TheSkySearchers

Not a big deal (or is it?) but the coarse focuser seems to "clonk" at a particular point. Anyone experience this? I'm guessing not specific to this scope. Am wondering if, when I first got it, I focused with the lock thumbscrew tightened down on ignorance. Could that have caused this? Can it be fixed? Presumably I don't need to go to the expense of a new focuser?

what type of focuser ? typical newt crayford ,or a refractor with the gear rack and pinion ? edit: i miss the title aha, yep ed 102 refractor ..

when you say clonk, do you mean that it's tight in one spot ? or in a postion the focuser is loos/shifting ?

Does this "clonk" happen with every rotation of the course knob or is it happening at one place in the length of the focuser travel?

I've not had this scope out for a couple of weeks so might need to get it out to remind myself. Been meaning to post about it for a little while. I guess it feels like it's sort of missing a tooth at one point on the rotation of the knob (as if it clonks onto the next tooth without stopping in between maybe) but that's a total guess and I've no reason to think that's the case. I'd have to check whether it happens on every rotation.

Check it out. It if happens once with each course knob rotation then maybe the knob is canted a bit and rubbing/ dragging in one spot. If it happens in one spot in the length of the focuser travel it could be a bit of hard grease or a piece of debris in the gear track.

John Donne wrote: ↑Sun Oct 18, 2020 5:22 pm Check it out. It if happens once with each course knob rotation then maybe the knob is canted a bit and rubbing/ dragging in one spot. If it happens in one spot in the length of the focuser travel it could be a bit of hard grease or a piece of debris in the gear track.

Great thanks, all sounds less terminal than I was fearing but who knows.

Focusers are fairly robust, so should not have damaged it.
Is your telescope a ES with the hexfocuser or a crayford?

The product page says it "includes a new 2.5" Hexagonal focuser" so I guess it's a hexfocuser??

munkster wrote: ↑Mon Oct 19, 2020 10:22 am The product page says it "includes a new 2.5" Hexagonal focuser" so I guess it's a hexfocuser??

I had an ES 127 that had a clunky hex focuser.
I contacted The folks at Explore Scientific and they sent me a new focuser no charge. The scope was less that 365 days old at the time. The new focuser was a good one.
I am interested in your outcome on this problem.

munkster wrote: ↑Mon Oct 19, 2020 10:22 am The product page says it "includes a new 2.5" Hexagonal focuser" so I guess it's a hexfocuser??

Check that all is tight, the first hexfocuser that I had to deal with had a loose gear plate for the R&P.
Inspect the teeth as well to make sure they are all straight.
One other thing to check if if the drawtube is staying flat or drooping after a certain distance.
Put some weight in the focuser and rack it in and out watching to see if the drawtube moves up or down as it goes.

The focuser may just need some tuning. I had ES 127CF and 102CF scopes in the past. For both I took focusers apart, re-greased and re-tensioned them, which improved smoothness and addressed focuser tube sagging.

Sounds a bit hardcore. I'm not exactly technically illiterate but might need to watch a few YouTube videos on this, if they even exist, before getting the spanners out!!

Adjusting focusers is fairly normal and usually is not that hard to do once you look it over and figure out how it works.
Good luck and have fun

Lady Fraktor wrote: ↑Tue Oct 20, 2020 7:28 pm Adjusting focusers is fairly normal and usually is not that hard to do once you look it over and figure out how it works.
Good luck and have fun

This is also a procedure you need to learn to be successful in the hobby, like collimating a reflector, or aligning finderscopes. You don't need to take it apart to the last screw, just take the focuser tube out, visually inspect, re-grease and adjust tension screws.

Think of a R&P focuser as a bit of a see-saw.
Your accessories are at one end, the pinion is the fulcrum and applied tension in the focuser balances it out at the other end.
Once you have it figured out you will be able to adjust it quickly in future.