Mountings and Controls For Widefield Imaging Rig

[Gina]

Thanks Magnus - I'll take a look at that

[Gina]

Thinking about the zoom control and zoom lenses in general, I see no point in including zoom control until I have established if these lenses are of sufficient quality to use for imaging.  They won't fit in the current rotation rig anyway.  Nor for that matter will the Jupiter 9 lens I've now found.  This USSR made lens is 85mm and f2 and is a hefty hunk of glass and too large in diameter to fit the current rotation rig.

[Gina]

To allow for possible zoom in the future I can simply not include the zoom driver module and its socket.  This means I can carry on making the current imaging rig whilst leaving the zoom option open for later.

[Gina]

I now have the software for the RPi sorted out and working so will be going ahead with building the electronics circuit and box.  It's "full steam ahead"   At least, once I've recovered from some high power Linux stuff!!

[Gina]

ATM I'm concentrating on the Esprit imaging rig for which I practically everything ready.  Just need to sort out and print the box to put the electrics/electronics in.  This rotation rig needs a bit more to provide the rotation, otherwise the same control box would have sufficed.  I shall probably be making up the electronics board for this while 3D printing the box for the scope rig.

[Davey-T]

No rush Gina, looking at the long range forecast we're in for a couple of weeks of wind and rain 

Dave

[Gina]

Yes, I know!!   I shall just plod on at my own rate   May disperse with another project or two for light relief

[Gina]

Diagrams of Nano pinout and Pololu Stepper Driver Module connections.

[Gina]

D5 - DIR,  D6 - STEP can be wired straight across.  Alternatively, since the Nano is 30 pin and the socket is 32 pin, the Nano could be moved down one strip so that the USB connector doesn't stick out beyond the stripboard.  The would mean D4 - DIR and D5 - STEP.  Makes no difference really

[Gina]

Here is a photo of the RPi and stripboard placed on the dovetail bar.  This would seem to be a reasonable layout.  I wanted to have the power connector reasonably close to the Ethernet socket as both cables would be in the umbilical that goes down to the pier.  I think the fuses should be easily accessible in case of needing replacing, though that's very unlikely.  Both power connector and fuses would be attached to the side of the box. 4 data lines plus Gnd connect from the GPIO pins to the Arduino Nano.

[Gina]

I've ordered some female-female jumper wires to use to connect to the GPIO pins.  Oh, and some 4700µF 25v electrolytic capacitors as the one shown is my last one and that's going in the scope electronics box.  I think I'm running low on RPi boards too.  Scope rig, widefield rig, ASC night, ASC daytime and 2 3D printers.  Oh and I may use another to control my observatory roof.  Beginning to approach my use of Arduino Nanos

[Gina]

As I think I said, I'm going to build separate electronics boxes for the two imaging rigs (widefield and scope) so save time swapping over.  Also, there's a chance that I shall put the widefield imaging rig in a second (mini) observatory - I haven't entirely given up on that possibility

[Gina]

I think I have pretty much sorted out the box design.  Put the fuses one above the other instead of side by side to save space.  I shall print a separate base plate like I did for the scope rig as that gives me more "wiggle room".

[Davey-T]

Annoys me when building stuff that they don't seem to make smaller fuses and holders and I end up soldering small ones onto the board when space is at a premium.

Dave

[Gina]

Yes, I've done that in the past.  I think you can get wire ended fuses.

[Davey-T]

1 minute ago, Gina said:

Yes, I've done that in the past.  I think you can get wire ended fuses.

Yes that's the ones.

Dave

[Gina]

Now printing the box - takes just under 2 hours.  Meanwhile I'm populating the stripboard.

[Gina]

Here's a photo of the box with parts laid in it.

[Gina]

I'm having a bit of difficulty with clearance - the current box will catch the cage if I add the lid and base   Oh well, new design coming up!!  I don't really want to raise the rotating part any more - I've already raised it be 10mm.  I can design a box with a curved top that will fit under the cage but still accommodate the electronics.  The high parts are away from the centre.

[Gina]

 Redesigned the box and now printing it.  The far end will be closed in by the lid which will have a curved shape to clear the cage.

[Gina]

The box printed fine and since then I have designed and printed the top for it.  A base isn't needed since the box fits straight onto the dovetail bar (the RPi is attached with screws from the top into the printed posts which were tapped with a thread).  A couple of little blocks glued to the wheel rings will hold the top in place that end and it's fastened to the dovetail bar at the other end.  I'll take some photos later.  It all fits nicely between cage and dovetail bar

I have received the electrolytic capacitors and the jumper leads so I should be able to proceed with the construction today.

[Gina]

#define IN1 RPI_BPLUS_GPIO_J8_29    // GPIOO5
#define IN2 RPI_BPLUS_GPIO_J8_31    // GPIO06
#define IN3 RPI_BPLUS_GPIO_J8_33    // GPIO13
#define IN4 RPI_BPLUS_GPIO_J8_37    // GPIO26

[Gina]

The Esprit 80ED + EFW mini + ASI1600MM-Cool rig control and image capture box is finished and tested and it all works.  I need to accustom myself with the new software - KStars in particular.

However, I've been doing some data processing and find I could do with more SII data for the Heart and Soul Nebulae and since they're still available at least for a few hours after dark, I would like to capture that if we get any clear nights in the next week or two.  This requires the 135mm lens so I need to get a widefield imaging rig back action.

[Gina]

The hardware is ready is ready for using the 135mm lens with the exception of the electronics board.  The box is finished and it's just a matter of adding a few components to the stripboard and making the breaks.  Shouldn't take too long

[Gina]

Gradually making progress but rather slower than I would like!  Fingers and eyesight not being what they were doesn't help!  Amazing how tedious wiring up stripboard is   Doubt I'll be ready for imaging tonight but the forecast isn't very good - though that probably means the clouds will vanish and give us a totally clear sky!!!!