Stuart1971

If something was slipping, then you would have flat parts all over the graph, not just at the start, this shows it’s backlash….👍🏼

Exactly…👍🏼👍🏼 there is always some play in a mechanical gear system, like a rack and pinion focuser, so when you move from inward to outward it changes direction in the gearing and so has to remove any slack first, before it will move the actual gears..as you see in the image below, this then means that a certain amount of steps is needed to remove this backlash first before any movement will be noticed…which are the flat parts on your V curve graph…

The autofocus routine seems to have done it’s job, so just go with that, take a 3 min image and check the stars…

Why do you need to use a mask, if focus is good it should set it for you at the end of the autofocus routine…?

You can use the motor manually with the in and out buttons in the software, and take an image and then tweak it…moving say about 20 to 50 steps at a time…

If you look at the bottom under the graph where it says position, 24.616, that is the focus point in steps…

No, those white dots are the point in which the image is taken to check focus, each white dot is an image to check, as the graph goes down it means the star is getting more into focus, as it starts to go up it’s going out of focus, so your focus point is at the very bottom, of the V curve, so in the example above that would be approx 24600 steps…

There is actually 2 moves there of 120 steps each at the start, which took out the backlash, so it only really needs to be set at 250 to be sure to remove all the backlash, any more is not needed…

As you can see the first two moves are flat, this means that the focus did not change at all, the draw tube did not move so these moves were taking up any backlash, as it wasn’t until the third move that the curve dropped, so I am a bit confused by this really….🤔🤔

It’s deffo backlash, and that setting of 120 is not enough as you have the first two moves of the Autofocus routine as flat spots, so that means there is about 240 steps of backlash….because the focus did not move at all in the first two steps…

Backlash is the slack in the focuser, and motor, so the amount it has to move to engage the teeth on the focuser when changing direction, 800 is far too much, as you see on the graph curve, the flat spot is there because it was taking up the slack and not actually moving the focus tube until the second movement…and the flat spot is approx 120 to 130 steps so that should be your figure to use, if you have it on 800 and are still getting a flat spot then something is seriously wrong…or you need to change it from out to in on the settings, but you can’t use both…

Looking at the graph it’s about 120 steps of backlash so try that in the backlash setting and run it again, and you will get an even better V curve, if you still have a slight flat spot at the start, then increase the 120 to about 140 and try again till you remove it completely….

That is not slipping, it is backlash in the focuser and the motor this is normal and you need to work out how many steps of backlash to set on the software, then that flat spot will go…

Just as a matter of interest, what initial step size did you use in NINA..?

Yes, the should be a max position somewhere to enter this number, and then it will not go over that…so you have max and minimum set..

Yes, with it all the way in set to zero…now when you tell it to move to say 1000 it should move out to that point, so the next step is to set the max position, so it does not crash the tube…as if you have a rack and pinion focuser it can cause some damage, not an issue really on normal crayfords…

First of all, you only need to loosen the grub screw on the shaft collar to move manually… Secondly with the Pegasus motors you need to reverse the in and out setting in NINA, I have to do this on mine too…. Then move it all the way in except for a few MM, then sync on zero, this should then show its at zero steps, the move out all the way except for a few MM, and note the steps, and set a max position slightly lower than this number…

What you should do is move the tube all the way in all but a couple of MM then put zero in the steps box and Sync, then move all the way out and see how many steps it moves, in my case with the same motor it 19,000 then I set a max limit of say 18,500 this way it won’t go all the way in or out and crash the tube…

Yes I considered something like an upside down plastic bin, full of holes, and the TG cover over that….so it kept it off the kit…

The cable DOES NOT go from the ST4 port on the camera to the hand controller port, if you are using the ST4 cable for guiding, it goes from camera to the ST4 guide port on the mount, but you are better to use pulse guiding, which does away with this cable and just uses the USB connection from camera to PC…so which one are you actually using…??

This was my issue, the cover was great while not in use with low wattage heater under, but then when I used the mount and it was covered in frost at the end of a session, I did have an issue, I had to put the cover on but loosely until the next day when hopefully it was dry weather and could remove the cover and let it dry naturally, this became a real pain, and the observatory was built…👍🏼

I had my mount under a TG 365 cover, and tied it tights around the bottom, but I had a 12v 25watt dew strap on all the time under it, and never got to dew point at all, without that not sure whether it would have dewed up or not, but did not want to take the risk….👍🏼

Yes, that was the first think I tried, also it’s the same on mini PC with Ubuntu, so not RPI issue, or USB issue…👍🏼

Yes, have tried on fresh set up with only mount connected directly to the RPI, and nothing else…still the same…👍🏼

The dealer in question has a very very expensive business in Spain to fund, he must have over £150k worth of kit there, so he must be doing well….😮 Rather than moan, just dont buy from him….simples….👍🏼