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About Jim09

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  1. Thanks Hugh, I haven't heard of that so I'll do some research on that with my setup. I'm really pleased with all the help and new suggestions guys, thanks very much again.
  2. Thank you James , that was new to me , I will have a look. The other option would be to use .net core and publish the application from a PC to RPi, so it will be full blown .net but still has the hassle of dealing with linux
  3. Thank you Julian and Gina I guess I'll stick with my preferred windows/.net path and see how things go , failing that I can try it with RPi as the last resort.
  4. Since the limitation on floating point precision on arduino , I'm planning to use arduino to control stepper motors in my DIY mount with RPi or a PC working as the master giving commands to the arduino I'm a C# developer so my plan is to control the arduino from .net application via serial ports, which I managed to get the proof of concept working with a simple LED blink app. Plus I have a powerfull small PC which s the same size as a mac mini whcih woudl be perfect to go in the mount. Now with RPi I can still use .net core or some other language (probably python? which i'm not familiar with) , and I was never comfortable with Linux as well. So I'm a bit reluctant to go this path. If I go with windows/.net path I will be playing for my strengths when it come s to coding but are there other limitations on windows compared to Linux when it comes to a DIY tracking mount project? does stellarium or any other astro SW has limitation on windows?
  5. Thank you I will have a look and play around a with it when my gear gets delivered. What exactly do you mean by processor cycle time? speed of the chip or something else?
  6. Thanks very much Julian, I went ahead and ordered couple of A4988 and a sensor shield for arduino uno which makes things easier.
  7. Thanks very much Alan, that was very informative and cleared the doubt I had.
  8. Sorry if this sounds like a really silly question but I can't seem to find any information online Can you switch from different stepping modes from the arduino code? full, 1/2,1/4 etc or does that need to be set physically from the driver module? My plan is to switch between stepping modes to achieve necessary speeds during slewing and tracking, so I need to be able to switch from the code in order to achieve that. Sorry I never had a chance to work with stepper motors before so this might
  9. Thanks John, Shouldn't be hard to find one for the weight I needed as larger ones are rated nearly 200-300kg , I was more worried about the smoothness of the rotation from amazon reviews it seems like the type 1 bearings are either hit or a miss so I guess I'll give them a miss and go with type 2 which has decent reviews.
  10. I'm building a dobsonian mount for my DIY goto project, not sure what kind of lazy susan to get, tube is a 200p skywatcher I've come across three types on ebay so far (sorry about large images , can;t figure out how to set max width for image uploads ) Can I please get any advice on what type to use? thank you. 1. This seems like the obvious logical choice but I've seen some videos on youtube with not so smooth operation which worries me a bit if that's the case generally with these bearings? 1. 2. 3. 3.
  11. Thanks Vroobel, I just picked few examples from ebay for stepper motors, that's why you don't see the model you have in that list. I'm worried about the noise, I've seen youtube videos a terrible clanking noise coming from Nema 17 motors when they are horizontal, is that what you mean? or just the general motor whining noise? if it's the first one I will have to rethink as I don;t want to disturb my neighbours middle of the night.
  12. I have a question regarding stepper motors, I'm sketching a gear system to achieve 2880:1 gear ratio before the stepper motor, which will be archived with three sets of pulley systems which has gear ratios of 45*8*8 There are multiple stepper motors available on the market which I'm not sure which one will be best for me, eg Nema 17 0.9deg 400 steps 1.68A 0.44Nm Nema 17 0.9deg 400 steps 2A 0.46Nm Nema 17 1.8deg 200 steps 2A 59Ncm Nema 17 1.8deg 200 steps Bipolar 1A 13Ncm I'm not familiar with stepper motors and how to choose the right one for this project , my worry is with my gear ratio will it take forever for the scope to goto the location before it starts tracking? or should I forget about steppers and go with a DC motor and a separate encorder? Is there any reason why I should consider 200 steps one over 400 steps one when they both have similar torque ratings? do these have different max speeds? Thanks
  13. Thanks very much for detailed post Vroobel Regarding the large worm gear , I would struggle to do your way because I don't have proper equipment, but I guess I have to rethink about gear combinations to get the gear ratio I want . As you said if the gearbox has backlash then whole thing fails. The link to the other project looks really cool, thanks for that.
  14. Hello all, My recent attempts to build a ROR shed for AP is on hold due to several issues. Small garden , not enough open south sky are the major ones so now I'm thinking to motorize my Skywatcher 200p dobsonian to have GOTO and tracking. I'm more interested in the DIY route rather than buying something off the shelf. So here is my plan so far. 1. Build a mount with 18mm plywood or MDF. I got a router, jigsaw , mitre saw and a table saw at home, plus I'm fairly competent with them so this part shouldn't be much of a problem. 2. Use a lazy susan bearing for AZ axis and use flange bearings for Alt axis. 3. Two Nema 17 100:1 geared stepper motors with MXL timing belt and pulleys which gives 8:1 ratio, I already have MXL pulleys with me. 4. Arduino mega with motor drivers to drive the telescope, I have an arduino uno and a motor driver from another project so I can reuse them if uno is able to handle these computations. That's the basic motorized mount I have in mind Then for the short exposure AP I have a setup with hacked 1080p webcam and a adapter which I can use. I assume I will need another one for the finders scope as well. For on board computing to connect with webcams and controlling I can use a RPi or a small PC with stellarium. My goal is to once I set this up in the garden I can remotely connect to the RPi or the PC and then control the mount. So that's the whole idea I have in my mind which I have been thinking for last couple years ever since I bought the telescope. Stepper motors and pulleys will give me 200 steps per revolution + 100:1 inbuilt gear ratio + 8:1 gear ratio with pulleys + micro stepping (this part I'm not sure how it works as I never dealt with stepper motors) 200x100x8 = 160000 steps per revolution without any micro stepping, I assume this will be sufficient for basic tracking to be used with planetary AP and observing? Does that sound feasible at all or are there any obstacles I haven't considered? Thank you ps. I came across this thread which has lot of useful information for me.
  15. I live in Hertfordshire and not so much light pollution near me apart form a halogen street light bit further away from us which I think not on all the time during the night, apart form that it's pitch black at nights and I live on top of a hill as well if it makes a difference.
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