How does Phd2 know where I live??

[Notty]

Strange question, but having upgraded my HEQ5 to a belt drive mod to try and get rid of the backlash and improve Goto, I set it all up tonight to have a look. I have had Phd guiding on this set up ok before by the way.

On calibrating guiding though I started getting all sorts of strange errors... firstly calibration failing as the star didn't move enough. I upped the steps to 1500 and that seemed to take, but then at the end of calibration I got a warning that my calibration data was "suspect", I can't remember the exact reason, something to do worth orthogonality between RA and DEC, so I tried again using different stars and this time at the end I was warned that some relationship or other between my RA and my DEC does not make sense due to my DEC being 42deg something or other! Is here is it getting this from? Obviously my guiding is going to make no sense at all if it thinks I'm ten degrees further south than I actually am! I checked my coordinates in EQASCOM as I can only think it gets the. From there but they are correct at 51. I couldn't see any other settings in Phd for location.

Anyway I accepted the calibration and it looked ok for a while but then I began getting errors so far outside the normal 0.5 circle I was getting warnings that my max correction time wasn't long enough for phd to issue corrections. I upped it to the max 2000ms and it brought it back in again but it was a hell of a jump. I'm wondering if it's all tied in. The only other thing I'm doing differently is using a finder guider rather than my ST80 guidescope to try. And keep the weight down

Does anyone have any ideas? I can't believe it's my belt mod as the Goto seems ok. Any pointers from Phd2 experts would be gratefully received.

Thanks

[Notty]

I forgot to mention but I did check my PA was ok, it definitely wasn't this putting it out so.

[FunkyKoval35]

Mabey I am wrong, but Phd2 does not have to know where do you live at all. Phd2 makes correction for you mount tracking only, and how this correction needs to be done is calculated during calibration process. The only thing that have to know where you are is your mount(polar alignment), and EQASCOM - if you are using goto.

I believe, your problem is caused by finder scope. Did you check what noise level do you have on Phd2? Also, make sure your finder scope is clean, and your guiding camera is in correct position. It is very important to set guiding in correct order, because usaly Phd is very sensitive for any inaccuracies.

[FunkyKoval35]

And one more thing... what is total weight of your tube? With guiding, camera etc...?

[Thalestris24]

Hi Notty

I had lots of issues after recently installing a belt mod on my heq5. I've not managed to improve guiding so maybe it wasn't worth the effort... You might like to have a squiz at the thread I posted: http://stargazerslounge.com/topic/237793-rowan-belt-mod-help/

It's worth installing and using Astrotortilla for accurate goto's. Obviously your mount needs to be running properly and smoothly first! You might need to go over the belt installation and check that the mount slews through 360 deg in RA and DEC both unloaded and with the scopes attached. You can observe the belt operation with the cover off. You should be able to move the RA and DEC axes smoothly by turning the motor cogs by hand (with power off!). 

Hope that helps

Louise

[lensman57]

Strange question, but having upgraded my HEQ5 to a belt drive mod to try and get rid of the backlash and improve Goto, I set it all up tonight to have a look. I have had Phd guiding on this set up ok before by the way.

On calibrating guiding though I started getting all sorts of strange errors... firstly calibration failing as the star didn't move enough. I upped the steps to 1500 and that seemed to take, but then at the end of calibration I got a warning that my calibration data was "suspect", I can't remember the exact reason, something to do worth orthogonality between RA and DEC, so I tried again using different stars and this time at the end I was warned that some relationship or other between my RA and my DEC does not make sense due to my DEC being 42deg something or other! Is here is it getting this from? Obviously my guiding is going to make no sense at all if it thinks I'm ten degrees further south than I actually am! I checked my coordinates in EQASCOM as I can only think it gets the. From there but they are correct at 51. I couldn't see any other settings in Phd for location.

Anyway I accepted the calibration and it looked ok for a while but then I began getting errors so far outside the normal 0.5 circle I was getting warnings that my max correction time wasn't long enough for phd to issue corrections. I upped it to the max 2000ms and it brought it back in again but it was a hell of a jump. I'm wondering if it's all tied in. The only other thing I'm doing differently is using a finder guider rather than my ST80 guidescope to try. And keep the weight down

Does anyone have any ideas? I can't believe it's my belt mod as the Goto seems ok. Any pointers from Phd2 experts would be gratefully received.

Thanks

The belt conversion gets rid of the backlash in the motor gear train but the worm gear still remains and there lies the major issues.

A.G

[Notty]

Hi thanks for the inputs well regarding the weight of my setup, with his tube I know it's an issue on an HEQ5 (200pds) which is why my previous try with my ST80 guider AND the extra counterweight was overkill for the poor little HEW5, hence the finder guider. I'm not sure what the total weight is but compared to before I think it's ok. I had a nice sharp guide star profile in PHD and it moved itself all round the calibration circle it does but then gives me the warnings about the calibration being dodgy, and this is what concerns me.

Louise I'm sorry to hear about the troubles you've had with the mod, if only I'd coma across your post a couple of weeks ago as all I could find were rave reviews saying "do it!" though I must admit it all seemed to go on ok. I'm happy with my belt tension and freedom of movement, no funny noises etc and the Goto seems ok (although about the same as before maybe - maybe my mount was quite good before). I never minded the bringing noise it was the backlash I was hoping to get rid of, and all the stories about near flat guiding that reeled me in. Half the stuff you talk about going deeper still into the guts of the mount terrifies me to be honest, I haven't adjusted anything else before so I think I need to to work out what's happening here first before I break something else that ain't broke.

In terms of guiding I was pointing in the region of the Pinwheel galaxy, and by and large my errors were mostly in the region of 0.5 for 5 mins or so when suddenly it started to want to move it more than 4 hence telling me to up my max corrections. To be honest I've no idea what's "normal" "ok" or "acceptable" or "poor" etc.

I never thought about trying my QHY on the main scope to see if that has the same affect; that would presumably then eliminate the finderscope. If it pleases the powers that be and we have clear skies I'll have another go and post some Phd graphs.