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ponytale

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Everything posted by ponytale

  1. I just saw this halo effect outside my house here in Perth Australia I have seen this before in the Uk but never this large , thought it was worth a post .
  2. Hi DIYR'S I HAVE BEEN OFF LINE FOR A WHILE ,HAVEING MOVED DOWNUNDER 2 YRS AGO. HAVE FINALLY GOT AROUND TO REMAKING MY SPLIT RING MOUNT AND THOUGHT I WOULD SHARE MY PROGRESS SO FAR. THE SPLIT RING AND BASE IS MADE OF 25MM PLYWOOD , THE DRIVE GEAR IS MADE FROM A CAR TIMING BELT WHICH HAS ZERO BACKLASH THIS ALLOWED ME TO CONSTRUCT A (GEAR WHEEL) IT ALL WORKS VERY EASILY,AND A LINEAR DRIVE SHAFT WHICH ALLOWS FOR STRAIGHT LENGTH OF THE BELT BONDED TO A GUIDED SLIDE ( SITS ON SLIDE ROD BETWEEN 2 PIECES OF PLY WITH CORESPONDING GROOVE ) WHICH IN TURN PICKS UP THE (SLED)ON THE THREADED ROD FOR THE STEPPER DRIVE .WHICH WILL BE FITTED SOON .WITH A FLEX COUPLING . SEE PICTURES ATTACHED. THERE IS NO POLARIS OR POLE STAR TO SET UP ON DOWNUNDER SO I FIGURE A MOUNT THAT IS EASY TO SET UP IS THE WAY TO GO. THE LATITUDE HERE IS 31.7 SO ALL I HAVE TO DO IS SET IT TRUE SOUTH TO GET IT REASONABLY CLOSE TO ALIGNMENT AND ADJUST FROM THERE
  3. this video may help you to adjust your binos I posted it back in 2009 but still useful I hope. http://www.youtube.com/watch?v=WHtOJAgo-DM&feature=share&list=PLD1AF18073D445B80
  4. Here is my post regarding the Arduino rev 3 and motorshield rev 3 this is relativly new and there is little info out there for this shield, so here is what i have found out so far. it has the ability to drive 2 dc motors independently OR a stepper Motor with 4 or 8 wires from 5v up to 12volts as absolute max 18v. the lateset arduino package 1.01 is required to drive it , this has the necessary drivers and software to modify sketches etc . http://arduino.cc/en/Main/Software I have a Nema 17 stepper with 1.8 degree steps and 6 wires , in my case the colours are standard Nema Colurs : Orange ,Blue , Yellow, Red ,and Black and White , Orange and Blue are one coil with White being Common , and Red and Yellow the other with Black being Common , it seems that Black and White can be ignored under most circumstances, so on the shield the Blue is B+ Orange B- Yellow is A+ Red A- put your power supply into Vin + and ground -neg 12volts or what your stepper requires . after installing the IDE,(Integrated develepment environment)you will be able to download a sketch ( script would be more apt) the sketches that come with this package are not relevent to this shield but can be modded to suit , the easiest way is to copy a sketch for this shield . I can't upload the sketch ( .ino) file so email me if you need it ! i had a few hassles trying to edit or upload sketches until i found the editor is turned off by default ? go to file prefs in the IDE and untick "Use external editor" you can then type in changes to your sketch such as speed and revs etc ,be aware it is absolutely a code and even spaces in the wrong place have an effect , there are tutorials in the arduino forums to guide you , however i found a sketch ,see next mod points [attachment=71164:steppersketch r3uno.doc] #include <Stepper.h> const int stepsPerRevolution = 200; // change this to fit the number of steps per revolution // for your motor // initialize the stepper library on the motor shield Stepper myStepper(stepsPerRevolution, 12,13); // give the motor control pins names: const int pwmA = 3; const int pwmB = 11; const int brakeA = 9; const int brakeB = 8; const int dirA = 12; const int dirB = 13; int x = 0; void setup () { Serial.begin(9600); // set the PWM and brake pins so that the direction pins // can be used to control the motor: pinMode(pwmA, OUTPUT); pinMode(pwmB, OUTPUT); pinMode(brakeA, OUTPUT); pinMode(brakeB, OUTPUT); digitalWrite(pwmA, HIGH); digitalWrite(pwmB, HIGH); digitalWrite(brakeA, LOW); digitalWrite(brakeB, LOW); // initialize the serial port: Serial.begin(9600); // set the motor speed (for multiple steps only): myStepper.setSpeed(200); } void loop () { myStepper.step(200); myStepper.step(-200); delay(2000); } end above. include bracket other links that are helpful http://www.instructables.com/id/Arduino-Motor-Shield-Tutorial/ http://gibsonsystems.com/sblog/index.php?/archives/23-Arduino-Motor-Shield-R3.html I hope this is useful to some one, who like me wants to automate their scope in one way or another , i will update from time to time as my knowledge expands any help/ comments welcome . steppersketch r3uno.doc
  5. Hi mike , my skate wheels are the black rubber type which are quite hard , they are nice and round and don't cog or flatspot ( i did read a comment when researching my project that the weight should be raised off the wheels when not in use to prevent flatspots) , i do have a 2.5 mm thick aluminium edge on my scope which is counter sunk screwed in place . for a smooth movement . I am working on the idea of using 2 halves of a 26" alloy wheel rim off a bycycle as a running face/edge , they are very strong and true and have machined faces and would support a lot of weight with only a minimum of added structure/frame work between them to support the scope , i could even incorporate a friction brake on the rim face as per caliper brake with adjusting screw. i envisage the rim edges running in a grooved skate wheel ( machined to suit) or teflon glide arrangement to create drag . it is in the drawing stage at the moment , i will post updates as i go along , great report from you by the way i am sure trial and error will fix your minor issues . tony
  6. I used a webber BBQ,( the Kettle type) and cut a plywood circle that sat inside the rim (or you could use a bigger board with 3 blocks to locate inside) on top of that board i had another board with a central bolt so i could revolve the mirror instead of walking around it , it worked very well for me , ps i did need a bag of sand hanging below to add weight for stability, i could remove the board and use the BBQ as needed.
  7. ponytale

    4

    flippin Brilliant!!!!!!!!!!!
  8. Hi Mike , The Blue Belt was just some tie down i had to hand to test if the idea would convert the motion to linear over enough distance /time to use a threaded rod to push pull the belt in a straight /linear motion and still allow a reset by slipping the cradle on the belt , i have given up on this idea as there is likely to be too much backlash . as i intend to do short lunar and solar photography eventually, a few minutes of tracking is enough, regards driving the roller , i have read quite a few reports of slippage at the roller / contact point , so i am probably not going down that route ?. one idea i am going to try is a backlash free cogged belt with a stepper motor and matching pulley possibly off the back bearing /axis there is plenty of room for a large drive pully wheel and a small motor to get a very large ratio, i will have to work out the gearing to achieve the right speeds, but around 4rpm i think for smoothness ? I have seen a few variations on horse she/split ring mounts on you tube and mostly American astro sites , Here in Australia we have no pole star for easy alignment . so i have a brick paved compass in my back yard, it is aligned to true south so i can basically plonk it down, level, and use . i will update as i go along cheers Tony
  9. Hi Sky badger: in answersto your queries : The aluminium Band is fixed with countersunk screws which are filled with epoxy putty and filed smooth, they are placed so as they miss the rollers in the most used zones such as perpendicular and about 30 degrees apart as the scope barely moves over 5 minutes whilst manually tracking i have not found it a problem . the blue belt is the best way i could convert the rotation into a linear movement as i was intending to use threaded rod linked to the belt to the drive motor , i may just drive one of the rollers instead ? . the front horseshoe is 2 x12mm ply sheets screwed and glued together giving a very strong 24 mm thick piece which with the Aluminium band added is very rigid, i also have the same size and thickness ply on the rear horseshoe that runs against a roller on the face of the rear panel which keeps the cradle very square on the front rollers ( Three points of contact, the rear bearing pin is only keeping it central to the axis and is slightly adjustable left and right to get a true centre point so the front rollers run true and square . regarding the side panels slumping i haven't had that problem so far i do have some play between the trunnion bearing face and the side panels i have stuck some carpet on the bearing plates which has taken up the play and adds a bit of drag /friction which helps with the steadyness /balance . in the video you can see holes in the cradle side panels this is where i put bolts through to hold the scope square while i marked out the bearing support points these to my mind must always be on the axis line to keep the eyepiece in as true an arc as possible when rotating the cradle and keep tracking errors to a minimum . when i remake in alloy i would have very small tolerances inbetween the trunnions and the cradle side panels with bolts throught into the ota so i could adjust friction and prevent sideways shift when the scope is leaning over at steeper angles. i do have a large weight on the back of the Mirror box which helps a lot to keep it steady , the secondary mirror cage is a bit too heavy really but it is sturdy and in my case holding my 4 strut tubes square, as this is fundamental to colimation i am loathe to lighten it at this stage , i have messed around with springs and counterbalance systems but they add other problems, i am still trying to perfect counter balance issues by moving the trunnions in small increments on the mirror box as well as the bearing blocks on the inside of the cradle, it is a juggle to get balance and clearance correct. My main intention was once i have the measurements right and the balace sorted to remake the cradle and frame in aluminium plate and tube, then cut out a lot of unnecessary material in an aesthetically pleasing style . my base frame has pivot points where the front panel joins the lower frame so i can fold it flat for transport, and in aluminium i think i can make the cradle part foldable / dismantleable also using simple threaded holes and knurled bolts . hope this is helpful. regards Tony
  10. thought you might like to see my horshoe mount prototype, http://youtu.be/KCp-uk46v_Q
  11. Thanks Peter , i suspected as much , never hurts to ask though .
  12. Hi all , I finally adapted an old 102mm meade ota into a solar scope with a badder film filter, I had it in time for the transit of venus but here in Perth australia we were completly cloud covered for the whole day , pooh pooh, I did manage a short glimmer of sun this past Friday and readily saw two distinct sun spots before the clouds rolled in for more rain and heavy winds of 125kms per hour, the forecast is for more cloud and storms for at least a week !!! this is what happens when i buy new kit. I can't wait to have another look and take some pics . ps is there any other filter /film that goes over the top of this film to show more detail ?
  13. waiting for an update good luck!!! Tony:)
  14. hI Gina , just thinking about your cold finger problem, hope this is not stupid in any way as electrical circuits are not my area , why not use copper cable with insulation to make cold finger perhaps with copper disks (eg small copper coin ground flat and soldered on to each end or even several small cables that you can thread around the circuit boards , if the small circuits that power the chip can deliver the energy to heat it why can't the same sort of cuircuits diisipate it if there are conected to a cooling device? sorry if it sounds too simplistic but thats the 1st way i always think about a problem then move on from that. best o luck with it anyway. Tony
  15. Gina would it be possible to use a vacuum cleaner bag the 5 layer paper type with the lens poking through the inlet hole and the fan sucking through the camera spaces and exhausting outside of your cooler box , I am sure air will flow better being drawn in than pushed out eg: car radiators . these bags are supposed to filter down to micron levels to remove allergens and pollen , also some anti static spray to repel particulates ? would be useful . regards Tony
  16. see this link below it will do everthing you need if you pay the gold membership , i did and it is great. http://settingcircles.robertwillett.com/
  17. Hi Gina, i have been following your threads with interest, i have been thinking about your issues , 1: have you tried an earth jumper ( a short piece of wire with clips to bypass the system chassis/ ground with) . 2: using a sd card from camera 2 with different battery you know is good, 3: removing all batteries for a hard reset . 4 reflashing firmware using copy from your camera 2 5: is the inbuilt battery holding a charge ? 6: continuity test with ohmeter on ribbon cables to rule out hairline cracks ? i would love to see you beat this problem !! hang in there and best of luck !!!
  18. an update on progress so far : tested tracking on the moon during the day and was pleased with the way it worked only needing a slight nudge on the cradle to track the moon after ten miutes of gentle nudges in one direction only the moon was still in the eyepiece which is great, i am happy that a motor on the ring edge will give me what i need for some basic imaging rather than a tangent arm set up which by all accounts has potential for introducing more error. I am going to fit some levelling feet to the base and make it more compactable with the cradle part being the heaviest part i am hopeing to make it out of ally tube if i can get the tube bent into accurate rings for not too much cost, i have thought about using alloy bike rims for the half circles with 18mm ply inserts for the trunnion/brgs to run on , just an idea running around in my head at the moment !! i will sketch it up and see whats involved . Tony
  19. I have looked at this idea a few times and wondered about a washing machine motor and some of the controls it seems they run from slow wash cycles can oscillate back and forth and can spin from 400- 1200rpm via control panels . they can be had for free on freecycle etc , any thoughts/comments would be appreciated ,Tony
  20. this link is for anyone who wants to print setting circles etc for their Dob base , I just paid rob for his software use and i got a personal email while he is on the train , how nice is that and brilliant software to boot!!! Setting Circles -
  21. I cut less than the cutout initially but had insufficient room for scope to reach zenith so out came a bit more!! it is quite strong as it is 24mm plywood 2x 12mmm glued and screwed together , I tried to make from existing dob bases and now know i should have used bigger diameter circles to start with , i have slightly modified the split into cradle type which is stronger and more ridgid , I want to try what i have first before i remake to something a bit smarter , but it is an excersize in itself,especially the working out of the angles and joints , i have a rudimentry knowledge of geometry etc so found it a bit hard at first. here are a few more pics of the set up with cradle it allows more movement in where the scope bearings sit, hence better balance and greater movement, the two rings of the cradle are now on bearings and i am working on a tangent arm and threaded rod setup to test out accuracy . Tony
  22. Photos of split ring mount during construction/conversion, angles all seem good and ota assembly fits in and is stable at 30 degrees of rotation either side of perpendicular, a total of 60 degrees rotation , balance is not perfect yet but i can fiddle with that , i am more concerned with the polar axis alignment being stable/consistant throughout rotation, which means very accurate bearing alignment especially at the rear/north bearing, i am thinking of making a bearing mount that is eccentric that i can rotate in a cylinder and adjust as required , or even a disc with a bearing in the centre that is spring loaded at 3 points with adjusting screws at 120 degrees , any ideas /comments welcomed . tony
  23. Hi John , yes i am at 31.4 South just north of Perth, pics soon ! Ps i am happy with my mirror and plan to do my other piece of glass soon , and i now work in a tile shop so mosaic tiles no problem , there are broken porcelain tiles with no coating/glaze i may use some of that? Tony
  24. my new diy project is converting my existing dob to split ring type mount which will allow easier southern polar alignment and easier viewing with a plan to motorize the split ring to sidereal rate for planetary video and photography, after 2 days work with a few snags with angles etc it is almost assembled , the attached sketch is my aim based on the web link below. Telescope Mount Details i will take a few photos to post if there is any interest ? tony
  25. jam1e1, try cuting a circle out of paper the same diameter as your mirror ,fold in half very precisely and then fold in half again , snip off the corner point only and you have centre of your circle, use as a mask to mark your mirror, ps the spot lies in the shadow of your secondary so will have no effect on image . another way is to use drawing tool in word , select donut from shapes menu and scale outer circle to your mirror diameter using rule function and scale centre down to spot size, print and cut out. tony
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