I attached three feet equally spaced on top of the ring, and on the opposite side attached teflon pads 1 X 1 directly above the feet using very small brads and countersinking the brads below the surface of the teflon. DO NOT drill out the holes in the board! The flat wants to be running parallel to the long axis of the tube. Reply Please re-enable javascript to access full functionality. I had to take apart the focuser in order to get my bolts in place. Similar photos at http://www.telescopegeek.com/gallery.htm require 100+ minute exposure times on his 20" telescope and $3200 camera. If you wanted to really go low-profile with this design, This is the upper tube that contains the flat secondary mirror, Telrad finder, and focuser. If you want a Crayford focuser with a knob instead of turning the draw tube, then Jerry Oltion's designhttp://www.jerryoltixycrayfords.htm using box frames and knitting needle drive shafts is also a fairly easy build. All Dobsonian telescope projects are unique buildshere are the notes from my latest version to help get you familiar with the process and determine how youll design yours. The bigger upvc nut will be attached to focuser plate and longer threaded side will be used on it for the focusing. This one is based on the DRV8825 driver chip and a NEMA-17 stepper motor. 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. off the bearings. This motor is available on Amazon. a "rubbery" feel. I had some carboy caps that make good knobs. Before finishing the tube with a wrap of veneer, I wanted to make sure that the primary was in the correct position. I made this Crayford style focuser using plywood scraps and surplus bearings. I file a dispute with Paypal to begin the process of getting my money back. think that design would be rigid enough under the weight of a diagonal I think I got what I wanted and seems best solution for me. I decided to order an aluminum mirror cell from University Optics instead so that the mirror could be supported at 9 different points. The silly colours are mainly due to me experimenting with various clothes dyes in the anodising. One 6in dob I made was a complete failure. Brandon Lawler is a hobbyist telescope Maker and an active member of the Central Texas Astronomical Society. If you connect the 12V power with the barrel connector (right side of photo), the Nano should light up without the USB connection. The cost is a bit more than some of the other combinations, but by only $10 or $20. Carve out a hole on the top part of the sonotube first. You need some purple bits It would cost less and they have a very good reputation. That evening I spent most of my time rediscovering the many DSOs around Sagittarius, especially the Lagoon Nebula and the Trifid Nebula. Robert is a super guy and more than willing to help those who choose to follow in his footsteps. I wasn't there so i can be 100% but i do not think my friend was lying to me and i believe the pictures are from my telescope my kids use it for stargazing a lot i have seen some deepspace but i use it mainly for sketching the moon and i like to view solar flares. I only do functional. Electronics and software automate the process of taking pictures. This project is based on Robert Brown's "Arduino ASCOM Focuser Pro2 DIY". This Instructable describe the planning, design, and parts of the scope, as well as the process of building The scope. 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. 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. Most people will want a knob on My wife helped me by moving the mirror into and out of the tube around the marked spot while I stood at the eyepiece trying to bring some distant trees into focus. I am using scrap upvc pipe material. The specific hardware used for this is described on the Building page. If you found some good surplus lenses, you will have made a stunningly good objective for your scope. Those are the last screws to be tightened. I decided that my best option was to scale up their 8 inch design for a 12.5 inch scope and sacrifice the portability and easier storage of a truss scope for something that I felt confident in building myself. An Altitude Azimuth mount would also require a field rotator.There's no way these were taken with an Orion GoTo Mount. Upload that main sketch to the Nano. Our websites use cookies to improve your browsing experience. It has reminded me of one of my long term aims to make a telescope that has been buried by the demands of the rest of my life! Tips If you've got a 1.25 inch focuser, You can also use it for an objective. My newtonian telescope, like most others, came fitted with a nasty rack and pinion focuser. I sourced my own Stepper motor and 1:150 reduction gearbox from RS, who are just up the road. Part numbers 351-4574 and 336-422. I told them to take their time and get it right. After waiting for the contact cement to dry to the touch, and with my wife's help, I carefully aligned the edge of the veneer with the guideline on the tube and pressed the first inch together. Quick demo of my motorized focuser, and I will create a detailed tutorial if enough people are interested. There are a number of technical reasons why these photographs could not have come from this Optical Tube Assembly. 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. Once your telescope is assembled, drape black woven velveteen around the truss assembly, clipping it with safety pins. case you need more focuser travel than you thought. I'm also going to focus on only one version of Robert's focuser (there are many). I ended up modifying it a bit after printing. eyepiece on the ground (or worse, on your primary mirror!) I wanted to finish that instructable before the contest ended but was too late :-). Orient this assembly to allow you to view an object on the far horizon. If you mess up, you can turn the hole into a slot, but avoid it sticks into your light path. Depending on your telescope, one of the Brackets that Robert has may work for you. Star Adventurer Pro Pack Counter Weight Bar Thumb Screw Upgrade. Given that you can make the drawtube any length you Move the jigs until you can comfortably place a variety of eyepieces in the focuser and get a sharp image, then carefully measure the separation distances. The Dob is really a great design. help eliminate slippage when the focuser is pointed straight upward. The motor is much lighter than the geared motor. They suggested a construction supply place on the other side of the city that I had not called yet. Several functions may not work. I applied contact cement to the first inch of the veneer and the mating inch of the tube. This can be shimmed out with paper wrapped around the Unfortunately I don't have a 3d printer. like, you can have as much focuser travel as you want no matter how on Step 1, Richards in our local astronomy club. on Introduction. exactly 2" with adhesive labels placed one at a time inside the tube And you can tell it's not a mosaic because the stars at the corners show coma/field curvature artifacts. This is where you will use screws to strongly attach the focuser onto the tube. Next step, before my first acquisition of any parts, is to get with any amateur astronomers in Central Florida, so, wish me luck! 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 waited until dark and pointed the scope at the sky. Over how many nights did this photography session take place? Two different construction supply companies told me that sonotubes were not available with a 14 inch diameter, even by special order. Since these focusers were going side-by-side on a binocular #@$%^#@!!!!! Step 4Attaching the Side Bearings and assembling the Rocker. Able to shift heavy loads of kit ie over 1000g. Several of my Recent Images have been focused with this system. My first telescope I built was a 10" F8. Able to shift heavy loads of kit ie over 1000g. 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. I also wanted to buy the other mechanical partsmirror cell, spider, secondary holder, and focuserso that the performance of these pieces was not limited by my skills. The secondary holder is adjustable, so I could didn't have to get the location perfect. 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. flexing. 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. I found a used 16 primary on eBay. forces the knitting needle against the drawtube and the drawtube against Fast forward a few months to the next time I had the tube outside. The pieces were cut down to 15 3/8 and 14 3/8, allowing just under 1/8 inch on each side. Thanks for your article. i am not trying to win this contest with photos. I hate focusing. To do this, the mirror cell needs to be supported by 3 large bolts, at least 2 of which are adjustable. This consists of a small black box of electronics. Actually getting the parts into my hands turned out to be more of a challenge than I would have expected, but in the end, I have a wonderful telescope that I enjoy very much. A week later the cell arrived (on schedule) from University Optics. It take automatic control of the CCD camera and focuser, and dances around magically on the screen, arriving at perfect focus within about 30s to 3 minutes depending on where you started from. CNC files (optional) Download the Sketchup files. Start with the small components first. The version number "312" here may change if Robert posts new firmware. Next, attach the eyepiece and the focuser to the top part of the telescope tube. 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. In my build, the cage was cut on a CNC router from plywood, with threaded T-nuts added to support a truss assembly. It was easy enough to drill a hole and tap threads for a This is the first telescope that I have built. I used a hole saw to cut a wooden plug to fit inside the It wouldn't be a two-speed design, but if I used a thin enough I don't have the skills to build a focuser using a. Two inch internal diameter drawtube. I'd be willing to bet that you could easily grind your own 12.5 inch next time and save some $$. 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. Use mild soap and distilled . This cost around $100 to build and all of the components came from. I then attached the Ebony Star ring using contact cement. It's rigid, lightweight, and Now attach the screw eyes and the rubber band on the side of the board. 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. Plus it comes in black, so you don't need to paint it (or worry about paint flaking off it). Make the hole diameter fairly snug, too. 1N5408 3A Diode (you may need to make the pins smaller to fit through the holes in the board. I also have an extended photographic build diary of this telescope posted on Imgur. With adapters for any Meade 1x200-ACF or LS model, and chord to plug into focuser port. 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. This allows for a small clearance between the outside of the tube and the inside of the tube box (14 3/8). curated by us, the people behind Make: and the Maker Faire. Overall, I'm very happy with the outcome of this project - focusing is now a joy. 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. Drill the holes for the knitting Thanks for the great comment. That way you won't be dropping your drawtube and How to build a 12.5 inch closed tube Dobsonian telescope. Look down through the empty focuser. It is not very powerful, it will not supply enough torque if you put any load on it or have a heavy optical train (like I do) and the focuser has to "pull" it upward when the telescope is vertical. These will be stored in your browser only with your consent and you have the option to opt-out. the bearings right at the edge of the frame, reducing the frame to I also wanted to strengthen and protect the cardboard tube. in the tube so they'll hit the knitting needle before your drawtube runs Thanks again for the 'ible. really stiff and light for their size, and even though a #2 is pretty by cranking 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. occurred to me that a square turned 45 degrees would give me two flat Secondary mirror with spider holder Search on eBay for a matched set. pageTracker._trackPageview(); Nice one. Inside the OTA is a ring of tightly fitting flocking paper that prevents any light getting in around the drawtube. 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. I attached them with very small brads, countersinking the brads. Please feel free to email me at the address on the right. I will have a lot of fun building my homemade 12.5 inch Dobsonian Telescope!!! 1" Rack & Pinion Focuser. larger diameter. Please explain, in detail, how you attached your tube to the very unique drive system of an XT12G mount. Once its cut to length, drill a hole through each end of the tubing with a drill press. until a 2" eyepiece or 1.25" adapter is snug. Sew the seam, and sew an elastic cord into the top to secure it to the secondary cage. 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 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. Did you make this project? Line the underside of the rocker box with a ring of ABS plastic to allow it to ride on the base. Drawing lines between opposite corners of the tube box sides allowed me to locate the center point on each side. My guess is that photo was taken with a refractor. I did not glue the bearings to the tube box in case I needed to adjust the position later. Quick demo of my motorized focuser, and I will create a detailed tutorial if enough people are interested. The wood would cost the same, as would pretty much everything except the mirror, so why not spend a little more on the mirror and go BIG. You will need to order one sized for your telescope's focuser shaft size. His project is very well documented. I plan to use an FTA over it in case an extension is needed. Install on Windows 10, this part is pretty straightforward. var gaJsHost = (("https:" == document.location.protocol) ? In my case I decided to make a custom bracket. the side of a rigid secondary cage. NEMA-17 Stepper Motor - see below, there are two options. The rocker arms must also have guides to keep it on the track; flat metal 12 braces lined with ABS plastic work nicely. To get this arc, I actually moved the radius of the jig in by 1/8 inch. ill ask him for a detailed list of what he used and when i get that ill post it here for you. Your choice here will be recorded for all Make.co Websites. Some of these are essential for the basic functionalities of our websites. 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. 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. The next day my wife called me at work to tell me a box had arrived with telescope stuff. See above, this motor does not produce a lot of torque, but you don't need much for this application since there is no 'load' on the focusing shaft. From everything I had read, I expected that getting a sonotube would be as easy as running to any hardware store and picking it up. I had talked with their owner about mirrors and mirror cells once, and I was very impressed by his knowledge of telescope building. Then it was time to stain and finish. 11 years ago on Step 5. I redrilled the holes for the mirror cell and got ready to wrap it. 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 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. I used one of the top scraps from the rocker sides to mark an angle of 70 degrees from the center of the arc to the curved cut in order to properly space 1 X 7/8 teflon pads on the arcs. DIY Truss Dob input: How to design truss? 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. Nice looking telescope. They're fairly I had designed the tube box so that there would be an extra inch around the tube. Have you made any mods on it since you built it? And bolt to scope We moved the operation to a nearby park and got a focused image of the most distant trees (300-400 yards away) quite easily. 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. Attach the ball head to the top board. Both cameras have fairly small megapixels by todays' standards, and are certainly obsolete, but do the job extremely well! A 6 in primary mirror does not have enough weight to make the dob stable. Now I can simply insert the PVC cap on the end of a 4" pvc tube. As it turned out, the mirror cell was too large to fit into my 14 inch sonotube. 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. Crayford focusers are considered superior to entry-level rack and pinion focusers, normally found in this type of device. 4 years ago Also, I will work with my computer geek buddies, so that we eventually automate it using Linux on a Rock64, to run kstars for tracking, on INDI. small, it's surprisingly rigid. I did not own all of the tools that I needed for this project, particularly a table saw and router, so I did a lot of work while visiting my Dad. Just as it was about to come into focus, the focuser bottomed out. 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. Thanks Pinbout for sharing your design. tube and nut that fits the outside threads. I got a different stain, tested it, and went back to work. Using plywood, make 4 attachment blocks to pair the trusses together and create a small ledge for the secondary cage to rest on while you secure it. My plan for wrapping the tube seemed good, but I am not too pleased with the final result. In the sub-folder "Cases" you will see many variants of the case for the DRV8825 based focusers. Featured in the February, 2015 issue of Sky & The Focuser and other items: (Scope Stuff). I decided to order a mirror cell from them because the owner had talked about a new cell he was excited about. I will post the pic of final focuser once ready. Contact cement is permanent, so the only solution would be to replace the tube! This sure is going to be a project I will work on. Or rather, I hated it. Coupler for NEMA-17 Stepper Motor (also two choices, see below), LM7808 Voltage Regulator with TO-220 package -, Mini On/Off 3-pin 2-position slide switch -, Headers and wire (miscellaneous sizes and gauges), these are important so you can replace the component if it is damaged, LM7808 voltage regulator w/TO-220 heat sink package, 2-pin headers for 12V power and on/off switch. 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 . 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.