homemade telescope focuser homemade telescope focuser

Interfaced with a computer, so the computer can make the decisions about where the best focus is. widening the hole. I then temporarily installed the secondary mirror so that I could measure the approximate distance to the center of the secondary in order to locate the holes for the focuser. Funny how the bigger they are the better for dobs. Pierre Lemay, thanks for sharing your simple and incredible design. focusers for that project. I set things up in daylight and collimated the scope. Next step, before my first acquisition of any parts, is to get with any amateur astronomers in Central Florida, so, wish me luck! 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. While a sling or whiffletree provide the best edge support, a two-point edge support is much easier to construct. I had installed the mirror about an inch too far away from the focuser. I also wanted to strengthen and protect the cardboard tube. help eliminate slippage when the focuser is pointed straight upward. curated by us, the people behind Make: and the Maker Faire. : "http://www. This arrangement turns 100% true, no wobble. wobbly knob still works, and adds character. You currently have javascript disabled. telescope page, I wasn't really eager to buy two commercial Crayford The premier publication of maker projects, skill-building tutorials, in-depth reviews, and inspirational stories, We all know the problems with focusing. 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. Made of plywood, the rocker box supports the mirror box on 1 teflon pads, allowing it to rotate vertically. 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. With the DRV8825 and Arduino Nano plugged in, the basic board is complete. A week after they said they would send the secondary and other parts, I called to ask if things had been sent. As the authors describe the benefits of a truss design, it is hard to dispute their arguments. microcontrollers including Arduino and Raspberry Pi, Drones and 3D Printing, and more. So I decided to make my own, using my normal "blunder in naively and see what happens" approach to making things. - Bill. both sides. So, am curious to see what others have designed and built and proud to show off here on the homage to Crayford thread. Pierre's Helical Crayford gets my vote hands-down for elegant simplicity. I had some carboy caps that make good knobs. To get this arc, I actually moved the radius of the jig in by 1/8 inch. 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 only do functional. 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. 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 If you wanted to really go low-profile with this design, Built one of these http://emediadesigns.com/focuser/ working really well only cost less than 40.00. To view, go here: http://emediadesigns.com/focuser/ control. 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. (actually, it ended up a smidge more than 2 inches). I plan to use an FTA over it in case an extension is needed. When the skies were dark enough for observing I found that the scope moves easily into position and holds that position well. Cost is $25 - $30, and you will have 5 PCBs in about a week. 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. tube and nut that fits the outside threads. 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. I was still doing some construction on the morning of the event, but I succeeded in making first light on that clear, dark night in late July. After waiting for the stain to dry for a day, I applied polyurethane in two coats, going over the surface with 0000 steel wool between coats. Total cost for supplies for this project: It took a lot longer than I expected to receive my mirror and other parts from Discovery. The cell from Anttler's, for which I had received a refund, had arrived. I started with a spacer that with a inch outer diameter. Ideally, the spacer would be 1 inch long and have a smaller diameter, but I didn't get this one right the first time. The wide square footprint would make it pretty stable when mounted to 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. Trim off any unused fabric along the base. The project took several months off and on to complete, although a skilled Maker could put a similar one together in a few weeks. Inside the OTA is a ring of tightly fitting flocking paper that prevents any light getting in around the drawtube. Slide the eyepiece into the focuser and try it out. Thicker knitting needles would be even Thanks again for the 'ible. I redrilled the holes for the mirror cell and got ready to wrap it. flexing. Another thing, the resolution on the Dumbell nebula seems a bit too high for that telescope. I found a used 16 primary on eBay. You will look through these as you rotate the wheel. try { 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 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. and hope it doesn't fall off Look down through the empty focuser. stronger, but would give me a coarser focus action because of their Low, or Zero slop when changing direction. Measure the diameter of the exposed shaft. Thin-wall aluminum tubing is used to attach the mirror box to the secondary cage. Yet I was also becoming infected with aperture fever. corners of the squares provide nice nooks for the eyepiece and eyepiece Now I can simply insert the PVC cap on the end of a 4" pvc tube. Find a special something for the makers in your life. 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 told them to take their time and get it right. To cut the circles, I used a router with a straight cutting bit and a circle cutting jig. I had some carboy caps that make good knobs. installations. Building the mirror box is tricky, because the entire optical assembly (mirror cell, mirror box, trusses, secondary cage) must balance at the center of rotation of the arms. 1" Rack & Pinion Focuser. After cutting the circles for the side bearings, I set up the jig to cut the curved edges of the rocker sides. Nice work and great instructable! It stalled when tension on the belt increased. It's easy to shim it to The core of the telescope, the steel mirror cell holds and adjusts the heavy, curved primary mirror. the nylon screws going up from the bottom, but I found the knitting really stiff and light for their size, and even though a #2 is pretty Before attaching the sides and front to the bottom with wood screws, I wanted to make sure those screws would not interfere with the Ebony Star ring that would be attached to the rocker bottom. As it turned out, the mirror cell was too large to fit into my 14 inch sonotube. I attached keepers 1 inches wide by 5 inches long, extending above the bottom of the arcs by about 1 inches. Parts List (the full story of acquiring the parts), The primary, secondary, spider and secondary holderDiscovery Optics. Other supplies that I bought for this project include wood, various bits of hardware, stain and finishing supplies, and a circle cutting jig for a router. 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 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. 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. Our websites use cookies to improve your browsing experience. 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. 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. 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. They have many items for ATMers and I had frequently visited their website when planning my scope. This will determine the size of the coupler you will use to connect the stepper motor. 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. 4 years ago Download the Gerber Files. Crayford focusers are considered superior to entry-level rack and pinion focusers, normally found in this type of device. This project is based on Robert Brown's "Arduino ASCOM Focuser Pro2 DIY". Telescope Magazine. 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. 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. More commercial crayford focusers are of a more enclosed form, whereas mine is more "open frame" approach. 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. 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. Here is what I was working on but looks like I need a better design. If not, you may need to design and print your own bracket(s), gears, and so on. Those are the last screws to be tightened. ill ask him for a detailed list of what he used and when i get that ill post it here for you. After the second call, I received a response that it would be ready at the end of the following week. 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. After looking at many focuser options with a big range of prices, I decided to order a GSO 2 speed Crayford focuser from ScopeStuff. A free program that lights childrens creative fires and allows them to explore projects in areas such as arts & Step 4Attaching the Side Bearings and assembling the Rocker. The last time I checked, that particular SBIG camera used on TelescopeGeek had an eight month lead time.A 20" scope gathers 2.6 times more light than a 12.5" scope, therefore equivalent exposures on this one would take 200+ minutes, at least. Remember: It is the quality and SIZE of the capture chip, NOT the megapixels that determines quality. Tips If you've got a 1.25 inch focuser, You can also use it for an objective. Maker-written books designed to inform and delight! 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. "https://ssl." 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. When you're ready to go on to testing with the windows driver, you want "myFP2_DRV8825_312-1", open that folder. Best Wishes, Reply needle so the knitting needle will be snug against the drawtube without DIY Truss Dob input: How to design truss? Two different construction supply companies told me that sonotubes were not available with a 14 inch diameter, even by special order. Line the underside of the rocker box with a ring of ABS plastic to allow it to ride on the base. 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 used the "LEDandBuzzer" and "TestStepsDRV8825" tests. You can see that my Moonlite focuser was slightly larger than the sides of the tube. Here is a simple 3D printed helical focuser that cost just a few cents (assuming you have a 3D printer). I built a second set of electronics, and I had the NEMA 17 Direct Drive motor left over since it didn't work for my Orion ED80T-CF refractor. Knitting needles are That helps with low-profile I used one of these scrap pieces to draw an angle of 70 degrees to the edge of the arc so that I could later place the teflon pads on the arcs. These are mounted 120 degrees apart and use 4 inexpensive bearings to support the tube. 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. 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. For my project I needed a 14 inch diameter, and I had a tough time finding one. But, especially on cold evenings, the focus may go out in the middle of the night. It turned out that they had an incorrect zip code and the package was still waiting to be sent. The spider, or secondary mirror holder, will suspend the mirror in the optical path in order to direct light into the focuser.