Swimming, 31st May 2019

Last swim of the month and it was completely chaotic. No lanes in the pool, people getting in the way everywhere, all a bit messy. I think I had two failed reps, but it was honestly hard to count it as a worthwhile session.

USRPT distance this year: 134,100m
Total distance this year: 136,650m

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Repairs to a cheap illuminated reticle eyepiece

Hopefully when the sky is next clear at night I can get around to polar aligning my mounts, but before that I wanted to align the finders and main telescopes so I dug out an illuminated reticle eyepiece that I have mostly used to align targets for planetary imaging. I’ve had it quite some years and it’s very similar to the Skywatcher one:

It has a number of issues however.

The thread on the adjuster at the top of the eyepiece is quite loose and allows the top to wobble quite a bit. I found that (quite) a few turns of PTFE tape around the thread took a lot of the wobble out. I think that should be sufficient now as it feels fairly firm when the crosshairs are in focus.

The on/off switch isn’t great either. It also wobbles, and more often than not I forget to turn it off after using it. The knob is held on with a grub screw, so I undid that, pushed the knob on as far as I could and re-tightened it. That has improved the wobble, though it’s a little more stiff now.

I also discovered that it no longer works. Unscrewing the LED barrel revealed a couple of possible reasons:

I cleaned up the corrosion on the battery contact with some fine emery paper and resoldered the broken wire. Pleasingly that was all that was required to get it working again.

I am quite tempted to look at some means of fitting it with an external power supply. Having it plugged into a cable might actually make it easier for me to remember to disconnect it from the power. I need to give that some more thought though.

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Swimming, 30th May 2019

A more interesting day today, as whilst I was warming up someone who used to be a member of the club appeared on poolside and asked if she could join me and do my set (there was only one lane set out and I was the only one in it, so not an unreasonable call). She’s not swum much for the last six months and as it turned out we were reasonably well-matched in terms of speed over the set. I’d been hitting around 47s for most of the reps and before the last one she said “Push hard and go 46s on this one.” So I did, and touched the wall on 43s plus a few tenths, which I think is the fastest I’ve ever done a rep whilst swimming this set, regardless of target/turnaround time.

Two reps missed again, on thirteen and twenty.

USRPT distance this year: 132,400m
Total distance this year: 134,950m

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Building an observatory. Design #7

An addendum to my previous design post. The builder dropped the motor units off for the stair lifts that he thought might be butchered to make an automated roof mechanism.

This first is the lighter weight one for the rack made from multiple steel plates. The pinion wheel here is the same.

The second is for the solid steel rack. This one also has lots of microswitches that are undamaged and might be useful as limit switches.

For the moment however they’re going to remain on one side. I want to get all the existing planned work completely before adding more. I just need to bear it in mind for the wiring and so on.

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Swimming, 28th May 2019

No swimming on the Monday thanks to the bank holiday, but same set again today. For the time being I think I’m going to keep these postings short unless there’s something new and interesting to report.

So, fails on reps fourteen and twenty today.

USRPT distance this year: 130,700m
Total distance this year: 133,250m

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My first meteor image

Ok, so this was accidental, but I’m sure it counts 🙂

I found it whilst reviewing frames for my last star trails image. I’d seen a meteor that night and wondered if it was caught on camera, but didn’t initially find it when I ran through the original frames. Only when I went back through them again looking for aircraft trails did I spot it. Sadly it wasn’t entirely in the frame, but as it was only caught by chance I’m not going to complain.

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Another star trail photo and something “unidentified”

I got a couple of hours out in the observatory after dark and set up the 450D again to capture some subs to make a star trail image. This is better than the previous night, but I’d cut the exposure time down to try to reduce the sky brightness, not realising that either the camera or APT had reset the ISO setting when I was setting up the focus so there aren’t as many stars as I’d have liked. The good news is that even without a hood, the dew heater appears to have worked and kept the lens clear for the entire duration.

However, what really interested me was the diagonal trail at the left hand edge.

At first I thought it was a meteor. I definitely saw at least one, though I can’t be sure those I seem to catch out of the corner of my eye aren’t just odd reflections off the lenses of my glasses these days 🙁 Looking at the individual subs it’s certainly way brighter than the aircraft trails that pass overhead, but it definitely looks man-made. It actually starts much fainter, appearing from behind the barn roof in this first crop:

And continues the same way in this next one:

There appear to be white spots alternating either side of the main red line, which makes me think it has to be some sort of aircraft. And in the last frame it appears on, this happens:

It wasn’t until some time later that it occurred to me to have a look at the flightradar24.com site, but of course then it was too late. Or was it? Clicking around the site I discovered it has a “playback” mode that allows a review of earlier flights, even from previous days, so I played back events around the timestamp of the image.

It turns out that a flight from Faro to Cardiff passed within two miles east of me at just over 7,000 feet at exactly the right time according to the timestamp on the image. I feel sure that has to be the explanation. Perhaps the sudden increase in brightness is down to landing lights being turned on or something like that.

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Star fails

As the rest of the family has been seeing the observatory slowly being constructed over the last year and we had some clear sky I thought I’d have a go at something fun to show them now I’ve reached the point that it’s usable (though some way from complete), so I set the 450D up on a tripod with the kit 18-55mm lens wide open, pointing back at the house with the intention of taking some subs to combine into a star trail image.

Sadly the clouds didn’t appear to have read the forecast and the five hours of clear sky I was promised turned into an hour or so of mostly clear sky, and the cloud was worst to the south west — the direction of the house. So this is all I ended up with:

Perhaps the most interesting thing about it is that there are no lights on in the house at all. The lit windows are all illuminated by power indicator LEDs on chargers, clock displays and suchlike.

It’s not all negative though. I’ve been visual-only for quite some time whilst we’ve been having work done in the house because it made sense to pack kit up to keep it out of the dust, and during the construction of the observatory, so this is my first image of any kind in a fair while.

I did also grab some frames looking back over the observatory towards Cassiopeia, but struggled with the lens dewing up. I don’t have a hood for this lens which probably doesn’t help (and in fact the ones I’ve found online don’t look as though they’d be much help anyhow). I might try a dew heater, or attempt a 3d printed hood of my own. I should also have a go with my 14mm Samyang, though I suspect that will be even more prone to dew.

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Building an observatory. Construction #73

Pace has slowed a little of late, but I’ve kept things moving forward even if I haven’t been doing that much.

Because it gets quite warm inside the observatory when it’s sunny, I installed a 100mm vent in the northern gable and then finished cladding that gable. I’m not sure the single vent will be sufficient, but if it isn’t I’ll probably add one in the southern gable. If that’s still not enough then I think insulating the inside of the roof will be the next step, as most of the heat appears to be coming in through the roof.

The other step forward has been fitting the posts to support the ends of the roof rails where they extend beyond the main structure. This has meant that my bodged-up supports could be removed at last. No bad thing, as one of them kept falling out.

At the same time I also added some sections of aluminium angle to act as stops at the ends of the rails, so the roof can’t roll off the end when it is opened.

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Swimming, 24th May 2019

I don’t know why I type this any more 😀

  • 400m f/c warm-up
  • 24 x 50m f/c, target time 50s, turnaround 70s
  • 200m swim down

I felt quite tired today so I wasn’t sure how things would go. I certainly wasn’t expecting too much. Just to get as far as yesterday would have been good. But as it turns out I managed to complete fifteen reps before failing on sixteen: one better than yesterday. I failed again on twenty-one before swimming the set out. As a result I was quite pleased with my performance. Hopefully I can continue to improve next week.

USRPT distance this year: 129,000m
Total distance this year: 131,550m

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