What’s the most someone has pushed their AM5 without a counterweight. I have an OTA that is right on 13kg which is the max weight an AM5 is rated to carry without a counterweight.
Don’t have AM5 sorry, but from memories, reading on the forums, the counterweight is not so much to ‘help’ the mount as the harmonic drives have plenty of torque, but to keep the centre of gravity close to the tripod’s centre, so the whole thing doesn’t tip over when the scope is at extreme angles.
I've run 17.5kg with mine.. actually might be closer to 18kg.
It works fine. The counterweight is there for stability of the tripod, not for counterbalance of the RA.
But I use the counterweight now, anyway. If you don't and your tripod isn't stable, it'll induce a fair bit of wobble especially closer to the horizon.
It is interesting, this thread is more or less talking about what I had always thought about mounts that don't have a counterweight. the movement of the COG would likely mean you need to have a quite solid tripod to put it on to avoid flexure or the whole lot potentially just falling over.
Recently had Mr Bunn make an adapter top plate for my Losmandy Tripod which is a more studier platform upon which to place the mount but I don't see the logic in pushing the envelope capacity wise although I have seen many that have on the AM5 Fb page, IMO this will inevitably put unnecessary strain on the mount.
It is interesting, this thread is more or less talking about what I had always thought about mounts that don't have a counterweight. the movement of the COG would likely mean you need to have a quite solid tripod to put it on to avoid flexure or the whole lot potentially just falling over.
Indeed. I use the AM5 on both an EQ8 Tri-pier and an EQ6-R tripod. The EQ8 Tri-pier needs no further support. Using something of that strength means I don't have to use a counterweight.
On the EQ6-R tripod though, I've added Geoptik spreaders and still use the counterweight.
Mine is mounted on a pier and when I first tested it with a CF RC8 and a Sharpstar HNT 150 newt on a side by side, with no counterweight, it was reluctant to return from vertical at meridian, see pic, weight of RC8 is 9.3kg, HNT is 7.2kg.
As port of my recent obs work, I added a DIY counterweight shaft (12mm threaded rod with some threaded joiners on it for further stiffening, plus 5kg of barbell weights, total about 30cm long. No problems now. I presume that the counterweight probably does help to take some of the load off the ARM5 motors, which should be a good thing, and the cost of the rod and used weights was only about $10 all up.
Last edited by mldee; 24-06-2023 at 08:31 PM.
Reason: splelling
I have 15Kg of C9.25 Edge HD, 0.7 reducer, Esatto focuser, 6200MM and 7 pos filter wheel on my AM5. At slow slew speeds the rig moves quite happily, however at full speed (like a meridian flip or a Home command) it makes an odd noise and just stops.
The solution is to use the hand controller and slowly, manually slew it back to Home.
Adding a 1.5 kg Eagle and 1 kg of counterweights has solved the problem. It still tracks and guides extremely well without the counterweights, but any sort of fast slewing causes problems.
I would not push the AM5 too far, it is not such a cheap item as that!
I have used my AM5 with smallish triplet refractors in the 102mm area, a 140mm triplet and I have done a little imaging with the C11. Had no issues with the refractors. Had a test run on Saturn with the C11 at f10 plate solving limited a bit by the moon. My XL C11 being fitted with a lomandy dovetail up top and a light guidescope weighing in still around 15kg, not counting the counterweight.
Then as I tried for f15 with a planetary cam, I had slippage a few nights ago even with a 5kg counterweight after a meridian flip. I heard high pitched whining and reversal of the drive with the scope being headbutted into the tripod leg and I could not get the scope to a horizonal level using the controls of either on the ASIAIR or the mount software without it again reversing into the mount. At the time I had the counterweight high up on the shiny low friction pole ZWO sells for the AM5. I reported the incident to TESTAR and they just assured me it was likely a balance issue. I guess that time will tell and I am going to keep the counterweight at the far end and see if that avoids such issues.
