Okay, I've installed the ATC-02 telescope control software & set up for bench testing. I powered up the scope and connected to the PC. Fans & heaters work, secondary focusser works and environment variables are being measured. Spiffy interface too! So far so good. Just need to I make up the RS-232 cable for the Pyxis now, then I can test everything.
wow, thats all looking very smick indeed Marcus. I like the scope controler, humidity control is a nice touch. Interesting heating is automated, but not cooling, as in auto fan control?.
Did a collimation check this morning. Out of the box it looks like no adjustment is needed - see attached (and commentary under the PBase version). I find this astonishing and a testament to the quality of crating and packaging.
wow, thats all looking very smick indeed Marcus. I like the scope controler, humidity control is a nice touch. Interesting heating is automated, but not cooling, as in auto fan control?.
Cheers Fred. Interesting point, fans are manually controlled. I guess once the fans have hastened equilibration - their only purpose really - they're not needed. Could they be turned off when temps have equalised? Dunno, this is new territory for me. The nice thing about measuring humidity is that the heaters will keep the mirrors at the selected threshold above the dew point, not ambient. So, if the dew point is way below ambient they won't be turned on.
Quote:
Originally Posted by Paul Haese
Awesome Marcus. That laser collimator, I take it that is one by OS? Looks very good.
Cheers Paul. Yes, supplied by OS.
Quote:
Originally Posted by Peter.M
I take it the ribbon cable to the secondary focuser is in line with the bottom vein and that is why it is slightly wider than the other shadows?
Correct. I'm trusting this has no noticeable impact on diffraction spikes. It worth noting that the veins are very thin - 1.6mm. Also, the ribbon cable is flocked so that adds to thickness.
[QUOTE=marc4darkskies;1034112]Cheers Fred. Interesting point, fans are manually controlled. I guess once the fans have hastened equilibration - their only purpose really - they're not needed. Could they be turned off when temps have equalised? Dunno, this is new territory for me. The nice thing about measuring humidity is that the heaters will keep the mirrors at the selected threshold above the dew point, not ambient. So, if the dew point is way below ambient they won't be turned on.
I have gotten dew on the mirrors of the CDK17 about 3 times in 3 years. Its not really a problem. As far as auto when it hits ambient that is also a nonissue as the mirror always seems to be a tad above ambient and the closest is .1C difference I have seen. Maybe once in a blue moon it goes below ambient. That is more ideal anyway as you don't want a boundary layer on the top of the mirror.
Talk to Paul Hease or Bird about thermal effects on mirrors. They cool theirs to get it below ambient a few degrees to get rid of thermal currents.
Ideally there should be fans blowing across the mirror. The latest CDK17 has this. Mine does not. It gets rid of the boundary layer. I was thinking of rigging up some fans facing across the mirror. 2 should do it.
Ron Wodaski talked about thermal currents and sideways fans at AIC this year.
Auto dew heating could be handy on some nights but you most likely will find dew only occurs on those nights early in the morning. I have not really lost any imaging time because of dew or at least minimal amounts.
I think the main thing is turning on the fans early enough to allow the mirror to get quite close in temp to the ambient. If its more than 1C then it will be hard to focus and won't be at its sharpest. .3 to .6 is OK. .1 is sweet. It takes the CDK about 1.5 hours to get close. I am sure it will be similar for this scope.
I have gotten dew on the mirrors of the CDK17 about 3 times in 3 years. Its not really a problem. As far as auto when it hits ambient that is also a nonissue as the mirror always seems to be a tad above ambient and the closest is .1C difference I have seen. Maybe once in a blue moon it goes below ambient. That is more ideal anyway as you don't want a boundary layer on the top of the mirror.
Talk to Paul Hease or Bird about thermal effects on mirrors. They cool theirs to get it below ambient a few degrees to get rid of thermal currents.
Ideally there should be fans blowing across the mirror. The latest CDK17 has this. Mine does not. It gets rid of the boundary layer. I was thinking of rigging up some fans facing across the mirror. 2 should do it.
Ron Wodaski talked about thermal currents and sideways fans at AIC this year.
Auto dew heating could be handy on some nights but you most likely will find dew only occurs on those nights early in the morning. I have not really lost any imaging time because of dew or at least minimal amounts.
I think the main thing is turning on the fans early enough to allow the mirror to get quite close in temp to the ambient. If its more than 1C then it will be hard to focus and won't be at its sharpest. .3 to .6 is OK. .1 is sweet. It takes the CDK about 1.5 hours to get close. I am sure it will be similar for this scope.
Greg.
Interesting - thanks for the info Greg! Surprised dew hasn't bothered you that much. Dew used to cause all sorts of problems for my Tak before I put a dew heater on. On many occasions the whole observatory was dripping wet and the objective fogged over before 1:00am.
Interesting - thanks for the info Greg! Surprised dew hasn't bothered you that much. Dew used to cause all sorts of problems for my Tak before I put a dew heater on. On many occasions the whole observatory was dripping wet and the objective fogged over before 1:00am.
I suppose I should put the caveat of that's whqt happens where I am. But I think because the mirror is so far inside the tube, it has the fans blowing air across it, the shroud around it, its not that exposed really.
Hopefully its the same for you. It hasn't been enough of a bother for me to get dew heaters installed yet.
Yep, thanks Logan, I saw that. Made me feel warm & fuzzy
Quote:
Originally Posted by gregbradley
I suppose I should put the caveat of that's whqt happens where I am. But I think because the mirror is so far inside the tube, it has the fans blowing air across it, the shroud around it, its not that exposed really.
Hopefully its the same for you. It hasn't been enough of a bother for me to get dew heaters installed yet.
Greg.
Yes, I'll have the same. The shroud should minimise the need for heaters but on the worst nights (as you're saying I think) they'll still be necessary. My fans suck air down towards the mirrors too so on wet nights would this increase the risk of dew on the primary requiring the heaters? Also wondering whether it's best to run with or without the shroud.
Yes, I'll have the same. The shroud should minimise the need for heaters but on the worst nights (as you're saying I think) they'll still be necessary. My fans suck air down towards the mirrors too so on wet nights would this increase the risk of dew on the primary requiring the heaters? Also wondering whether it's best to run with or without the shroud. [/QUOTE]
I often wonder about dew heaters. We go to so much trouble to get the mirror cooled and per Paul Hease and Bird you actually want the mirror cooler than ambient rather than warmer. I have thought it would be worth an experiment to get one of those AC units with the hose output and angle one on a stand to blow cold air on my mirror as an experiment to see what effect it has. AC air is also dry and are great for demisting the car windscreen. So it may also stop dewing? But on those nights where it would prevent an image wrecking problem of dew it would be worthwhile. Certainly in Florida/Qld or high humidity areas it would be a must.
I have not imaged with the shroud off mainly because I was worried about the small amount of light we often have in the observatory from transformer LEDs and in my case my computer screen around a corner.
But yes I think you could get some better cooling and air flow by leaving it off. Would it be worth it? I think other factors would probably influence the image far more but every little bit adds to the final result.
Looks the goods, Marcus. Time for it to produce the goods.
Well done on the purchase...am awaiting first light.
Thanks Jase. Nope, not going to rush things. One step at a time.
Today I made up the RS-232 cable for the Pyxis 3" rotator (6P/6C RJ12 to DB9), and tested it out. I installed the drivers and connected to it via TheSkyX and all was well. Also attached the imaging train assembly - just for a photo op!
Looking good Marcus. Are you putting the AO and STL 11 on there?
The MMOAG guide camera chip needs to be the same distance from the pickoff prism as the imaging camera's sensor. If you are more than about 5mm away from it the star images in the guide cam will be so out of focus they become invisible. I found this frustrating when I first tried to use my MMOAG.
Just looking at yours I would say your guide cam will be sitting in air above that helical focuser. I don't use the helical focuser as its too short plus how do you focus it when its got a guide camera sitting in it?? Spin it and tangle the cables? The designer must have been a bit soft in the head.
I substituted a Televue Barlow body and removed the lens bit on it at the bottom to get more height to fit the guide scope. My camera sensor seems a bit closer to the prism than yours. I have MMOAG then about a 12mm wide adapter then the filter wheel (20mm) then the camera and the sensor is 23mm inside the body. So that is 23+20+12+ half the thickness of the MMOAG about 10mm = 62mm.
Anyway something to be aware of when using a MMOAG for the first time.
The other thing is to make sure the adapters areall seated without any minor push out. In my first use the MMOAG prism was sticking back a bit causing the adapter to not seat 100%. I wondered why one side of the images were very soft. The prism has 2 allen key screws on top and you can slide it forward or back to suit and then retighten if its an issue.
Have to say that looks like a real pro instrument mate and once mounted will be the envy of us all While perhaps a tad daunting at the moment, you must be just sooo excited and I think your cautious careful approach is a good idea
Looking good Marcus. Are you putting the AO and STL 11 on there?
The MMOAG guide camera chip needs to be the same distance from the pickoff prism as the imaging camera's sensor. If you are more than about 5mm away from it the star images in the guide cam will be so out of focus they become invisible. I found this frustrating when I first tried to use my MMOAG.
Just looking at yours I would say your guide cam will be sitting in air above that helical focuser. I don't use the helical focuser as its too short plus how do you focus it when its got a guide camera sitting in it?? Spin it and tangle the cables? The designer must have been a bit soft in the head.
I substituted a Televue Barlow body and removed the lens bit on it at the bottom to get more height to fit the guide scope. My camera sensor seems a bit closer to the prism than yours. I have MMOAG then about a 12mm wide adapter then the filter wheel (20mm) then the camera and the sensor is 23mm inside the body. So that is 23+20+12+ half the thickness of the MMOAG about 10mm = 62mm.
Anyway something to be aware of when using a MMOAG for the first time.
The other thing is to make sure the adapters areall seated without any minor push out. In my first use the MMOAG prism was sticking back a bit causing the adapter to not seat 100%. I wondered why one side of the images were very soft. The prism has 2 allen key screws on top and you can slide it forward or back to suit and then retighten if its an issue.
Greg.
Thanks for the advice Greg. I think I got the distance calculation reasonably close so we'll see. The adaptor you see is for the STL only, no AO-L. I have the short adaptor as well for the AO-L + STL but that means guiding with the camera - an option I'll have (leaving the MMOAG in place). I won't know the true configuration until I get it out under the stars of course. If I have to mess around with adaptors so be it - no problem - I'm expecting to have to do that anyway.
Have to say that looks like a real pro instrument mate and once mounted will be the envy of us all While perhaps a tad daunting at the moment, you must be just sooo excited and I think your cautious careful approach is a good idea
Mike
did you pickup that ping pong ball?
Cheers mate! Yes, a bit daunting but with some familiarisation I'm starting to relax I'll get nervous again when I put some starlight through it. Will it all work as advertised??! Will my stars be tight?
Yes, the ping pong ball has been returned to its rightful owner - Sweetie and her brother Buddy. Below is Buddy after the box passed inspection.