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About Vox45

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    Brown Dwarf

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    Born in Montreal 45°27'39.9"N 73°35'05.4"W Living in Fontainbleau 48°23'59.6"N 2°41'38.1"E
  1. I think you will find what you want in this thread. Kevin wrote a driver for a Waveshare HAT and motor for INDI https://www.cloudynights.com/topic/688855-building-myself-a-stellarmate-gadget-any-advice/?fbclid=IwAR1JzM0L1agNdF7NavsCPY7hG-9U2tT49pR9FTNRurAi1cQX_Ja7JDrWYlM The driver is here https://github.com/k-ross/indi-wmh-focuser "INDI focus driver for Waveshare Motor HAT stepper motor controller board. This allows controlling a stepper motor directly from a Raspberry Pi, with no external controller necessary. Additionally, the HAT can power the Raspberry Pi, so only a single 12V power connection will be needed, instead of a 12V and a 5V connection."
  2. I bought a Waveshare HAT for the RPI4 and it has built in DRV8825 Motor controller it seems that the DRV8825 is equivalent to the A4988 with minor differences, so it should work. http://qqtrading.com.my/blog/key-differences-between-the-drv8825-and-a4988
  3. Sorry I don't understand what you mean by : "the sketch is a bit more complicated" ?
  4. as soon as I read your comment I looked through my "bazarbox" and lo and behold I have one of these gathering dust. I was quite stunned by the size difference but when I tried to rotate the shaft on that little guy, I had to exert a LOT of pressure just to move it a little I did not know that those small motors were gearbox stepper motors!
  5. Interesting, I was planning to go with a planetary gearbox as there are many other pros to them and you just gave me more reasons to. Now I may be overthinking this and maybe there is some overkill in getting this kind of motor but for the price, I'd rather futur proof my motor if I ever have to attach heavier equipment to my focuser
  6. Yes I am planning on changing my focuser to a Baader steeltrack with a built in pulley between the 2 knobs (coarse and fine) I find this very elegant, placing the motor underneath the focuser instead of sticking out on the side.
  7. Short focal lenght haver smaller CFZ ? I thought it was the opposite ... Here is the formula for the CFZ from the arduino document: [CFZ in microns = focal_ratio * focal_ratio * 2.2] So in my case that would be : CFZ = (((600*.85)/80) * ((600*.85)/80))*2.2 = 89.41 microns Now let's change the focal lenght to 1000 CFZ = (((1000*.85)/80) * ((1000*.85)/80))*2.2 = 248.35 microns By George ! you are right But let's put real number from a real optical formula like a newton 200/1000 CFZ = (((1000/200)*((1000/200))*2.2)) = 55 microns So the diameter also plays a role not only the focal lenght, but really the focal ratio.
  8. I own a NEMA 17 motor (17HD34008-22B) I did not know about this gearbox advantage, this model does not seem to have a gearbox. I will be using an RPI4 with a Waveshare Stepper Motor HAT. This is neat as I only have to provide 12V to the HAT for the motor and it also provide the 5V to the RPI, so only one power source for both. Someone wrote an INDI driver for this and what the driver does is stop on a full step. "only stop on full steps, it only uses microstepping to make things smoother and quieter. A stepper motor can't hold position at one of the microsteps without power applied, and even then, it's just an approximation. It can hold position at a full step even without power, which is what I do, I kill power to the motor when it isn't actively being driven." So that would mean that using a motor without a gearbox makes you lose 32 microsteps, maybe this is ok on a short focal refractor that has a larger Critical focus zone (CFZ) ... I need to dig deeper into this, I might have to buy a gearbox motor then... This is the thread on CN https://www.cloudynights.com/topic/688855-building-myself-a-stellarmate-gadget-any-advice/
  9. I noticed that a lot of the captions are "formated" the same way and look very professional (text placement, font, border). Is there a prefered software to add captions ?
  10. I can imagine plugging my DSLR to 3.5V AC !! Fortunatly, this is one of the main reason I have a power distribution box is that everything remains plugged in inside the box so I never mix up USB 2 and 3 ports or plug into the wrong voltage (12v mount and DSLR 9v) there will be only one plug outside the box and it will be the one for the flat panel That is also the reason I want to change the connector as it is not surface mountable and hard to clip/unclip with frozen fingers ! so tiny ... I've started building my new box with a RPI4 4GB inside and a stepper motor using a Stepper motor HAT. I started today a cardboard mockup and I will design everything in Fusion360 so I can 3D print it. As you can see, I have a LOT of time on my hands Here is an exclusive look at the mockup (only half the box) And it will be mounted as such (minus the guide scope on the top)
  11. Haaaa now I get it ! mixing up plug ! yes I understand what you mean ... good point
  12. Thanks for the advice James! I do not understand this paragraph though, something must be lost in translation The power for the inverter comes from a 12V DC USB powered hub, so the USB port is outputing 5V DC, then the inverter goes to 3.5v AC... as far as I understand so why would this have an effect on the rest of my devices 12V DC devices ? Thanks
  13. yes they look very nice indeed but I am quite lazy so I want a connector that I can plug/unlug without having to screw them on. I just need to plug my flat panel for a couple of minutes and unplug and pack everything so these might be a bit of an overkill. They do look nice for the mount though
  14. So I bought an Electro luminescent panel a while back and it came with 2 littles connectors (marked in red in the picture below, I cannot figure out what they are... I think they are JST connectors...) I've decided to build version 3 of my power distribution box and would like to have the inverter inside the box and the connector surface mounted outside. The inverter convert from 5v DC (USB) to some 3.5v AC ... Would any connector do ? Does the fact that the inverter converts to AC is an issue, I see connectors marked as "DC" like these one but why would it not work with AC ? Sorry if this is a dumb question!
  15. The focuser does not slip under the weight per se, it just does not always move the draw tube "in", in a reliable manner. There is a fair amount of slippage when pointing to or near the Zenith and I am not always aware that the focuser is in fact not moving at all when I issue a move "in" order to the electric focuser (moving "out" is fine). I did follow the turorials out there to make it "better" to no avail...
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