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Gemini GTD E.Fric new mount or?

astrophotography equipment mount
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#76 GeminiGTD-Italy

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Posted 13 July 2020 - 03:29 PM

Thank you for your kind words! I am glad you appreciate my efforts to provide a mount with good performance and an interesting appearance.

#77 lillo78d

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Posted 17 August 2020 - 05:56 AM

hello everyone, I also bought an E.Fric Gemini mount, and an OnStep Instein control unit, but when I go to point the objects / star, for alignment, it points me much lower, of the selected object of a few hours , even if the mobile takes all the coordinates and the time with the GPS.
doing the alignment with Skysafari 6 pro, this problem is not there indeed it points very close to the selected object, do you have any ideas or advice?
thank you



#78 GeminiGTD-Italy

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Posted 17 August 2020 - 07:23 AM

Hello, as I explained you in private, OnStep when started up for the first time, assumes you have the mount parked in a specific position and makes the first slew to init the telescope starting from this presumed position. Once you correct the error and sync on your reference star, the slews are correct.

András



#79 ajaymandke

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Posted 17 August 2020 - 09:45 AM

Hello, as I explained you in private, OnStep when started up for the first time, assumes you have the mount parked in a specific position and makes the first slew to init the telescope starting from this presumed position. Once you correct the error and sync on your reference star, the slews are correct.

András

Hi Andras,

 

Using platesolving (in astroimaging scenario) the successive slews will get more accurate. Is that correct? 

 

Ajay



#80 GeminiGTD-Italy

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Posted 17 August 2020 - 10:03 AM

Hi Andras,

 

Using platesolving (in astroimaging scenario) the successive slews will get more accurate. Is that correct? 

 

Ajay

Hello Ajay, yes this is correct. Also, saving a home/park position after the mount has been correctly initialized (supposing a permanent setup) solves the above problem. 

Building a sky model will further enhance pointing and tracking precision (makes sense in a permanent setup).

András



#81 ajaymandke

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Posted 17 August 2020 - 12:06 PM

Thank you Andras,

 

Since my setup will not be permanent, will following steps work -

1) Initialize the mount 

2) Save the park position as CWD

3) Use index marks on axis cover/housing for quickly identifying the home position.

4) Always return to park position at the end of session.

 

Once established, by quickly aligning index marks at the start of session and initializing the OnStep driver, I can hope to be in general area of the target. 

 

Again, since I plan to platesolve during imaging, this may not be critical, but its good to know if above procedure will work in case of visual observing or planetary imaging etc.

 

Ajay



#82 GeminiGTD-Italy

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Posted 17 August 2020 - 01:01 PM

Yes, your idea will work!

 

My method (will take about the same amount of time) is the following:

 

1) I start OnStep with the Android app

2) set date and time (GPS on)

3) Release the clutch and point the OTA roughly at the Pole

4) Start the init on a well visible bright star

5) After it points the star I center it (in the finder) with the slew buttons of the App and sync on it

 

After this operation the mount will point decently, just as well as my centering in the finder was. A plate solve and sync will bring it to perfection.

 

András


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#83 lillo78d

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Posted 20 August 2020 - 05:02 AM

yesterday I tried again to align the E.Fric mount with the OnStep system, turned on, took the coordinates of the place and the date and time, with the GPS, checked the home position, and then I proceeded with the pointing of the star Arturo, which I had in the west.
The frame also this time had the declination pointing where it should point and the R.A., pointing from the opposite side, when I went to correct (a lot), I saw that the problem is precisely the R.A. that moves to the opposite side of the object, and also correcting and aligning then if I point other objects they are far out of the field, always in A.R. and not in DEC., a disaster, never had any problems in the past with any GO TO system, and I've changed several.



#84 GeminiGTD-Italy

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Posted 20 August 2020 - 05:49 AM

I am sorry for this. I am sure if you follow the instructions above it will work.

Please note that I am not a vendor or manufacturer of the OnStep, I made a favor for you and programmed the firmware with the parameters of the mount only.

Please post your problems relative to the controller to the OnStep forum. Thank you.

András



#85 lillo78d

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Posted 22 August 2020 - 11:44 AM

well, the problem was solved, directly by Andras Dan of GTD, he sent me a file to put in XLoader, with all the data to fill in, and everything worked now point where it should point, tonight I will do the tests for the 'Chase.
I emphasize that Andras Dan, has also made himself available to make a video called in case I was not able to fix everything via software, and even if no further help was needed, price availability.
Oh I forgot it was the A.R. engine, which turned backwards


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#86 Gregory

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Posted 28 August 2020 - 09:29 PM

Hello all,

 

I just received an E.fric from Gemini Telescope Design.  I am using the

Pulsar2 controller.  The intent is to replace my current mount, which has

a very reasonable imaging capacity of 21kg (~46 lbs.) with one that is

rated to carry a little more than my current equipment load of 24kg

(~53lbs.), and which retains the capability of doing mobile imaging.

 

I have not yet tested the heavy load, since I am waiting on a shipment

of counterweights, but I have run initial tests with a very much lighter

load, a 75mm refractor weighing about 6 kg including camera equipment.

 

The mount is supported on an Astro-Physics Eagle tripod pier, using

off-the-shelf adapters, with only two minor modifications: the drilling/tapping

of a hole for the azimuth pin, and the drilling out of the center bore of

the pier adapter.

 

Attached is a photo of the mount on the Eagle pier.  A couple more photos

will follow as separate postings.

 

If there is interest, I will post about my impressions, testing results, and

purchasing experience.

 

Gregory

 

backyard_image5_50p.jpeg

 


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#87 Gregory

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Posted 28 August 2020 - 09:31 PM

Here is another photo of the E.fric on the Eagle pier.

 

Gregory

 

backyard_image4_50p.jpeg

 



#88 Gregory

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Posted 28 August 2020 - 09:32 PM

And, a photo of the refractor atop the E.fric.

 

Gregory

 

backyard_image0_50p.jpeg

 



#89 Paul Garais

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Posted 28 August 2020 - 10:37 PM

Thanks for sharing. I am interested in more ;).

#90 mikefulb

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Posted 28 August 2020 - 10:57 PM

Lovely mount and I am interested in it as it doesn't require a proprietary controller like practically all other mounts.

#91 Gregory

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Posted 29 August 2020 - 01:19 PM

Since there was interest expressed, I herein give my initial

impressions of the E.fric mount.

 

----- ---- ---- ---- ---- ---- ---- ---- ---- ---- -----

 

This mount is not for everyone.  :-)

 

Why do I say that?  Because, in several ways, the E.fric is going against
some of the trends of recent times.  Mounts in general seem to be
getting more electronics, more integration, and encoders, encoders,
encoders.  They are also in many cases becoming more massive, albeit
perhaps in clever ways that try to make good use of that extra mass.
For example, iOptron is taking advantage of the weight-centered CEM

design to reduce the needed mass somewhat, and is also going for a

high degree of electronics integration.

 

Mounts with harmonic gearing have also appeared recently, and are
eminently portable and compact, though perhaps a bit noisy and difficult
to guide smoothly.

 

Lots of choices are now available, so why look at the E.fric ?

 

The E.fric is *different*.  It makes use of an "old" technology (friction
drive) in an elegantly re-envisioned package.  Despite the appearance in
photographs of the E.fric seemingly taking up a lot of space, when you
unbox it and lift it out, you realize that in essence it is still a
"small" mount.  The materials have been chosen for light weight and
high strength, and there is a lot of "air" in the mount.  Even the central
axes are hollow (which does not seem to diminish their strength).  The
knobs that control the RA and Dec locking mechanisms are almost tiny,
and require very little torque to reach their intended locking position.
The mount exudes a sort of graceful, airy rigidity.

 

And it achieves this without adding the mass that other mount makers
seem to require.  When I put it in place on the tripod/pier, the well-
designed base provides a rock-solid support that is surprisingly
unmoving.  When the equipment is in place, and the current from the
controller is on, there is a feeling of secure firmness to the position
that again belies the mount's apparently almost delicate construction.

 

The E.fric is also beautiful in an architectural sense, for those that
prefer to see a little of the inner workings of the machine.  It is
impressive in an understated way, which is partially why the E.fric is
not for everyone.  Some prefer the ostentation of a lot of highly polished
metal, covering the inner workings of the mechanism.  They get joy from
the featureless, monolithic appearance of an enclosed appliance.  I
understand that; it is like the appeal of the Saturn V rocket, which
from the outside is a solid cylinder of technology serving a complex
purpose.

 

The E.fric is definitely not that, and its appeal lies in a different direction.

 

This is reflected again in its *lack* of an integrated controller.  The
idea is that one of several controllers may be used, one from the
mount maker, or a few others from independent parties.  The connections
are explicitly external, like the old days, but with updated electronic
sensibilities such as WiFi and USB, that make use of the component-
oriented modern digital world.  This pluggable, almost DIY philosophy
extends further, in that (conceivably) a repair could be done if
something on the mount were damaged or had failed.  Replacing the motors,
for instance, is eminently possible, simply by finding one of several
on the market that fit the mechanical and electrical properties.

 

This makes the E.fric somewhat unique to talk about, since we must
clearly separate what is the mount, and what is the controller.  We
cannot confuse those two, or project the shortcomings of one upon the
other.  For most modern mounts, those two cannot be separated as
readily.

 

The E.fric hits a sweet spot of portability, capacity, and precision,
in a package that for me may be the last mount I will ever purchase.

I have some early test results using a small refractor, and will be
posting those results, and additional results, when I can test with
the projected final equipment load (~24kg) after a counterweight
shipment arrives.  :-)

 

Gregory

 

 

 

backyard_image1_50p.jpeg


Edited by Gregory, 29 August 2020 - 01:34 PM.

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#92 GeminiGTD-Italy

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Posted 29 August 2020 - 02:34 PM

I don't think I could ever have explained this better! I just have had the impression I have to go in this direction to express and materialise my views on astronomical equipment.

Thank you,

András


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#93 ajaymandke

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Posted 29 August 2020 - 06:16 PM

Hi Gregory,

That's a great looking mount. I have ordered the E Fric mount too after detailed review from OP of this thread. It will be my last mount that I will purchase too.
I am looking forward to your report of using it under stars.

Ajay

#94 Gregory

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Posted 29 August 2020 - 10:36 PM

Hello Ajay,

 

You recently posted:

 

That's a great looking mount. I have ordered the E Fric mount too after detailed review from OP of this thread. It will be my last mount that I will purchase too.
I am looking forward to your report of using it under stars.

Since you asked, I will try to get at least the preliminary test data together

sooner rather than later -- the counterweight shipment is delayed.  :-(

 

BTW, have you decided yet which controller and counterweights you will

be using?  And, what sorts of OTA(s)/payload(s) will the mount be carrying?

 

Gregory



#95 Paul Garais

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Posted 30 August 2020 - 03:13 AM

Gregory, do you have dumbbell weights? All of my weights at home have 30 mm central opening. So should be fine as temporary solution.

If I may add some further questions:

Is there a particular reason for choosing the Pulsar instead of a cheap controller like Onstep? Did you choose it, because you want to work without a notebook?

What is the longest scope you will put on it? Is the mount sensitive to long moment arm? I have a 152mm f/8 triplet with a full length of over 1,60 m in imaging configuration.

How sensitive is it to disbalance?

I am mostly interested in guiding performance, because I will add a longer focal length scope to my equipment in the next years and will have an imaging scale of 0.47".

Thank you for sharing your findings and opinion!


—Paul
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#96 mikefulb

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Posted 30 August 2020 - 06:47 AM

Gregory - thanks for the quick look at the mount.  I love the idea behind this mount.  I do not like the trend to throw every technological gimmick possible into the mount that so many are doing now.   I just want the mount to handle tracking and I can accessorize it as I see fit with hubs, etc.  Currently I am using a G11 but will be watching your experience with interest.



#97 ajaymandke

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Posted 30 August 2020 - 11:13 AM

Hello Ajay,

 

You recently posted:

 

Since you asked, I will try to get at least the preliminary test data together

sooner rather than later -- the counterweight shipment is delayed.  :-(

 

BTW, have you decided yet which controller and counterweights you will

be using?  And, what sorts of OTA(s)/payload(s) will the mount be carrying?

 

Gregory

Hi Gregory,

I chose to go with OnStep controller for E Fric. The counter weight shaft diameter is1.25", so I will use the Losmandy 22 pound CW.

I plan to use SV 110ED refractor and AT6RC as my OTAs. I have used SV110ED on my previous Losmandy mount. AT6RC needs to be collimated :(

Both OTAs with imaging cameras,guidescope/OAG weigh close to 20 pounds. I plan to upgrade a long focal length scope later on once I get better at imaging/processing.

I hope the E Fric mount performs well even at longer FL (just as the OPs review)

 

Ajay



#98 Gregory

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Posted 30 August 2020 - 11:14 AM

Hello Paul,

 

You recently asked:

 

> do you have dumbbell weights? All of my weights at home have 30 mm central opening. So should be fine as temporary solution.

 

Right now, I have only a couple of counterweights from 10 Micron, which

are beautifully made (see the attached photo), but not nearly enough for

the 314mm Harmer-Wynne that the mount will be carrying (~24kg).  I am

awaiting a shipment of a couple of 10kg counterweights with a 32mm bore,

which is a bit large, but which I will modify slightly with a teflon sleeve.

 

The counterweight shaft of the E.fric is made for 30mm bore counterweights.

I don't quite understand why the ones you have would be "temporary" ( ? ).  Is

it because they are insufficient for your planned payload?

 

> Is there a particular reason for choosing the Pulsar instead of a cheap controller

> like Onstep? Did you choose it, because you want to work without a notebook?

 

Yes.  My reasons were:

 

1) Operation without a notebook/laptop/phone computer.

2) Slewing rates of up to 5 degrees/second

3) Support from the manufacturer of the mount

4) Tried-and-true tested electronic components

 

> What is the longest scope you will put on it?

 

I have no plans to put other than the above-mentioned 314mm f/5

truss Harmer-Wynne on the mount, and occasionally the 75mm Pentax

refractor.

 

> Is the mount sensitive to long moment arm? I have a 152mm f/8 triplet

> with a full length of over 1,60 m in imaging configuration.

 

The short answer is: I don't know. :-)  If you want an opinion, I would

say that a 152mm f/8 triplet (sounds heavy) might be beyond the

capacity of the mount, but the mount designer will have to weigh in

to get a better assessment.  My Harmer-Wynne is an f/5, so is "only"

about 800 mm in length (not including the imaging train).  And I have

yet to test that configuration.

 

> How sensitive is it to disbalance?

 

Going by my short evaluation, it is very sensitive.  I would say you

would want a near-perfect balance.  Interestingly, a counterweight

with a *slightly* larger bore may make this easier, since it can be

rotated to offset Dec imbalances (like the placement of the Dec

motor assembly) a little bit.

 

On the question of image scale, my Harmer-Wynne plus the

camera yields an image/pixel scale of 0.49".  So my upcoming

tests (perhaps a week away) will be very close to your intended

image scale of 0.47". 

 

However, what I *can* say is this: My Astro-Physics Mach1 (soon

probably to be for sale) easily handled an Edge11 working at 1960mm

focal length (reduced).  The E.fric, in my initial short focal-length tests,

is slightly out-performing the Mach1 for both guided and unguided

exposures. But keep in mind that the Edge11 was only about 16kg with

imaging gear attached, and my upcoming tests will increase that to

about 24kg.

 

Gregory

 

counterweights_image0_50p.jpeg

 

 

Gregory, do you have dumbbell weights? All of my weights at home have 30 mm central opening. So should be fine as temporary solution.

If I may add some further questions:

Is there a particular reason for choosing the Pulsar instead of a cheap controller like Onstep? Did you choose it, because you want to work without a notebook?

What is the longest scope you will put on it? Is the mount sensitive to long moment arm? I have a 152mm f/8 triplet with a full length of over 1,60 m in imaging configuration.

How sensitive is it to disbalance?

I am mostly interested in guiding performance, because I will add a longer focal length scope to my equipment in the next years and will have an imaging scale of 0.47".
 

 


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#99 Paul Garais

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Posted 30 August 2020 - 11:32 AM

Thank you, Gregory, for taking the time to answer the questions :)

Looking forward to your experience with the fine pixel scale. Below 0.5" should show every flaw of a mount ;)

The weight of my big refractor is not that crazy (18 kg full setup with camera etc.). Even the EQ6-R can handle it at 0.6" to 0.8" total RMS (sometimes worse, depending on seeing, never over 1").
András already told me, that my scope should be working fine with the mount. He is very responsive and answered all of my questions. But I never buy expensive toys without getting some reports and oppinions from real life usage. Even if the mount is cheap compared to what it can deliver. If it can guide as well as it seems, there is no need for overly expensive encoder mounts. Why pay over 10k for a mount, if you can get the same or even better performance below 5k?

What I like the most about the mount is the simple construction and very low amount of parts, that can break over time. I can get the motors used in the mount in a store 5 minutes away from my house. So even if they die after years of usage, I can easily handle it myself. That is a lot better than any premium mount full with high-tech, that I never would touch myself. It is just nice to have a thoughtfully constructed product, that you can use a life long and totally independent of the vendor or manufacturer.

And sorry for the misunderstanding regarding the counterweights: I just mentioned the dumbbell weights as a hint for you, while you wait for the delivery of your regular weights. Just in case you have workout equipment at home.


—Paul

#100 GeminiGTD-Italy

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Posted 30 August 2020 - 11:55 AM

IMG-20200822-WA0006.jpg Hi Paul, this is so far closest to your 6" APO, I hope the owner will soon share some info or guide graph!

András

 

 
 

 

 


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