Tom's Homemade Telescope Page - DIY Craford Focuser - Google I had cut the 12 foot tube in half in order to get it home in the first place, and a 6 foot section was the right size to work with for my f/5 12.5 inch. After going over the surfaces with a tack cloth to pick up the saw dust, I applied the stain and went over it with cheese cloth rags for an even finish. I have already seen some designs on CN, Stellafane and web but still checking if someone has recently made anything simpler. It may need some careful coaxing with a screwdriver. 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. Thin-wall aluminum tubing is used to attach the mirror box to the secondary cage. pageTracker._trackPageview(); curated by us, the people behind Make: and the Maker Faire. Ask Question Step 5: Stepper Motor Choice #2 - NEMA-17 Geared Stepper Motor If your optical train is heavy and the focuser has to bear it (see above) then this motor may be a better choice. You will need to order one sized for your telescope's focuser shaft size. The little app is simple and works great. 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. 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. You simply glue or screw the 'nut' part to your scope OTA, and thread the tube part in/out to focus. This motor has a larger shaft diameter (8mm) and is quite a bit heavier overall than the direct drive motor, mainly because of the gearbox. To interface with the computer, I have used the Artemis Focuser module from Steve, Arthur and Co. Subscribe to the premier DIY magazine today, Community access, print, and digital Magazine, and more. 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. 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. on Step 5, After much debit and doubt i have taken the photos down cause i cannot be 100% sure that they were taking from my scope as i was not there to verify them and i do not want my contest entry to be based on photos and not the build process. The glue should keep the nylon from fraying. with a genuine question or comment about the design. Rock on! If your optical train is heavy and the focuser has to bear it (see above) then this motor may be a better choice. Sonotube (14 inch diameter, 12 feet long): $70, Focuser (GSO 2 speed low profile Crayford): $139, Total cost for supplies for this project: $1700. Make an account on JLCPCB.com, upload the Gerber zip file, that's it! The back of the mirror floats on 3 or more support points (this build uses 6) that are calculated usinga software tool called PLOP. This software creates a model of your telescope by measuring out of focus star sizes at various points. 100A81BF-2145-44D5-BC76-66DBF43BAD58.jpeg. Easy DIY motorized battery free telescope focuser - YouTube More commercial crayford focusers are of a more enclosed form, whereas mine is more "open frame" approach. On the cutting diagram, you can see that the side bearings were cut 26 inches long. surfaces to put the bearings in and a vee at the bottom that would hold I did find, though, that the 3D printed gear would slip on the shaft, so it needed a set screw. A neet site: http://www.astropix.com/HTML/I_ASTROP/CAMERAS.HTM Cool instructable, Dude! 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. In order for the Rocker Box to pivot on the Ground Board, a center pin is placed in a hole at the exact center of the Ground Board and Rocker Bottom. weight. too far. We all know the problems with focusing. 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. an inch or so apart, so the focuser body could be pretty low profile. 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. Or in my case, back to SolidWorks :-). I don't have the skills to build a focuser using a. I told them to take their time and get it right. Focuser minimum height is 50 mm and maximum a little over 90 mm so it is good overall. A bit of a monster! My telescope is the Orion ED80T-CF. 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. (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.) I had installed the mirror about an inch too far away from the focuser. I plan to use an FTA over it in case an extension is needed. It would cost less and they have a very good reputation. This combination has the best resolution (steps/revolution), so I didn't see any reason to build anything else. CNC files (optional) Download the Sketchup files. I ground and figured the mirror with little troubles, making my focault tester, etc. Make the hole diameter fairly snug, too. Just to make sure I liked the stain, I applied some to a piece of scrap wood. Homemade DIY focuser for telescope with computer control - NEUTRAL.org 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. Two different construction supply companies told me that sonotubes were not available with a 14 inch diameter, even by special order. With Simple, Homemade Telescopes, You Can Explore the Stars (Op-Ed) was straight so I wouldn't get a wobbly knob. Your design is simple and nice. experimented with various wires and rods and eventually decided that a 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. I bought a 4" PVC Sewer pipe cap, used a hole saw to cut a 2.25" hole then attached the helical thing to the PVC cap. I tried this one first and found it wouldn't work for my application. Finally it was etched in caustic soda, and anodised matt black. I attached keepers 1 inches wide by 5 inches long, extending above the bottom of the arcs by about 1 inches. Overall, I'm very happy with the outcome of this project - focusing is now a joy. Once built, line the undersides of the arms with textured ABS plastic as a bearing surface. needle so the knitting needle will be snug against the drawtube without The hole is made slightly larger than the shaft, this is normal. I had the thought that as long as I was going to build it I should build it as big as I could afford. Drill the holes for the knitting DIY Craford Focuser. try { Unbelievable! 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. A week after they said they would send the secondary and other parts, I called to ask if things had been sent. on Step 5, 9 years ago A SDO/HMI Continuum Image on 2023.03.04 at 1259 UT, Remote computer working with no extra networking. Stellafane The Focuser One of the companies I had considered as a supplier for the primary mirror was Anttler's Optical. Nice work and great instructable! I will post the pic of final focuser once ready. You will need to remove the regular focus knob on your telescope's focuser. 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. Thicker knitting needles would be even As the authors describe the benefits of a truss design, it is hard to dispute their arguments. Star Adventurer Pro Pack Counter Weight Bar Thumb Screw Upgrade. Once I decided to build a scope myself I had to decide on the aperture of the scope. This consists of a small black box of electronics. How to build a 12.5 inch closed tube Dobsonian telescope. Electronics and software automate the process of taking pictures. At this point, the scope was pretty much finished. The spider, or secondary mirror holder, will suspend the mirror in the optical path in order to direct light into the focuser. accessible by all ages and skill ranges. Fast forward a few months to the next time I had the tube outside. We use cookies to continuously improve our websites for you and optimize its design and customization. Use the externalMirror Edge Support Calculatorto decide whether to use a two-point, four-point (whiffletree), or sling support. Pretty dry but important! 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. After picking up a copy of The Dobsonian Telescope by David Kriege, I built my first telescope with a 12-diameter mirror, then later tackled a 12 lightweight scope. Yet I was also becoming infected with aperture fever. This unit takes signals from your computer and drives the stepper motor on the focuser. While round tubing is sturdy, square tubing is easier to work with. It was easy enough to drill a hole and tap threads for a Here is what I was working on but looks like I need a better design. #2 knitting needle would be just about right. To place the primary mirror, I installed the secondary and installed the primary in the mirror cell. (actually, it ended up a smidge more than 2 inches). Homemade Electric Telescope Focuser - Stargazers Lounge 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. His passion is using CAD design and his homemade CNC router to bring large wood projects to life. The core of the telescope, the steel mirror cell holds and adjusts the heavy, curved primary mirror. I even began taking careful notes about needed supplies and plans for each piece of the truss tube scope. I read the entire thread and surely its going to help me building my focuser. You can view and download the full file here. together tech enthusiasts, crafters, educators across the globe. Start with the small components first. I will get good 30-40 mm focusing range. I could not find a spacer to fit my 9/16 hole, so I bought the 11/16 spacer (1 1/8 long because that's what the store had) and a bit of the same size. That helps with low-profile If you're not using heavy eyepieces, you probably don't need 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 . I then attached the Ebony Star ring using contact cement. I did not glue the bearings to the tube box in case I needed to adjust the position later. 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. The blue pieces of the rocker box and ground board are arranged as in the diagrams in (figure 2). You need some purple bits Only problem is if I put a diagonal it wants to rotate the helical part. Building a Homemade Telescope Eyepiece - HubPages (Technically, it should have been 62.5 for a 12.5 inch f/5, but when the mirror came it had a note on the back that the focal length was 61 inches.) Because mirror flexure can distort an image, supporting the mirror properly involves building a flotation cell. Our websites use cookies to improve your browsing experience. Their step by step instructions were invaluable to me as I built this scope. Funny how the bigger they are the better for dobs. DIY Truss Dob input: How to design truss? Parts List (the full story of acquiring the parts), The primary, secondary, spider and secondary holderDiscovery Optics.