JamesF

Looks like they're having another go though.  I'll have to start it running on another screen.

James

2 minutes ago, Ags said:

Health and safety, James!

Ok, a *very* long pole.

James

7 minutes ago, Ags said:

When I was seven or eight, my rocket designs always used the well-proven technology of automotive spark plugs as the ignition subsystem. I should get in touch with Elon and give him some pointers.

I don't know what's wrong with a burning taper on the end of a long pole.

James

Anyone have any news on the cause for the abort or a new launch date yet?  I've not seen anything so far.  I gather there was the possibility of going again today or tomorrow, but I'd have thought we'd know by now if that was going to happen.

James

Officially game over now

James

LOL.  One of the commentators just said "It's not rocket science".  You know, I think it might be :D

James

It's not exactly compelling viewing so far, is it?  They surely need to get on with fuelling it soon if they're going to stay in the launch window.

James

I made a rocket like SN8 when I was about ten years old.  I can understand why SpaceX may be having a few problems today.  I had terrible trouble getting the tin foil to stick to the cardboard tube.

James

Good news for everyone, I think.  The dales and the north Yorks moors may well be "up north", but the more widely the idea that light pollution should be curbed is spread, the better for all of us I reckon.

James

5 minutes ago, DaveL59 said:

They seem to sell for £40-60 on the bay

I'm genuinely shocked.  I'm sure I've seen a DFK21.618 go for little more than that.  Perhaps I should dig mine out and stick them on the bay as well.  I must have at least three, possibly four.

James

I bought several for only a few pounds perhaps fifteen years ago, but then I recall them going for £100 or more at one point, after production stopped and they were still sought after.  But then all the high frame rate CMOS cameras came along and everything changed.  These days they're perhaps more of a historical curiosity than anything else.  I have a feeling I saw one on AB&S not too long ago for around the £20 mark and I'm not sure it sold even then.

James

Combined with platesolving, drift alignment works very neatly.  You can use a planetarium app to find a reasonably bright star close to the ideal position, get the mount to go to it and plate solve repeatedly until it is definitely pointing at the right one, then drift align against it.

James

I'm too young to remember these things having only been born in the late 60s, but I do love the cast iron pier with "C Frank" cast into it.  It's almost a shame they didn't make it more ornate, like those pre-electric Singer sewing machines with the cast iron stand and treadle to power the machine.

James

You need a pair of stars.  I think the ideal is if you can pick one as close as possible to the celestial equator and as close as possible to due east or due west, whilst the other should be as close as possible to the celestial equator and due south.  It doesn't matter if you can't do that though.  It may just take more iterations to achieve a given level of accuracy.

There must be some videos on youtube demonstrating the process, quite possibly using PHD.  Hopefully I'm not confusing my software, but my recollection is that PHD does it by showing a line over a live image from the camera and getting you to move a star from one end of the line to the other using the alt and az adjusters, repeating the process east/west and south in turn until you have a level of accuracy you're happy with.  I'm not certain though, as having an observatory and mounts on fixed piers I don't have to do it very often.

James

36 minutes ago, SStanford said:

That's very useful. 

Do I need to get a guide scope and guide cam for this or can I just use my DSLR plugged into the computer with PHD2 and scope for initial alignment? 

Will I need to do drift alignment everytime I setup or once aligned can I mark the tripod on the ground with the altitude left the same on the mount? 

Thanks again

Drift alignment is done with the main camera, not the guidescope.  Ideally you'd do it every time you set up.  You're getting down to very small fractions of one degree in terms of accuracy, so it doesn't take much movement elsewhere in the system to mess things up.

James

If you're interested in astrophotography then I assume you have a computer of some sort nearby?  Given that, PHD has a drift alignment facility as far as I recall.  No need to be able to see Polaris at all.

James

1 minute ago, Moonshed said:

It’s a sad and slippery slope.....

It was the right way up when I took it, onnist, ossifer.

James

Hmm.  Not sure why that first image isn't in the correct orientation :(

James

Something that should appeal to Nigella: a couple of oldies from a white light imaging session with my 450D and 127 Mak:

James

Given the apparent problems sourcing kit at the moment, they'll soon be turning up with stickers saying "May contain astronomy equipment".

James

19 minutes ago, Highburymark said:

I had no idea that Baader sells an imaging Ca-K filter. What a great way to get into Ca-K a little more affordably.

Nor I.  Once I have my Ha setup in action again I shall think on that.

And happy birthday, Nigella :)

James

Well, that's a right pain :(

I've just had a look back over your build thread and it's really not obvious where any water could be getting in.  If the underground elbows are buried in concrete then even if it were to weep a little I'd not expect it to be noticeable after a week.  Not unless you were needing to paddle out to the warm room, anyhow.

Trying to feed some flexible tube containing all the cables through does seem like the simplest way out at the moment, but will that actually be possible given the need to negotiate the elbows?  And personally I'd be much happier if I understood where the water was coming from in the first place so I could be sure it wasn't likely to affect anything else.  Is it perhaps worth drying it all out and then leaving everything for a couple of weeks with the pier removed to see if there's still a build-up of water?  Given the present weather if you even missed a single night of imaging it would probably be a surprise :(

James

5 minutes ago, John said:

On the plus side, there will be a tidal wave of used equipment for sale in due course ........ 

Good point.  There are a few things I'd not mind picking up on the used market.  I'd best start making a list.  And given the time of year, obviously I'll check it twice.

James

I wonder how many counterbalance weights were required to make up for the fact that one end is now far too light?

James

1 hour ago, Nigella Bryant said:

What a great milestone 15yrs, WOW. I'm just 2.5 lol, not even sure if I'll make 15yrs, being in my 60's, lol. Keep on going. 

You'll be absolutely fine, Nigella.  You're living in the land where time doesn't pass now

James