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Re: G11T questions

 

1200mm without dew shield extended

exposures are less than 10ms. For animations I use a solar guider and will take 300 frames every 60 seconds for 30-60 min
Re: G11T questions

Sonny Edmonds
 

Sounds interesting, Rene.
A 150 mm refractor still remains my dream telescope.
I have a friend in Albuquerque, New Mexico who likes imaging solar. He uses a Lunt, but not sure of the size, 60 or 80 mm.
Posts great images.
Any chance of following your work with this?
--
SonnyE


(I suggest viewed in full screen)
Re: Quite sticky mount

 

FYI working on the video now
Re: Quite sticky mount

Sonny Edmonds
 

Brian,
Thanks for the clutch tightening advice.
I wondered "How Tight?" Because conveying the torque to a hand over the Internet isn't easy.
It seems that if everything is in close balance, then the drive can easily move the load. So no need for over tightening.
(Assuming other factors, like wind for instance, aren't trying to move the equipment and causing slippage.)
--
SonnyE


(I suggest viewed in full screen)
Re: G11T questions

 

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Hi Rene

?

I think it’s a great mount for what you want to do. A couple followup questions

?

How heavy and long is your 150 f8?

?

I personally don’t do solar imaging, so forgive some basic questions. How long are the exposures for each subframe?

?

?

Thanks

?

Brian

?

portfolio https://www.brianvalentephotography.com/

?

From: [email protected] [mailto:[email protected]] On Behalf Of rene diamond
Sent: Friday, March 6, 2020 8:46 AM
To: [email protected]
Subject: [Losmandy_users_io] G11T questions

?

I am looking at adding a G11T. It will be used for solar imaging (animations) and viewing. I will use a side by side set up (2 -102//F7 refractors). Total weight is 48 pounds. The other option is ?my lunt 100DS (20#) mounted next to a 150/F8 refractor. ?Thoughts on this set up? I assume the weight will not be an issue with the shorter refractors but not sure with the 150mm. ?I notice the G11T lacks the RA spring loaded worm. Any disadvantage with RA compared to G11G? Any plans to upgrade the RA on the G11T to spring loaded worm?

Thanks

G11T questions

 

I am looking at adding a G11T. It will be used for solar imaging (animations) and viewing. I will use a side by side set up (2 -102//F7 refractors). Total weight is 48 pounds. The other option is ?my lunt 100DS (20#) mounted next to a 150/F8 refractor. ?Thoughts on this set up? I assume the weight will not be an issue with the shorter refractors but not sure with the 150mm. ?I notice the G11T lacks the RA spring loaded worm. Any disadvantage with RA compared to G11G? Any plans to upgrade the RA on the G11T to spring loaded worm?

Thanks
Re: PMC-Eight GoTo or Gemini?

Sonny Edmonds
 

You're welcome Deric.
That's it in a nutshell. Scott Losmandy knows how to track the Universe.
He also knows how the too drives differ in motion.

--
SonnyE


(I suggest viewed in full screen)
Re: PMC-Eight GoTo or Gemini?

 

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Thank you Sonny, the watch analogy is easy to remember. HAPPY SKIES Deric.



Sent from my Galaxy Tab A



-------- Original message --------
From: Les Niles <les@...>
Date: 3/5/20 11:32 PM (GMT-06:00)
Subject: Re: [Losmandy_users_io] PMC-Eight GoTo or Gemini?

The Losmandy digital drive uses steppers.
When the steps are a fraction of an arc-sec — small compared to the airy disc let alone the seeing-induced blur — there won’t be any detectable bloat. ?

? -Les



On 5 Mar 2020, at 20:54, Sonny Edmonds <sonnyedmonds@...> wrote:

There is zero torque to either type at zero volts. As the voltage ramps up, the servo begins to move and applies motion to the output shaft through the gearing. That happens in either case, if the motors have the same structure. There are many different types of motors, of either type.?
A stepper starts and stops at a step. In the electric utility industry, voltage regulators must step finitely to switch their winding's. It amounts to a windup, and a clunk to the next step where it rests until the next step, positive or negative, is called for by the voltage sensing relays. Those stepper motors also have a brake on them to freeze their motion at the moment the step is completed.

My GM811G does in fact "Soft Start" or ramp up if you will. A very nice and well thought out thing to have.
My point is, stepper motors step. So there is some form of twitch to them as the make the next step.
To the eye, indeterminable. To the camera, star bloating.
When multiplied over the distance to our space objects, hugely magnified.
The Earths rotation is a smooth movement. A stepper motor, no matter how fine, is a stop/start motion. ()
Whereas, a servo motor can be made a constant, smooth, clockwork motion. (You don't see the hour hand moving, but you know it does.)

;^)
--
SonnyE


(I suggest viewed in full screen)

Re: PMC-Eight GoTo or Gemini?

 

On Fri, Mar 6, 2020 at 03:54 PM, Sonny Edmonds wrote:
There is zero torque to either type at zero volts.
Not quite...they applied Vcc power supply in a 15Khz PWM to both motor terminals even when stopped.? If you move the pinion it strongly resists movement.? When the motors ramp up this 15Khz PWM duty cycle is instantly changed lowering the approximate Vcc on one motor terminal....it thus moves with huge torque.
?
--
Brendan
Re: PMC-Eight GoTo or Gemini?

 

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The Losmandy digital drive uses steppers.
When the steps are a fraction of an arc-sec — small compared to the airy disc let alone the seeing-induced blur — there won’t be any detectable bloat. ?

? -Les



On 5 Mar 2020, at 20:54, Sonny Edmonds <sonnyedmonds@...> wrote:

There is zero torque to either type at zero volts. As the voltage ramps up, the servo begins to move and applies motion to the output shaft through the gearing. That happens in either case, if the motors have the same structure. There are many different types of motors, of either type.?
A stepper starts and stops at a step. In the electric utility industry, voltage regulators must step finitely to switch their winding's. It amounts to a windup, and a clunk to the next step where it rests until the next step, positive or negative, is called for by the voltage sensing relays. Those stepper motors also have a brake on them to freeze their motion at the moment the step is completed.

My GM811G does in fact "Soft Start" or ramp up if you will. A very nice and well thought out thing to have.
My point is, stepper motors step. So there is some form of twitch to them as the make the next step.
To the eye, indeterminable. To the camera, star bloating.
When multiplied over the distance to our space objects, hugely magnified.
The Earths rotation is a smooth movement. A stepper motor, no matter how fine, is a stop/start motion. ()
Whereas, a servo motor can be made a constant, smooth, clockwork motion. (You don't see the hour hand moving, but you know it does.)

;^)
--
SonnyE


(I suggest viewed in full screen)

Re: PMC-Eight GoTo or Gemini?

Sonny Edmonds
 

There is zero torque to either type at zero volts. As the voltage ramps up, the servo begins to move and applies motion to the output shaft through the gearing. That happens in either case, if the motors have the same structure. There are many different types of motors, of either type.?
A stepper starts and stops at a step. In the electric utility industry, voltage regulators must step finitely to switch their winding's. It amounts to a windup, and a clunk to the next step where it rests until the next step, positive or negative, is called for by the voltage sensing relays. Those stepper motors also have a brake on them to freeze their motion at the moment the step is completed.

My GM811G does in fact "Soft Start" or ramp up if you will. A very nice and well thought out thing to have.
My point is, stepper motors step. So there is some form of twitch to them as the make the next step.
To the eye, indeterminable. To the camera, star bloating.
When multiplied over the distance to our space objects, hugely magnified.
The Earths rotation is a smooth movement. A stepper motor, no matter how fine, is a stop/start motion. ()
Whereas, a servo motor can be made a constant, smooth, clockwork motion. (You don't see the hour hand moving, but you know it does.)

;^)
--
SonnyE


(I suggest viewed in full screen)
Re: PMC-Eight GoTo or Gemini?

 

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Thank you Brendan, I was wondering about that. The New Losmandy GM8's Digital drives have stepper motors while the Ones with Gemini 2 have servo motors. I am going to buy one at some point for a grab and go rig. I guess I would be okay either way. I would rather have the digital drive, nice and simple they sell for $1699.00 vs $2449.00 for the Gemni 2 HAPPY SKIES Deric.



Sent from my Boost Mobile Phone.


-------- Original message --------
From: Brendan Smith <brenatlilydale@...>
Date: 3/5/20 2:18 PM (GMT-06:00)
Subject: Re: [Losmandy_users_io] PMC-Eight GoTo or Gemini?

The servos are given ramp up, slew or tracking torque or more precisely voltage (yes increases or decreased torque) ? They a pretty damn strong even.at start up due to the way the PWM and H bridge control.

That said steppers have excellent torque and micro step is so small ....points of an arc second...it’s not noticed. ?

Each system is good I prefer servos as having worked with them in avionics. ?A servi probably has better start torque.?
--
Brendan
Re: PMC-Eight GoTo or Gemini?

 

The servos are given ramp up, slew or tracking torque or more precisely voltage (yes increases or decreased torque) ? They a pretty damn strong even.at start up due to the way the PWM and H bridge control.

That said steppers have excellent torque and micro step is so small ....points of an arc second...it’s not noticed. ?

Each system is good I prefer servos as having worked with them in avionics. ?A servi probably has better start torque.?
--
Brendan
Re: Quite sticky mount

 

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Thank you Frank " Noted"



Sent from my Boost Mobile Phone.


-------- Original message --------
From: Frank <ffowsky@...>
Date: 3/5/20 12:55 PM (GMT-06:00)
Subject: Re: [Losmandy_users_io] Quite sticky mount

With regards to Wavy Washers, they are fabricated by a?punch stamping process.?
The stamping process leaves one side of the washer with a very rough/sharp edge.
I have spent quite a bit of time hand polishing?ALL surfaces of each and every wavy washer.
Tools used - oval diamond honing steel and diamond?hone flat plate as well as fine flat wet stone polishing.
The process would leave my fingers sore so I could not complete it in one sitting nor in one day.?

Re: PMC-Eight GoTo or Gemini?

 

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Sonny, correct me if I am wrong. I believe servo motors maintaine the same torque, no matter how fast they run even during initial start up.HAPPY SKIES Deric.



Sent from my Boost Mobile Phone.


-------- Original message --------
From: Sonny Edmonds <sonnyedmonds@...>
Date: 3/5/20 12:27 PM (GMT-06:00)
Subject: Re: [Losmandy_users_io] PMC-Eight GoTo or Gemini?

If you want to see an elongated summation of differences between Stepper drives, or Servo drives, .

Bottom line? The Earths rotation does not "Step". It moves in a smooth clockwork motion.
We fight enough variables as it is without adding steps into our tracking.
--
SonnyE


(I suggest viewed in full screen)

Re: Quite sticky mount

 

With regards to Wavy Washers, they are fabricated by a?punch stamping process.?
The stamping process leaves one side of the washer with a very rough/sharp edge.
I have spent quite a bit of time hand polishing?ALL surfaces of each and every wavy washer.
Tools used - oval diamond honing steel and diamond?hone flat plate as well as fine flat wet stone polishing.
The process would leave my fingers sore so I could not complete it in one sitting nor in one day.?

Re: PMC-Eight GoTo or Gemini?

Sonny Edmonds
 

If you want to see an elongated summation of differences between Stepper drives, or Servo drives, .

Bottom line? The Earths rotation does not "Step". It moves in a smooth clockwork motion.
We fight enough variables as it is without adding steps into our tracking.
--
SonnyE


(I suggest viewed in full screen)
Re: Quite sticky mount

 

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Thank you Astronut, I think that the first thing? is, to maybe see if grease has gotten on the clutch disk. Before trying something new. My last mount needed to be tight to track well. I probably did tighten the clutches on the G11 a little too tight.I know better now.This I will chock up to a Rookie mistake thinking the G11 works like my last mount.



Sent from my Boost Mobile Phone.


-------- Original message --------
From: Astronut <hg2u@...>
Date: 3/5/20 8:51 AM (GMT-06:00)
Subject: Re: [Losmandy_users_io] Quite sticky mount

Hi Everyone,

I too got the wavy washers and tried it to reduce the friction on the RA and DEC while balancing.
It did seem to reduce the friction some, especially with heavier payloads.

Mine came with specific instructions to put "this side toward worm", and I believe this is because that depending on the orientation and how much you might loosen the clutch, the washer could jump out of the groove.

Brian, could you please get official installation recommendations and post them?

Also, everywhere I have ever tried ptfe plumbers tape, regardless of it's thickness, it seemed to disintegrate over time, shredding into tiny filaments, at the contact points, when used on moving surfaces. I'd be curious to see after some use, if there is filament residue from the sharp edges of the washer where actual contact is made? I don't know what effect those filaments would have on the needle bearings...

Re: Leaving Mount in the sun

 

Hi Arun

I use the 365 version, which is detailed here:?

you choose the size based on your telescope

the one you linked to is for the tripod only (i am mean and don't really care about or cover my tripod) and is lightweight use. If you plan on leaving it out all year, you'll def want to look at the 365 series.
Re: Quite sticky mount

 

Hi Everyone,

I too got the wavy washers and tried it to reduce the friction on the RA and DEC while balancing.
It did seem to reduce the friction some, especially with heavier payloads.

Mine came with specific instructions to put "this side toward worm", and I believe this is because that depending on the orientation and how much you might loosen the clutch, the washer could jump out of the groove.

Brian, could you please get official installation recommendations and post them?

Also, everywhere I have ever tried ptfe plumbers tape, regardless of it's thickness, it seemed to disintegrate over time, shredding into tiny filaments, at the contact points, when used on moving surfaces. I'd be curious to see after some use, if there is filament residue from the sharp edges of the washer where actual contact is made? I don't know what effect those filaments would have on the needle bearings...
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