Advice for a new owner of an ES 127? - Forums

Topic starter

10 days ago

Hi all,

I’ve recently acquired a new-to-me ED 127 FCD-100 Aluminum with the 2.5” hex focuser. I’m planning out the imaging train for it, and I want to use it at its full focal length to complement the Askar 103 I already have. I’d love to hear from folks who have experience with this telescope and what advice they can share.

I have the Hotech 2” SCA flattener. I plan to use a rotator, an OAG, and a 2” filter wheel in front of the camera. Most setups would have about 5 pounds behind the flattener. The specs on the hex focuser claim a 10 lb. weight capacity. I will have an autofocuser.

Can I trust the hex focuser, or should I plan on buying the ES 3” focuser or a Feather Touch ($$$)?

Should I disassemble the flattener and thread it onto an M68×0.7 to M48×0.7 reducer ring rather than slide it into the compression ring?

Would the ES 1x flattener be a better choice given its 48mm exit lens (as opposed to the Hotech’s 42mm)? The camera will be an APS-C, not full frame.

I have an EQ6-r Pro mount that I’ll need to get the pier extension for. I’ve seen reports of an early model of this pier extension that had issues. Have they been resolved? I understand they now come with some sort of rubber gasket or something where the pier joins with the tripod?

Any other advice or learnings you might share? Thanks in advance.

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Tom Boyd

10 days ago

Stephen Girimont · Jul 13, 2026 at 01:36 AM
I have an EQ6-r Pro mount that I’ll need to get the pier extension for. I’ve seen reports of an early model of this pier extension that had issues. Have they been resolved? I understand they now come with some sort of rubber gasket or something where the pier joins with the tripod?

I had an EQ6-r that I used with the stock Skywatcher pier extension. My use case was that I would set up and take down every night. The pier extension components are aluminum and are attached to the mount via 3 stainless steel hex screws. I found that after about 6 months of use, the holes into which the hex screws sat began stripping. I ended up retapping the holes and installing heli coils into them and never had a problem again. That being said, I think the mount connections were designed poorly…

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Don

10 days ago

I have a couple of ES 127 FCD100’s. The focuser isn’t the best. But after snugging down the adjustment screws, it works OK with an EAF. I had good luck with the Hotech flattener (threaded in, not slipped in). But the Stellarvue SFFX1 worked better, you just need the Baader m68×1 adapter to attach it. The ES .7x also works really well.

The main issue I had with the scope, were that the baffles inside weren’t in the correct location, and were restricting the image circle. After shifting them (they are not fixed and slide easily) the scopes performed much better. There were also some protruding screws in the focuser that were causing diffraction spikes, I ground them down with a dremel tool.

While the scopes did require quite a bit of tweaking to get them right, they now perform very well. Very sharp, with no diffraction spikes. I’ve DPAC tested both with very good results.

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Stephen Girimont

Topic starter

10 days ago

Tom Boyd · Jul 13, 2026, 02:20 AM
I had an EQ6-r that I used with the stock Skywatcher pier extension. My use case was that I would set up and take down every night. The pier extension components are aluminum and are attached to the mount via 3 stainless steel hex screws. I found that after about 6 months of use, the holes into which the hex screws sat began stripping. I ended up retapping the holes and installing heli coils into them and never had a problem again. That being said, I think the mount connections were designed poorly…

I wonder if SW has made any improvements to those mount points?

Stephen Girimont

Topic starter

10 days ago

Don · Jul 13, 2026, 10:04 AM
I have a couple of ES 127 FCD100’s. The focuser isn’t the best. But after snugging down the adjustment screws, it works OK with an EAF. I had good luck with the Hotech flattener (threaded in, not slipped in). But the Stellarvue SFFX1 worked better, you just need the Baader m68×1 adapter to attach it. The ES .7x also works really well.
The main issue I had with the scope, were that the baffles inside weren’t in the correct location, and were restricting the image circle. After shifting them (they are not fixed and slide easily) the scopes performed much better. There were also some protruding screws in the focuser that were causing diffraction spikes, I ground them down with a dremel tool.

I’ve already ordered the ES .7x flattener. I figured I’d give that and the Hotech one a try and sell one at some point. I do have the Stellarvue SFFX1 on my list of alternatives (and the Baader adapter).

I haven’t taken a good look at the internals of the focuser yet. When you say “shifting them”, do they move forward and back? Is it a concern that they’d move during an imaging session, or does it take a bit of effort to move them?

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Tom Zepf

9 days ago

I have this scope and have had great results with the Hotech flattener threaded on. It will be fine for APS-C, but not for full-frame. The 2.5 hex focuser is a little wiggly, but if you snug things up a bit (not too tight), I’ve had good results with an EAF. The optics are really great so long as you don’t get deep cold. Below about 10° F I get a bit of pinched optics. I imagine I could loosen the screws a bit to get some relief, but it’s not worth it to me for the occasional very cold night.

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Don

9 days ago

Stephen Girimont · Jul 13, 2026 at 11:30 AM
Don · Jul 13, 2026, 10:04 AM
I have a couple of ES 127 FCD100’s. The focuser isn’t the best. But after snugging down the adjustment screws, it works OK with an EAF. I had good luck with the Hotech flattener (threaded in, not slipped in). But the Stellarvue SFFX1 worked better, you just need the Baader m68×1 adapter to attach it. The ES .7x also works really well.
The main issue I had with the scope, were that the baffles inside weren’t in the correct location, and were restricting the image circle. After shifting them (they are not fixed and slide easily) the scopes performed much better. There were also some protruding screws in the focuser that were causing diffraction spikes, I ground them down with a dremel tool.
I’ve already ordered the ES .7x flattener. I figured I’d give that and the Hotech one a try and sell one at some point. I do have the Stellarvue SFFX1 on my list of alternatives (and the Baader adapter).
I haven’t taken a good look at the internals of the focuser yet. When you say “shifting them”, do they move forward and back? Is it a concern that they’d move during an imaging session, or does it take a bit of effort to move them?

They are just press fit and not very hard to move. My scopes are 5 years old, so hopefully they are better now. The front baffle was so close to the lens, that it was reducing the scope to about 4 1/2”. The edges on the baffles were pretty rough too. I sanded mine down and repainted them. Tweaking it was a pain, but in the end it does produce very clean stars.

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