. Sew the seam, and sew an elastic cord into the top to secure it to the secondary cage. (I didn't have the primary mirror yet). While I applaud your building of a homemade Dob, (giving you the FULL benefit of the doubt here) your "friend" has provided photographs that make it look like you're trying to win by cheating. I have no dog in this hunt whatsoever, but if people are impressed by these photographs and vote for it because of them when there's no proof that this scope generated the photos and there IS data to the contrary (see below), then that's certainly not fair to the other contestants. You should now be able to drill the 4 holes at each corner. Plus it comes in black, so Made of plywood, the rocker box supports the mirror box on 1 teflon pads, allowing it to rotate vertically. A 10 inch scope would not be very much longer or heavier than my 6 inch, yet it would allow me to see much more. Whether you need a basic rack-and-pinion telescope focuser for your homemade telescope project or a premium Crayford-type model with dual-speed focusing as a performance upgrade, you have come to the right place. This design could be adapted to practically any telescope or focuser, so I've kept my outline on the project brief. I am a retired USAF electronics engineer, and might even do much of the construction of the base with welded structural tubing, as, I do have a complete metal working shop besides my wood shop, here. Topics such as
I am well versed in technology, have all the tools necessary to build my own! together tech enthusiasts, crafters, educators across the globe. The Crayford Focuser and DIY Focuser for Homemade Telescope By trukmeeilee in Circuits Cameras 3,461 3 1 Download Favorite By trukmeeilee Follow More by the author: The Crayford focuser is a simplified focusing mechanism for amateur astronomical telescopes. It takes the unknown out of focusing, and is easy to re-focus between filters, or refocus several times during a long exposure run as the world cools down. Share it with us! If you wanted to really go low-profile with this design, I also have an extended photographic build diary of this telescope posted on Imgur. I file a dispute with Paypal to begin the process of getting my money back. (The 8 inches from the center of the secondary to the field stop in the focuser is the same 8 inches from the center of the focuser to the top of the tube.) Able to shift heavy loads of kit ie over 1000g. corners of the squares provide nice nooks for the eyepiece and eyepiece Secondary mirror with spider holder Search on eBay for a matched set. I wanted the long focal length for good contrast. Here we see the following components installed: Notice we are NOT populating the parts of the board intended for Wifi or BLED. I used one of these scrap pieces to draw an angle of 70 degrees to the edge of the arc so that I could later place the teflon pads on the arcs. I had designed the tube box so that there would be an extra inch around the tube. how much travel you actually need, you can cut the tube off so none of This cost around $100 to build and all of the components came from Jaycar, except the brackets which were made with 1.2mm sheet metal. Every primary telescope mirror has a fixed focal length thats usually 4 to 6 times the width of the mirror. by cranking Cost is $25 - $30, and you will have 5 PCBs in about a week. A Pocket Sundial From a Broken Pocket Watch! As I mentioned on my binocular If not, you may need to design and print your own bracket(s), gears, and so on. The last time I checked, that particular SBIG camera used on TelescopeGeek had an eight month lead time.A 20" scope gathers 2.6 times more light than a 12.5" scope, therefore equivalent exposures on this one would take 200+ minutes, at least. an eyepiece. I do have another tube that can be used around the drawtube, but it doesn't really add anything. An electronic focuser, which moves the focus knob through a combination of hardware and software, solves this problem. Im sorry to hear you couldn't make the contest. It has a 6mm shaft. Once its cut to length, drill a hole through each end of the tubing with a drill press. I attached them with very small brads, countersinking the brads. Picture of DS-4. Thin-wall aluminum tubing is used to attach the mirror box to the secondary cage. To cut the circles, I started with a depth of about 1/8 inch, then lowered the bit and cut a little more with each pass until I was through the board. If you look in the FILES area on Robert Brown's site (see link above) you will see a sub-folder "3D Printed Parts". What materials did you use? Some of these are essential for the basic functionalities of our websites. The next day my wife called me at work to tell me a box had arrived with telescope stuff. Please re-enable javascript to access full functionality. In the sub-folder "Cases" you will see many variants of the case for the DRV8825 based focusers. Thanks for the great comment. i got a email that someone built a telescope close to mine that has seen the stuff in the photos here is a link to his site http://www.synapticsystems.com/sky/scopes/Dob.htmlif i seem a bit rude please forgive me i just spent 12hrs in a plane i have jetlag and im sitting in a airport.i would like to thank lvlasertech for keeping this instructable lively and informative. Unfortunately I don't have a 3d printer. needle to be just a little too flexible for the weight of a diagonal and Did you make this project? Headers for the LEDs, buzzer (2-pin) and temperature probe (3-pin). 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. Motion is very smooth. I described it two years ago in this thread:https://www.cloudyniuser/?p=8879835 . I took the whole tube assembly outside. If you don't want to go that route, contact me at gary.hethcoat@gmail.com since I have a lot of spare parts and I can sell you a "kit" with a PCB and only the parts you need.