Wyvern Posted October 31, 2020 Share Posted October 31, 2020 Not sure if this is a bit of a gimmick project but decided to do it after I found a couple of leaves in the telescope after a night's imaging session which had left marks on the lens. it was a fun build though.Parts needed:3D printer or the ability to have parts printedNema 11 stepper with 5:1 planetary gearboxArduino8825 Strpper controller.100uf CapacitorCableMotor HousingLens coverassembledThe code for the arduino lives here https://github.com/wyvernp/Auto_lens_cover/tree/mainWiring diagram (credit https://www.instructables.com/Controll-a-Stepper-Motor-With-the-DRV8825/ )To connect to the stepper from a windows PC launch powershell and use the following commands (substituting the correct com port)$port= new-Object System.IO.Ports.SerialPort COM6,9600,None,8,one$port.open()$port.Write("c")$port.Close()I have created a basic VB.net app for opening and closing the lens caphttps://od.lk/d/NjJfMTk0NTg1MTdf/AstroUI.zipSend o to open the cap and c to close.And the finished result.Wyvern 6 Quote Link to comment Share on other sites More sharing options...
Gina Posted October 31, 2020 Share Posted October 31, 2020 Nice one Wyvern ? 1 Quote Link to comment Share on other sites More sharing options...
Wyvern Posted October 31, 2020 Author Share Posted October 31, 2020 Thanks Gina! Quote Link to comment Share on other sites More sharing options...
Feock Posted October 31, 2020 Share Posted October 31, 2020 That is really very clever. In Cornwall with our maritime climate, our better seeing often does not start until after midnight, and imaging sessions go very late.. This looks like a useful project to pursue.Would you be happy to share any of the 3d print related files? Many Thanks Rossps just built 3 Myfocuser2 units this weekend and now printing off boxes and brackets for these. Quote Link to comment Share on other sites More sharing options...
Wyvern Posted October 31, 2020 Author Share Posted October 31, 2020 @feockFirst of all thank you!I absolutely can but they are specifically made for my William Optics GT81. Attached below.https://od.lk/d/NjJfMTk0NDUwNDFf/Lens%20Cover%20v6.f3dhttps://od.lk/d/NjJfMTk0NDUwNDBf/Lens%20motor%20housing%20v6.f3d Quote Link to comment Share on other sites More sharing options...
Feock Posted October 31, 2020 Share Posted October 31, 2020 Thank you .. will convert them to stl in the morning and have a look..with a little shim they should fit my ED72... with all this rain I have time to build stuff. Ross Quote Link to comment Share on other sites More sharing options...
MarkAR Posted October 31, 2020 Share Posted October 31, 2020 Nice work mate, glad it all came together in the end. ? Quote Link to comment Share on other sites More sharing options...
Wyvern Posted November 1, 2020 Author Share Posted November 1, 2020 Edit--Added a downloadable vb.net app for controlling lens cap Quote Link to comment Share on other sites More sharing options...
Gina Posted November 29, 2020 Share Posted November 29, 2020 I would like to do something like that for my lenses but I want to swap dew shield for a light tight lens cap and that isn't easy. 3D filaments are not opaque. The idea would be to be able to switch to doing darks without going out to the observatory. OTOH it isn't that much problem to walk the 20 yards to the obsy!! And the exercise is good for me. Quote Link to comment Share on other sites More sharing options...
Wyvern Posted November 30, 2020 Author Share Posted November 30, 2020 Posted by: @Gina I would like to do something like that for my lenses but I want to swap dew shield for a light tight lens cap and that isn't easy. 3D filaments are not opaque. The idea would be to be able to switch to doing darks without going out to the observatory. OTOH it isn't that much problem to walk the 20 yards to the obsy!! And the exercise is good for me.It may be worth waiting for John to test the black3.0 paint, if that blocks the light then it may be the way to go. I also put a layer of self adhesive black felt on the underneath of the lens cap which helps. I tend to do my darks by taking the camera off and put it in the fridge with a cap on so haven't tried with the lens cap setup. Quote Link to comment Share on other sites More sharing options...
Gina Posted November 30, 2020 Share Posted November 30, 2020 Posted by: @Wyvern Posted by: @Gina I would like to do something like that for my lenses but I want to swap dew shield for a light tight lens cap and that isn't easy. 3D filaments are not opaque. The idea would be to be able to switch to doing darks without going out to the observatory. OTOH it isn't that much problem to walk the 20 yards to the obsy!! And the exercise is good for me.It may be worth waiting for John to test the black3.0 paint, if that blocks the light then it may be the way to go. I also put a layer of self adhesive black felt on the underneath of the lens cap which helps. I tend to do my darks by taking the camera off and put it in the fridge with a cap on so haven't tried with the lens cap setup.Good idea Wyvern. With opaque plastic I could leave the dew shields on and cap the open end like you have done. Quote Link to comment Share on other sites More sharing options...
Feock Posted December 11, 2020 Share Posted December 11, 2020 @wyvernHi I am printing your files up after having converted them to .stl from the fusion 360 format. Would you mind if I posted them up here on your thread? Hope to get the lens cap built this weekend. ThanksRoss Quote Link to comment Share on other sites More sharing options...
Wyvern Posted December 11, 2020 Author Share Posted December 11, 2020 @feockNo problem at all, feel free :) Quote Link to comment Share on other sites More sharing options...
Feock Posted December 11, 2020 Share Posted December 11, 2020 STL files for 3d printing ... oops they are not an allowed file type... I can't upload them.. happy to email them to any one who wants them. Sorry Ross Quote Link to comment Share on other sites More sharing options...
Feock Posted December 13, 2020 Share Posted December 13, 2020 Wyvern I have printed your design off, rather nice. Awaiting the geared NEMA11 motor but that should be here soon. I have fitted a small EL panel (12volts) inside the lenscap and that seems to have the benefit of making a better cap for darks and also the capacity to take lights.I am flashing up an uno R3 for the code but I am having trouble reading your photo/schematic. I can see from the code that pins 2 is direction, pin 3 step there is a 3rd wire... is that the ground? or what pin on the UNO should it go to.. ThanksRoss ps seems to go to the enable pin on the stepper controller? Quote Link to comment Share on other sites More sharing options...
Wyvern Posted December 13, 2020 Author Share Posted December 13, 2020 Ahh yes the schematic doesn't look so good. If you click on the credited link below it there's a great instructional site on how to wire up. Quote Link to comment Share on other sites More sharing options...
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