Tuning backlash - locking up in the field

[Shimonu]

I've been working on the backlash on my SW NEQ6 to improve my guiding which I did quite successfully, I got quite stable guiding under 1" which I was very happy with. However as I reached a meridian flip them mount started slewing and suddenly locked up on the DEC-axis. I was surprised as I tested the axis before at home and verified it running fine. The only thing I could think of was the temperature difference or maybe I didn't really run through the whole range of the axis.

So does temperature affect the backlash in any significant way?

What is a good way to make sure the backlash is as tight as it can get? I read that you should ideally find the tightest spot and adjust the backlash there but is there a good way of doing that? Turn a quarter and repeatedly feel for where it gets tighter and then looser but is it really that noticable?

Thanks

[ONIKKINEN]

1 minute ago, Shimonu said:

I've been working on the backlash on my SW NEQ6 to improve my guiding which I did quite successfully, I got quite stable guiding under 1" which I was very happy with. However as I reached a meridian flip them mount started slewing and suddenly locked up on the DEC-axis. I was surprised as I tested the axis before at home and verified it running fine. The only thing I could think of was the temperature difference or maybe I didn't really run through the whole range of the axis.

So does temperature affect the backlash in any significant way?

What is a good way to make sure the backlash is as tight as it can get? I read that you should ideally find the tightest spot and adjust the backlash there but is there a good way of doing that? Turn a quarter and repeatedly feel for where it gets tighter and then looser but is it really that noticable?

Thanks

Temperature can indeed effect where the mount binds, especially if the temperature difference is large between when the mount was adjusted and when it was used. The RA axis on my EQM35 also experienced binding even though i had adjusted it as accurately as i could. Temperature difference at the time was about 30 degrees, so not even as large as it could be. I just quickly touched the adjustment screws a bit to free the axis, but i guess you could just do the backlash adjustment outside to get rid of this issue too.

[newbie alert]

When tuning the backlash out did you do it with the mount loaded or unloaded?

[Shimonu]

2 hours ago, newbie alert said:

When tuning the backlash out did you do it with the mount loaded or unloaded?

I did it unloaded, thinking it would be easier to feel any backlash. But I suppose binding could occur if the load is different?

[newbie alert]

32 minutes ago, Shimonu said:

I did it unloaded, thinking it would be easier to feel any backlash. But I suppose binding could occur if the load is different?

Yep, also doing it inside can also have a effect this time of year