#2 knitting needle would be just about right. All Orion 1.25" and 2" telescope focusers are engineered to provide smooth drawtube action to ensure you hit the exact focus point . with a genuine question or comment about the design. My homemade motorized telescope focuser for Celestron C8. help eliminate slippage when the focuser is pointed straight upward. To do this, the mirror cell needs to be supported by 3 large bolts, at least 2 of which are adjustable. 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. 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 also doubled the thickness of the rocker sides (not the front wall) to provide better support for the heavier tube. Similar photos at http://www.telescopegeek.com/gallery.htm require 100+ minute exposure times on his 20" telescope and $3200 camera. Perfect for astrophotography or during high power planetary observation. I carefully cut exactly through the center of each side bearing circle to make my semicircles. Above youll find an interactive 3D rendering of the Sketchup file I used to design and cut all of the parts for my telescope. While a sling or whiffletree provide the best edge support, a two-point edge support is much easier to construct. Here is a link to the main FILES area on Robert Brown's site. And bolt to scope Since my plan called for purchasing the mirrors and mechanical parts there were several decisions to be made and several vendors to contact. 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. My telescope is the Orion ED80T-CF. Drill a hole and attach the ball head using a shorter 1/4" 20 bolt. I first tried my 32mm plossl eyepiece. If you found some good surplus lenses, you will have made a stunningly good objective for your scope. 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. To get this arc, I actually moved the radius of the jig in by 1/8 inch. I waited until dark and pointed the scope at the sky. I found a used 16 primary on eBay. 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. When you're ready to go on to testing with the windows driver, you want "myFP2_DRV8825_312-1", open that folder. Some of these are essential for the basic functionalities of our websites. 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. I attached keepers 1 inches wide by 5 inches long, extending above the bottom of the arcs by about 1 inches. Download the Gerber Files. You need a drawtube of course. 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. Slide the eyepiece into the focuser and try it out. They suggested a construction supply place on the other side of the city that I had not called yet. Very simple and portable. With Simple | Space I made this Crayford style focuser using plywood scraps and surplus bearings. It stalled when tension on the belt increased. The glue should keep the nylon from fraying. 8 years ago my 12.5" trackball, but I didn't Several functions may not work. You will need to order one sized for your telescope's focuser shaft size. If you wanted to really go low-profile with this design, Here we see the following components installed: Notice we are NOT populating the parts of the board intended for Wifi or BLED. 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. 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. Just as it was about to come into focus, the focuser bottomed out. case you need more focuser travel than you thought. 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. on Introduction. Step 4Attaching the Side Bearings and assembling the Rocker. If you follow the procedures described above, your telescope's optics will be perfectly aligned. I have several of the books on building a Dobsonian Telescope. ill ask him for a detailed list of what he used and when i get that ill post it here for you. I set things up in daylight and collimated the scope. After the glue dried but before the clamps were removed, I added corner braces to all four corners of the tube using glue and brads to hold them in place. on Step 5. Dozens of projects in every issue covering electronics, craft, fabrication, and more, Learn tips and skill-building tutorials from experts in the maker community. This is where you will use screws to strongly attach the focuser onto the tube. on Step 1, interesting build, its just like my old Odyssey brand scope from the mid 1990's. This design could be adapted to practically any telescope or focuser, so I've kept my outline on the project brief. PhotoPictureResizer_190723_214534574_crop_2558x3105_copy_1023x1242.jpg. Secondary mirror with spider holder Search on eBay for a matched set. Tom's Homemade Telescope Page - Udder Nonsense - Google Line the underside of the rocker box with a ring of ABS plastic to allow it to ride on the base. It may take you a while to adjust the image correctly, but it's not hard to do, just time consuming. Inside the OTA is a ring of tightly fitting flocking paper that prevents any light getting in around the drawtube. I decided to keep this tube for now and if I run into problems with it, I can replace it later. I marked the spot and moved things back inside to install the mirror. The drawings are only approximately to scale. 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. 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. 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. The wide square footprint would make it pretty stable when mounted to After the second call, I received a response that it would be ready at the end of the following week. Thanks Bob. "); For my project I needed a 14 inch diameter, and I had a tough time finding one. Pioneered by John Dobson in the 1960s, the instrument combines a Newtonian reflector telescope with a unique two-axis movable base. You can view and download the full file here. 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. Most of these have one or two set screws. Once its cut to length, drill a hole through each end of the tubing with a drill press. This allows for a small clearance between the outside of the tube and the inside of the tube box (14 3/8). As the authors describe the benefits of a truss design, it is hard to dispute their arguments. Because mirror flexure can distort an image, supporting the mirror properly involves building a flotation cell. I had designed the tube box so that there would be an extra inch around the tube. Until I see photos of this scope setup for these pictures and an explanation of the exact equipment used, I cannot believe that these pictures were taken with this OTA. telescope page, I wasn't really eager to buy two commercial Crayford Building Your Second Homemade Telescope - Part 1 - HubPages I'd Also no obvious diffraction spikes in the m31 photo. If the telescope rotates forward or backward on its own, then the mirror box is too deep or too shallow. The project took several months off and on to complete, although a skilled Maker could put a similar one together in a few weeks. #@$%^#@!!!!! 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. 1" Rack & Pinion Focuser. wobbly knob still works, and adds character. Download and check them out, I just grabbed the first one and printed it. This combination has proved to be effective for all positions except when the tube is pointed directly up. Two of the holes for the bolts were blocked by knobs. DO NOT drill out the holes in the board! 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. . 10 inch or 12 inch. So, I duplicated the aluminum gear pulley in SolidWorks, and printed it out. 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. 1/4" x 20 bolt, and the nylon bolt end against the smooth knitting 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. Sh2-169 and Sh2-168, IC5146 Cocoon Nebula, Caldwell 19, Sh 2-125. Thanks for your article. I'd be willing to bet that you could easily grind your own 12.5 inch next time and save some $$. was straight so I wouldn't get a wobbly knob. After another 3 weeks, I was concerned that I had not received the mirror. 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. 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. You can see that my Moonlite focuser was slightly larger than the sides of the tube. One of the neat things about the square design is that the An electronic focuser, which moves the focus knob through a combination of hardware and software, solves this problem. I had nearly completed the base and put things together for the first time. Another vote for Pierre's helical Crayford design. Here is a simple 3D printed helical focuser that cost just a few cents (assuming you have a 3D printer). Make the drawtube longer than you think you'll need, just in I had talked with their owner about mirrors and mirror cells once, and I was very impressed by his knowledge of telescope building. My plan for wrapping the tube seemed good, but I am not too pleased with the final result. Since there is no drill bit that exactly matches the 13.1mm of the shaft, I had to do some rough enlargement of the hole. Over how many nights did this photography session take place? think that design would be rigid enough under the weight of a diagonal I told them to take their time and get it right. Pierre's Helical Crayford gets my vote hands-down for elegant simplicity. Homemade Electric Telescope Focuser - Stargazers Lounge 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. I didn't bother reading his whole article to figure out what f/# he used) I am not trying to say that good AP isn't possible with a sonotube scope, (the 'friend' may very well have pulled it out of the dob mount, added rings and a dovetail, and mounted it on his CGE-Pro or comparable) but in this case it is unlikely.". Plus it comes in black, so I did not wrap the tube until I had completed the base. scope, I only put knobs on the outsides. The Focuser and other items: (Scope Stuff). I am using scrap upvc pipe material. that is a great website that guy has some fantastic photos. try { 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. I will have a lot of fun building my homemade 12.5 inch Dobsonian Telescope!!! on my binocular scope for quite a while now and really like them. I then attached the Ebony Star ring using contact cement. Helicals are adaptable to both refractors and reflectors, but do not "play nice" with zoom eyepieces because "zooming" becomes a two handed operation to avoid changing focus. 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. Fairly easy to build and could be adapted to suit any SCT focuser. 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. I Hope to give you ideas if you are thinking about building one for yourself! I don't have the skills to build a focuser using a. So, for my telescope I used a 6mm to 5mm coupler available on Amazon. 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. document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); I am working on a diy focuser design for my 6" F/8 telescope and asking suggestions for simple focuser. 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 want to make this direct drive system work. The project creator Robert Brown made a good video on testing the board. And you can tell it's not a mosaic because the stars at the corners show coma/field curvature artifacts. Carve out a hole on the top part of the sonotube first. This project is based on Robert Brown's "Arduino ASCOM Focuser Pro2 DIY". how much travel you actually need, you can cut the tube off so none of All in all it seemed like a pretty robust design, so I gave it The one company that did provide a price quoted over $500more than I was willing to pay for cardboard! 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. 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. 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. Helical is one of the option i am considering. One of the companies I had considered as a supplier for the primary mirror was Anttler's Optical. Along with some silver bits he might just have a $3200 camera, they aren't very hard to come by. We were careful to press out any bubbles as we went, but when the job was done we found that there were multiple bubbles in the veneer. spambots that search the internet for addresses to send junk mail to.) Concluding that I would not be able to buy a tube off the shelf, I found a couple of companies that took special orders on cardboard tubes. My DIY Motorized Telescope Focuser - YouTube I use a 3D printer and an old gear motor to create an electronic telescope focuser.This is my first attempt at voiceover, I'm using a headset. This makes for better sky photographs as the exposure time can be lengthened,. These are mounted 120 degrees apart and use 4 inexpensive bearings to support the tube. 11 years ago 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. 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. Share a cool tool or product with the community. 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 really had to, since the underside of my telescope's focuser is all curves, no flat area for attaching the mounting bracket. astronowanabe, Pierre Lemay, LarsMalmgren and. As I mentioned on my binocular This means you lose much of the night's images. needle so the knitting needle will be snug against the drawtube without Once your telescope is assembled, drape black woven velveteen around the truss assembly, clipping it with safety pins. $299.99 More About Telescope Focusers once. I wanted to wrap the tube in veneer because I had seen a homemade telescope on a website that used veneer and I liked the look. I particularly like that the design can be integrated directly into the focuser board to make a very, very simple UTA. 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. You simply glue or screw the 'nut' part to your scope OTA, and thread the tube part in/out to focus. Orion Dynamo Mini for powering a Nexstar 6SE? The email bounced back to me. 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. Pretty dry but important! It has become an indispensable piece of equipment for me that so beats hacking and filing PVC pipes etc. Please explain, in detail, how you attached your tube to the very unique drive system of an XT12G mount. Im quite happy with the result, and the view in its large mirror is phenomenal. Headers for the LEDs, buzzer (2-pin) and temperature probe (3-pin). This means I can use FocusMax to do the focusing. The dimensions of the Tube Box Sides are based on the outer diameter of my tube14 3/16. I started by trying to drill out a metal gear for the focuser shaft. Today I purchased what is called atank nipple in India. 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! They use a simple plywood mirror cell, stating that for an 8 inch mirror this cell will be adequate. 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. you could probably space the bearings 3/4" apart instead of 1" and mount That way you won't be dropping your drawtube and It Sew the seam, and sew an elastic cord into the top to secure it to the secondary cage. The mount and tripod are pretty much useless for astrophotography. For a while I decided that 10 inch would be the best size. NEMA-17 Stepper Motor - see below, there are two options. needle to be just a little too flexible for the weight of a diagonal and Plus it comes in black, so you don't need to paint it (or worry about paint flaking off it).