Advice needed: G11 vs. Mach1

I could use a little advice and info specifically regarding a Mach1GTO CP3. I currently use a Losmandy G11 that I have had for about 6 years. It has been a great mount, not without the common issues but I have it tuned very well. However I have long lusted after an AP mount, and as the Mach1 is the only one that could potentially fit in my budget I am considering buying one.

One thing I love about the G11 is that it “just works” with SGP. Seriously, everything from plate solving to auto meridian flips etc work smoothly and perfectly with SGP.

So my question is, are there any drawbacks, issues or problems with using a Mach1 (and associated ascom driver) with SGP? I want it to be able to “just work” with SGP in the same way the G11 does.

Also, if anyone has used both of these mounts I would really appreciate hearing from you. The instrument rating of the G11 is 60lbs, while the Mach1 is 45lbs. However I have also read that the “imaging weight” of a G11 is less than the published capacity, while the rated weight of the Mach1 is accurate for imaging.

Again, any advice will be much appreciated.


I have been using an AP1100GTO mount with SGP for almost a year with no issues. While the 1100GTO is a larger mount than the Mach1, they both use the same controller box (CP3) and would behave the same with the AP ASCOM interface, which has been very robust with no known issues. At this time AP is transitioning from the CP3 to CP4 controller, which represents a major update that now supports USB, Ethernet, WiFi and serial interfaces. I don’t think there is any increase in price. Also, the Mach1 (and all AP mounts) can now be purchased without the hand controller at a substantial savings. Personally, I like having the hand box since it is a complete “PC” in that it controls all functions of the mount and has extensive “sky databases” of objects. Very nice when using the mount visually.


I used to have Mach1 and now have A-P1100GTO and there are no differences between the two concerning SGP controlling the mount via ASCOM driver. A-P V2 ASCOM driver is awesome, reliable and very robust.

Like your G11, A-P mounts also “just works” right out of the box especially with SGP.

I have seen comparison pictures of G11 and Mach1 together and it appears Mach1 looks a little bigger. I also believe Mach1 has greater “imaging” carrying capacity than G11. I think Mach1’s 45lbs carrying capacity is a little too conservative and should carry even more.

I also saw from ap-gto Yahoo Groups that A-P is redesigning the Mach1 for easier gear re-meshing but they don’t give much details.


Thanks for the replies. If I go with a Mach1 it will be a used version with CP3. That does concern me a bit because the Gemini2 system is very robust and I really like the communication protocols (i.e. Ethernet) between mount and computer. I will miss that more modern connectivity. I understand that the new CP4 modernizes things considerably, but I don’t see paying $1100 or more just for that vs. CP3.

Regarding meridian flips, I understand that AP mounts can’t flip until after they cross the meridian. Has that been an issue for anyone? If I set SGP to wait to flip until it is 1deg past the meridian, shouldn’t that solve the issue?

It also concerns me that there are no safety limits for AP mounts. How do you guys work around that?

Another question, how does one autoguide with the CP3? Do you have to have a direct ST4 cable connection, or can you guide via ASCOM? I’d hate to go back to having to use that %$^&*() cable. Oh man, I just realized I’d have to go back to serial connections to the computer. Ugh.

It’s not necessarily $1100 more. You can buy A-P mount without the Keypad and it’s $1100 less. Also, we don’t know how much the mount with CP4 is going to cost since there are no new prices posted at A-P web site. It might be $100 to $200 more than with CP3.

The only way to flip Meridian is to resend the same GoTo command of same DSO object when the DSO is already past or West of the Meridian. It has never been an issue regarding to Meridian Flipping for A-P mounts. Or I can slew the mount so the scope starts under the mount and track past the Meridian and the scope will end up above the mount and no Meridian flipping necessary. That’s called Meridian Delay which is a very cool feature. It’s still your responsibility to understand the limits of A-P mounts to prevent pier collisions but it’s not that hard. If you are reading Starhawk’s obnoxious Cloudy Nights posts about A-P mounts, please completely ignore him because he has no idea what’s he is talking about.

I personally prefer A-P not to have safety limits so I can easily image past the Meridian without flipping. That’s for DSOs at the Southern sky up to Zenith relative to my local location. I always flip Meridian when imaging DSOs at Northern sky. If you want safety limits, APCC software have these features at extra cost.

You can autoguide with ASCOM or ST4. I use ASCOM guiding and it works extremely well. Plus it reduces cable clutter in cable management. I am currently using FTDI chip USB-to-Serial adapter and works extremely well. But if you prefer ST4, you can. But you are using ASCOM anyway to work with SGP so why not use ASCOM for guiding. A-P serial communication is extremely robust.


Thanks Peter, it’s good to know that I can guide via ASCOM which is what I
prefer. I don’t relish the idea of getting used to a new system, but from
everything I’ve read the mechanicals are really nice.

I’ll be buying a used Mach1 with CP3, which is why I mentioned paying $1100
if I want to get the CP4.

And I haven’t read anything on CN yet. I’d much rather hear from actual
users on a forum that I trust (nothing against CN, I love it too, but you
know… :slight_smile:

I always use pulse guiding with PHD2 through the ASCOM interface. I have never even tried the ST-4 interface. While the CP3 controller is limited to serial communications, there are lots of ways to do that. For a long time I used a Bluetooth receiver plugged directly into the serial port and controlled the mount via the COM port the Bluetooth created. Now I have an FTDI USB to Serial cable plugged into a powered USB hub.

The mounts are manufactured with RA gears that have periodic error of +/- 3.5 arc seconds or less. With PEC, that can be cut in half. AP ships the new mounts with a PEC curve pre-installed. All you have to do is enable it.

While the CP4 controller is a major update, a used Mach1 with the CP3 will provide you a great imaging platform – whether you are portable or observatory mounted.


Is it necessary to build a pointing model with the Mach1 or can I simply turn the mount on, plate solve and sync the mount? With my G11 I don’t bother with a model at all, just sync it at the start and that is very convenient.

Pointing model is not necessary. All you need is a good polar alignment and the rest is easy. It’s called “SGP”. The procedure you do with G11 is very similar to what I do for my A-P mount.


I have a Mach1 CP3. I echo everything said. I can only once remember an issue with meridian flip because SGP made the call before the meridian and that was my own fault due to not setting the time correctly after daylight savings change. Other than that it’s pretty reliable and just works with SGP. I’d say most of the issues I’ve had with the mount involve USB-serial connectors.

I use the ST4 port for guiding and can confirm that this works perfectly as well if you decided to change to that route later.

I image with close to a 45 lb payload with a Mak-Newt that is pretty long and a piggy-backed refractor and I’ve never felt that my Mach1 was even breaking a sweat. I too think 45 lb is conservative as an imaging load and if I decided to upgrade to an OTA that put me closer to 50 lb I wouldn’t have many concerns about giving it a try.

Really happy with my Mach1. Good luck with your decision.

Well guys, I am BITTERLY disappointed to say that the seller backed out of
the deal for me to buy his Mach1. I went to bed thinking we had a deal and
then I wake up to read that he sold it to someone else. Thanks for the
advice and hopefully I’ll find another good deal soon…but I’m not holding
my breath. I can’t afford a new Mach1. ARRRRGGGGGGG!

That’s a bummer.


What do you think about the 10micron GM1000 ?
I own one since 2 years, and I m very satisfy.
SGP work fine, and pier flip is perfect.
Ethernet communication is supported too.
I make 20mn sub without autoguiding (thanks to the absolute encoders…).


I’m sure that the 10micron mount is superb. But it is way out of my price

Is the link to the advertisement for Mach1 still available? I just wanted to see whether it’s an older or newer design.


This looks like a really good deal unless this is the one you were looking at. It does not say “SOLD”.


This is the original ad which is now sold:

The CN ad does look like a good deal. I wonder why I didn’t see it in my searches? In any event I am glad to say that I have found a similar deal with anothe seller who responded to my wanted ad. I didn’t want to say anything until it was official but it looks like I’ll get a Mach1 after all.

Good luck!!!


I looked at the Astromart ad that got sold, that’s an older design built before Feb 2010 but it has an upgraded rotating pier adapter which is a cool upgrade. This allows you to adjust Azimuth while the base is still “locked”. No need to unlock the base which can shift the polar alignment. If the Mach1 you are currently interested does not have this base, I suggest to get it.