Pondering upgrades!

[Budgie1]

8 hours ago, Rustang said:

what do you mean by it doesnt have a thread on the end!?

On the standard SW focuser there's a M56 thread on the end of the focus tube that the 2" eye piece adaptor or (in my case) the reducer/flattener screws on to. On the upgraded focuser I linked too, it doesn't have this thread and I had to get a 2" push-fit adaptor to mount the reducer/flattener to the scope.  

8 hours ago, Rustang said:

I've got other things that need sorting aswell now as it turns out Ive been reading my guide RMS error wrong so actually mu guiding isant that great so looking to get my mount belt modified and tuned then I can turn my attention back to the scope to either upgrade or modify if it turns out to be ok!

I think you'll be pleased with the belt mod. I fitted it to my new HEQ5 when I got it and it takes out all the play in the drive motor gears and reduces the noise. It took me a couple of hours to fit and I highly recommend getting the pinion extractor tool. You may only use it once but it's worth it because you'll be hard pressed (pun intended ) to get the gear off otherwise.  

[Rustang]

43 minutes ago, Budgie1 said:

On the standard SW focuser there's a M56 thread on the end of the focus tube that the 2" eye piece adaptor or (in my case) the reducer/flattener screws on to. On the upgraded focuser I linked too, it doesn't have this thread and I had to get a 2" push-fit adaptor to mount the reducer/flattener to the scope.  

I think you'll be pleased with the belt mod. I fitted it to my new HEQ5 when I got it and it takes out all the play in the drive motor gears and reduces the noise. It took me a couple of hours to fit and I highly recommend getting the pinion extractor tool. You may only use it once but it's worth it because you'll be hard pressed (pun intended ) to get the gear off otherwise.  

I see, thanks. I have an upgraded holder on the end of my focus tube which was threaded on so I guess I wouldn't be able to use that then! Do you think the belt mod would definitely improve my guiding too!? 

Edited August 6, 2021 by Rustang

[Budgie1]

It wouldn't necessarily improve your guiding in itself but what it will do is remove all the slack (backlash) in the gears between the motor and the worm drive gear.

At the moment you have three gears for each axis, one on the motor, an intermediate and the worm drive gear. For these to rotate smoothly there has to be some clearance between each of the gears, otherwise they bind. This clearance is also classed as backlash and even on my brand new HEQ5 there was quite a lot of movement between these gears. 

The belt modification removes the intermediate gear so there is direct drive between the motor and the worm drive gear, so removing the backlash in this part of the mount. Now your only backlash will likely be in the main worm gears on the RA & DEC axis.

On older HEQ5 mounts, just fitting the belt mod has improved guiding but it should be done in conjunction with the worm gear backlash adjustment to get the mount working as best it can to get the best out of it.

There are quite few videos about the belt mod and it's worth watching these so you know what you're in for.

[ollypenrice]

Because I haven't ranted on here about Crayford focusers in several years, and because I'm getting mellow with old age,  I'll just say that I would always choose a rack and pinion focuser over a Crayford if possible. Of the many Crayfords I've used, including Baader and Moonlite, none has been without issue. Finding the compromise between sufficient smoothness and sufficient grip is the problem, made worse by the heavy cameras I mostly use. The Crayford was designed to carry eyepieces, not heavy cameras.

There are ways to refine your guiding without spending a penny, too. You may know them but here goes.

- Running the mount slightly east-heavy by adjusting the counterweights outwards when they are east and inwards when they are west tends to stop the RA from oscillating across any backlash in the gears. The worm will always be pushing the wheel.

- Using the Guide Assistant in PHD and applying its recommendations is often conducive to better guiding.

- Experimenting with different durations of guide sub is interesting. I've found no one duration suits all mounts. Three or four seconds is fine with our roller-drive Mesus but I've gone as short as 0.5 sec with EQ sixes and an Avalon I had also thrived on subs shorter than those recommended by the maker. It used to be argued that very short subs gave a good graph because the scope was locked onto the stellar image, but that the stellar image itself was moving around due to the seeing, so the true guiding was not so good. This was called 'chasing the seeing' but, more recently this claim has been contested. I have to say that short subs seemed to work for me with the EQ6.

Olly

[Rustang]

49 minutes ago, ollypenrice said:

Because I haven't ranted on here about Crayford focusers in several years, and because I'm getting mellow with old age,  I'll just say that I would always choose a rack and pinion focuser over a Crayford if possible. Of the many Crayfords I've used, including Baader and Moonlite, none has been without issue. Finding the compromise between sufficient smoothness and sufficient grip is the problem, made worse by the heavy cameras I mostly use. The Crayford was designed to carry eyepieces, not heavy cameras.

There are ways to refine your guiding without spending a penny, too. You may know them but here goes.

- Running the mount slightly east-heavy by adjusting the counterweights outwards when they are east and inwards when they are west tends to stop the RA from oscillating across any backlash in the gears. The worm will always be pushing the wheel.

- Using the Guide Assistant in PHD and applying its recommendations is often conducive to better guiding.

- Experimenting with different durations of guide sub is interesting. I've found no one duration suits all mounts. Three or four seconds is fine with our roller-drive Mesus but I've gone as short as 0.5 sec with EQ sixes and an Avalon I had also thrived on subs shorter than those recommended by the maker. It used to be argued that very short subs gave a good graph because the scope was locked onto the stellar image, but that the stellar image itself was moving around due to the seeing, so the true guiding was not so good. This was called 'chasing the seeing' but, more recently this claim has been contested. I have to say that short subs seemed to work for me with the EQ6.

Olly

Thanks Olly, I have been looking more so at a rack and pinion but will probably not get one for the 80ED. If the replacement focuser I got off Steve works, which is still an 80ED focuser, then I will leave it as is and choose and upgraded scope as I'm still considering one, with a rack and pinion. it appears after chatting with Vlad (thanks Vlad) and understanding the PHD2 readings with the correct calculations, my guiding is worse than i thought, as I need to be at 1.1 arc secs and I'm normally 1.49 approx and over!! Vlad has also giving me somethings to try and I wont be spending out on anything just yet as Ive got lots to work out and try first! Thanks again for spending the time to give some advice.