AM3 periodic spikes

coolhandjo

Hi. Im a proud owner of a AM3. I like it a lot. However I cant get it to stay constant and not spiking periodically. I have followed all the forum advice and calculated my step sizes via the periodic sheet provided with the mount.

detail - Image scale 1.23 (80mm triplet at 600 fl) total weight 5kg includes all cam filter wheel etc.
RA and DEc ms set at 80 each
Ra aggression 45 Dec aggression 35
guide duration 1 sec (tried 0.5 sec but was worse)
Calibrated at correct location in sky and uses the correct step size calculated on my guide scope FL and um

Im using OAG with a ZWO 220 mm guide cam

I get about 0.4 to 0.6 consistent well below 1 rms But at regularity intervals it will spike to 1.2 or 1.8 rms

any help appreciated

Kevin_A

coolhandjo recently the skies have been very bad so it depends on how often you get spikes and an image of the spikes may help diagnose better. 80ms on Ra and Dec may be a bit low but that depends on your calculations. Each mount is different and these mounts need good guide stars. There are lots of variables from oversaturated guide stars to also not enough camera gain when using an OAG. What does your guide graph look like when it spikes? More info needed.