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Post by davy on Apr 6, 2014 11:49:09 GMT
[/sub greetings folks thought we could start a thread on remote viewing. .to be more precise stand alone type. .ive been watching the forum posts for a long time and have seen us mostly all look at various tupes of remote viewing. .karls set up in paticularly with his various cameras..and with ardrino hardware/software now getting implemented into astronomy more..how can this benifit us.??
Have seen on ebay that stepper motor controllers are available for peanuts controlled by ardrino ..any budding experimenters out there done a full star trek set up.. What I was thinking camera boxes controlled by twin axis stepper motors remotely controlled by a controller board via ardrino..
Imagination time...could be pier mounted for a quick set up or to a stash away box type .and software chappies devising a way of controlling tracking speed..could end up a cheap project I f we all jumped in and done a bit each..
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Post by Deleted on Apr 6, 2014 14:01:11 GMT
[/sub greetings folks thought we could start a thread on remote viewing. .to be more precise stand alone type. .ive been watching the forum posts for a long time and have seen us mostly all look at various tupes of remote viewing. .karls set up in paticularly with his various cameras..and with ardrino hardware/software now getting implemented into astronomy more..how can this benifit us.??
Have seen on ebay that stepper motor controllers are available for peanuts controlled by ardrino ..any budding experimenters out there done a full star trek set up.. What I was thinking camera boxes controlled by twin axis stepper motors remotely controlled by a controller board via ardrino..
Imagination time...could be pier mounted for a quick set up or to a stash away box type .and software chappies devising a way of controlling tracking speed..could end up a cheap project I f we all jumped in and done a bit each.. Sounds good Davy, I'm thinking of a pier next but want to copy the expert Carlos the Jackal! I shall be watching his progress with interest. I have two car brake discs ready for welding
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Post by Deleted on Apr 6, 2014 14:01:48 GMT
I will comment seeing as I have experience with Arduino and stepper motors. I built a very accurate CNC router, down to about .005-.01% accuracy. However that is in no way accurate enough for astronomy. Can it be done absolutely? and has been done by many.
In researching this DIY approach the first thing you have to consider is Gearing and bearings. The quality of these things will determine you accuracy. With low accuracy you need a wider FOV to compensate.
I guess the question is, what do you have in mind? A quality DIY mount that will hold a reasonable sized scope would probably end up costing more than a new one. Is your goal is a cctv camera with a wide lens on a 2 axis gimble, then it should be fairly easy to accomplish, but not super cheap.
An option would be to get a PTZ cctv camera and redo the control board to provide some kind of tracking/goto capability.
I see this as a fun project, but not an economical solution. For me, I would just find a way to slap a CCTV camera to a cheap used goto mount such as the celestron single fork mounts. These can be had for dirt on ebay. Also cheap zoom cctv electric zoom/focus lenses can be purchased (they can be modified for handpad control). I produced some neat views with a samsung and a motorized zoom lens on an old celestron SE mount.
Please don't get me wrong, I'm not trying to discourage you. I find this to be a fun topic, and would even assist however I could. Just be aware it will not be a cheap super cheap project if you want results.
Probably the absolute cheapest solution would be a single axis polar aligned system. This could use a stepper and an arduino to control the clocking to produce the desired rate. This could be as simple as the barn door system for a camera or and eqplatform for a DOB.
A second non tracking axis could be added for slewing to objects. But adding this axis serious adds to complexity and cost.
Post up your thoughts on what your thinking and I will try to help. As someone that has built a goto Dob, I have done a good bit of research on this subject.
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Post by davy on Apr 6, 2014 14:50:08 GMT
Now were getting there..nice comments hemmi.. I was thinking along the line of a cheapo remote set up..
How about a skeleton type mount holding twin micro stepper motors to move a platform mounted samung type camera with a lens of choice.. This could be pier mounted. .basically a ptz cctv system but lets try and computer control instead..
More of a scrapyard challenge. .cheap as possible. .
This is a fun project that can be done virtual reality if you wish and see how it would work out and take it from there..just to keep us all amused during the lean posting just now.
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Post by Deleted on Apr 6, 2014 15:38:15 GMT
I guess the question is, what do you have in mind? A quality DIY mount that will hold a reasonable sized scope would probably end up costing more than a new one. Is your goal is a cctv camera with a wide lens on a 2 axis gimble, then it should be fairly easy to accomplish, but not super cheap. Yes, I think that is pretty much KEY to all this? Having been "reared" on Alt-Azimuth, I put off moving to a equatorial mount in the hope that the usual suspects manufacturers would come up with something! No HUGE requirement - maybe a 16lb scope? Meanwhile, I was never overly taken by the small Synscan Alt-Azimuth mount. My first example had a dodgy motor, the second was better, but struggled with my "fully accessorised" MAK127. I once had a Giro III (Wonderful - A reluctant sale!) - Great basic hardware. I made degree SCALES and used it for PushTo (successfully!) supported by a Palm Pilot App. I even had a few "parts" machined, but was never too sure how to support the "gears" or whatever. Then along came the Ioptron Mk.I. Sadly for me, again, hardly a success. Worked well for a while, but then became just a source of frustration(!) - The interminable "overload" messages - Eventual motor failure with ONLY a (well balanced) MAK150 on board. The remains of this still sit glowering defiantly in the cupboard under the stairs. Simply, my current level of *patience* is not what it was? So I GAVE UP, cut my losses and bought an HEQ5! LOL. Still took a while to get full (working, conventional?) "remote control" up and running. Some of you may be aware, I steadfastly *refuse* to be seduced by the ubiquitous "TeamViewer approach" - Preferring to get a working (ICRON) 30m long USB 1.1 extender - To do the job "in the hardware"! Even Upgradeable to USB 2.0 if I ever need it? Me? Now "Hard up, but Happy" as they say!? Like almost everyone (teasing) I have an Arduino too? Recently bought a rather nifty (Velleman) I/O board. Pondering using the mini-relays to control obsy (IR perhaps?) lighting - Still a bit worried about scope collisions in the dark! Maybe an alternative PWM focusser control? Nothing too exciting or demanding. I sense the Arduino (like me!) albeit a fine thing, is fairly limited re. CPU / Memory. For the real enthusiast, perhaps a Rasberry Pi? As implied above, once you begin to do some serious "Scope Positioning" you probably need at least a library of Matrix (inversion etc.) routines etc. etc. www.geocities.jp/toshimi_taki/aim/aim.htm Perhaps I'll stick with... www.amazon.co.uk/FroliCat-Bolt-Automatic-Laser-Cats/dp/B0021L8W6K/ref=sr_1_1?ie=UTF8&qid=1396795692&sr=8-1&keywords=automatic+laser+cat+toyThough even my "Millie" is now a bit too plump, ancient (cynical?) for such frivolities.
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Post by Deleted on Apr 6, 2014 17:10:09 GMT
Now were getting there..nice comments hemmi.. I was thinking along the line of a cheapo remote set up.. How about a skeleton type mount holding twin micro stepper motors to move a platform mounted samung type camera with a lens of choice.. This could be pier mounted. .basically a ptz cctv system but lets try and computer control instead.. More of a scrapyard challenge. .cheap as possible. . This is a fun project that can be done virtual reality if you wish and see how it would work out and take it from there..just to keep us all amused during the lean posting just now. You will need a lot of gear reduction in order to make it useful. Gearing is where the cost comes. You will need a ratio near 1000 to 1 for smooth tracking even in wide field. The cheaper you go on gearing the more backlash etc. A simple low backlash solution is belt and pulley. But you would have to figure out how to get a large ratio.
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Post by davy on Apr 6, 2014 18:44:34 GMT
Could the motors not be direct drive and speed controled via software. .. no gears ..no backlash. .or as you said toothed drive belt..
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Post by Deleted on Apr 6, 2014 19:57:57 GMT
I will comment seeing as I have experience with Arduino and stepper motors. I built a very accurate CNC router, down to about .005-.01% accuracy. However that is in no way accurate enough for astronomy. Can it be done absolutely? and has been done by many. In researching this DIY approach the first thing you have to consider is Gearing and bearings. The quality of these things will determine you accuracy. With low accuracy you need a wider FOV to compensate. I guess the question is, what do you have in mind? A quality DIY mount that will hold a reasonable sized scope would probably end up costing more than a new one. Is your goal is a cctv camera with a wide lens on a 2 axis gimble, then it should be fairly easy to accomplish, but not super cheap. An option would be to get a PTZ cctv camera and redo the control board to provide some kind of tracking/goto capability. I see this as a fun project, but not an economical solution. For me, I would just find a way to slap a CCTV camera to a cheap used goto mount such as the celestron single fork mounts. These can be had for dirt on ebay. Also cheap zoom cctv electric zoom/focus lenses can be purchased (they can be modified for handpad control). I produced some neat views with a samsung and a motorized zoom lens on an old celestron SE mount. Please don't get me wrong, I'm not trying to discourage you. I find this to be a fun topic, and would even assist however I could. Just be aware it will not be a cheap super cheap project if you want results. Probably the absolute cheapest solution would be a single axis polar aligned system. This could use a stepper and an arduino to control the clocking to produce the desired rate. This could be as simple as the barn door system for a camera or and eqplatform for a DOB. A second non tracking axis could be added for slewing to objects. But adding this axis serious adds to complexity and cost. Post up your thoughts on what your thinking and I will try to help. As someone that has built a goto Dob, I have done a good bit of research on this subject. Some good info Lee and good idea on the cheap Goto mount! I have a ptz camera I use to keep an eye on the mount but it is pretty much useless in the dark and I can only use it when i turn the lights on! I am planning to replace that with my Dynamic pro cam so maybe I'll have a tinker with that.
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Post by Deleted on Apr 6, 2014 20:34:28 GMT
Could the motors not be direct drive and speed controled via software. .. no gears ..no backlash. .or as you said toothed drive belt.. I would have to do the math, but with direct drive you will only have 200 steps per rotation (almost a full degree per step) with micro stepping you may get that to a 1/4 degree per step. That would be some super jerky tracking I would gear it to at least down to a few arcmin per step. It all really depends on your FOV, but if you go wide enough not to notice 1/4 degree steps, than whats the point IMO. The earth turns at a rate of about 1/4 degree a min. With a direct drive stepper (micro stepping enabled) your looking at one tick a minute. Not quite smooth tracking
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Post by davy on Apr 6, 2014 20:42:30 GMT
How's the maths on 1/8 th motors..was looking to get rid of gear backlash. .belt drive would sort that out..what gear ratio would be recommended 4:1 or higher.
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Post by Deleted on Apr 6, 2014 21:53:35 GMT
How's the maths on 1/8 th motors..was looking to get rid of gear backlash. .belt drive would sort that out..what gear ratio would be recommended 4:1 or higher. Well I have never seen a 1/8th stepper. Most steppers are 1.8 degree (200 steps per revolution). My thinking on this subject is you want a steps in the sub second range. If the earth turns a .25 degree a min. That is .004 degrees a sec. If you had the stepper tick every sec, that would require a gearing of 450 to 1, and that even IMO would show serious star trails even at 60mm f2. I would at min double or triple this to 2-3 steps per sec. And then you would need very fast optics.At 2-3 steps per sec would be a gearing ratio of 900-1350:1. My dob has a gearing ratio in the neighborhood of 3000 to 1 To not notice stepper jerks of 1.8 degrees, you would need the FOV of an allsky cam. And then why? The blur(star trails) will be very noticeable until you have enough gearing to smooth it out. I do not know, as I have not experimented, what the acceptable movement for a given FOV. So I can only go by experience in building my CNC and Dob. 1.8 stepper motors are very jerky and require massive gearing to smooth this out. For this reason most manufactures use servos. with a fast lens and short exposure I would shoot for as close as you could get to 1000 to 1 (i.e. it takes 1000 steps to move the scope 1.8 degrees). This gives a resolution of .108 arcmin per step. Ok now my head hurts!
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Post by Deleted on Apr 6, 2014 22:06:44 GMT
Just for reference: Mars is about .5 arcmin Moon is about 30 arnmin So at 1.8 degree step of a conventional stepper is like moving the size of 6 moons every step ungeared So now you see the need for gearing! Or 36 times the diameter of mars LOL
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Post by davy on Apr 6, 2014 22:08:24 GMT
Jings ..so is mine..sorry it was 1.8 degree motor.. So we need gearing of 3000 to 1 ratio ..what motor would you recommend. .
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