Please feel free to email me at the address on the right. During on-site assembly, attach each truss to its mounting T-nut using a bolt with a thumbscrew knob. 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. 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. Another vote for Pierre's helical Crayford design. It just on Step 5. Orion Dynamo Mini for powering a Nexstar 6SE? 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. There was the expense, for one, but also the The cost is a bit more than some of the other combinations, but by only $10 or $20. 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. 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. 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. A week later the cell arrived (on schedule) from University Optics. 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. When you want to focus, you just open the program and press focus. 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 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. So, am curious to see what others have designed and built and proud to show off here on the homage to Crayford thread. an eyepiece. One of the neat things about the square design is that the It took a lot longer than I expected to receive my mirror and other parts from Discovery. . This is the mirror box for my 16", with Jim doing a bit of cleanup sanding. Knitting needles are I started with a spacer that with a inch outer diameter. The heaviest piece is 40 lbs, and the total scope weighs about 60 lbs (not counting the baffle). Another thing, the resolution on the Dumbell nebula seems a bit too high for that telescope. It was easy enough to drill a hole and tap threads for a 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. Secondary mirror with spider holder Search on eBay for a matched set. An electronic focuser, which moves the focus knob through a combination of hardware and software, solves this problem. When you add the minimum distance from the eyepiece to the secondary mirror together with the distance from the secondary mirror to the primary, the total length should be the primary mirrors focal length. Once built, line the undersides of the arms with textured ABS plastic as a bearing surface. Both cameras have fairly small megapixels by todays' standards, and are certainly obsolete, but do the job extremely well! 11 years ago the bearings, totally eliminating any flex. Nice looking telescope. And you can tell it's not a mosaic because the stars at the corners show coma/field curvature artifacts. I had designed the tube box so that there would be an extra inch around the tube. 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. This can be shimmed out with paper wrapped around the Here is what I was working on but looks like I need a better design. Since these focusers were going side-by-side on a binocular rod for the drive axle it would have a fairly fine motion. an inch or so apart, so the focuser body could be pretty low profile. Inside the OTA is a ring of tightly fitting flocking paper that prevents any light getting in around the drawtube. knitting needle where it goes through the hole, so it's not a big deal, I did not glue the bearings to the tube box in case I needed to adjust the position later. 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. When you're ready to go on to testing with the windows driver, you want "myFP2_DRV8825_312-1", open that folder. Most people will want a knob on 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. Then it was time to stain and finish. 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. on Introduction. a 3/4" thickness. (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.) It took yet another call a week later for the items to actually be mailed. 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. A bit of a monster! Plus it comes in black, so 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. like, you can have as much focuser travel as you want no matter how Because thebasic movement and optics requirements are relatively simple, much of the design is left to the builder. eyepiece on the ground (or worse, on your primary mirror!) When you figure out To interface with the computer, I have used the Artemis Focuser module from Steve, Arthur and Co. The shroud made from two 22 inch tall containers came out short, so I had to add an eleven inch strip of nylon. Fairly easy to build and could be adapted to suit any SCT focuser. both sides. 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. 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. 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. 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. While round tubing is sturdy, square tubing is easier to work with. Edited by sunrag, 28 May 2020 - 10:44 PM. If you found some good surplus lenses, you will have made a stunningly good objective for your scope. I don't have the skills to build a focuser using a. I wanted the long focal length for good contrast. I was finishing this inner debate when I got a copy of the book The Dobsonian Telescope by Kriege and Berry as a Christmas gift. Because mirror flexure can distort an image, supporting the mirror properly involves building a flotation cell. The lumber yard also gave me a lower price than I expected. Im sorry to hear you couldn't make the contest. I ground and figured the mirror with little troubles, making my focault tester, etc. I file a dispute with Paypal to begin the process of getting my money back. For my project I needed a 14 inch diameter, and I had a tough time finding one. My homemade motorized telescope focuser for Celestron C8. stronger, but would give me a coarser focus action because of their 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! The part is very strong! The overall project is super cheap, we're building this thing for something like $50 in materials. Accordingly, with 1.25 focuser, you can use 1.25 eyepieces, with 2 focuser - both 2 eyepieces and 1.25 (through a special . As I read the book I decided that I should build a 12.5 inch truss tube scope. 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. Built one of these http://emediadesigns.com/focuser/ working really well only cost less than 40.00. I want to make this direct drive system work. Please explain, in detail, how you attached your tube to the very unique drive system of an XT12G mount. Earthbound1 likes this #2 dave brock Mercury-Atlas Thicker knitting needles would be even To get this arc, I actually moved the radius of the jig in by 1/8 inch. I installed the spider first, about one inch down from the end of the square end of the 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. 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 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. and an eyepiece. If you're going for simple, have you considered a helical focuser? Here is what I was working on but looks like I need a better design. This software creates a model of your telescope by measuring out of focus star sizes at various points. Two such companies would not give me a price because the order of a single tube was too small. Thanks Bob. The bearings only need to be (actually, it ended up a smidge more than 2 inches). Let me see if I am able to collect all the parts needed. Likewise, the side bearings are made of two identical semicircles of 5/8 inch plywood glued together, creating side bearings that are 1 inches thick. Pioneered by John Dobson in the 1960s, the instrument combines a Newtonian reflector telescope with a unique two-axis movable base. As I mentioned on my binocular Before you do this, the stepper motor will probably move, but it will make a 'stuttering' sound instead of moving smoothly. in the tube so they'll hit the knitting needle before your drawtube runs After the second call, I received a response that it would be ready at the end of the following week. It has a 6mm shaft. You won't need to write any sketches from scratch, but you will at least need to figure out how to upload them to the Nano. I drilled the holes in the center of the ground board and rocker bottom using a 9/16 bit, thinking that I needed the extra 1/16 so that the spacer could move. 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 design could be adapted to practically any telescope or focuser, so I've kept my outline on the project brief. Here is a simple 3D printed helical focuser that cost just a few cents (assuming you have a 3D printer). His passion is using CAD design and his homemade CNC router to bring large wood projects to life. I've been using the above pair Dobsonian telescopes are popular with amateur telescope makers for their ease of design and construction, portability, and their use of large optical mirrors. Edited by Pierre Lemay, 25 May 2020 - 08:10 AM. The project took several months off and on to complete, although a skilled Maker could put a similar one together in a few weeks. 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. CNC files (optional) Download the Sketchup files. In my build, the cage was cut on a CNC router from plywood, with threaded T-nuts added to support a truss assembly. narrow the frame. larger diameter. And a couple of upright bearing blocks. Picture of DS-4. Thanks for your article. The extra force will also The one company that did provide a price quoted over $500more than I was willing to pay for cardboard! work really well, for a fraction of the cost of a commercial Crayford I have already seen some designs on CN, Stellafane and web but still checking if someone has recently made anything simpler. I hate focusing. my 12.5" trackball, but I didn't 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.". I As the authors describe the benefits of a truss design, it is hard to dispute their arguments. Focuser (GSO 2 speed low profile Crayford): $139 Ebony star strips: 2 @ $10 Ebony star ring: $59 Teflon strip: $11 Telrad base: $10 Baltic Birch " sheet (60X60): $42 Baltic Birch 5/8" sheet (60X60): $48 Circle cutting jig: $30 Birch Veneer (4X8 piece): $65 Hardware, stain, other supplies: $80 Total cost for supplies for this project: $1700 Step 4Attaching the Side Bearings and assembling the Rocker. You should now be able to drill the 4 holes at each corner. See the images how I plan to assemble it. This project is based on Robert Brown's "Arduino ASCOM Focuser Pro2 DIY". on Introduction. Bill, Impressive work and great idea about LSDF focuser. A smart collection of books, magazines, electronics kits, robots, microcontrollers, tools, supplies, and more As it turned out, the mirror cell was too large to fit into my 14 inch sonotube. occurred to me that a square turned 45 degrees would give me two flat 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 . This might have been tempting if I wanted to build a 6 inch scopeat that size, they say that first-timers do pretty well at grinding and figuring their own optics. Next step, before my first acquisition of any parts, is to get with any amateur astronomers in Central Florida, so, wish me luck! 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. Download the Gerber Files. he might just have a $3200 camera, they aren't very hard to come by. On the cutting diagram, you can see that the side bearings were cut 26 inches long. We then spread contact cement over the remaining veneer and tube surface, waited for the glue to dry, and carefully rolled the tube over the veneer. 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. I am thankful to enjoy the inspiration, and the details, that you provide, as I will soon be constructing a Dobsonian Telescope. 4 years ago But, like many of you I'm sure, the biggest reason I'm doing this is for the pure geeky fun of it! I used my router to "mill" a flat area for better contact with the focus adjustment rod. Depending on your telescope, one of the Brackets that Robert has may work for you. I will have a lot of fun building my homemade 12.5 inch Dobsonian Telescope!!! Only problem is if I put a diagonal it wants to rotate the helical part. 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. What materials did you use? wobbly knob still works, and adds character. NEMA-17 Stepper Motor - see below, there are two options. I have several of the books on building a Dobsonian Telescope. In my case I decided to make a custom bracket. You should watch (and bookmark) this video. 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. The belt and pulleys are off-the-shelf items available on Amazon. and hope it doesn't fall off Make the drawtube longer than you think you'll need, just in 4 years ago Now I can simply insert the PVC cap on the end of a 4" pvc tube. This arrangement turns 100% true, no wobble. This means I can use FocusMax to do the focusing. As the telescope tilts toward the horizon, the mirror must be supported on its edge.