HEQ5 worm adjustment

[Anthonyexmouth]

Having a bit of a Frank Spencer moment here. 

I've read the astro baby section on worm adjustment but getting nowhere

Yesterday I fitted a belt mod and noticed a bit of play in the RA, now I should have left it alone, but I tried to adjust it and last night had worse guiding than I ever had before. 

My problem is I don't know where my starting point should be for the grub screws now. I release the 3 hex bolts a turn each, adjust the grub screws as described but finding I can get rid of the play and rotating in one direction is smoother than the other.

Is there a way to effectively start this procedure from scratch? Is guiding at the night the only way to truly test everything is working and backlash is minimised?

 

[FaDG]

8 minutes ago, Anthonyexmouth said:

I release the 3 hex bolts a turn each, adjust the grub screws as described but finding I can get rid of the play and rotating in one direction is smoother than the other

 Is guiding at the night the only way to truly test everything is working and backlash is minimised

Question 1: the screws act in a push-pull way, first release the Central one to get the System free, tighten the external ones to reduce play. When you feel that the axis still moves without stress but  the backlash is acceptable, tighten up the third one. Caution : the two external screws shall be balance, or you'll turn the block on a side. 

Operate in an iterative way, until you're convinced that you have it "just right". 

Second question: the way to feel for backlash and smoothness is by turning the axis as mentioned above. But the proof of the pudding is in the eating (especially in dec) ; and this you can only get at night. 

[Anthonyexmouth]

These 3 screws? 

[Anthonyexmouth]

I think my problem is I have no idea what it SHOULD feel like. 

[Anthonyexmouth]

Ok, I've just followed a YouTube video explaining the procedure on an NEQ6 and it seems to have worked. Just having a coffee and will check again. Only issue now is I've found a stiff 30° ish section in the Dec worm. 

Is this something that can be tuned out or does it need striping down?

Here's the video I followed. Hope it's similar enough to the heq5

 

[FaDG]

Yes, sorry I had the EQ5 in mind. 

For the HEQ5, those three screws only Lock the worm structure in place, they do not set the distance (which is what originates the backlash). 

So you have to loosen them, and then play with other two small Allen screws in the side to increase/reduce the distance of the worm wheel to the Gear. 

Look on astrobaby's tutorial, where this is explained. 

[Anthonyexmouth]

Yeah I read that astro baby one, ended up following that video I posted. Just got that little stiff bit in Dec I have to sort now. Could be a grindy bearing. 

[Dan13]

On 26/02/2019 at 15:28, Anthonyexmouth said:

Yeah I read that astro baby one, ended up following that video I posted. Just got that little stiff bit in Dec I have to sort now. Could be a grindy bearing. 

did you sort this Anthony? i also have that stiffness in a certain position with my HEQ5