PST Tuning Ring
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PST Tuning Ring
Hi All...
My clumsy fingers dropped the little bolt that threads in to lock the tuning ring on the PST etalon and despite searching for over an hour I can't find the little thing in the grass
Can anyone tell me what the thread size is so I can hunt down a replacement? The smallest machine bolt I have is a 4-40 and it doesn't seem to want to thread in and I don't want to force it.
Thanks for any guidance
Brian
My clumsy fingers dropped the little bolt that threads in to lock the tuning ring on the PST etalon and despite searching for over an hour I can't find the little thing in the grass
Can anyone tell me what the thread size is so I can hunt down a replacement? The smallest machine bolt I have is a 4-40 and it doesn't seem to want to thread in and I don't want to force it.
Thanks for any guidance
Brian
Brian Colville
Maple Ridge Observatory
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Maple Ridge Observatory
Cambray, ON Canada
Photos: https://www.flickr.com/photos/185395281@N08/albums
10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM
2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
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Re: PST Tuning Ring
I have used it on a mod, but in this case I had re-assembled the PST to its original form and found I had to change the tuning more than the ring would allow. I was just careless and dropped the little bolt that locks the tuning ring in place, and can't find it in the grass. I heard it hit the tripod as it fell and did not see which way it was deflected.
Brian
Brian
Brian Colville
Maple Ridge Observatory
Cambray, ON Canada
Photos: https://www.flickr.com/photos/185395281@N08/albums
10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM
2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
Maple Ridge Observatory
Cambray, ON Canada
Photos: https://www.flickr.com/photos/185395281@N08/albums
10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM
2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
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Re: PST Tuning Ring
Hello Brian,
As a last resort, you might consider "fishing" the area with a strong magnet.
Fabio
As a last resort, you might consider "fishing" the area with a strong magnet.
Fabio
Flickr album https://www.flickr.com/photos/190949744@N08/
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Re: PST Tuning Ring
Hi Fabio...
The magnet was my first try after I couldn't find it in the grass when it first fell. It bounced off the tripod leg and I have no idea which direction it went or distance which makes it more difficult to pin down a search. I am going to look again today and see fi I get lucky!
Thanks,
Brian
The magnet was my first try after I couldn't find it in the grass when it first fell. It bounced off the tripod leg and I have no idea which direction it went or distance which makes it more difficult to pin down a search. I am going to look again today and see fi I get lucky!
Thanks,
Brian
Brian Colville
Maple Ridge Observatory
Cambray, ON Canada
Photos: https://www.flickr.com/photos/185395281@N08/albums
10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM
2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
Maple Ridge Observatory
Cambray, ON Canada
Photos: https://www.flickr.com/photos/185395281@N08/albums
10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM
2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
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Re: PST Tuning Ring
Brian,
EDIT: correction. It's obviously a M2.5 screw!!!!
EDIT: correction. It's obviously a M2.5 screw!!!!
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Re: PST Tuning Ring
I assume it is this screw that you dropped:
Here are some measurements. Maybe it's a M2.5 screw? The screw just threads into the outside ring. The etalon itself has no threads. In theory, you could drill and tap any size hole. I actually removed the ring entirely and just use a match stick as it allows access to all the little holes and you can have a wider tuning range (since the tuning changes with time due to compression of the spacers inside).
I tested to see if it is even magnetic. With a very strong N42 magnet, it is just barely able to be picked up. I suspect that if it were embeded in grass, a magnet would not be able to catch it.Here are some measurements. Maybe it's a M2.5 screw? The screw just threads into the outside ring. The etalon itself has no threads. In theory, you could drill and tap any size hole. I actually removed the ring entirely and just use a match stick as it allows access to all the little holes and you can have a wider tuning range (since the tuning changes with time due to compression of the spacers inside).
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Re: PST Tuning Ring
Hi Ken...
Yes, that's the one!
I tried with the magnet and found nothing...similar sized bolts I had were not overly attracted to the magnet and the grass would tend to bush it off if it did catch it. I'll take a look for a replacement int he size you suggest, and can keep it working for the time being.
Thanks,
Brian
Yes, that's the one!
I tried with the magnet and found nothing...similar sized bolts I had were not overly attracted to the magnet and the grass would tend to bush it off if it did catch it. I'll take a look for a replacement int he size you suggest, and can keep it working for the time being.
Thanks,
Brian
Brian Colville
Maple Ridge Observatory
Cambray, ON Canada
Photos: https://www.flickr.com/photos/185395281@N08/albums
10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM
2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
Maple Ridge Observatory
Cambray, ON Canada
Photos: https://www.flickr.com/photos/185395281@N08/albums
10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM
2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
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Re: PST Tuning Ring
To Brian: actually, the photos of the screw came from me, your fellow Canadian (not Ken). I took a look at the specs for M2.5 and the thread seems to approximately match the photo I took (around 0.5/mm). So M2.5 x 10mm Philips flathead countersunk appears to be the likely replacement. Doug
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Re: PST Tuning Ring
Sorry about that mix up...what I get for looking on the phone and small screens cut off the full post.
What part of Canada do you call home?
Brian
What part of Canada do you call home?
Brian
Brian Colville
Maple Ridge Observatory
Cambray, ON Canada
Photos: https://www.flickr.com/photos/185395281@N08/albums
10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM
2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
Maple Ridge Observatory
Cambray, ON Canada
Photos: https://www.flickr.com/photos/185395281@N08/albums
10'x15 Roll-off Roof Observatory
Takahashi EM400 Mount carrying:
C14 + Lunt 80ED
Deep Sky Work - ASI294MM Pro+EFW 7x36/Canon 60D (Ha mod), ONAG
Planetary Work - SBIG CFW10, ASI462MM
2.2m Diameter Dome
iOptron CEM70G Mount carrying:
Orion EON 130ED, f7 OTA for Day & Night Use
Ha Setup: Lunt LS80PT/LS75FHa/B1200Ha + Home Brew Lunt Double Stack/B1800Ha on the Orion OTA + Daystar Quantum
WL, G-Band & CaK Setup: Lunt Wedge & Lunt B1800CaK, Baader K-Line and Altair 2nm G-Band filter
ASI1600MM, ASI432MM, ASI294MM Pro, ASI174MM, ASI462MM
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