AM5 Heavy Duty Mode

I leave it on all the time, hot or cold. I do think it helps with guiding (maybe 30% reduction in total error), and I’m not too worried about the additional seconds in meridian flips and initial target acquisitions.

📷 IMG_3336.jpgSo going to watch all the eyeballs pop on this one. 12” Meade SCT with 2600mc pro, guide scope with 120mm guide camera. I use heavy duty mode all the time with this setup for over 2 years now, with 2 10lb counterweights as well. Guiding runs .33 to .70 arc seconds with round stars. This scope is over 27 years old, so the correction on the optics aren’t as good as todays optics. Oh BTW before you ask the scope alone weighs in at 46lbs so yeah mount is definitely overloaded but has worked flawlessly like I said for over 2 years with fantastic guiding. CS Tony

BlackStarsAstro · Nov 18, 2025 at 08:53 PM

Anthony (Tony) Johnson · Nov 18, 2025 at 07:08 PM

📷 IMG_3336.jpgSo going to watch all the eyeballs pop on this one. 12” Meade SCT with 2600mc pro, guide scope with 120mm guide camera. I use heavy duty mode all the time with this setup for over 2 years now, with 2 10lb counterweights as well. Guiding runs .33 to .70 arc seconds with round stars. This scope is over 27 years old, so the correction on the optics aren’t as good as todays optics. Oh BTW before you ask the scope alone weighs in at 46lbs so yeah mount is definitely overloaded but has worked flawlessly like I said for over 2 years with fantastic guiding. CS Tony

I definitely agree Tony.

Black stars Astro. I’m looking at the photo of your setup, nice BTW, but my question, do I see a pole master camera mounted on the front of your AM5. Your pic is small and it’s hard to tell, but I can see you have something on the front that doesn’t normally come on the mount.

Been running a SVX130T with guide scope and image train running around 36 lbs. In Heavy Duty mode on the AM5N and a bit extra time to settle it has worked well. What is important is the base. Using the ZWO pier but love the stability of a EQ6R Pro tripod.

I read somewhere that the threads in the AM5 for the counterweight bar are the limiting factor and additional weight may be a long term concern. With my configuration and the single weight is works very well with guiding in the 0.3-0.4 range normally and some dips into the 0.25 range on good nights.

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Anthony (Tony) Johnson · Nov 19, 2025, 02:37 PM

It is like a sail. I does have to be dead calm. I’m planning some wind sheilds but haven’t popped for them yet. But otherwise works great.

Yeah my TOA-130 catches the wind a lot too but I also figured out (right after that pic!) that I have less vibration if I don’t use the counterweight, it adds some sort of resonance to it, but I’m OK without it, I don’t think you have a choice.

My AM5 also makes hideous grinding noises in the winter weeks (cant really say months here). I contacted ZWO and the original vendor and both denied there was any known issue. I was actually told by ZWO to open the mount up and tighten it..which I am glad I didn’t do.

I do not have any ‘heavy duty mode’ that I can see but I have learnt to make slow slew movements, prior to a meridian flip or a return to home, to warm it up and then I either continue at half speed or sometimes I can go full speed at that point. Come the warmer weather the noise goes away.

I have my AM5 and FF130 scope driven by Indigo. I have used it for 20 months and have been generally happy. The polar alignment was getting more difficult these last months and it turned out to be a number of AM5 screws slowly working loose. Now I have found that, alignment and tracking are very good.

Nothing in the manual tells me how to select heavy duty mode. Is it accessed by software on ASI Air? Would be interested to know, even though I haven’t experienced much cold weather.

Thanks

Andrew

R. Jay GaBany · Nov 18, 2025 at 05:49 PM

The payload of my current setup (Askar 130PHQ;  ZWO ASI2600MC-Air, CAA, 5-position filter wheel and EAF) weighs a bit over 32 pounds including the mounting hardware.  This pushed the mount very close to it's advertised limit without a counterweight.  So, I also added a 10 pound CW and switched to heavy duty mode. This returned the camera's guiding calibration  and auto guiding accuracy to what I experienced with a  less heavy scope (ZWO FF107 @ 15 pounds).   I also use heavy duty mode when using my Tak 180C.  Like others have mentioned, heavy-duty mode does not enable the mount to handle a payload heavier than the manufacturer's recommended limit.

That is one beefy setup! Did you ever find any balance issues with TC40 given the overall weight of the CW+OTA+mount combo?

ArchStarGazer · Jan 18, 2026 at 09:21 AM

Andrew Lamond · Jan 18, 2026, 07:37 AM

I have my AM5 and FF130 scope driven by Indigo. I have used it for 20 months and have been generally happy. The polar alignment was getting more difficult these last months and it turned out to be a number of AM5 screws slowly working loose. Now I have found that, alignment and tracking are very good.

Nothing in the manual tells me how to select heavy duty mode. Is it accessed by software on ASI Air? Would be interested to know, even though I haven’t experienced much cold weather.

Thanks

Andrew

It is swithed on in ASIAir.

Hello Andrew,

Can you please precise about your difficulties to align : which value did you get before and after ?

Then which screw did you “tighten” ?

Thanks

Yves