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I was so pleased with the white light, bino-view of the Sun that I decided to improve the mechanics of the Vixen 90. It is the perfect telescope for solar viewing being so easy to handle while providing a decent sized objective. I just clamp the telescope into the rings of the old MkIII mounting, slip on the home made, solar film filter and I'm ready to go.
First real solar time with H-alpha and white light side by side. 120mm f/10 equivalent and 90mm /11. The detail is mind blowing in the H-alpha. With the texture of the prominences clearly visible. There was even a bright surface feature showing altitude variation near the limb.
The major problem with the Vixen is the inadequate drawtube connection to the heavy binoviewer load it must now carry. Intended only for a solitary eyepiece, the single little thumbscrew has already damaged the nose-piece of the heavy binoviewer plus its two LP eyepieces. No amount of tightening would hold the binoviewer against sag and general floppiness.
So I needed a serious upgrade in the mechanical support of the star diagonal which carries the binoviewer. I could have drilled two more holes for screws 120° apart but searching online suggested a much better alternative. A Baader compression ring, 1.25" adapter which should fit inside the larger screwed ring.
The original components are shown here. The long drawtube has a female threaded ring and another, 1.25" ring screws into that. The weakness, for my binoviewing purposes, lies in the single thumbscrew.
A compression ring adapter with three thumbscrews seems the perfect answer. Better images on arrival from Teleskop-Service. I just hope the 36.3mm thread fits the Vixen ring as claimed. It measures exactly 36.3mm with my calipers. Which is the stated size of the male thread of the Baader adapter. Now I need a 90° star diagonal with a compression ring fitting that doesn't cost the earth. My two, dirt cheap 1.25" diagonals were both no-name purchases. I can't honestly say that either of them noticeably spoilt the image. The star diagonal will become the weak link in supporting the heavy binoviewer.
No solar viewing today as snow falls steadily. I dismantled and reworked the rather stiff 1.25" Vixen focuser after noticing an eccentric focusing wheel. The rack pinion shaft was dismantled and put in the 3-jaw chuck of my lathe. I then, very carefully, used a ring spanner to very gently straighten the bent shaft. I realised the extreme danger of snapping the pinion shaft if it was hardened. So used repeated gentle pressure on the ring spanner until the shaft finally ran true when the lathe was spun up.
The grease in the focuser was incredibly thick and took some cleaning to remove it completely. I then added some thinner grease. Careful adjustment of the tiny grub screws followed. These set the pressure on the long pad, on the opposite side of the drawtube, from the rack. To produce smooth and even drag from end to end of drawtube movement. Final adjustment was via the pinion plate screws to achieve smooth rotation of the focusing wheels. The focuser movement now feels much smoother than I have ever known it.
First real solar time with H-alpha and white light side by side. 120mm f/10 equivalent and 90mm /11. The detail is mind blowing in the H-alpha. With the texture of the prominences clearly visible. There was even a bright surface feature showing altitude variation near the limb.The major problem with the Vixen is the inadequate drawtube connection to the heavy binoviewer load it must now carry. Intended only for a solitary eyepiece, the single little thumbscrew has already damaged the nose-piece of the heavy binoviewer plus its two LP eyepieces. No amount of tightening would hold the binoviewer against sag and general floppiness.
So I needed a serious upgrade in the mechanical support of the star diagonal which carries the binoviewer. I could have drilled two more holes for screws 120° apart but searching online suggested a much better alternative. A Baader compression ring, 1.25" adapter which should fit inside the larger screwed ring.
A compression ring adapter with three thumbscrews seems the perfect answer. Better images on arrival from Teleskop-Service. I just hope the 36.3mm thread fits the Vixen ring as claimed. It measures exactly 36.3mm with my calipers. Which is the stated size of the male thread of the Baader adapter. Now I need a 90° star diagonal with a compression ring fitting that doesn't cost the earth. My two, dirt cheap 1.25" diagonals were both no-name purchases. I can't honestly say that either of them noticeably spoilt the image. The star diagonal will become the weak link in supporting the heavy binoviewer.
No solar viewing today as snow falls steadily. I dismantled and reworked the rather stiff 1.25" Vixen focuser after noticing an eccentric focusing wheel. The rack pinion shaft was dismantled and put in the 3-jaw chuck of my lathe. I then, very carefully, used a ring spanner to very gently straighten the bent shaft. I realised the extreme danger of snapping the pinion shaft if it was hardened. So used repeated gentle pressure on the ring spanner until the shaft finally ran true when the lathe was spun up.The grease in the focuser was incredibly thick and took some cleaning to remove it completely. I then added some thinner grease. Careful adjustment of the tiny grub screws followed. These set the pressure on the long pad, on the opposite side of the drawtube, from the rack. To produce smooth and even drag from end to end of drawtube movement. Final adjustment was via the pinion plate screws to achieve smooth rotation of the focusing wheels. The focuser movement now feels much smoother than I have ever known it.
Click on any image for an enlargement.
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