Turning Stepper Motor Off

@inq I realize you were joking, but seriously one my eyepieces cost more than that and it doesn't look like it fits in my backpack. Did you not see the pictures I posted?

The serious astro guys build a shed over the scope and now it's actually possible to rent time on scopes in really great astro locations. Like photography, it's all digital today, nobody looks through an eyepiece today when you can see images on anything from a phone to a 60" HDR 4K TV.

My favorite picture was the Jackolope and Sasquatch.  That you have a nice camera... not really.

I had begun to think your addition to this thread was about moving a camera laterally.  Then @will corrected me that it was just rotating it around two axes.  That $5K was too rich for your blood... so you wanted to make an equivalent.  My last post was actually dead serious and my point about the larger scopes was ONLY about the weight that their computer controlled mechanism must be able to support would far exceed your camera/lens combination.  If it offends your sensibilities to put your Canon on top of a $300 tripod, then I can't help you out with that problem. 

The fact that you also want to pan it is fractional seconds (I guess to catch live action or two parts a scene with minimal time between) adds to the problem.  When you actually define your project publically with pictures or sketches... then we might be able to contribute ideas or solutions without playing twenty questions.

Now if somewhere in the weeds of the last five pages we switched to the actual viewing item... be it camera, lens or scope... I must have missed it.  I quit using my Nikons years ago because I was never going be hung in the Louvre.  A buddy of mine is still a professional photographer using current Nikon equipment.  None of his gear can take night pictures, stars, Milky-way type pictures near as well as my Pixel Smartphone.  The admittedly superior optics, sensor and electronics are no match for Google's superior software and my camera is always just my pocket away... Priceless.

Back to the problem at hand...

I did not find a solution to turning off the stepper motor that would also disable the "holding" power being used. 

I even brought out the sledge hammer.  I tried making them dynamically allocated and actually deleted the objects when set to zero speed and re-created them when having some speed.  It caused reboots.  I may look into this further, to see if it was my code or something special in the Stepper library, but as @will pointed out, anything more sophisticated than this toy, and I won't be using this library.

Some things of I learned

• These stepper motors actually drain more power not moving than when run at full speed.  Don't know if that is consistent with Nema type steppers and/or maybe it has more to do with the drivers... A4988 or in my case the TMC2209's.
• The switch on the 18650 shield only switches the USB-A port for output.  It does not switch the 5.0V and 3.3V outputs on the circuit board... thus the reason I wanted to de-power the steppers.  Right now, I have to remove the battery or add some external switch and plastic structure to hold it.  🙄 

@inq Sorry you missed the post of the actual device I use for remote wildlife photography. Terrestrial mounts are very different from astro, I have owned and used both. You also must have missed the posts where I said I already had a commercial unit but wanted to gift a friend of mine with one that I thought I could make using stepper motors. Sorry if I don't speak the same language, but I thought panning and tilting were understandable. Astro scopes as you know have to counteract sidereal motion so are totally different.

I have only recently met you here on the forum and have been always impressed with the breadth and depth of your knowledge on many fronts so when I saw you post the picture of an inexpensive scope I was 100% sure you were pulling my leg as I have seen you do in the past. I apologize if you were being serious and I subsequently insulted you, that was not my intent.

This very long and rambling post has taught me a few things about building my own with the need to somehow lock the motors in a fixed position for long periods of time with no power draw as we have to carry everything on our back. I thought I had an answer until @will in his usual way pointed out a flaw in my approach. I really want my friend to have something but now I am stuck for the time being.

Again, sorry for any miscommunication on my part.

Posted by: @zander

I apologize if you were being serious and I subsequently insulted you, that was not my intent.

No need to apologize... It was totally my fault.  I should have used more Emoji to signify my mind-set while writing.  With all the nationalities, languages, dialects, ages, races, religions, gender and sexual preferences, it hard to say anything without offending someone.

Us really going into the weeds on this thread put me in scanning mode.  I was ferreting out a coding problem I'm having and only casually reading posts.  Also, with my whopping 8kbit/sec Internet during the day, I was lucky to even get half the postings in a timely manner.  Most of the time pictures wouldn't even show up.  If they did, it was so slow... watching pixels paint on the screen made me pass them by.  

I did miss the packing-in feature but I had assumed some kind of terrestrial photography anyway.  The photo/link was never about the scope... that was a dumb weight as far as I was concerned.  And because it is cheap, I imagine the weight of that cheap unit is far lighter than the German model... thus better for packing.  If it were me, I'd be far more inclined to hack/tear apart/re-design a $300 tripod than a $5000 one.  Or... it might be worth a call to their tech support and ask some pointed questions about the guts.  You might find someone willing to tell you how they approached the power problem... as that certainly is just as significant to celestial photography as it is terrestrial. 

VBR,

Inq

Posted by: @inq

These stepper motors actually drain more power not moving than when run at full speed.  Don't know if that is consistent with Nema type steppers and/or maybe it has more to do with the drivers... A4988 or in my case the TMC2209's.

@zander - More as a point to your project.

I've only played with these little drivers typically used on 3D Printers.  You can see them (A4988) used in Bill's video.  All of them that I've seen including the A4988 and my TMC2209's have the ability to enable/disable them.  But as pointed out... unless you have a mechanism, brake, paw, or a worm-gear solution that can hold the position, or "perfectly" balanced, you'll start moving.  

Having lots of inertia AND wanting to move it fast... frankly... there isn't going to be low-energy solution.  It's that law of physics thing.  You ether move is slow or rent yourself a pack mule.  

VBR,

Inq

Now maybe... you can use pneumatics.  Blow up your air-mattress with a hand air-pump and sit on it like a whoopee cushion to power your camera motion.  Air is free and packed-in already and you have the air-mattress and pump already while out in the wilderness... so their weight is already accounted for, for comfort.

Now that was a 100% joke!  🤣 😋 

VBR,

Inq

@inq Ok, I was worried you were really upset with me and I didn't really understand why. Yesterday was very freewheeling and I at least forget sometimes you are lacking the bandwidth to stay up. Hopefully that will change in the not too distant future.

Having owned a decent sized GEM I can tell you how they do it. It is counterbalanced and only rotates around the one polar axis using the motor. It is geared drive The telescope is always pointed up, a camera lens is generally between + and - 45 degrees from level, almost never straight up unless mounted on a GEM or AZ or barn door tracker. All those are astro types as opposed to terrestrial. I am not sure if you saw the following picture, I have reduced it's resolution so you don't spend all day downloading it. This is my Canon 7D II with 100-400 lens sitting on the pan and tilt wifi controlled head on my tripod. I can also remotely control the camera except for zoom. This is packable, my old astro scopes counter weights weighed this much.

@zander 

So, my mind is kind of spinning right now. Do you want to construct an equatorial mount that can actually compensate for the Earth's rotation or are you just looking for a simple pan and tilt (or azimuth and elevation) mount ?

@will Pan and tilt. I have a friend who is a photographer and I would like to create a mechanism like I have for him but I am rapidly coming to the conclusion it is not doable within any sane power and/or weight parameters. My rig as you see it is probably overloaded, it wasn't until just a few moments ago that I realized I have not weighed that combination of lens and body. It is limited to 6lbs. BTW, it runs on 4xAA batteries. Now I am off to weigh.

Posted by: @zander

@will Pan and tilt

Great, thanks for the clarification.

Darn, the wt so far is 6 lbs 2 oz. Seems ok, but I need a battery pack as well. Now I have to see if there is such a thing as an off board battery pack and how does it connect. That could actually save weight.

Posted by: @zander

Darn, the wt so far is 6 lbs 2 oz. Seems ok, but I need a battery pack as well. Now I have to see if there is such a thing as an off board battery pack and how does it connect. That could actually save weight.

You might look at the soft sided lithium packs. They'll provide lots of power and less weight because there's no metal cans around the cell material and you can just velcro them to the legs of your tripod.

An AC adaptor might work, less wt although some power losses. Might have to make that trade off. And build an inverter. run off a bunch of 18650's maybe.

@will Of course, I will see what sizes they have. Now I have to design and build a small inverter.