A few questions on Losmandy G11 G2

[Manav]

Hi guys,

I'm in the market for the G11 G2 and had a few questions regarding the mount as follows:

1. What's the PEC (p-p) range for the mount? I've heard PEC can vary mount to mount and need to know what I can expect.

2. Is it worthwhile to upgrade to the single worm block since the existing ones have the 76 error?

3. Do the new G11's have a different motor or is it still the Hurst stepper motors?

Let me know

Regards

[TrevorW]

Plus or minus 5 arc seconds or better remember this is not a AP or Bisque mount, but is the best step up or two IMO from an EQ6 both in price and performance.

Made in America very solid and very well supported. All I can suggest is do some homework check out the Yahoo Losmandy Gemini forums

I'm selling mine only because it's taking up room, I have no space for an observatory and it's not being used as often as it should.

Cheers

Check out this thread when I was asking the same questions

http://www.iceinspace.com.au/forum/showthread.php?t=71821

[wasyoungonce]

The reason I purchased a G11 is that I wanted a mount that would last for a long time....and I could buy any part I needed as a spare to keep it in tip top service.

1. Current G11 PE is around +/- 5 arc seconds PP (or better) out of the box. This was due to Losmandy changing to a newer High Precision Worm (HPW), around early/mid 2009 onwards. G11's prior to this had a little larger PE (on average) but this can be reduced by installing a HPW.

2. The new One Piece Worm (OPW) block allows better orthogonality and adjustment of the worm train and some users have reported PE as low as +/- 2 arc seconds PE (http://helixgate.net/G11opw10.html). I haven't upgraded to the OPW as my mount came with a PE of +/- 4 arc seconds and the errors were easily guided out. A lot of this depends on the scope used. Some scopes demand more of the mount (ie: a long refractor) and PE can be worse or better.

Since the OPW keeps the worm and bearings in alignment then the 76 second tick should reduce (the tick is caused by worm tight spot caused by misaligned worm bearings (http://helixgate.net/G11opw8.html)).

3. The G11's come in 2 flavours of control systems: The Digital drive system (non-go-to), which uses a stepper motors (from www.mechtex.com (http://www.losmandy.com/hi-rez-images/SM.jpg)); and The Gemini2 (go-to) which uses servo motors (http://www.losmandy.com/hi-rez-images/SVM.jpg). You could purchase the Gemini system with higher torque Maxon servo motors although I don't see that on their website at the moment. I never felt the need for these but that's my opinion.

An answer without a question...get a G11 with Gemini2...IMHO;).

Hope this helps.

[mithrandir]

Brendan, Losmandy are changing the Gemini motors again.That might be why there aren't any shown on the replacement parts page. A mount ordered now might have Maxons or the new ones depending on when it was built.

[wasyoungonce]

Ahhh thanks Andrew. They are probably changing due to availability issues? Suppliers never last forever.

The old one's were not cheap but they are repairable.

[mithrandir]

The new ones are supposed to have more torque, but are also alleged to be noisier (but that might be in the gearboxes). There has been some talk about them on various Y! Losmandy groups.

[White Rabbit]

Hi guys.

i too am looking at getting one.

can anyone tell me if the bugs have been ironed out of the Gemini 2 software. When it frist came out, as I understand it the software was no where near complete. Has this been rectified?

thanks

[TrevorW]

In a short answer "Yes"

[White Rabbit]

Mmmm, what would the long answer be??? Lol

[wasyoungonce]

A visit to the Gemini 2 yahoo group (http://www.iceinspace.com.au/forum/tech.groups.yahoo.com/group/Gemini-II/) might help.

I have a G1 but from what I can tell, the early teething issues have been well sorted and the system is quite usable. A few things still need attention but these are being done.

This is no LX800 disaster here.

[Geoff45]

Maybe I was unlucky to get a buggy mount, but I could never get consistent guiding with my g8. Finally resorted to an SX-AO unit, after which round stars and 30 min exposures were the go. Still, based on my experience I'm pretty much turned off Losmandy mounts.
Geoff

[mithrandir]

It might be a bad mount, but if you were using the 12" newt in your sig on a G8 that is pushing the envelope. The G8 was designed for an 8" SCT - hence the name.

[Geoff45]

Nope--only used the 4" refractor. I'm not that crazy!
Geoff

[Manav]

Thanks everyone for your replies!

Brendan - So the suggestion is that I get the standard G11 G2 and not bother with upgrade just yet.

I'm tempted to ask the Australian retailers to do a PEC (p-p) for me before purchase. I don't want to stuck with a dud especially as I've heard a 1 or 2 horror stories with G11 purchase and very high pec.

I'm already in touch with Peter from ATS and will request if he can do this for me.

[wasyoungonce]

I doubt that a retailer will do a PE test run prior to sale.....you never know though,....cannot hurt to ask! :question: You can be pretty assured you will get a mount with +/-5 arc sec's or better PE these days. The PE is adjustable via the worm blocks. If it's high or "wild" then there is something wrong or it is not adjusted properly.

I believe all mount worms are adjusted by Scott Losmandy prior to boxing. He mentioned something like that a few years back on a Yahoo forum. Could be a tall story though :shrug:.

IMHO...now's the time to buy with the $Aust high.

[Capricorn1(Tom)]

I see Robert has a G11 Gemini 1 with hand made containers. See his post in the for sale section. I would have bought my self, but just purchased and recieved a G11s from bintel for my C14. The quality of the G11s leave the chineese mounts for dead ( I also have a HEQ5 Pro for my WO Megrez 88) next couple of years will upgrade to the Gemini Kit......Cheers:D

[Manav]

Its a G1 but the price is tempting. God what do I do?

Brendan is it worth splurging extra for the G2?

[mithrandir]

You can probably get a used G11+G1 faster and later upgrade to a G2 for less than a new G11+G2. If the 76 sec behaviour is unacceptable, the Ovision upgrade is probably better than the Losmandy one but is more expensive.
I'm in no hurry to replace my G1. I'll probably wait until it fails. You do want a 1.0.4 or 1.0.5 EPROM. Those aren't user upgradable without an EPROM programmer whereas the G2 is. ATS can program EPROMs for you.

[marki]

There is a second hand G11 GII for sale in the classifieds.

Mark

[wasyoungonce]

IMHO get a G2 unless the G1 price is right. You can upgrade from G1 to G2 for ~$1k. You re-use the motors and change the controller and handset. I'm keeping my G1 till it dies...although repairing them is pretty easy for me...so it may never die!:(.

The G1 is a nice kit, a bit dated, has some small quirks and is subject to damage if you plug in the motor connections wrong way around (these leads carry +12V for motors and encoder pulses). There are at present plenty of parts available for G1.

The G2 is much more modern, still a little dated in they way it presents information (IMHO), but, connectivity is excellent and they fixed the motor connection issue. Same connectors and motors (as G1) but different encoder IC's that withstand miss-connection.

I like the way the Gemini handsets (G1/G2) present info...the facts...just the facts and they manner in which they work. I used a gotostar (Gotonova) 32 bit RISC 8 line LCD readout, very modern, bling bling. But the Gemini is much better in the way it works....it just works, does the job no fuss, 100% every time. Goto's are spot on.

[White Rabbit]

Hey Manav.

From what I can see, you seem to settled on going with ATS. Would you mind PM'ing me the price they gave you for the G11?

Thanks

[midnight]

If you're really keen about the investment in the mount and with G2's ease of upgrading firmware etc, then G2 is the way.

I got mine last year and worth every cent. I don't have any lengthy experience with the G1 but G2 has so much connectivity straight out of the box with ethernet and good possibilities of easy and cheap remote setups.

I am looking into this remote operation seriously as I had not planned for my current job to take me out of the country so much and be away from home for weeks even months at a time.

G2 does have its quirks but I like it even after coming off an Autostar.

Good luck which ever way you do go!:thumbsup:

Darrin...

[Manav]

Darrin - I will get the G2 once the tax payment comes through. My biggest concern is making sure I get a mount ready out of box. I will talk to ATS next week about this and keep an eye on classifieds.

[wasyoungonce]

Wow I didn't see that mount for sale...good price....probably same vintage as mine...2009. Very slick price...and for that you can upgrade to a G2 later and still be just under the cost of a new G11 G2.

Could even sell the G1 later (if you upgrade) making the $1k upgrade to a G2 even less.

Wow "is all I can say" $3K for a G11 G1 ....I repeat...wow!:eyepop:

[UniPol]

I don't like to be negative but I bought brand new a G11/Gem 1 around four years ago and it was not "all right" straight out of the box. Both the Gemini and hand controller were faulty and were obviously not tested. The annoying part of it is that the agent made out as if I didn't know how to operate the Gemini operating system. The other annoying aspect is that the Gemini and hand controller were sent back at my expense for something that should have worked properly in the first instance. To add further insult I was sent a used hand contoller because it was known to work. PM me if you like to know who the agent is. I like to think this may have been an isolated instance however ....

On a positive note, the Gemini 1 is quite easy and intuitive to use once you have mastered the system. The Gemini 2 is just great and definitely is much better than the Gemini 1 but you have to weigh up the added expense for the new system. I recall G11's costing over $8000 some years ago and there has been a steady decline in prices till the present day. To be able to purchase a G11/Gemini 1 for around $3000 or less (albeit second hand) is a bargain. Of course the Gemini 2 is not a bad price either for a new one. The latest Gemini 2 has certainly devalued the G 1 considerably. I cannot understand why Losmandy couldn't have supplied the Gemini 2 at a far more reasonable price particularly as they have a long and loyal list of customers over the years.

[Manav]

I heard of a similar case where the PEC was over 20 peak to peak the retailer said it was within operational limit. The said person went through loops to get their money back. I want to have a peace of mind that the kit works when I have spent that much money. PM sent

Brendan - I have sent the PM to the owner of the G11 ad asking a few questions.

[Geoff45]

+1. Maybe the same case?

[Manav]

Sorry to resurrect an old thread but I finally get my Gemini G2!

I would also like to apologise for the clouds in Sydney... my bad! :sadeyes:

[White Rabbit]

So did you end up getting the opw block. Have you had a chance to measure your pe?
After I got the opw installed I got my PE down from 35 to 12, not great but can guide it out thankfully. My mount guides well now.

I hope you have a better result out of the box than I did.

[multiweb]

35 was pretty big to start with. 12's not bad as a difference but you should be a lot lower. Which program did you use to measure your PE and what camera/scope config?

[White Rabbit]

Hi Marc

I used pem pro to do the measurements, and used my guide scope orion st80 and a meade dsi II. Image scale is about 4 arc seconds pp.

Cheers

[multiweb]

Cool. The drop in PE is definitely because of the worm block but the bulk of your PE is clearly coming from somewhere else. Have you tried swapping the gearboxes and motors between RA and DEC ans see if it changes anything. Next you can change the gear. Put the DEC in RA and vice versa then take measurements each time. Can you posta pic of your worm including coupling etc...

[Manav]

on a side note while Marc helps out; I haven't actually checked my PE and to be honest I'm still trying to figure out the how to use Gemini 2. Early days yet...and yes I got Matthew from T&A to install the OPWB.

[White Rabbit]

No worries Yugant, have you got pem pro?

Personally, I haven't bothered with the gemini. I only use it as an interface to The Sky X pro.
Here is my set up for the G11.

G11-Ethernet-pc-gemini ascom- The Sky X pro for brains and plate solving and PHD for guiding.

I'd highly recommend, if you don't have The Sky X to get it as well as the camera add on. With the two of these pointing is a breeze. It's very accurate and easy. You just slew to a star, doesn't matter if it makes it as long as is with in 8 fields of view, image link the image in TSX (that's plate solve speak in TSX) sync on the linked image if plate solve was successful, then re slew to the object and bang, centre of the chip pretty much every time. It's very impressive and the support for the TSX on the forum the best customer support I've seen, ever.

If you haven't already make sure you update the gemini ASAP, the latest build is quite stable. There is an update software that makes the the whole process much easier. Make sure you have both the gemini and the gemini ascom up to date because if they are not both current they don't play we'll together.

Marc, I'll tackle the remaining PE in due time. I have it working pretty well now and with all that I've been through to get it to this stage I don't have the energy for it, but its on my list of things to do....soon. I'll pm you when I'm ready to start, your help would much appreciated.

Thanks

[Manav]

Hi Sandy - I have a slightly different setup to yours only because I purchased my software a while back. I'm currently connected to Gemini 2 using Ethernet to laptop and using the following software:

1. Stellarium scope for Gemini 2 (Which I haven't had chance to test yet) - http://cooledpix.com/2012/05/09/g11-gemini-ii-ascom/
2. Will use PHD for guiding and drift alignment
3. Will use nebulosity for post processing

I have downloaded PEMPRO and have no idea how to use it so will probably target this first when the skies clear.

Let us know when you start addressing your PE issues. Would love to understand what drove your PE so high.

Regards

[multiweb]

Any deviation in PE in excess of 20 arc sec over one revolution you can feel by winding the worm by hand or a small screw driver. Something that big is to do with the worm or the meshing. Bad bearings will only give you noise and the occasional pop but the worm accounts for most of your PE. You should be well within +/-10 out of the box without PEC with proper meshing and good alignment.

[Raydar]

G'day Steve,

This is probably irelavent now but what you have explained above is exactly what happened to me with my hand controller. Didn't work, got told I needed more practice, still didn't work, sent it back at my expense got a second hand one back, lol.

A few years later purchased two Maxon motors, got second hand ones (no box, just bubble wrap, motors were dirty and dusty; at least wipe them and pretend they are new).

I'm reading this thread because I am currently modifying my G11. I haven't tested it yet but I think the Maxon motor is the culprit.

Ray