brian nordstrom
12-09-2014, 04:34 PM
:D Well , here is a continuation of my thread concerning my Long Perng 60mm triplet .
I was in an Australian Geographic shop last week and they had this 70mm f11 achromat on a strange looking alt/az mount , I had not seen anything like it , it is similar to the AZ3 mount ? , anyway it was on sale for $200 so , what the hey ? I grabbed it .
Getting it home and setting up , which took all of about 10 miniutes , but the supplied manual was very good so a newby would not have any problems .
Ok I grabbed this solely for the mount as I had been looking for one , and for only $200 { fathers Day special ? } it looked good , easily up to the task of holding the LP60mm , but I soon discovered that it suffered from the 'AZ3 droop' :sadeyes: that is at about 45 degrees and above the OTA takes a backward dive ,, the dreaded AZ3 Droop, bugger :question: , so what to do , what to do ??? .
This is what I knocked up at work , a stainless steel 10mm threaded rod mounted under the dovetail at about 50 degrees pointing down with 2 small counter weights screwed on so they are moveable by turning them , and you know what ? :thumbsup: it works a treat the OTA now happily points to the zenith , nice ..
I have a small knob on the way ( Thanks Matt ) as the slomo altitude knob fouls with the focuser , but that's no big deal .
I will fill the bottom 1 inch diameter tripod sections with sand to give it a little more stability , its ok as is but a little more weight wont go amiss .
On the slo/mo alt and az adjustments they are smooth with no backlash and are 360* worm and wheels , a nice setup .
One more strange thing is that the whole head is adjustable in latitude ( you can see this rod pointing down under the mount head in the first photo ) , it even has degree markings on the shaft , like the Meade ETX psudo EQ mounts have , I have no idea why ?:shrug: as it wont work well without counter weights , AG probably thought it looked scientific ? :rofl: , no bother as when its locked down its nice and solid .
All in all a good little mount for my LP triplet .
A quick word on the 70mm f11 , it looks well made with good coatings , a 1 1/4 inch P&P focused that seems solid , a red dot finder , 1 1/4 inch diagonal , clamshell with Vixen dovetail mounded into the bottom and the real surprise was the 2 x Super Plossls of 10 and 25mm and of good quality , these are almost worth as much as the whole set up , a very nice touch indeed .
I will test this OTA and probably remount it if its good and either sell it on or give it away to an aspireng young amature astronomer .
Enjoy the photos , its today wiewing the sun using my Hershell wedge , and :eyepop: there is some massive sun spots at the moment .
Comments welcome as always .
Brian.
I was in an Australian Geographic shop last week and they had this 70mm f11 achromat on a strange looking alt/az mount , I had not seen anything like it , it is similar to the AZ3 mount ? , anyway it was on sale for $200 so , what the hey ? I grabbed it .
Getting it home and setting up , which took all of about 10 miniutes , but the supplied manual was very good so a newby would not have any problems .
Ok I grabbed this solely for the mount as I had been looking for one , and for only $200 { fathers Day special ? } it looked good , easily up to the task of holding the LP60mm , but I soon discovered that it suffered from the 'AZ3 droop' :sadeyes: that is at about 45 degrees and above the OTA takes a backward dive ,, the dreaded AZ3 Droop, bugger :question: , so what to do , what to do ??? .
This is what I knocked up at work , a stainless steel 10mm threaded rod mounted under the dovetail at about 50 degrees pointing down with 2 small counter weights screwed on so they are moveable by turning them , and you know what ? :thumbsup: it works a treat the OTA now happily points to the zenith , nice ..
I have a small knob on the way ( Thanks Matt ) as the slomo altitude knob fouls with the focuser , but that's no big deal .
I will fill the bottom 1 inch diameter tripod sections with sand to give it a little more stability , its ok as is but a little more weight wont go amiss .
On the slo/mo alt and az adjustments they are smooth with no backlash and are 360* worm and wheels , a nice setup .
One more strange thing is that the whole head is adjustable in latitude ( you can see this rod pointing down under the mount head in the first photo ) , it even has degree markings on the shaft , like the Meade ETX psudo EQ mounts have , I have no idea why ?:shrug: as it wont work well without counter weights , AG probably thought it looked scientific ? :rofl: , no bother as when its locked down its nice and solid .
All in all a good little mount for my LP triplet .
A quick word on the 70mm f11 , it looks well made with good coatings , a 1 1/4 inch P&P focused that seems solid , a red dot finder , 1 1/4 inch diagonal , clamshell with Vixen dovetail mounded into the bottom and the real surprise was the 2 x Super Plossls of 10 and 25mm and of good quality , these are almost worth as much as the whole set up , a very nice touch indeed .
I will test this OTA and probably remount it if its good and either sell it on or give it away to an aspireng young amature astronomer .
Enjoy the photos , its today wiewing the sun using my Hershell wedge , and :eyepop: there is some massive sun spots at the moment .
Comments welcome as always .
Brian.