The bearings only need to be 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. needle to be just a little too flexible for the weight of a diagonal and . Membership connects and supports the people and projects that shape our future and supports the learning We are now ready for some testing. 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. I did find, though, that the 3D printed gear would slip on the shaft, so it needed a set screw. If you wanted to really go low-profile with this design, Topics such as Before you do this, the stepper motor will probably move, but it will make a 'stuttering' sound instead of moving smoothly. I Hope to give you ideas if you are thinking about building one for yourself! I only use the OTA. Two different construction supply companies told me that sonotubes were not available with a 14 inch diameter, even by special order. 8 years ago love to hear from people who are interested in this focuser design. ASIAIR - Is there an easy way to load Messier catalog into Autorun? The rocker sides are each made of two identical pieces of inch plywood glued together, creating two sides one inch thick. control. The silly colours are mainly due to me experimenting with various clothes dyes in the anodising. The original Crayford Focuser is on display there. Total cost for supplies for this project: It took a lot longer than I expected to receive my mirror and other parts from Discovery. 100A81BF-2145-44D5-BC76-66DBF43BAD58.jpeg. on Step 1, Richards in our local astronomy club. I suppose that one could complete this project without these two tools, but it would be difficult to cut the pieces accurately enough for a good fit. It took yet another call a week later for the items to actually be mailed. This allows for a small clearance between the outside of the tube and the inside of the tube box (14 3/8). a 3/4" thickness. Since my focuser shaft is 6mm, I ordered the coupler shown here in the 6mm to 8mm version from Amazon. The email bounced back to me. Some of the very best planetary and deep sky pics I have seen have come from a Fuji S3 professioanl camera [based on a Nikon body] and a Canon 20Da, which was designed with [I think] a user replaceable inside the mirror box filter for astral photography. Not worth the effort, price is tooo high. Many sources point out that 10 inches is a kind of sweet spot in the balance between power and portability. I also figured that the extra expense was worth it, considering the amount of money I was investing in the project overall. 11 years ago I tried this one first and found it wouldn't work for my application. Thank you for your pages. The focuser is very smooth. The glue should keep the nylon from fraying. 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. I carefully cut exactly through the center of each side bearing circle to make my semicircles. It turns out the the extra 1/16 allowed far too much side to side movement between the rocker and ground board. The focal length of the mirror is 61 inches. on Introduction. Attach the eye piece to another cardboard piece and pass it through the hole from the inside of the tube. As the authors describe the benefits of a truss design, it is hard to dispute their arguments. 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. Built one of these http://emediadesigns.com/focuser/ working really well only cost less than 40.00. 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. The next day, I called back to ask their opinion about the kind of spider and secondary holder to order. Using heavy grit sandpaper I brought back the surface of the keeper enough for the side bearings to fit inside the felt pads. All that remained was to design and print a bracket, and buy the needed parts. I have already seen some designs on CN, Stellafane and web but still checking if someone has recently made anything simpler. larger diameter. Realizing that it could not be the University Optics cell already, I thought, Noit couldn't be but, in fact, it was. My secondary is 4; for tips on choosing size, click here. . Or rather, I hated it. You really need a step ladder even for my 10" when pointed overhead. I used my router to "mill" a flat area for better contact with the focus adjustment rod. Download and unzip. And bolt to scope The focuser knob had two set screws. I also doubled the thickness of the rocker sides (not the front wall) to provide better support for the heavier tube. As the telescope tilts toward the horizon, the mirror must be supported on its edge. in the tube so they'll hit the knitting needle before your drawtube runs It has become an indispensable piece of equipment for me that so beats hacking and filing PVC pipes etc. They use a simple plywood mirror cell, stating that for an 8 inch mirror this cell will be adequate. On the cutting diagram, you can see that the side bearings were cut 26 inches long. Share it with us! 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. Fast forward a few months to the next time I had the tube outside. A week after they said they would send the secondary and other parts, I called to ask if things had been sent. All i did was supply the telescope as far as his camera equipment i dont know what he used i never saw it all i know is he had my scope for about a month while i was traveling and he gave me these photos. Both cameras have fairly small megapixels by todays' standards, and are certainly obsolete, but do the job extremely well! Only problem is if I put a diagonal it wants to rotate the helical part. It was May 12th. New Creation Tamil 6.96K subscribers Welcome to New Creation Tamil Our Channel include of Guiding Videos: 1.DIY Projects 2.Awesome Ideas 3.Tips You are inter with New Creation Tamil you can enjoy. I wanted to finish that instructable before the contest ended but was too late :-). So, I duplicated the aluminum gear pulley in SolidWorks, and printed it out. Feel free to take on that part if you like, but you're on your own :-). Building Your Second Homemade Telescope - Part 1 - HubPages After a dry fit of the rocker to make sure that the tube box with side bearings would fit well, I glued the rocker sides to the rocker front, holding them in place with small nails and clamping overnight. initiatives for the next generation of makers. try { If you enter it in the next contest please let me know and i will make sure to vote for you. Homemade astronomy. The specific hardware used for this is described on the Building page. And a couple of upright bearing blocks. Shorter thread side will be used to attach the eyepiece. Dobsonians come in all shapes and sizes, from small 4-8 builds all the way up to massive 24-36 creations. 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 widening the hole. Step 3The Side Bearings and Rocker Sides. Pierre Lemay, thanks for sharing your simple and incredible design. astronowanabe, Pierre Lemay, LarsMalmgren and. After the second call, I received a response that it would be ready at the end of the following week. This software creates a model of your telescope by measuring out of focus star sizes at various points. I'm also going to focus on only one version of Robert's focuser (there are many). I file a dispute with Paypal to begin the process of getting my money back. 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. Then it was time to stain and finish. It turns out that sonotubes are a stock item in 8 inch, 10 inch, 12 inch, and sometimes even 16 inch diameters. Just as it was about to come into focus, the focuser bottomed out. 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. corners of the squares provide nice nooks for the eyepiece and eyepiece I gave them a call and they said they had one on the shelf14 inches in diameter and 12 feet long! Contact cement is permanent, so the only solution would be to replace the tube! The premier publication of maker projects, skill-building tutorials, in-depth reviews, and inspirational stories, More commercial crayford focusers are of a more enclosed form, whereas mine is more "open frame" approach. I attached keepers 1 inches wide by 5 inches long, extending above the bottom of the arcs by about 1 inches. After the second call, I received a response that it would be ready at the end of the following week. Given that you can make the drawtube any length you After researching several possible sources for a primary mirror, I decided to order an f/5 12.5 inch mirror from Discovery Optics. They eyepiece height ended up being about 5'10" high at zenith. I attached small felt pads to the inside of the keepers to protect the side bearings from scratches, but discovered that the side bearings would not fit because of the thickness of the pads. But by this time I had thought about building my own scope for several weeks, and getting one off the shelf seemed pretty boring by comparison! I ground and figured the mirror with little troubles, making my focault tester, etc. 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! Homemade DIY focuser for telescope with computer control - NEUTRAL.org To place the primary mirror, I installed the secondary and installed the primary in the mirror cell. Before finishing the tube with a wrap of veneer, I wanted to make sure that the primary was in the correct position. 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. once. I then attached the Ebony Star ring using contact cement. wobbly knob still works, and adds character. I made a similar helical focuser with a nice 2 inch thing I found in Classifieds. 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. My DIY Motorized Telescope Focuser - YouTube the tube is cardboard as well, you can also get a quality mirror at telescope.com for much cheaper. 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. 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. Accordingly, with 1.25 focuser, you can use 1.25 eyepieces, with 2 focuser - both 2 eyepieces and 1.25 (through a special . I built mine entirely from CNC-cut plywood, and fastened it together with 2 bolts. Most people will want a knob on I started by trying to drill out a metal gear for the focuser shaft. Like i said these are not my photos and i cannot coment on exactly how he set it up as i was not there all i can say is i saw the mount he used when he picked up the telescope. Focusers of telescopes. Types, difference, specifications - Star Hunter Here is what I was working on but looks like I need a better design. 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. Tom's Homemade Telescope Page - 14 inch dob - Google (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.) Carve out a hole on the top part of the sonotube first. Make the drawtube longer than you think you'll need, just in In my build, the minimum eyepiece-to-secondary mirror distance (13) plus the primary-to-secondary mirror distance (57) equals the focal length of 71, which is roughly 4.5 times the width of the 16 mirror. Line the underside of the rocker box with a ring of ABS plastic to allow it to ride on the base. I off the bearings. I have no idea how much mail this idea will generate, so I can't Telescope Focusers | Orion Telescopes: Shop Home centers and hardware stores did not carry large sizes. Inside the OTA is a ring of tightly fitting flocking paper that prevents any light getting in around the drawtube. This means I can use FocusMax to do the focusing. It had been described by many as the most important recent volume for anyone planning to build a dob, and I have to agree. You will have to line up the diagonal and primary so that you see a centered image of the sonotube opening and the spyder in the eyepiece hole. (actually, it ended up a smidge more than 2 inches). 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. 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. This motor has a 5mm drive shaft. 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. 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. This arrangement turns 100% true, no wobble. You will look through these as you rotate the wheel. I then ran a bead of glue on the mark, and after it dried I cut out the nylon up to the glue. To get this arc, I actually moved the radius of the jig in by 1/8 inch. There are a number of technical reasons why these photographs could not have come from this Optical Tube Assembly. At their suggestion, I also ordered a 2.6 inch secondary mirror. Cost is $25 - $30, and you will have 5 PCBs in about a week. 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. The Dob is really a great design. It is size 1.25 inch with a clear inside dia-meter. I paid the 50% deposit and dreamed of DSOs. 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. I used a hole saw to cut a wooden plug to fit inside the Please re-enable javascript to access full functionality. Next step, before my first acquisition of any parts, is to get with any amateur astronomers in Central Florida, so, wish me luck! Able to shift heavy loads of kit ie over 1000g. This means you lose much of the night's images. Now I can simply insert the PVC cap on the end of a 4" pvc tube. Thanks Pinbout for sharing your design. tube and nut that fits the outside threads. The bigger upvc nut will be attached to focuser plate and longer threaded side will be used on it for the focusing. This is the first telescope that I have built. That's pretty much the focuser. 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. Share it with us! After another 3 weeks, I was concerned that I had not received the mirror. Thicker walls also required thicker side bearings so that the outside of the bearings would line up with the outside of the rocker sides. The part is very strong! Just to make sure I liked the stain, I applied some to a piece of scrap wood. The Crayford Focuser and DIY Focuser for Homemade Telescope 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. how much travel you actually need, you can cut the tube off so none of experimented with various wires and rods and eventually decided that a 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. Fairly easy to build and could be adapted to suit any SCT focuser. Im sorry to hear you couldn't make the contest. OK, no, I do not have a homemade Crayford focuser but am planning to build a 3 incher for next years 17" reflector telescope project and to hold my new 30mm ES 100 degree EP. I started with a spacer that with a inch outer diameter. A week later the cell arrived (on schedule) from University Optics. It was easy enough to drill a hole and tap threads for a Here we see the following components installed: Notice we are NOT populating the parts of the board intended for Wifi or BLED. I told them I was on my way. I am well versed in technology, have all the tools necessary to build my own! SDO/HMI Continuum Image on 2023.03.04 at 1259 UT, Remote computer working with no extra networking. The box should be deep enough to allow the mirror box to swing all the way down. There was the expense, for one, but also the That evening I spent most of my time rediscovering the many DSOs around Sagittarius, especially the Lagoon Nebula and the Trifid Nebula. After cutting the circles for the side bearings, I set up the jig to cut the curved edges of the rocker sides. 11 years ago 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. Similar photos at http://www.telescopegeek.com/gallery.htm require 100+ minute exposure times on his 20" telescope and $3200 camera. but try for a snug fit if you can. Here is what I was working on but looks like I need a better design. My homemade motorized telescope focuser for Celestron C8. This Instructable describe the planning, design, and parts of the scope, as well as the process of building The scope. Place the focuser, draw the position of the screws with a pencil and remove the focuser. I phoned in the order in the last week of February and was told that it would take about 4 weeks to deliver the mirror. I decided to order a mirror cell from them because the owner had talked about a new cell he was excited about. Picture of DS-4. I decided to use baltic birch because it is recommended by Kriege and Berry as well as many online sources. I have not yet figured out a better way to hold the tube. on Step 5. The hole did need to be enlarged slightly by moving the bit within the hole , but in the end, the fit seems right. This unit takes signals from your computer and drives the stepper motor on the focuser. Yet I was also becoming infected with aperture fever. My newtonian telescope, like most others, came fitted with a nasty rack and pinion focuser. Crayford-style design with four bearings and one driveshaft. 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. The belt and pulleys are off-the-shelf items available on Amazon. on Step 3. 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. The mirror box encloses the mirror cell and allows the entire telescope to rotate vertically. Pierre's Helical Crayford gets my vote hands-down for elegant simplicity. Just drill holes in both ends and mount the lenses. This motor is available on Amazon. DIY focuser design - ATM, Optics and DIY Forum - Cloudy Nights 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. 10 inch or 12 inch. The back of the mirror floats on 3 or more support points (this build uses 6) that are calculated usinga software tool called PLOP. A celebration of the Maker Movement, a family-friendly showcase of invention and creativity that gathers too far. 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. Let me see if I am able to collect all the parts needed. This motor is available on Amazon. a "rubbery" feel. 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. Share it with us! This cost around $100 to build and all of the components came from. The diameter of the focuser is usually indicated in inches. A 6 in primary mirror does not have enough weight to make the dob stable. If not, you may need to design and print your own bracket(s), gears, and so on. Make sure the shroud can slip on and off of the assembled scope, and that it stretches along the circumference (not lengthwise). Made of plywood, the rocker box supports the mirror box on 1 teflon pads, allowing it to rotate vertically. (actually, it ended up a smidge more than 2 inches) Lighter than the existing focuser. forward and back along with the drawtube when you focus, and you'll get 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.