Single axis RA clock drive for EQ5

[N3ptune]

Hi,

I have a new RA motor for my EQ5 (To hold my image while sketching), tonight is going to be my second attempt using it. (last time my polar alignment was so poor, it didn't work very well)

On this clock drive there are 4 buttons, I wish to validate how to use them. 

First 2 buttons

[<<BACK] 8x [FORWARD>>]

Second set of 2 buttons

[<<STOP] 2x [PLAY>]

I noticed that the play button should keep the view at the center of the EP, compensating earth rotation. But because my polar alignment was so bad, the planets were going away up or down.

Viewing with my 28mm EP, giving 37x and a large TFOV the image is not moving quickly so I guess the motor will keep the image still at "[PLAY>]"  (with proper polar alignment) 

But what f I use my 4.7mm EP giving me 212x with a small TFOV?, can the motor keep up with the speed required? I know the earth rotates at only one speed, but manually I turn the handle much more with the 4.7mm then with the 28mm

that's why there is doubt a little bit, maybe it's an illusion.

Does anyone has experience with these motors?

Thanks

[Stu]

The RA motor will keep track of the stars regardless of the magnification; it is an effect of the reduced field of view that makes the stars move faster at higher magnification. Of course accurate PA ensures that the target stays centred for an extended period.

[spaceboy]

Get your pa bang on and a simple Ra drive will keep most objects in the centre of view until your batteries run dry. I say most as you will notice some drift when observing the moon or sun (with filter) at high magnification. Goto and the dual drive enhanced versions both have rates for tracking in lunar and solar but the basic motor controllers don't support this feature.

[N3ptune]

Ok ok that's what I thought, the RA will do the job with whatever the EP, my PA was so bad last time... this must be why the result was so false.

So I guess the 8x speed FF and REW are for fine tuning, maybe useful fore people with dual axis motorization?

My drive is the basic one if it can hold a crater on sight for a few minutes in my 82 degrees AFOV EP, i will be happy. 10 minutes would be nice, I can't wait to succeed in this task and focus on my sketching exclusively. 

 

[djh]

I'm not sure if the controller is anything like the EQ2 one. That has various fast forward/reverse buttons, but you don't need to press any to get it to track objects as it runs by just turning it on. I have yet to polar align mine, just using a compass to get a rough alignment, but it still tracks the moon for ages before any noticeable drift.

Could this be the problem with yours, as by pressing play, it is moving twice as fast as it should, when maybe just turning it on is all you need to do?

[N3ptune]

djh

Good question, last time I did my PA with a compass, it was terrible, 2 times out of 3 I get a really bad result with the compass. (Because I want to watch Jupiter at the sunset)

I had difficulties with everything.. the clutch gave me a hard time because I had to use the scroll wheels manually because of poor PA. I think the 2x play is an unique speed, play and stop. If I press stop, I have tu press play to engage the motor in its regular speed again.

It's not clear in the instructions really but ill know tonight.

This is a picture, this is my motor remote, really cheap made in china device, quite overpriced. Hopefully it will work fine.

 

[djh]

The controller looks exactly like mine (apart from the 8x speed. Mine is 4x). In future just turn it on with the switch at the top left and it should run normally. 

I have not used mine in the dark yet (still practising) so have been pleased with the rough and ready polar alignment results.

[Alien 13]

The drive is the same as mine as said it starts tracking as soon as its switched on no need to press any buttons apart from centering the target.

The control box uses a crystal controlled oscillator so its not that simple and I have found it quite accurate when the mount is polar aligned enough for many tens of minutes when observing and perhaps two minutes for AP with short focal lengths.

The box has one issue though in that it contains no protection circuitry so any over voltage will kill it but the one benefit though from this is that it will run quite happily from a 5V supply like a mobile phone battery bank.

Alan

[N3ptune]

Yep it's tracking has soon has it's switched on, I tried it a few minutes.. not much because of the intense mosquitoes presence, they won the war against me.. I had to leave the site.

But this time I did a good PA and the motor could hold the image in the middle (:, If I press and hold 2x play, it's going a little bit faster but I am not sure yet.

For the power, i am going to use a 12v 7Ah battery later, with a simple circuit it can be transformed to 6 volts.

[Stu]

2 hours ago, N3ptune said:

Yep it's tracking has soon has it's switched on, I tried it a few minutes.. not much because of the intense mosquitoes presence, they won the war against me.. I had to leave the site.

But this time I did a good PA and the motor could hold the image in the middle (:, If I press and hold 2x play, it's going a little bit faster but I am not sure yet.

For the power, i am going to use a 12v 7Ah battery later, with a simple circuit it can be transformed to 6 volts.

I think the idea of x2 is that it goes effectively x1 faster than sidereal, and equally Stop goes x1 slower than sidereal, does that make sense?

[N3ptune]

I can't say yet if it makes sense but it looks like it. The stop should stop the motion but it seems I have to hold the button to do so, I am not sure stop is the regular speed. 

Ill loook at this today.

 

[alexbb]

Hi,

I bought one of these recently. When you start it, it automatically starts tracking. If you press on "Play", it speeds up the rotation with 1x sidereal rotation speed. That's why you get 2x (1x auto + 1x manual).
Stop will decrease the rotation with 1x so it will basically stop the tracking (1x auto - 1x manual). The fast forward and reverse will work at +8x and -7x according to the manual.

One more hint: you could power this controller from an USB power source, perhaps an USB powerbank. But you have to make the adapter cable yourself, I doubt that you'll find easily an adapter of the correct size.

Alex

[N3ptune]

Quote

If you press on "Play", it speeds up the rotation with 1x sidereal rotation speed. That's why you get 2x

 

I think I noticed that effectively. (Ill see in a few days when the rain stops or a could do it inside the house..)

For the power source, I want to deliver 6 volts to this motor, even if 5 volts works. (I think it could change the speed to give another voltage then 6 volts). There is this little circuit I could weld for  5$, the LM7806 chip "step down" i have some large lead batteries doing nothing here and ready for action.