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GEM45

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17 replies to this topic

#1 Riccardo_italy

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Posted 16 August 2019 - 03:56 AM

https://www.instagra.../p/B1N6AgUC4QK/

 

New product?



#2 whwang

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Posted 16 August 2019 - 06:15 AM

I don't get the point at all.  It just moves the Dec assembly of CEM40 from the back to the front.  What difference does this make?  Other than this, it's a CEM40.



#3 Luca Artesky

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Posted 19 August 2019 - 04:13 PM

Hello, here you can find some news about GEM45 - German Equatorial Mount

 

Official images just released from iOptron - Maybe 2000€ and release on November/January

 

Prices and specs may vary without notice

 

 

Prestazioni
Tipo Montatura equatoriale
Portata massima (kg) 20/22
Contrappeso/i 1
Interfacce USB
Lingua del Menu Inglese
Regolazione dell'altezza della polare (°) 14-68°
Piastra montatura Losmandy & Vixen con nuovo sistema USCS
Diametro cuscinetti a sfera DEC (mm) 68
Diametro cuscinetti a sfera AR (mm) 68
Diametro ruota elicoidale DEC (mm) 110
Diametro ruota elicoidale AR (mm) 110
Denti della ruota elicoidale (DEC) 216
Denti della ruota elicoidale (RA) 216
Diametro albero DEC (mm) 17
Diametro albero AR (mm) 17
Diametro asse Ascensione Retta (mm) 45
Diametro asse Declinazione (mm) 45
Diametro della barra per contrappeso (mm) 28
Contrappeso lungo (mm) 410
Contrappeso della montatura (kg) 5kg
Regolazione micrometrica azimutale +/- 6
Tensione d'entrata 12
Amperaggio (A) 5
Tipo di motore Motore passo-passo (1.8°/128 micro-steps)
Guidacavo interno
Particolarità
Sistema GoTo si
Controllo manuale si
Bolla si
Cercatore polare si
Equipaggiamento
Cavalletto Treppiede
Valigetta da trasporto no, consigliata borsa Artesky per montature o FoamBag per GEM45
Cavalletto
Diametro gambe treppiede (mm) 52
Materiale del cavalletto Acciaio
Generale
Serie GEM
Sistema di controllo GoTo
Precisione +/- 7
GPS si
WLAN opzionale con sistema StarFi
Correzione PEC si
Lingua della funzione GoTo Inglese
Software Go2Nova 8407
Autoguiding si
Interfacce Autoguider, USB
Database 359.000



#4 whwang

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Posted 20 August 2019 - 12:16 AM

All the specs look exactly like CEM40, except for the small change in payload, which means almost nothing.

I still don't get the point of this product.


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#5 TxStars

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Posted 20 August 2019 - 12:28 AM

Having the Dec moved to the north side of the EQ head and tripod may not seem like anything.

But when a longer telescope is pointed south there will be more room around the tripod and tube reducing the chance of it hitting.


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#6 OldManSky

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Posted 20 August 2019 - 08:12 AM

Altair Astro has a pretty complete page on it...

 

https://www.altairas...rial-Mount.html

 

Replacement for the iEQ45Pro.  Same materials (and production line) as the CEM40, better drive setup, a bit more load capacity, better setup for longer scopes (as TxStars mentioned).

Wouldn't surprise me at all to see a new 60-lb. capacity mount coming with the same color scheme/production line/changes in the near future.  Whether it will be CEM or GEM is anyone's guess...:)



#7 photoracer18

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Posted 20 August 2019 - 04:07 PM

Its now a traditional GEM mount. Sort looks like a Paramount MyT with a different paint scheme.


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#8 photoracer18

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Posted 20 August 2019 - 04:35 PM

All the specs look exactly like CEM40, except for the small change in payload, which means almost nothing.

I still don't get the point of this product.

Synta is coming out with CEM mounts so iOptron wanted to upgrade their GEM mounts to counter compete I am guessing.



#9 whwang

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Posted Yesterday, 06:43 AM

Altair Astro has a pretty complete page on it...

https://www.altairas...rial-Mount.html

Replacement for the iEQ45Pro. Same materials (and production line) as the CEM40, better drive setup, a bit more load capacity, better setup for longer scopes (as TxStars mentioned).


Hi,

From that page, I can’t find any claim of better drive setup. Do you mind explaining more about this? Thanks in advance.

#10 OldManSky

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Posted Yesterday, 09:33 AM

Hi,

From that page, I can’t find any claim of better drive setup. Do you mind explaining more about this? Thanks in advance.

iEQ45: 337 sec. worm period, 0.09 arcsec resolution

GEM45: 400 sec. worm period, 0.08 arcsec resolution

 

Also, the GEM45 uses the magnetic-lock worm engagement system like the CEM120, CEM60, and CEM40, instead of the manual-tension setup of the iEQ45.

For the GEM45, the specs claim "zero backlash."  We'll see.  If true, the above sure sound "better" to me! :)


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#11 whwang

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Posted Yesterday, 12:54 PM

Ah!  I see.  You are comparing GEM45 with iEQ45.  What I had in mind is GEM45 vs. CEM40.

 

I am in the market for a small EQ mount of this class.  I haven't made any purchase yet but a local vendor loans me a CEM40.  (He says: test it as much as you want, and buy it only if you like it.)  So I really want to know exactly what's different between CEM40 and GEM45 other than the different locations of the Dec unit.  Given the huge similarity between CEM40 and GEM45 at almost every level, I also wonder why there is a difference in payload.  Practically, 40 and 45 lb are the same.  However, if the manufacture claims such a difference, there should be a reason.  If there is true mechanical difference between GEM45 and CEM40 that leads to the slightly higher payload, then I may get a GEM45 instead of CEM40.


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#12 tjugo

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Posted Yesterday, 01:04 PM

Interesting, however the load capacity doesn't make sense. The big selling point of the CEMs is stability, a more stable design will translate into higher payload capacity. However this is not the case with these mounts. The traditional GEM design is advertised to carry 12.5% more than the twin CEM40 using the same motors, worm wheels etc.

 

It looks like:

 

-- The CEM design is less stable than a GEM configuration or

-- The CEM40 is underrated or

-- GEM45 is overrated or

-- iOptron arbitrary rate their mounts not based on actual capacity but on marketing needs.

 

Cheers,

 

José



#13 whwang

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Posted Yesterday, 01:34 PM

José, you summarized my thought pretty well. When I first heard about GEM45 a few days ago, I was hoping that the additional payload means something fundamentally different, but I can’t find any evidence of such a difference from its spec sheet. When I played with the CEM40 in my hand, I feel the RA bearing(s) has some play. I was hoping that the new GEM45 can improve this, but I don’t find an indication of any real improvement (yet).

#14 Chris Ryan

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Posted Yesterday, 04:27 PM


Also, the GEM45 uses the magnetic-lock worm engagement system like the CEM120, CEM60, and CEM40, instead of the manual-tension setup of the iEQ45.

Could you provide the source for your statement that the CEM120 has a "magnetic-lock worm engagement system"?  I can't find any information on this.


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#15 gotak

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Posted Yesterday, 04:51 PM

Only the cem60 had the magnets.

All the other one uses springs.
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#16 gotak

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Posted Yesterday, 09:17 PM

Interesting, however the load capacity doesn't make sense. The big selling point of the CEMs is stability, a more stable design will translate into higher payload capacity. However this is not the case with these mounts. The traditional GEM design is advertised to carry 12.5% more than the twin CEM40 using the same motors, worm wheels etc.

 

It looks like:

 

-- The CEM design is less stable than a GEM configuration or

-- The CEM40 is underrated or

-- GEM45 is overrated or

-- iOptron arbitrary rate their mounts not based on actual capacity but on marketing needs.

 

Cheers,

 

José

Well the smaller CEMs (as others have noted) are sort of reversed GEMs with the DEC at the back instead of the front. And if you want to nit pick I supposed the transfer of force between CW shaft and the DEC axis through the RA axle can suffer from twisting in the axle but since we are talking a very slowly moving system likely doesn't have a big impact. On the flip side because the CW shaft does not rotate with the DEC axis on the CEMs it means you can attach off set weights to it to balance any RA offset mass something you can't do on a GEM with rotating CW shaft.

 

To be honest I have never put much value to the idea that the CEM design is better for the reasons iOptron states. We carry tiny loads for the material thickness and materials used for our mounts that I don't think it really matters.

 

From info on other forums it looks like the major differences between the two is the 45 has a thicker CW shaft and a new 1.75 inch tripod. Those might be the reason it got a 5lb increase. 



#17 whwang

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Posted Yesterday, 09:35 PM

From info on other forums it looks like the major differences between the two is the 45 has a thicker CW shaft and a new 1.75 inch tripod. Those might be the reason it got a 5lb increase. 

 

This still sounds very strange to me.  The payload shouldn't change with tripod (provided that the users always put it on a sufficiently strong tripod).  Otherwise I can jut put CEM40 on the new tripod and make it CEM45?

 

A thicker CW shaft can increase the payload also sounds strange to me.



#18 TxStars

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Posted Yesterday, 10:06 PM

I would guess that there was no real world testing done

, but a difference in payload listed, just so the specs are not the same..

It would take several months of testing to really see if there is a 5 lb carry difference.


Edited by TxStars, Yesterday, 10:08 PM.



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