I took the whole tube assembly outside. Contact cement is permanent, so the only solution would be to replace the tube! This makes for better sky photographs as the exposure time can be lengthened,. I'd be willing to bet that you could easily grind your own 12.5 inch next time and save some $$. To view, go here: http://emediadesigns.com/focuser/ Crayford-style design with four bearings and one driveshaft. (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 have already seen some designs on CN, Stellafane and web but still checking if someone has recently made anything simpler. Picture of DS-4. I then attached the Ebony Star ring using contact cement. I had chosen a boxy, rigid design for the binocular scope, so Pretty dry but important! The current needs to be adjusted on the DRV8825. Most of these have one or two set screws. It When you figure out As the authors describe the benefits of a truss design, it is hard to dispute their arguments. To cut the circles, I used a router with a straight cutting bit and a circle cutting jig. You simply glue or screw the 'nut' part to your scope OTA, and thread the tube part in/out to focus. 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. You will need to remove the regular focus knob on your telescope's focuser. together tech enthusiasts, crafters, educators across the globe. This can be shimmed out with paper wrapped around the I was annoyed to have made the mistake, but very glad that I checked the position on stars before wrapping the tube in veneer. The rocker arms must also have guides to keep it on the track; flat metal 12 braces lined with ABS plastic work nicely. on Step 1, interesting build, its just like my old Odyssey brand scope from the mid 1990's. and hope it doesn't fall off As I understand, you are using it for a refractor. One of the neat things about the square design is that the Finally, I attached Keepers to the sides of the rocker at the bottom of the arcs using screws and glue. I waited until dark and pointed the scope at the sky. 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. 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. I am working on a diy focuser design for my 6" F/8 telescope and asking suggestions for simple focuser. In order to check your measurements, you can construct jigs for your mirror cell and secondary cage, positioning them on a straight, adjustable track such as 2 planks of wood. the drive shaft close against the drawtube. Read the documentation though, there are a lot of functions and options. Thin-wall aluminum tubing is used to attach the mirror box to the secondary cage. } 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. I had the thought that as long as I was going to build it I should build it as big as I could afford. A Pocket Sundial From a Broken Pocket Watch! The telescopes size is classified by the size of its mirror. 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. 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. 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. It features 2 semicircular arms, and mounting points for the trusses (T-nuts are fine), as well as a lid to keep the mirror safe when the telescope is not in use. I used the "LEDandBuzzer" and "TestStepsDRV8825" tests. Thanks Pinbout for sharing your design. guarantee a response, but I'll do my best to answer everyone who writes Many sources point out that 10 inches is a kind of sweet spot in the balance between power and portability. 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. Several functions may not work. 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. On the bottom of the Bottom board is a ring of Ebony Star laminate that glides over the three teflon pads located directly above the feet on the ground board. 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. I file a dispute with Paypal to begin the process of getting my money back. Given that you can make the drawtube any length you A 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. Tips If you've got a 1.25 inch focuser, You can also use it for an objective. 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. In amateur astrophotography, we run our telescopes overnight. You will need to order one sized for your telescope's focuser shaft size. The lumber yard also gave me a lower price than I expected. I decided to keep this tube for now and if I run into problems with it, I can replace it later. Line the underside of the rocker box with a ring of ABS plastic to allow it to ride on the base. The shroud made from two 22 inch tall containers came out short, so I had to add an eleven inch strip of nylon. There are a number of technical reasons why these photographs could not have come from this Optical Tube Assembly. Dobsonian telescopes are popular with amateur telescope makers for their ease of design and construction, portability, and their use of large optical mirrors. narrow the frame. You can see that my Moonlite focuser was slightly larger than the sides of the tube. At this point, the scope was pretty much finished. Now I can simply insert the PVC cap on the end of a 4" pvc tube. After the second call, I received a response that it would be ready at the end of the following week. try { initiatives for the next generation of makers. 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. 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 currently have javascript disabled. 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. I redrilled the holes for the mirror cell and got ready to wrap it. This simple homemade device will reduce star trails far better than if the camera was mounted on a tripod alone. It is named after the Crayford Manor House Astronomical Society, Crayford, London, England where it was invented by John Wall, a member of the astronomical society which meets there. I used a hole saw to cut a wooden plug to fit inside the A celebration of the Maker Movement, a family-friendly showcase of invention and creativity that gathers The cell from Anttler's, for which I had received a refund, had arrived. Again from the main FILES page, go to "ASCOM DRIVERS" and download everything. It had been described by many as the most important recent volume for anyone planning to build a dob, and I have to agree. tube and nut that fits the outside threads. Unfortunately I don't have a 3d printer. A neet site: http://www.astropix.com/HTML/I_ASTROP/CAMERAS.HTM Cool instructable, Dude! homemade Crayford focuser. The Crayford focuser is a simplified focusing mechanism for amateur astronomical telescopes. Community Forum Software by IP.BoardLicensed to: Cloudy Nights. 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. I started with a spacer that with a inch outer diameter. 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. an eyepiece. Slide the eyepiece into the focuser and try it out. See the images how I plan to assemble it. Orion Dynamo Mini for powering a Nexstar 6SE? It is used to setup water outlet from overhead water tanks. Some of these are essential for the basic functionalities of our websites. Drill the holes for the knitting Knitting needles are Part numbers 351-4574 and 336-422. I wanted the long focal length for good contrast. I attached keepers 1 inches wide by 5 inches long, extending above the bottom of the arcs by about 1 inches. After you've done that, put a couple of tiny pan-head screws Two inch internal diameter drawtube. Since these focusers were going side-by-side on a binocular 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. The Artemis module works extremely well, and is to be strongly recommended. That's pretty much the focuser. Able to shift heavy loads of kit ie over 1000g. surfaces to put the bearings in and a vee at the bottom that would hold The pieces were cut down to 15 3/8 and 14 3/8, allowing just under 1/8 inch on each side. (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.) One 6in dob I made was a complete failure. 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. You need a drawtube of course. The only thing on the list that was a bit difficult to find was baltic birch plywood, which had to be special ordered from the lumber yard. Put it all together accessible by all ages and skill ranges. 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. Crayford focusers are considered superior to entry-level rack and pinion focusers, normally found in this type of device. Thank you for your pages. Upload that main sketch to the Nano. The bearings only need to be All in all it seemed like a pretty robust design, so I gave it This proved fatal for the stepper motor! Obviously an open truss telescope. Next, attach the eyepiece and the focuser to the top part of the telescope tube. This is the first telescope that I have built. This one is based on the DRV8825 driver chip and a NEMA-17 stepper motor. My secondary is 4; for tips on choosing size, click here. Share it with us! the interior diameter is just a nudge over 2". In my case I decided to make a custom bracket. It turns out that sonotubes are a stock item in 8 inch, 10 inch, 12 inch, and sometimes even 16 inch diameters. 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. In my build, the cage was cut on a CNC router from plywood, with threaded T-nuts added to support a truss assembly. Among amateur telescopes, the most common are focusers with landing diameters of 1.25 ", 2", rarely 0.965 ", and even less often - 3". I do it with aluminium alloy, aluminium tube and nice work. 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. knitting needle where it goes through the hole, so it's not a big deal, With adapters for any Meade 1x200-ACF or LS model, and chord to plug into focuser port. off the bearings. While I will freely admit that most astro-photography is WAY beyond me, you certainly do NOT need a $3200 camera to do so. Quick demo of my motorized focuser, and I will create a detailed tutorial if enough people are interested. If you enter it in the next contest please let me know and i will make sure to vote for you. I'm only hoping to supplement it a bit with some info and pictures aimed at those with limited skills (such as myself) :-) I'm not an electrical engineer, I'm more of a software guy with some limited knowledge of electronics and basic soldering and assembly skills. While round tubing is sturdy, square tubing is easier to work with. 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. The glue should keep the nylon from fraying. Feel free to take on that part if you like, but you're on your own :-). Your design is simple and nice. How to build a 12.5 inch closed tube Dobsonian telescope. Funny how the bigger they are the better for dobs. 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. A project collaboration and documentation platform. A Pocket Sundial From a Broken Pocket Watch! Headers for the LEDs, buzzer (2-pin) and temperature probe (3-pin). If your optical train is heavy and the focuser has to bear it (see above) then this motor may be a better choice. 1N5408 3A Diode (you may need to make the pins smaller to fit through the holes in the board. This software creates a model of your telescope by measuring out of focus star sizes at various points. Post 10 of the same LSDF focuser thread also links to Art Bianconi's archived 2008 original flush valve focuser posts. In the "ARDUINO FIRMWARE" folder, in it you will find a ZIP file "myFP2-Firmware 312-1.zip". His project is very well documented. focuser. This allowed me to cut perfect identical circles. I drilled holes for the screws that avoided the location of the ring, and attached the rocker bottom. A bit of a monster! Given any mirror measurements, PLOP will provide the ideal support layout and how much distortion to expect for any number of flotation points. I did find, though, that the 3D printed gear would slip on the shaft, so it needed a set screw. Next step, before my first acquisition of any parts, is to get with any amateur astronomers in Central Florida, so, wish me luck! This motor has a 5mm drive shaft. I don't *do* pretty. Let me see if I am able to collect all the parts needed. Another vote for Pierre's helical Crayford design. occurred to me that a square turned 45 degrees would give me two flat This consists of a small black box of electronics. 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. If you connect the 12V power with the barrel connector (right side of photo), the Nano should light up without the USB connection. Download and unzip. Here is what I was working on but looks like I need a better design. An electronic focuser, which moves the focus knob through a combination of hardware and software, solves this problem. A wide hole will let the knitting needle creep I particularly like that the design can be integrated directly into the focuser board to make a very, very simple UTA. Not sure how your toilets are built over there, but here they use what is called a tank flush valve. The focuser is very smooth. This is where you will use screws to strongly attach the focuser onto the tube. 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. 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 ended up modifying it a bit after printing. Plus it comes in black, so you don't need to paint it (or worry about paint flaking off it). I would also like to know about how you can take such fantastic pictures without a field rotator and an autoguider system. The focuser shaft on the telescope is 13.1mm in diameter. 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. 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. To make the hole for the focuser, I used the focuser tube to mark a circle in the shroud. All that remained was to design and print a bracket, and buy the needed parts. 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 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. Shorter thread side will be used to attach the eyepiece. 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. flexing. I described it two years ago in this thread:https://www.cloudyniuser/?p=8879835 . Someone is pulling someone's leg here. It may need some careful coaxing with a screwdriver. 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.". The base and the rocker box in my telescope are secured with a skate bearing assembly but could be more simply attached with a bolt through the center. My homemade motorized telescope focuser for Celestron C8. 11 years ago Earthbound1 likes this #2 dave brock Mercury-Atlas 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 applied contact cement to the first inch of the veneer and the mating inch of the tube. If you're not using heavy eyepieces, you probably don't need Fast forward a few months to the next time I had the tube outside. I decided to order a mirror cell from them because the owner had talked about a new cell he was excited about. To glue the side bearings and rocker sides to full thickness, I covered a side with wood glue, then carefully lined up the pieces and put two small nails into the pieces to hold them in place. 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. Pioneered by John Dobson in the 1960s, the instrument combines a Newtonian reflector telescope with a unique two-axis movable base. I want to make this direct drive system work. 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. It doesn't. A tilted focuser will have no effect on the image quality. Please re-enable javascript to access full functionality. I first tried my 32mm plossl eyepiece. astronowanabe, Pierre Lemay, LarsMalmgren and. case you need more focuser travel than you thought. the bearings right at the edge of the frame, reducing the frame to 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). I also wanted to strengthen and protect the cardboard tube. It has a 6mm shaft. But, especially on cold evenings, the focus may go out in the middle of the night. a "rubbery" feel. 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. Make the hole diameter fairly snug, too. The base of the telescope should be a wide, sturdy square or circle of wood with teflon bearing pads matched to the ABS plastic ring of the rocker box. Quick demo of my motorized focuser, and I will create a detailed tutorial if enough people are interested. The mount and tripod are pretty much useless for astrophotography. Deep space photos like these require HOURS of exposure for each one. I don't have the skills to build a focuser using a. I was certain not to move the jig at all before cutting the second circle. on my binocular scope for quite a while now and really like them. 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. The focuser 'knob' on the Celestron is just a rubber sleeve that usually pulls off easily. I After a few weeks of no communication from them, no ability to phone or email them, and no mirror cell arriving. But who cares, really? the nylon screws going up from the bottom, but I found the knitting The cage should be a hollow cylinder about wider than the mirror, with the focuser mounted directly facing the secondary mirror. 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. (actually, it ended up a smidge more than 2 inches) Lighter than the existing focuser. Attach the eye piece to another cardboard piece and pass it through the hole from the inside of the tube. The project took several months off and on to complete, although a skilled Maker could put a similar one together in a few weeks. Their step by step instructions were invaluable to me as I built this scope. We are now ready for some testing. But, like many of you I'm sure, the biggest reason I'm doing this is for the pure geeky fun of it! Thanks Bob. You should now be able to drill the 4 holes at each corner. It may take you a while to adjust the image correctly, but it's not hard to do, just time consuming. Orient this assembly to allow you to view an object on the far horizon. This is not recommended for shared computers. I had talked with their owner about mirrors and mirror cells once, and I was very impressed by his knowledge of telescope building. Since my focuser shaft is 6mm, I ordered the coupler shown here in the 6mm to 8mm version from Amazon. eyepiece on the ground (or worse, on your primary mirror!) It just Sew the seam, and sew an elastic cord into the top to secure it to the secondary cage. This is the mirror box for my 16", with Jim doing a bit of cleanup sanding. but try for a snug fit if you can. needle to be just a little too flexible for the weight of a diagonal and widening the hole. 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. weight. We moved the operation to a nearby park and got a focused image of the most distant trees (300-400 yards away) quite easily. was straight so I wouldn't get a wobbly knob. exactly 2" with adhesive labels placed one at a time inside the tube If you look in the FILES area on Robert Brown's site (see link above) you will see a sub-folder "3D Printed Parts". Yet I was also becoming infected with aperture fever. Be creative! After cutting the circles for the side bearings, I set up the jig to cut the curved edges of the rocker sides. a 3/4" thickness. The project creator Robert Brown made a good video on testing the board. I don't have the skills to build a focuser using a. it sticks into your light path. (I didn't have the primary mirror yet). The core of the telescope, the steel mirror cell holds and adjusts the heavy, curved primary mirror. I think I got what I wanted and seems best solution for me. The balance point determines the height of the rocker sides, so I had to get this far before I cut the wood for the base. I have one on my 12" f/5 truss dob and the focuser knob is on the top surface of the UTA. Trim off any unused fabric along the base. A smart collection of books, magazines, electronics kits, robots, microcontrollers, tools, supplies, and more When the skies were dark enough for observing I found that the scope moves easily into position and holds that position well. Gift the gift of Make: Magazine this holiday season! 3D Printed Futuristic Space Age Wall Clock, http://www.cloudynights.com/ubbthreads/showthreaded.php?Cat=0&Number=4721255. Thin 1/16 Kydex plastic should be cut to length to line the inside of the cage as a baffle to block outside light. All Orion 1.25" and 2" telescope focusers are engineered to provide smooth drawtube action to ensure you hit the exact focus point . Crayford-style design with four bearings and one driveshaft. I began building it in the spring of 2008, but the bulk of the work was done in July of 2008 with first light occurring on July 25. large in diameter (1.6") so that adds to the fine-ness of the focus Thicker walls also required thicker side bearings so that the outside of the bearings would line up with the outside of the rocker sides. I do have another tube that can be used around the drawtube, but it doesn't really add anything. Using heavy grit sandpaper I brought back the surface of the keeper enough for the side bearings to fit inside the felt pads. the side of a rigid secondary cage. These will be stored in your browser only with your consent and you have the option to opt-out.
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