Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.


  • Content Count

  • Joined

  • Last visited

Community Reputation

11 Good

About pete98

  • Rank

Profile Information

  • Location
    Boston MA
  1. Have to give all the credit to this project to a guy named Joe B. Saw his video about a year ago, and knew I just had to build one of these. https://www.youtube.com/watch?v=gA-wQFrSTGY While he does a great job of showing what he did, it wasn't a very good job of showing how, so will do my best to show how I built mine. What I was looking for was a fine focus unit. Something that would allow me to manually rough focus, and finish fine focus with a remote. Wanted a pulley system that had the largest ratio, and yet would slip when I was manually focusing. Unit had to be small enough so it did not interfere with moving the scope in declination, specifically when trying to point scope at NCP. Also had to be small enough not to interfere with any equipment (cameras etc.) The robots are usually available on ebay. First one I got (and one I used) was a little different from Joe's. This one uses a small rechargeable battery vs the 3 button cells. When I first started all of this, assumed I would be de-soldering the IR sensor off the robot, but turned out to much easier than that. All that really needed to be done to the robot was remove it from it's case, cut the leads going to the robot's motor leaving as much wire as possible, and cutting the leads from the rechargeable battery leaving enough wire on the robot board to solder two wires to. I would imagine if using the same robot Joe used, it would mean having to solder 2 wires to the connection point on the circuit board where the button cell holders connect. I always have 110 power when using the telescope, so rather than try to do a power pack, just found a box mountable DC power jack that would mount to the finished unit. There was a small resistor attached to the Robot's circuit board that ran in series with one of the motor leads that I decided to leave on. Not sure how much faster my end product would have run should I have decided to remove the resistor. I got lucky with the first (of 3) servos that I bought. Redcat Racing Tornado S30 Hexfly HX-3CP Standard 60oz Steering Servo I am running 4.5v to the robot. Never put a meter to see what the robot was outputting to the motor, but has to be less than 4.5v. The other servos I got, but did not use (MG996R 55g Gear Servo Motor ) will run fine it I hooked them up directly to the ac power adaptor I am using, but would not turn if I connected them to the Robot board. But, they did come with a little gear pack that proved to be invaluable when hooking up the pully to the servo drive gear. Adapting the servos turned out pretty easy too. Took out the 4 screws holding the unit together, and dropped the top case cover off. Cut the 3 wires going to the servo board. De-soldered the motor from the circuit board, and discarded the circuit board. No need for the servos potentiometer either. Re-soldered 2 of the 3 wires from the servo connector cable to the motor. No polarity issues here, unless I wanted to make sure when I hit a button on my remote, the motor would rotate a certain way. two leads pictured will get attached to the wires from the robots circuit board that originally went to the robot motor Put the top cover back on, and removed the bottom (the gear section) cover off. There is a pin here that has to be removed that stops the servo from turning 360. Seems some pins have to be cut, some pins are just a press fit, and have to be pushed out. Plenty of pics one the web of the servo gears in case someone can't figure out how it all goes back together again. So now I have a servo that turns 360, have the original servo wiring coming out of the servo case, and the other ends of the 2 wires I soldered to the servo motor will get connected to the two leads on the robot circuit board that use to go to the Robot motor. This is all on a vintage C8. The collar on the back plate of the scope where the focusing knob comes out was a great place to mount the unit. Being limited to what materials I can work with, and not wanting to use wood, I stumbled on a small (5inx7in) plastic cutting board about 3/8th thick for less than 2 dollars. It was easy to cut, and painted up much better than I expected. I didn't have a hole cut bit that gave me the tight fit I wanted, and ended up having to make a slotted collar. The large gear on the focus knob is from the same material. this slips onto collar on back plate that focus knob comes out of. The plastic gear/pully set i got off ebay had the smaller pullies I wanted, but they had axle shaft holes, and I needed something with a spline to attach to the servo gear. This is where the gear pack that came with the second servo I bought came in handy. I used the small round gear from the servo gear pack to attach to the servo drive shaft, then super glued the pulley I used to that. Finished unit Four screws are holding the servo, two green led's are the Robot's "eyes". and IR sensor is sticking out above the eyes. To show how slow it all turns, put a red dot on the pulley, and this is how much it moves if the remote is held for 3 seconds. There is enough slip in the unit so manual focusing is easy. Rubber band does have a tendency to "load up" on one side when manually focusing, so when I let go, focus knob moves back a tad. But not having an image bounce around when I put my fingers on the focus knob to hit that last few mm of focus is a dream come true. And while my dslr does not have live view, my Philips webcam does, and being able to just look at the laptop and push buttons on the remote vs reaching over to focus while watching the laptop is great.    
  2. Whew, outstanding pictures Mike. I'm banking on the mask working as well as some people say it does.
  3. Yes, to say I am behind the curve is an understatement. Everything in it's own time I guess.
  4. Thanks, just ordered a T adaptor with a 68mm ext tube. The Canon 300d does not support live view. But once I get the mask, I should be good to go on focus.
  5. Ok, I took my first Deep Sky pic the other day, and am thrilled, but pretty sure I can do better. Have to fight off the temptation to do more deep sky objects, and focus more on just getting stars as sharp and crisp as I can. Hopefully that will make any deep sky stuff I do much better. Focus for me has always been an issue. Just purchased a Farpoint Bahtinov mask. My Canon 300d does not have live view, and the viewfinder is ALWAYS in the worse possible place to be looking thru, so going to assume I will have to take a series of short exposures, and adjust my focus that way. I did watch Farpoint's video (https://www.youtube.com/watch?feature=player_embedded&v=aMdkXrkygDk), and am wondering, they are using Vega, and ok, its a bright star, but at focus, the star is still a pretty big object. When I see all these fantastic images others have take of deep sky objects, and they are getting pin-point stars, what is it they are doing to achieve this over the "larger dots" you see in most peoples first attempts, Hopefully its not just a matter of equipment I can not afford to buy. vintage c8 canon300d
  6. Wow, just the "save as 16bit tiff" in DSS did wonders. This is the stacked picture. Opened that up in Photoshop, and if I understand you right, the triangle on the left is pretty much already at the beginning of the curve. If I move it at all to the right, the sky gets darker, but the nebulosity starts to disappear. But at the moment, I am pretty happy with what I have. Nigel, I will take your advice and get Star Tools. Really appreciate the help guys.
  7. Thanks for all the advice. Will try everything suggested and post results.
  8. Was the first rainless/cloudless nite in about a month here, and temperature was up to a balmy 40° F , so just had to take the scope out. Considering back in the 60's, when I was an avid amateur astronomer and spent countless hours trying to photograph this object without any luck, I was pretty happy. But, know this needs a lot of improving. Registax and DSS make my head spin. Really need to find some step by step "stacking for dummies" tutorial. Not that I am a dummy, cause im not...im just getting very old I guess. Vintage c8 at prime w/.5 focal reducer. 30sec @ 1600 iso. Canon 350d. Seeing conditions: fairly good sky, but light pollution an issue. Exposures longer than 60sec get very washed out. One of 10 images. But when I stacked using DSS, I got this. Can anyone tell me why I lost the "dark sky" background?
  9. Have an older black tube c8 fork mount on a wedge, very similar to the one pictured. Credit to http://neffj.people.cofc.edu/WWW/observatory/IntroLabs/celestron_manual.pdf for the picture. Tube assembly is a bit off of alignment with the fork mount. If the fork is pointed at the NCP, the tube is pointing at a point a little off. Not too much, but probably too much to do unguided photography. There are 2 allen screws holding the tube to the fork mount. (yellow circles in the picture) Was wondering how much adjustment I would get if I loosened them, and tried to shimmy the tube assembly a bit. With reference to the picture, I would try to move the tube assembly East or West a bit. Anyone every tried this, or had to do it? Not even sure if there is any play in the mount where the 2 allen screws are.
  10. For what it may be worth to anyone, this serial adaptor does have all the serial pins, and worked fine (under xp) search ebay for: High Speed USB 2.0 To RS232 PL2303 Double Chipset Serial Convert Adapter HR very soft plastic case, cut away very easy. Less than 2 dollars vs 9.00 for the Sabrent adaptor.
  11. Thanks for the reply Julian. Guess I should have mentioned I have a 20+ year old Black tube C8. I don't even have slew on the dec axis (other than a thumb knob). I've seen some of the other ideas for focusers (including the one you pointed out), but what I am looking for is something that will give me a fraction of a degree turn over a couple of seconds....ie real fine focusing.
  12. A little relicutant to even post this topic, cause bringing up such an old posted subject got me banned on another forum. And as always, if this has been discussed in another post and I missed it, my apologies. Not that long ago I stumbled over this YouTube DIY IR Focuser by Joe B. I have always wanted something that let me do my rough focus manally, but have some sort of slip connection in there that let me do my super fine focus motorized. Being able to do it with an ir remote was a bonus. Video shows what he did, but does not do a good job of showing how he did it. Not knowing much about IR sensors, and servos, I went out and got the Robot and servo, and as you can imagine, was not able to duplicate what Joe did. All my google searches on controlling an servo with an IR sensor took me to "Arduino". A little control board that needs to be programmed. No where in the video does he mention Arduino, and looking as hard as I could to determine what is involved in his set-up, am not so sure he used an Arduino control board in there. I have ordered an inexpensive servo tester to see just how bad I messed up the servo I have, a couple of robots that I think are more like the ones Joe used, and another servo. And now that I know a little more about servos and IR sensors, does anyone know if the pulses an IR sensor give off when triggered are sufficient to send a signal to an RC Servo motor on that orange wire. Am also thinking that what Joe did was de-solder the servo motor from the servo control board, remove the servo control board, and then place the robots control board into the servo housing, and have the robots contol board control the servo motor. If anyone has any knowledge or experience with this project, would appreciate their feedback.
  13. Having never completed my PCV675 mod, I just had to do this mod for piece of mind. With all the talk about the bad usb-serial adaptors being sold, I decided to get mine direct from Sabrent. I'm going to guess they changed the way they made the molded plastic on the ones being sold now. It's almost a "hot-dip" Very difficult to cut away from the board. And to make things worse, they changed that capacitor (the CC30PB in the OP pictures) from a board mounted cap to one with 2 very thin leads. I broke one lead off at the base of the cap getting the enclosure off. Not enough to solder too, but think I succesfully super glued the wire back on. The computer recoginzes the device, but guess I won't know till the rest of the mod is done. Funny, as soon as I noticed I broke the lead, I went on ebay and got another cheap adaptor. Do belive I got the same one pictured by Nebula. Never noticed there were only 5 leads on the serial side, but damn it looked so easy to break away the clear plastic case.
  14. Just wanted to clarify that while the mod will allow me to use polar alignment software, I will also be using the camera for LX exposure.
  15. Know this has been discussed in other threads, but thought best to start a new one. Have ordered everything I should need for the outstanding mod described here: https://stargazerslounge.com/topic/109153-spc900-lxmod-yesyes-style/?page=1 and btw want to say congrats to the OP for his outstanding work. I have been looking at this and other threads on the modded camera for quite some time. I attempted the PCV645 mod, and while it wasn't a total disaster, it didn't work either. Was going to resurrect the project until I realized I would have to be stuck with XP. Other then the simplicity of the SPC900 camera mod, what has always gotten my attention is the little fans I would see attached to the end result. My first impression would be "isn't that going to shake??" So now that the project is in the works, have to address that, and some other questions. So first question to all those who might know. Assuming I use a decent quality fan, in a Prime Focus application (8" vintage Celestron black tube if that has any bearing), will the scope experience any shaking from the fan. With all the projects out there that have used fans, going to assume the answer will be no. Placement of fan(s). Have read some posts where people have indicated there is a need to get air flow over 2 chips, and not just one. Seems to me this would be better accomplished by having a fan mounted on the side of the unit vs on the top, or bottom. In other words have my air flow going across this part of the unit pictured below, and not down onto it. Not sure how much air flow I should be looking to achieve here, and not sure if I should be considering a push or pull fan. Do want either an intake or exhaust vent on the other side of the housing. have been looking at these items pictured below. (apologizes, am having a hard time figuring out how to place the pics in the body of the post) When I do my build, will not be trying to use the smallest case available, but rather one that will allow me to get the best air flow over those parts that need it. Application for the project (assuming it works) will be primarily Polar Alignment. I do have a DSLR (canon eos 300d), but it lacks live view.
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.