More focuser woes

[KathyNS]

I'm trying to avoid shelling out big bucks for a Feathertouch focuser. But I can see that that may be in my future.

I thought I had my GSO LF dialed in and working fine. Just crank the tension up to max and it was working well. Or so I thought. Last night, it wouldn't autofocus to save its life.

I am making progress on diagnosing its problem. It looks like it objects to operating upside down. Pointing east of the meridian, it is right-side-up; pointing west, it is upside-down. All my problems seem to be on the west side. Last night, even with the tension cranked up, it lost traction. It still moved, but the movement was not linear with respect to motor steps. (See screen shot below. That fourth run is way too far over!) And, in the parked position, with the focuser hanging downward, I noticed some flex in the up/down direction. That could explain the loss of traction.

It looks like, once the weather warms up enough to work out there, I'll have a tune-up to do. Meanwhile, I'll have to stick to the east side of the sky, so I can't finish this year's M42.

[Lady Fraktor]

Before spending on the Feathertouch (though they are fantastic) have you compared the Moonlite or Baader Steeltrak for capability?
Very sturdy and a bit cheaper options.

[man1]

I have the same focuser on my XT10i, I had no issues but I like to improve where ever I can my setup. I read about people grinding
the flat spot on the tube (to be truly flat). Some folks are using a grinding stone and got very good smooth results. I went the other way
using my milling machine and got the surface absolutely flat. Also replaced the lube at the bearings. The GSO works super smooth,
I tried some one elses moonlight and other than the looks - it works just as smooth and reliable.

My be your problem is related to weather conditions being right on the ocean.... ???

On the other hand it's only money..... a very big part of astronomy....LOL....

[KathyNS]

I have the same focuser on my XT10i, I had no issues but I like to improve where ever I can my setup. I read about people grinding
the flat spot on the tube (to be truly flat). Some folks are using a grinding stone and got very good smooth results. I went the other way
using my milling machine and got the surface absolutely flat. Also replaced the lube at the bearings. The GSO works super smooth,
I tried some one elses moonlight and other than the looks - it works just as smooth and reliable.

My be your problem is related to weather conditions being right on the ocean.... ???

On the other hand it's only money..... a very big part of astronomy....LOL....

The GSO LF is different from the regular GSO Crayfords. There is no flat spot on the tube. Instead, there is a steel plate bolted onto it. It is supposed to be better. Apparently, it prevents play in the tube. But not on mine, apparently, which is why it might need to be tuned up.

I am sure it's not a weather-related effect, though I did encounter some problems at very low winter temperatures. I think those were related to the focuser having to extend more to compensate for thermal contraction of the OTA.

[man1]

Thanks for explaining your version of the GSO focuser, I am always learning something new! I have never seen the inner workings of
your version, I always thought they were working on the same principle (for refract. and reflect.). Maybe measure with a small
digital scale if there is any change in pressure needed for movement as temperature changes. Also you are mentioning this happens
when leaning towards a certain side... something must be binding. Stick with it, you'll figure it out and get it going.!!!

[kt4hx]

Before spending on the Feathertouch (though they are fantastic) have you compared the Moonlite or Baader Steeltrak for capability?
Very sturdy and a bit cheaper options.

The Moonlite CR-2 on my 17.5" dob has been trouble free for over 10 years now. Couldn't be happier.

https://focuser.com/products.php