jed2i

You need to add another weight to balance the dec.

I did it like this: 

A little update on this....
I made a custom DEC counterweight so my mount stays balanced in ANY position...this is extremely important

Check it out

Closeup view

And full view

Now, you can see here that the right side of my OTA is heavier then the left side, that's why my custom weight is on the left side on the main counterweight

You can not balance that with just one weight, no chance, that's why you must add another weight, it needs to be on different axis.

Because of this, my scope stays balanced in any position, and that is really important, guiding is now 0.6-0.7 arcsec with 12kg on the mount, i think that this is a really good result with AZ-EQ5 and this scope (fully loaded 115/800 triplet)

Disable Dec guiding and see where it drifts (north or south) then enable Dec guiding but just in one direction, opposite of the drift.

That will solve your problem.

Just a little update.

I experimented with different type of grease and i think i found the best one so far, it is teflon based, sticky and handles high pressure really well - Weldtite TF2

Result of continous 25min guiding with 12kg of equipment : 

Guiding will improve when i build custom DEC counterweight, maybe i'll adjust DEC worm again

I am using DIY usb 3.0 Sony imx290 chip with 330mm focal length scope (TS optics 50mm f6.6)

Under 1 arcsec performance with  12-14kg of equipment on mount

Hello guys
i have a AZ-EQ5 so i would like to share my experience and to help anyone who wishes to tune their mount.

There were many problems with this mount
Overtightened, unproper grease, worm gear adjustment....

So lets start
I will describe DEC axis, RA is the same.

Unscrew the cover, take it off
Disconnect the cable

Unscrew the counterweight arm holder, you need to unscrew 3 small and 2 big screws, watch out for the small round plates, there should be NO GREASE on them.

Unscrew the clutch

Unscrew the bottom cover, 4 screws

Unscrew 2 screws holding down 2 round metal plate and bearings

Now remove bearings and 2 plates
There was some thick, sticky "grease" on this, do not use THICK AND STICKY grease on this part
Because when you are tightening the clutch you will transfer large amount of force to the WORM GEAR and you can damage it or move it a little and this will cause backlash and other guiding issues!!!!

Remove the motor and belt, 2 screws

Remove the worm gear assembly, 4 screws and 1 screw on top

Next - remove this big DEC wheel tightener, it has 3 screws which you need to loosen a bit, and the unscrew it, be careful, it has thin rubber washer between itself and a DEC wheel
Remove the tightener

Carefully remove the DEC wheel, do not drop it, you risk damaging it
Clean it, clean it's upper side, there should be NO GREASE on it's upper side - also - clean the mount part side where this DEC wheel is connected to - there should be NO GREASE there.

Now, clean the DEC wheel, regrease it, i use Mineral EP grease with MoS suitable for worm gears.
Grease lightly inner part of DEC wheel and carefully assemble it to mount shaft, remember NO GREASE to the upper part of the DEC wheel and mount.
Cleaned DEC wheel:

Next part is important, take is slow and calm.
Screw back DEC wheel tightener, you need to adjust it so it doesn't allow DEC wheel to be moved but it should allow it to rotate almost without effort, when you are done tighten the 3 screws so it doesn't move
Watch the video, it rotates with no effort but it is not moving away from the mount head.

Now let's clean the roller bearing
This was so sticky i had to use degreaser
I let it in degreaser for about 2 hours and it ate away all the grease
Wipe it out and grease it with proper grease

I used Aeroshell 33ms
Now when i mount it to the bottom of the dec and press it with hand, DEC axis rotates, this is good!
Watch the video

Next - screw clutch lightly and mount the counterweight shaft holder, tighten CW shaft holder.
Now tighten the clutch
Clutch needs to be tightened when you want to align worm gear assembly

I do it like this
Put my telescope on my mount, balance it as good as you can get and then i start alignment process(remember to tighten the clutch)
Be patient and calm
Alignment procedure was described on this forum so you can find it.

After alignment try to rotate worm gear with your hand, it should rotate equally for the whole worm gear turn!
And also, try it for the whole wheel turn, often DEC and RA wheels are not equal for the whole 360 degree turn.
For the RA, you only need 180 degree so choose the best part.
Also try to rock gently your telescope in the DEC and RA axis direction, it should not rock!!! If it rocks then the worm gear is not tight enough.
For worm gear alignment, i do it like this.
Install the worm gear assembly and tigthen it, lightly.
Tilt it to one side, it doesnt matter which one and then start the alignment process, that way you will now that you need to align it to one side only and you wont have to guess which one
I did it like this and now my mount is under 1 arcsec with 12-14kg of payload.
I am guiding with phd2, resist switch algorithm on DEC an RA, no ppec.
Minimim move on RA and DEC is 0.15-0.20
I am guiding in only one direction for the DEC, i do this with all of my mounts. 

When you are done, install lower cover, install motor and belt, connect it, connect cable from upper cover and install upper cover.

Result:
You can balance it really precise, if you aligned worm assembly correctly you should see better guide performance.
After my procedure, i balanced it, tried guiding and got really good result

Balance after tune
RA

DEC

That's it, i hope i helped someone

I have that telescope and i am also thinking about cem40 and i believe that you are wrong

If you balance it correctly, then only thing that matters is a mass of an object, it is the same if you have an object that is 100cm long or 200cm long if the weight is the same

That optical tube is 6.4 kilos, mount the guidescope, camera, filterwheel..... and you are well beneath the 18 kilos that mount can handle, just balance it carefully

Thanks, i missed the spacing from sensor to the flattener

i will do better next time

First light with 183mm pro

TecnoSky 115/800 triplet v2 with WO Flat 6A II 0.8 reducer/flattener

ioptron ieq45 tuned mount

sony imx291 usb 3.0 camera as a guider

60/330mm ed guidescope

45 frames, 180 seconds each, R,G,B