Like a new NEQ6 now! Well worth upgrade.
Wednesday, 8 September 2021 | Michael
When I bought a second hand Skyshed Pod, as part of the deal it came with this older second hand NEQ6 mount. I already had a nearly new CGX mount and fitted this in the observatory and apart from a quick look over, the NEQ6 lay with a lot of other expensive astronomy equipment I seem to have acquired over time and probably should not have! My long term plan was to clean this mount up and use it as a 'portable' mount when I went on holidays in the camper. However, last week week my CGX developed an issue with the motor boards and had to be sent back to be investigated and repaired under warranty, just as the dark skies started to return from their summer vacation up here in north Scotland. Therefore, I was forced into taking action now on the NEQ6. I had looked into the belt kit and this zero backlash upgrade already so knew about it. Anyway, even before my CGX was picked up I put in an order for this upgrade with FLO along with the belt modification and the essential bearing locking ring removal tool. Since this was all in stock it arrived the next working day - usual FLO efficiency and top notch packaging.
I then proceeded to strip down the mount as per the instructions (I did also watch a couple of YouTube videos on the belt mods - particularly good one by an Aussie chap). It was really straight forward. I did have to jump from the belt modification instructions to the zero backlash instructions and back again a few times but still fairly straight forward to do both upgrades at the same time. (Note - you need to have done the belt mod first before do this zero backlash mod if you are not doing it at same time.) It took me about four hours one evening and I had everything back except the motors and front panel. Another couple of hours the next day I put the motors in and adjusted the backlash. The backlash is simple to adjust in the sense you leave the four cap bolts loose and work the grubs screws to engage the worm into the pinon gear. I did note whilst doing it that you should also ensure the four bolts are not too slack but also not too tight to allow the plate to move. With the RA adjustments it is basically the same, except when you have found the correct engagement you then add a further 1/2 turn putting preload on the worm gear. You also need to set the two spring limit screws but this is as easy as screwing them in to touch the carriage and then screwing out a half turn. You then rotate (drive) both the RA axis and the DEC axis fully 360 degs to ensure no binding (one at a time). Wow, how quiet the mount is now with the belt mod too, it's like night and day.
That evening I did read up a bit more on setting the backlash as I was not fully confident on when the right engagement is. One great thing I found was another YouTube video where a chap removes the black bearing caps to reveal the worm shaft (at the control panel side) and using some long nose pliers turn the worm shaft using the flat on the shaft and ensure this is easy. This allowed me to be less conservative (especially on the DEC which does not have the zero backlash upgrade) and I achieved an even better result. There is now no backlash at all in the DEC (RA was already good due to the preload as discussed above).
That same day I set the NEQ6 on my pier and spent a good hour getting the best polar alignment possible (just 7arc secs and 14arc secs Alt/Azm respectively) using Ekos. I then used the internal guiding module in Ekos to try it out. I have to say the skies were very good (could see shading in Milky Way from East side to West - we have good skies up here (when clear) anyway but this was particularly good). Anyway, I was guiding 0.35arc sec RMS on both axis, I might not even put my CGX back when it returns! Very happy with the improvement and highly recommend. I actually enjoyed doing the modification itself too, I'm an engineer anyway, but everything went to plan although I did have to grind 4mm off the RA worm shaft (side with flat drive end that is on outside of bearing and lock ring) which was not in the instructions - but even that was a good challenge working this out.
To summarise - If you have an old NEQ6 and considering upgrading to another mount, consider this and the belt mod first - the results will be as good as a new mount (even better if you take your time) and it save you a good bit of money.
Does what it says on the box...
Thursday, 20 May 2021 | Keith
This unit has completely eliminated the RA backlash on my 15 year old NEQ6. Once adjusted, there is a small amount of flex (rather than the clunk/clunk of backlash) when you try and rock the RA axis when locked, which I assume is the worm loading spring doing its job. It has certainly improved the guiding accuracy at first glance. On a quick test I got around 0.7" RMS without even trying to optimise PHD settings, so it seems to have done its job. I am not particularly mechanically minded but had little difficulty fitting this ( I did the belt mod at the same time). I did have a minor problem fitting the worm assembly back into the new housing but Rowan responded quickly with an e-mail telling me how to do it (you need to tilt it when you slide the block into place). Very pleased, makes a big improvement to the NEQ6 performance.