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  1. It's an ED80 with the stock focuser. I think there is some astigmatism somewhere as my stars can be a little stretched and so I want to see if I can use a collimating laser to check if the focuser is in straight. (I'm also going to make a determined effort to get the spacing right between the FF//FR and the sensor, but that's another story). I can't see any threads that get into the detail of lining up the focuser with a laser. If I put the laser in with the target bit facing up, then the red dot that bounces back off of the lens is slightly off centre on the target on the collimator. If I loosen the screws, turn through 90deg, retighten and look again, then the red dot is in a different place and so on all the way through 360 deg. I'm thinking that the red dot should be central (as when collimating a Dob that I used to have). Is that right? It may be that the laser needs collimating, but I'm not sure how to do that. Any advice on whether this approach is going to get me anywhere would be appreciated.
  2. Hi All I thought I would share how I fixed my sloppy rack and pinion focuser on Skywatcher 130p. The issue? When using or collimating the slop in the focuser would put the target or centre dot way out of line. With the tube tilted downward I removed the 4 screws/nuts of the focuser to remove it from the OTA. Loosen the lock and 2 adjusting screws, I used a small torx screwdriver as i did't have an allen key small enough. Remove the 4 screws holding the adjuster bar in place, and remove the adjuster. Note: Be careful to avoid the very sticky grease used on the drive! Remove the draw tube assembly, remove the lock/adjusting shim located at the top of the main body. There were 2 plastic shims 1 each side of the drive I removed both of them. Thoroughly clean everything with degreaser and isopropyl alcohol except the drive itself. I cut 2 plastic shims from food packaging, cleaned them, and using 50mm double sided tape I lined out the main focuser body. Be careful to cut to the correct size and shape before installing and don't cover the drive or lock/adjusting shim areas. Next using teflon tape purchased from eBay I covered the draw tube exterior. I then did the same covering the plastic shims in the main body. It was still a little loose so I doubled the teflon tape at the top of the tube either side of the adjusting shim. Next I added a plastic shim onto the adjuster shim and covered with teflon tape. Put it all back together and almost no slack! I can now move the focuser from fully in to fully out without the collomation moving out of the centre ring on the primary. Complete success I think.
  3. Having suffered for some while with broken teeth on my Tracelscope 70s plastic focuser rack; I finally got around to doing something about it. First of all I cut a piece of aluminium (aluminum for our friends across the Pond ) the same size and dimensions as the plastic one on the focuser tube. Using the damaged one on the tube as a template, I marked out the replacement and began to file it down to size. Once this was done I copied across the positions of the valleys between the teeth onto the aluminium replacement. Using a manual mitre saw with a blade suitable for metal I cut the valleys. Some rough filing and the rack was almost complete. A hole was drilled at each end to receive a screw. I then cut off the plastic rack from the focuser tube, filed the cut flat and the glued and screwed the replacement into position. Due to the rough hand marking, cutting and filing it is not 100% smooth running, but at least it gives me full travel. A couple of pics: Broken plastic rack (removed). New aluminium rack glued & screwed in place
  4. Hi all, for my next upgrade on my Skywatcher Startravel 120mm refractor I'm thinking of upgrading the focuser to a dual speed 2" Crayford focuser http://www.firstlightoptics.com/skywatcher-focusers/sky-watcher-dual-speed-2-crayford-focuser-for-sky-watcher-refractors.html A couple of questions though before I possibly fork out for one in the next month or so; 1) Does it need any other adapter ring or anything to fit OK into the existing place where the stock focuser sits on the ST120? It is just a straight swap right? 2) Does the two speed focuser action significantly improve the action to get a sharper focus much better and easier? I currently have a Skywatcher Auto focuser fitted to the stock focuser on the scope, but find the constant small jabs back and forth you have to do on the keypad a little annoying to get good focus, and hope the finer focusing option on the Crayford focuser might be easier to achieve by hand again if fitted to the scope. Regards, Gus
  5. Ardufocus is a full open source Moonlite compatible focuser. The source is still under heavy development so things move around a bit. To access source code and detailed instructions visit the Github repository, for the 3D objects visit Thing #2446069. Motivation After buying the CCD, filter wheel and filters I was broke but still wanted to have an automatic focuser. Design Goals Moonlite compatible: This was a very important part of the design as I didn't want to spend time and effort dealing with ASCOM and INDI drivers, the Moonlite focuser is a well known, reputable rock solid focuser. The serial protocol used by them was easily reversed engineered (plain ASCII) and most of it was already documented on the Internet. Cheap: Another big point was to made it as cheap as possible recurring to as few parts as needed. That's the reason why the 28BYJ-48 stepper motor was chosen, out-of-the-box using the ULN2003 gives you a really cheap (less than 2€) focuser for medium loads (380gcm). If you require the focuser to driver heavier loads (800gcm) then the motor itself can be modded into a Bipolar stepper motor and driven by the A4988 step stick which will cost you less than 1€. Builder friendly: Using off-the-shelf components such as the Arduino Nano and easily available parts Ardufocus is aimed to be build by anyone with a soldering iron and some patience, no degree in electronics required. Hardware It was built on top of a standard ATmega 328 Arduino such as UNO, Pro or Nano; currently it does not support the Mega or any other ARM based board. BOM 1x Arduino Nano 1x A4988 Stepper Motor Driver Module 1x Electrolytic capacitor 10uF 1x NTC 10K 5% 1x Resistor 1/4W 10K 1x DC Power connector (male, female pair) 1x DB9 connector (male, female pair) 1x 28BYJ-48 Stepper motor 3D printed parts To download and print instructions for the 3D printed parts have a look at the Thing #2446069. A4988 driver with a Bipolar motor Example schematic how to building and Ardufocus using a modded 28BYJ-48 Stepper motor.
  6. I am selling my Moonlite installation kit for 8" newtonian focuser as shown here https://www.firstlightoptics.com/moonlite-focusers/moonlite-installation-kit-for-newtonian-focusers.html The installation kit was fitted on my 8" dobson in Italy and used very little (it is essentially new). I no longer need it as the focuser now sits on my 12" dob. New £58, my price: £40 (including RM 1st class signed-for). PayPal (pay as a friend) or direct bank transfer. Also advertised on ABS. Thanks for looking, Piero
  7. I've upgraded my focuser so have a Skywatcher Dual-Speed Low Profile 1.25/2" Crayford focuser for sale £70 delivered to UK only. Bank transfer or Paypal F&F preferred.
  8. Anybody used a Lacerta Dual Speed 1:10 Microfocus Upgrade Kit for Skywatcher Crayford Focuser? Are they any good? easy to fit? or should I just spend the extra to get a full dual speed focuser? cheers for your thoughts
  9. Hi, I have a 3" focuser on my APO 5" telescope. High quality and works very fine, except it could slip sometimes in the friction coupling. Even if I set the force higher with the adjust screw it slip sometimes. When the telescope get wet from moisture the water act as an oilfilm and lubricate the axis and steel plate friction surfaces. Now I must do something about this problem, took the focuser apart yesterday and looked after what was wrong with it. I have as usual documented what I do, for myselfe and all other that maybe have the same problem: http://www.astrofriend.eu/astronomy/projects/project-focus-friction/project-focus-friction.html I will update the page when I have done the first test after my fix. Any smart ideas how to increase the friction? /Lars
  10. Hi, Earlier I have made a calculator to find the telescopes depth of focus: http://www.astrofriend.eu/astronomy/astronomy-calculations/depth-of-focus/depth-of-focus.html Now I have continued with a gear ratio calculator for the motor focuser: http://www.astrofriend.eu/astronomy/astronomy-calculations/focus-gearbox-ratio/focus-gearbox-ratio.html Sometimes it could be tricky to find the correct gear ratio and maybe this could be of some help. It's important to have the stepsize about 5 times smaller then the depth of focus. Note: This is all new, I may have done some mistakes, check carefully before ordering any parts! /Lars
  11. Hi all gazers, i am having second thoughts about getting a crayford for my C9.25 (non HD) and that is because of the 0.63 Reducer / Flattener that i am imaging with. As camera i use the Nikon D7100. According to my calculations, and what i have read on internet, the optimal distance between the reducer and the chip is 105mm, the only focuser that allows for this distance (107-ish mm) is the feathertouch with the "shorty" sct-adapter witch is 56mm, my nikon T2-flange to the chip is 50mm. The Steeltrack and moonlite is far to long (93 and 91mm) But, according to some people, i can put my FR after the focuser with good performance, but how would that effect the reducing, and flattening? are there any out there who use crayfords and reducers on their SCT's with DSLR's? If nothing seems to work, i am getting the feathertouch microtouch replacement for the stock SCT-focuser. // Daniel
  12. Hello all! I want to upgrade the focuser on my Skywatcher 8" truss dobsonian. I want a dual focuser that's a direct fit to my Skywatcher. Any suggstions ?
  13. I've mostly finished the bulk of my scope's parts design but I'm stuck on the focuser now; specifically on where it should be along the optical axis and how much travel to allow for. My main concern is, when the focuser is fully racked in, how far outside of the focuser tube should the primary focal point be, and how far inside should it be when fully racked out? Some info that might be useful: I'll be using it for astro observing, no imaging or terrestrial viewing. It's a 150mm f/5 scope and I'll use a range of EPs and Barlow with it. Do you have any guidelines for me on this topic? Some further reading references to theory and literature will also be helpful.
  14. Hi folks, I wonder if I may ask advice for what software to use for observatory automation and imaging. I am currently working on a little newt for astrophotography. I've come to the point of making the focuser. Now I was just going to make a simple manual focuser because it will just be one camera mounted there all the time. In an ideal world I would just set the focus and forget it, now I'm getting the feeling I may have to adjust it more often then I anticipate. Being a remote observatory, I thought it might be silly to have to run out to do it manually. So this leaves me with an electric focuser. I spent some time last night looking into a few options, I am going to go the DIY route. I guess the crux of my question is do I go down the ASCOM path or the INDI path? This should really be a question I decide on my own, but I'm not prepared at this point and want to continue with designing the focuser project. Essentially I want to run a small observatory from inside. Open the obsy shutter, slave the observatory to the mount, get weather, maybe a skycam, goto, tracking and Stelarium. I'm a little overwhelmed, I guess I need to decide the "main" software before building the little accessory computers? SGP sounds interesting, then again so does EKOS... Should I go ahead with the "ASCOM myfocuser" type build?. I'm not even sure how the camera interfaces with everything, ie: does it communicate with the focuser for auto focus, or is it all controlled by the main piece of software? Actually I'm unsure if I can even do this with a Sony camera, perhaps I need a Canon, I know they are a little friendlier when it comes to using extra software. Any info and experiences would be appreciated.
  15. Is it possible to fit a dual-speed focuser from a Sky-Watcher Equinox Pro 80 (following on from an upgrade) to the Sky-Watcher Evostar 80ED that came with a single speed focuser? Is there an adapter that can be sought for it?
  16. Hi again, another newbie question. I bought a used Skywatcher Quattro 10" CF ota. In the future I intend on some astrophotography but currently i'm interested in visual. Regarding the focuser, it did not come with any accessories, only the 2" focuser itself...and all of my EPs are 1 1/4". I bought a 2" to 1 1/4" twistlock adaptor and tried a meade 32mm plossl. I seemingly could not get close to focus. This did not really suprise me as the scope is primarily intended for imaging. Is it correct for me to assume that I require a 55mm extension tube/spacer to be able to reach focus on the eyepiece? If so, would a 50mm spacer maybe work? Many Thanks for any info.
  17. I just bought an Istar 150mm F12 lens and cell and will be building the telescope to hold it. The guy I bought it from has generously given me some excellent advice, so I know where I will get the aluminium tube and how I will cut it, how I will plan the light path and baffles, and how I will flock it internally. He also suggested a couple of focusers that he has used and likes. I think I will probably go for a Moonlite focuser as I have one on a newtonian and I really like the smoothness and precision of it, but I am also considering a couple of others. Do any of you have either the TS Monorail or the Baader Steeltrack? What do you like and dislike about them? I will be using the scope for visual observing only and the heaviest eyepiece I will use on it will be my Explore Scientific 30mm 82° at 1.4kg. Thanks.
  18. A couple of months back I began contemplating a new focuser for my LS60. Original post In the end I decided to go for a Moonlite (from FLO) and it arrived yesterday . I'm very happy with it! I'd identified a few possible options: Baader Steeltrack (~£210 delivered from TS) JMI Event Horizon (RVO said they could supply but did not respond with a price ) Feathertouch (I contacted Widescreen - where I bought my LS60 - but they did not respond with a price ) Moonlite (£330 delivered from FLO) In the end I went with the Moonlite because I have a Moonlite on my Dob and it's lovely (and because it looks cool in orange!) Andrew
  19. Second sunny day in a row so another chance to play with my new Lunt 50 Ha scope. I had read Gary’s post so I knew there was plenty of limb activity on show. The large prom at the 2 o’clock position was fairly easy to spot but I struggled to find the others . I could see there was something there further down the limb but it was very indistinct. I played around with the pressure tuner but to no avail. It then occurred to me it was probably a focussing issue. I replaced the supplied focuser with a Feather Touch focuser. What a difference. Easily spotted the other proms and could make out a fair bit of detail. Although this is only a single action focuser it is very smooth to use and fine focus adjust is easy. Now after a warming coffee I will get back out and try to sketch the proms. Not that I am much good at sketching, but it is fun to try.
  20. I've been struggling to find an answer to whether a 2.5" focuser is likely to cause vignetting on a full-frame (36x24mm) camera sensor. This would be for an f/7 130mm scope, probably used in conjunction with a 3" 0.79x focal reducer (stated to have an illuminated image circle of 45mm). Whilst the focal reducer should fully illuminate the sensor (having an M68 connector on the scope side and M48 on the camera side), it is not clear whether any "mechanical" vignetting might occur with a 2.5" focuser drawtube. I imagine this would depend on the backfocus of the scope - i.e. how far the focal plane is behind the end of the focuser. If it's a long way back, I can visualize the light cone potentially being restricted when it enters the drawtube inside the OTA. Hopefully, the scope isn't designed this way, but it's hard to tell. If there is no mechanical vignetting, it does raise the question of what the benefits of larger focusers are. Greater load capacity certainly; improved stability? maybe. But does it actually give a wider unvignetted image circle? I'd like to apply some science to this question, rather than buying a bigger focuser "just in case"! Thanks for any answers! John.
  21. Okay folks, so, for a variety of reasons, including but not least an appalling sequence of poor weather since my last post on this particular topic, I have been unable to obtain an accurate measurement of the focal length off my 8” EdgeHD incorporating Baader SteelTrack Focuser and Click-lock Diagonal. I managed to remedy this situation over the weekend just past. Initial measurements based on adding the optical path of each of the components together, had the complete resulting optical path at about 2400mm, however this was not bourne out in practice. Using my 22mm T4 Nagler, at 2400mm focal length this should have given approx 45’ TFOV. Using M81 and M82 as a yardstick (approximate separation 36’), they should easily have been visible in the same field of view, however they were not. Extrapolating back from these values seems to be indicating a focal length somewhere between 3000 and 3225, which makes the revised speed of the system a whopping F15 to F16. This must be having a significant detrimental impact on the sub-aperture correction inherent in the Edge HD design, so I’m thinking of removing the Steeltrack from the system and replacing with a FeatherTouch or equivalent. This measurement is actually consistent with a drift measurement I made last year, (instructions courtesy of Don Pensack), but discarded due to it being so far removed from the expected result nearer 2400mm. But the proof as they say is in the pudding. So for those considering adding a Crayford to their EdgeHD, based on this experience I would say don’t. From feedback on this topic in CN, it is very possible that it is something to do with either the slightly faster primary/secondary combination in th EdgeHD and/or the sub-aperture correction in the baffle tube, possibly resulting in significant vignetting. (Thanks to Don Pensack and Edggie from CN, for their input). If you are interested in reading the CN thread discussing this you can find it here: https://www.cloudynights.com/topic/574002-calculating-effective-focal-length-of-an-edgehd/ Kind Regards Paul.
  22. Do somebody using Dual-Speed SCT focuser for Cassegrain? Read about it and all of users say the same-it's a huge improvement. Can anyone share your experience with me in case? I found one on FLO - MoonLite CS Dual-Speed SCT Crayford ,looks impressive.
  23. I've decided the Skywatcher dual speed focuser is not up to astrophotography, there's too much play in it, I've tried tightening it up but it still flops about. My sweatheart has asked me what I want for my birthday/xmas presents, as the are very close together I don't mind just the one. So the question is which should I go for, either the Baader Diamond Steeltrack or the Moonlite CR2 dual speed crayford which with the installation kit will be quite a bit more in price.
  24. I've been whiling away my shipping wait for my hardware by watching and reading about Arduino and Stepper Motor control (Specifically). I was watching one rather informative video where the author hit on another library for the Arduino, AccelStepper. It appears to be a bit simpler than regular Arduino coding, which was attractive to me. But what really brought me running was that it can accelerate and decelerate on either end of the command. Think of it being a Soft Start for a stepper motor running your focuser, or a Filter Wheel. Soft Start? Yes, a Soft Start, and also a Soft Stop. Making your stepper motor gently begin to move, traveling to your selected point, then slowing the travel so it coasts in to what you requested. Soft Start is becoming quite common for a lot of motor driven devices. So my thoughts on it were to program my upcoming Arduino projects with my own Soft Start and Soft Stop to bring the focuser to Step XXX and when trying to toy in a best focus, the automatic Soft Start could aid in getting gentler adjustments. I bounced this idea off of my friend and he said that ramping speed was more for CNC machines and the like. And that tweaking in a focuser was more like around 70 steps to get the human eye to see the difference. I don't know (yet), but it seemed to me making any command gentler on the overall equipment might be a better idea. Arduino (I've been led to believe) doesn't have this Soft Start - Soft Stop in their library yet. If you would like, Here are the links to this idea: The Maker Show by Bret Stateham. If you scroll down on this page, there are quick links to the different parts he covers, including the AccelStepper part. Quick Link to the AccellStepper Part. Or a bit before, where he refers to the Library, and where this software will be if you choose to download it for your Arduino Programming. I did, so it is there when I get my hardware here and actually begin my developing. (I prefer to have things in front of me as I prototype. I'm a hands on kinda guy.) I searched to see if this had been posted here, but found nothing. So I thought I'd offer it up to anyone who might be interested. OK, back to hammering on my brain. (Think: A BB in a Boxcar.)
  25. Interested to hear what other XT10/XT10i owners have upgraded their focuser to, and how they are finding it. The Orion own low profile dual speed 2" crayford style hybrid looks ok at around £225 although some people mention gaps left after fitting - need to be plugged eg with foam to keep out stray light. As it should be a straight swap over, though, that is good - I'm not going to start drilling my OTA. I like the idea of low profile to help achieve focus when attempting simple AP. Moonlite focusers seem well liked and there is a vast array of them. But as they are not low profile I'm tempted to go for the Orion instead. Is there likely to be much noticeable difference between the Moonlite and the low profile Orion focuser? Are the Moonlites an easy swap over? Any comments at all about focusers much appreciated. Thanks. Tot
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