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Introducing the new mount. RST-135E

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#1 xuranus

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Posted 01 March 2021 - 11:44 PM

Hi, I'm Byoungjun Jeong from RainbowAstro.

 

First of all, I would like to announce the news that my company (RainbowRobotics) has been listed on the Korean stock market (KOSDAQ).

We have an opportunity to grow into a bigger company.

 

We have eliminated the need for counter weights in our previous products (RST-150H, RST-135, RST-300).

This time, the need for an auto guider system has been eliminated.

 

Renishaw encoder have been added to the RST-135.

As a result, the periodic error is +-2.5 (peak to peak 5)arcsec and the period is 430 seconds.

This is a performance that can be unguided astrophotography at a focal length of 500mm.

 

We focused on adding a high resolution encoder but not changing its size and weight.

The new mount still has almost the same size and weight as the RST-135.

 

Product Name: RST-135E

Weight: 3.4kg (0.1kg increase compared to RST-135)
Appearance: same as RST-135
Price: 5,495 USD
Release Date: Delivery starts in May
Promotion: 250 USD discount for reservations made before April 30

 

Expected Questions and Answers

1. Is RST-135 discontinued?

   No.    The RST-135 and RST-135E will continue to be sold as separate products.

 

2. Does this support auto guide?

  Yes. Support.  Auto-guided performance is similar to that of RST-135.

 

3. Who needs this?
  For those who are bothered or afraid of the auto-guide system
  Those who mosaic large areas overnight
  Those who need to reduce the weight and volume of equipment for mobile observation

 

4. Is it possible to upgrade RST-135 to RST-135E?

  Sorry. Unfortunately, it is not possible to upgrade.

 

 

Orion_RST-135E_Redcat51_ASI2600MC_300sec_21f_UNGUIDED_1400px_q7.jpg

High resolution link - https://www.astrobin...g2e89l/?nc=user

 

Telescope : WO Redcat51 (fl250mm)

Camera : ASI2600MC

Exposure : 5min x 21

Unguided

No flat, dark, bias

 

I took 21 five-minute exposures, and I didn't throw away any of them.

You can download the original fit files from the following link.
https://drive.google...ohk?usp=sharing


Edited by xuranus, 01 March 2021 - 11:51 PM.

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#2 xuranus

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Posted 01 March 2021 - 11:50 PM

M45 UNGUIDED
 

Telescope : Pentax105SDHF (fl700mm)

Camera : Canon 6D mod

Exposure : ISO 1600 5min x 8

UNGUIDE

No flat, dark, bias

 

I took 8 five-minute exposures, and I didn't throw away any of them.
You can download the original jpg files from the following link.
https://drive.google...zxE?usp=sharing


Edited by xuranus, 01 March 2021 - 11:59 PM.

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#3 Howard Gao

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Posted 02 March 2021 - 12:09 AM

This is great news. Next time when such product upgrade is planned it will be better to share some news early so we can order the enhanced version instead of the old one. Now question - is it possible to give some discount to existing users?

 

 Thanks

Howard


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#4 rockstarbill

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Posted 02 March 2021 - 12:20 AM

Sweet!!! Is the Renishaw Encoder an Absolute Encoder?



#5 xuranus

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Posted 02 March 2021 - 12:31 AM

This is great news. Next time when such product upgrade is planned it will be better to share some news early so we can order the enhanced version instead of the old one. Now question - is it possible to give some discount to existing users?

 

 Thanks

Howard

Thanks Howard,

There are no discounts for existing users.

 

 

 

Sweet!!! Is the Renishaw Encoder an Absolute Encoder?

It is an incremental encoder. 

We haven't yet found a small sized absolute encoder that can be applied to the RST-135E.


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#6 kel123

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Posted 02 March 2021 - 12:48 AM

This is great news. Next time when such product upgrade is planned it will be better to share some news early so we can order the enhanced version instead of the old one. Now question - is it possible to give some discount to existing users?

 

 Thanks

Howard

Maybe we will start seeing that one in the used market.



#7 Christopher Erickson

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Posted 02 March 2021 - 12:50 AM

I assume that the new incremental encoder was added to the RA axis only?


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#8 rockstarbill

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Posted 02 March 2021 - 12:58 AM

I assume that the new incremental encoder was added to the RA axis only?

Strain waves have no backlash, correct? If so then it would make sense to only put one on the RA axis. 

 

Is the residual peak to peak error of 5" a result of the encoder being incremental? Is the residual error also dependent on weight or can it be modeled with PEC/PEM? Do you plan to create sky modeling software for the mount?


Edited by rockstarbill, 02 March 2021 - 03:03 AM.


#9 orlyandico

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Posted 02 March 2021 - 01:52 AM

why is the periodic error only 5" p-p?

 

I did some research on this, the Renishaw Quantic 0.2um incremental encoder with a 75mm RESM ring should have about 1.1" resolution and sub 1" SDE.


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#10 xuranus

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Posted 02 March 2021 - 04:22 AM

I assume that the new incremental encoder was added to the RA axis only?

Right. :)

I don't want the mount's price to go up a lot.

 

 

Strain waves have no backlash, correct? If so then it would make sense to only put one on the RA axis. 

 

Is the residual peak to peak error of 5" a result of the encoder being incremental? Is the residual error also dependent on weight or can it be modeled with PEC/PEM? Do you plan to create sky modeling software for the mount?

We developed and tested something similar to PEC to eliminate the remaining peak to peak 5 arcsec PE. But the results weren't good.

I am not planning on making modeling software. Since this is a portable emphasizing mount, I want the user to simply polar align and use it conveniently.

 

 

 

why is the periodic error only 5" p-p?

 

I did some research on this, the Renishaw Quantic 0.2um incremental encoder with a 75mm RESM ring should have about 1.1" resolution and sub 1" SDE.

I think the cause is because the distance between the encoder read head and the scale is different or the angle is different.

The strain wave gear mount has no physical real axis. It has an imaginary axis that relies solely on its cross roller bearings.

I think it will have very little movement because of this. 

 

We don't use Quantic and RESM. It's not small enough to be used with the RST-135E. :)
We use ATOM DX. Our goal is always extreme portable.


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#11 Eltavito

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Posted 02 March 2021 - 06:02 AM

Does the Renishaw encoder have any benefits for a visual user of the mount?


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#12 alan.dang

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Posted 02 March 2021 - 06:14 AM

Wow! That’s impressive!
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#13 rockstarbill

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Posted 02 March 2021 - 01:28 PM

Does the Renishaw encoder have any benefits for a visual user of the mount?

Not at all.



#14 rsalva1

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Posted 03 March 2021 - 04:16 PM

@Byoungjun - Where can I pre-order? 



#15 xuranus

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Posted 03 March 2021 - 08:07 PM

@Byoungjun - Where can I pre-order? 

Hi,

You can contact your local deal to make a reservation.

A list of dealers can be found at the following link.

http://www.rainbowastro.com/dealers-2/

 

Thank you. :)



#16 kel123

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Posted 04 March 2021 - 04:44 PM

Does the Renishaw encoder have any benefits for a visual user of the mount?


That will be an overkill. A visual user doesn't need that encoder.

#17 xuranus

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Posted 04 March 2021 - 08:05 PM

Here's another picture taken with the RST-135E.

 

Rosette nebula (UNGUIDED)
 
I took 16 five-minute exposures, and I didn't throw away any of them.
You can download the original fit files from the following link.
https://drive.google...uuc?usp=sharing

 

Full resolution

https://www.astrobin...pf0fvx/?nc=user


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#18 Lead_Weight

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Posted 08 March 2021 - 12:04 PM

I'm wondering if the E version would improve guiding on longer focal length telescopes (2000mm) to make this a regular option? Have you tried any guiding at long focal lengths?



#19 Astrojedi

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Posted 08 March 2021 - 12:19 PM

I am interested to know this also. If I were to speculate I would say the primary benefit you would get is the ability to use longer guide exposures say 1s or 1.5s. I think that would benefit accuracy although I am not sure how much. Even with multi-star guiding using 0.5s guiding I do notice the RMS creeps up in poor seeing (although the delta between multi-star and single star does not change - so single star would still be much worse). So longer guide exposures could make the performance more consistent.



#20 xuranus

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Posted 08 March 2021 - 07:23 PM

I'm wondering if the E version would improve guiding on longer focal length telescopes (2000mm) to make this a regular option? Have you tried any guiding at long focal lengths?

 

I am interested to know this also. If I were to speculate I would say the primary benefit you would get is the ability to use longer guide exposures say 1s or 1.5s. I think that would benefit accuracy although I am not sure how much. Even with multi-star guiding using 0.5s guiding I do notice the RMS creeps up in poor seeing (although the delta between multi-star and single star does not change - so single star would still be much worse). So longer guide exposures could make the performance more consistent.

I have been focusing on the convenience of unguided so far.

I'll experiment more with long focal lengths and longer guide exposure times.


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#21 AstroSteppy

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Posted 09 March 2021 - 02:00 AM

This new RST-135E, if it works well, is a good idea.

 

But for those who use ASIAIR PRO it could be a problem to do the "dithering" without the guide.



#22 Lead_Weight

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Posted 09 March 2021 - 11:21 AM

This new RST-135E, if it works well, is a good idea.

 

But for those who use ASIAIR PRO it could be a problem to do the "dithering" without the guide.

Until ZWO adds a non-guide dither pulse option, you will not be able to dither unless you manually move the camera every 3-4 frames. ZWO has stated they prefer "ease of use" over new features. And not many have a mount that can go unguided so easily. So I suspect they might not add it unless Byoungjun has some influence with them. 

 

As an alternate to ASIAir, there is a StellarMate, and it does provide non-guide dither pulses for mounts that are not guiding.


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#23 xuranus

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Posted 16 March 2021 - 09:02 PM

M13 (NEW e-160ED, NEW RST-135E)

full resolution - https://www.astrobin...ixp6r6/?nc=user

 

Telescope : Takahashi e-160ED (D:160mm, fl:530mm)
Camera : ZWO ASI2600MC
Mount : RainbowAstro RST-135E
Tripod : Supermount CYG48P
Guide : Unguided
Exposure : 180s x 60
Location : Jangsu, Korea
No Dark, Flat, Bias

 

This is the first light of the new e-160ED.
I used the RST-135E mount and it is unguided.


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#24 dcacloudynights

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Posted 20 March 2021 - 10:15 AM

Any plans to add an encoder to the RST-300...?

 

Thanks,

Dave



#25 BlakPhoenix

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Posted 28 March 2021 - 06:51 PM

Any plans to add an encoder to the RST-300...?

 

Thanks,

Dave

Quote from their FB page a week ago:

 

Yes. We will add encoders to the RST-300 in the future as well. No specific date has been set yet.




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