Wisdom Tooth Extraction

I finally gritted my teeth and agreed to have my impacted wisdom tooth extracted. I've had a trauma of dentists since I was in kindergarten, when a surly dentist at the UP Infirmary pulled out both of my front incisors in one go because I wouldn't behave. Those were just milk teeth but without the benefit of anesthesia.

Since then I've always avoided going to the dentist which wreaked havoc on my teeth.



(panoramic X-ray image of the evil tooth; I just held up the X-ray to the light and took a photo with my cellphone camera, hence the visible background)

I've always heard how painful wisdom tooth extractions are so I kept putting it off. However this particular tooth caused the good tooth in front of it to develop caries in an area that can't be restored unless the impacted tooth was removed. And I can't afford to lose more teeth! with dental implants going for $2,000 a pop..

Anyway, all in that wisdom tooth took three hours of surgery, six ampoules of anesthetic, and a lot of painful cutting and re-sectioning.

And now, two days later, my face is still mis-shapen like a gourd.

More Cheap Telescope Upgrades

I've replaced the aluminum tripod legs on my cheap Barska with some wooden legs I had from a previous project. I even spray-painted them orange several years ago so they look like Vixen tripod legs.



These are more stable than the aluminum legs (more stable and with better damping, than the collapsed aluminum tripod). As such, the eyepiece is in a convenient position for seated observation even when pointing close to the zenith.



I just used some 1/4"-20 bolts to attach the wooden legs to the EQ hub. The bolts which came with the Barska are too short for the wooden legs.



This is a full-frame (uncropped) image of the full moon. I used a 32mm Vixen Plossl (giving 28X magnification) and the Pentax K10D with 50mm f/2 manual focus lens, afocal projection:



I'll just tweak the leg mounting, find a reticle eyepiece so I can guide through the main tube and take photos of DSO's using a 200mm Super-Multi-Coated Takumar piggybacked to the scope. That way I can do 30-second to 2-minute exposures without a motor.

If results are promising, I'll buy an EQ-1M motor for the thing.

Fixing The Cheap Equatorial

Today I went to the mall and bought some stuff to fix the cheap and shoddy EQ-1 clone which came with my $110 Barska 90060 department store telescope.

To summarise, the problems with the Barska were:

• Too much slop in the worm gear; this caused an unacceptable level of backlash when operating the Right Ascension slow motion control knob.
• The counterweight is too light to balance my Celestron Vixen 80mm f11 refractor tube, which caused severe problems when trying to use the EQ-1 clone with my (decent) telescope.
• Needed to adapt the non-standard dovetail to my 80mm scope rings.

To fix the first item, I bought a cheap (168-peso, roughly $3.50) set of Allen hex wrenches. Actually there was a Stanley-branded one for $6.00 but I am a really cheap person.



I loosened the tiny Allen screw at the three o'clock position in the above photo, adjusted the brass bushing with a long-nosed pliers, and tightened it up again.

To fix the lack of counterweight mass, I bought four 1.25-pound barbell weights ($1.00 each). Turns out three are enough:



I just wrapped some cardboard around the counterweight shaft because the holes in the middle of the barbell weights are much larger diameter than the shaft; I then tightened a hose clamp to hold the weights in place. Primitive! but effective.



A whole stack of washers and two ordinary 1/4"-20 bolts was sufficient to bolt the tube rings to the non-standard dovetail. I did hack at the dovetail holes with a screwdriver last night to make them large enough to thread a 1/4" bolt through.

In action:



I didn't extend the tripod legs, which left me almost lying on the ground (the moon was at the zenith). This made for much better stability but is not usable in the long run; I think I'll try my wooden tripod legs and see how much better that is. Wooden tripod legs are long and don't collapse though. They would be a pain to put in the back of the car.



Tracking was very good even with my very approximate polar alignment, and I can finally put that rolled sheet metal 60mm Barska toy refractor behind me (might make a good guide scope though). But now I want an EQ-1M motor, so that I don't have to turn the Right Ascension knob manually anymore.

Cheap Equatorial Mount

I've been seeing these Barska 90060 telescopes at True Value over the past couple months. They always sell out really quickly but yesterday Dennis spotted a pair at True Value in Shangri-La Mall. I asked him to reserve one for me, and bought it last night. Cost around $110. This is in contrast to $70 to $100 in the US, however not factoring in the hefty cost of shipping a 20-pound box to the Philippines.

I really was only after the mount (or more specifically, the equatorial head).



I did not have high expectations (these things have 200-arcsecond periodic error, a wobbly aluminum tripod, and a poor-quality telescope). I did not even intend to unpack the telescope, instead I planned to mount my 80mm Vixen refractor on the mount.

A few conclusions are in order:

• The 100-tooth Right Ascension gear has a significant amount of slop;
• However the biggest source of inaccuracy is slop in the worm gear caused by an improperly-tightened end bushing. I intend to adjust this when I can get an Allen wrench set.
• It uses a non-standard dovetail, however the entire EQ head is made of some pot metal so I enlarged the dovetail bolt holes with a screwdriver so I could bolt my tube rings to it.
  
• The Celestron/Vixen 80mm f11 is way too heavy for the tiny counterweight.

The view of the moon at 28X (with a 32mm Vixen Plossl) and 90X (with a 10mm) was razor-sharp, with only a tiny hint of CA on the limb. The equatorial mount works as advertised, allowing hassle-free tracking (so long as the tube isn't so unbalanced by the tiny counterweight), even with only an eyeball polar alignment.

Due to the really heavy Vixen OTA, I decided to give the telescope tube (a 60mm f11) which came with the Barska a try.



To my tremendous surprise, the cheap plastic focuser is a 1.25" one, not the usual 0.965" on cheap telescopes. So I was spared the indignity of using the supplied Huygenians and Symmetrical Ramsden (17th-century technology!) eyepieces with the kit.



The view of the moon is decidedly less impressive than with the Vixen (as expected). The cheap plastic focuser doesn't quite reach focus with the 32mm Vixen Plossl, but the 10mm works fine and I could see the Straight Wall quite well near the lunar limb.

The 5x24 finder which comes with the kit has a very small eye relief, tiny field of view, and is pretty useless (I used the hole in the mounting stalk to aim the main telescope tube). Good thing I intend to use a Telrad or Rigel Quick-Finder (I have one of each) with the Vixen tube.

In summary, the Barska 90060 is a piece of crap which should not be purchased by newbie star-gazers, who will gnash their teeth in frustration at the many limitations of this mount and telescope. But it's a relatively cheap entree into equatorial mount land, and with enough tuning up and tooling, I'm confident that I can make it competent enough.