Gina

Thank you Wim

With little chance of dark side imaging for the next few days, I've decided to install the solar scope on my EQ8 in the observatory. This has several advantages over an open setup on some sort of tripod. Not only is the mounting really solid and stable but all the tracking, power and other facilities are there. I just need to sort out the dovetail arrangements. The forecast is for sunny spells today - I wonder Currently the sun is out but the sky is hazy with loads of contrails. Still quite low as yet, of course.

The thoughts that result in this are from the thread Ideas for a BIGGER 3D Printer. This may be referred to until I copy relevant parts from there to this blog.

Following on from my abandoned original Giant printer project, this uses the same size printing platform of 400mm square but a much smaller frame. The build height will be around 500mm. It will use the Core-XY drive principle for the X and Y axes and the print bed will be raised and lowered to provide the Z axis.

YIPPEE!! I've seen my first ever prom Quite small but also quite distinctive Sun spots were easier to see. The sun appeared in a small gap in the clouds for a few minutes. I think that's it for today - more cloud and the sun is about to set behind a tree. A few things are clear from this first observation. The mount support is insufficiently rigid for this focal length and image magnification, and the focussing is rather critical. I am not surprised at either of these - the pillar mount is really only suitable for widefield imaging. This ground location is also not ideal - it's too near the fence - the view of the sun will be quite adequate further back and this pier will revert to widefield DSO imaging use. As expected the eyepiece needs a hood to keep the light out. The magnification isn't too bad at 24mm focal length though 40mm would show more of the sun's disc. I shall need to think about a much more rigid pier - either put the telescope on my main concrete pier in the observatory and EQ8 mount or provide a new platform outside the observatory. There is not really a great need for a full observatory for solar observing and some sort of roll off shed or cover would do.

Should have eyepieces but can only find one ATM and that is a 2" fit 8-24mm Baader zoom. It had various adapters and could be attached to a 1.25" scope like the Coronado but I've mislaid the other bits. So I'm 3D printing an adapter. I've also ordered a 40mm Plossl from FLO as this is the recommended eyepiece.

I had originally intended my Skywatcher Pillar Mount for use with my widefield NB DSO imaging rig but want to try out the Ha solar telescope ASAP. The dovetail on the solar scope won't fit the EQ8 but the NEQ6 takes both sizes. I haven't got a spare 75mm dovetail bar for the EQ8. Progress so far has been to put the NEQ6 onto the pillar and then the solar scope on the NEQ6. I have added the Coronado with diagonal etc. but not yet sorted out an eyepiece, Here is a photo of the present setup.

Thank you Already modded and ready to go. Just been setting it up. I can add that this Ha solar telescope was developed and produced by Peter Drew and he deserves the credit plus my thanks

I have just acquired an Ha Solar telescope consisting of an Antares 127mm 1200mm FL telescope with Coronado PST. I plan to set this up for both observing and imaging. I have yet to decide on the final mounting for this but will start with a Skywatcher Pillar Mount with an NEQ6 SynScan Pro mount for testing as I want to reserve my EQ8 and main observatory for DSO imaging.

This thread has become relevant again as I hope to get my enthusiasm for astro imaging back following treatment for a health problem. The problem that arises though is that I seem to be short of observatory facilities for all the different imaging rigs I have and which I would like to use. I'm now trying to find where I had got to with my various imaging rig projects and see which might be viable. I have just added another in the form of a rather large Ha solar telescope which has similar dimensions and weight to my MN190 Mak-Newt and will need the EQ8. I currently have my Esprit imaging rig on the EQ8 and the solar scope sitting on the arms of my warm room chair. Of course, I want to set up for solar so the Esprit will need moving. I have a micro observatory on the books which will take my widefield rig using vintage SLR camera lenses but isn't big enough to accommodate the Esprit. So what I really want is another observatory (or something) to take the Esprit imaging rig probably mounted on an NEQ6. Having two piers in my main observatory would have been ideal but unfortunately I didn't design it that way!

As I've posted in other threads, I'm looking into getting back into astro imaging and trying to sort out where I'd got to since it's been quite a while since I've done anything in this line. Looks like I shall be needing this mount and its associated dome enclosure for widefield imaging as the EQ8 may be taken over by an Ha solar telescope of similar size and weight to my MN190. Following on from a suggestion by Ant, I have been using blogs for some of my projects and I think these are more suitable for projects where the input is more from the OP than replies by others. In other words, where a project is pretty much already designed and not really needing suggestions from other members. So my plan now is to post ideas and requests for suggestions and advice in the forums and use blogs where the project is either well under way or already completed.

The heater should give you a quick warm-up I find a 300W 24v heater on my Titan 300mm square bed takes about 3-4m to heat from 20°C to 100°C. I have a 1200W 220v Lenovo heater for my 400mm square bed which I'm looking forward to trying in my bigger than BIG 3D printer under construction I think I may re-adopt the name Giant for this over 400mm cube build volume printer as it will be using many of the parts I bought and made for my original and abandoned, Giant printer project.

The other parts have arrived and I have finished assembling the frame. Another small advance ATM I'm just doing little bits to several projects.

Printing drum axle brackets.

The picture frame arrived this afternoon so maybe tomorrow I'll sort out the box. Having gone this far with the mechanical parts I think I may as well stick with it - I seem to have a bit of a habit of changing my mind and scrapping many hours of work!

To use this mechanical perpetual calendar as the project stands would not need a Real Time Clock, just a source of good timekeeping such as the 50Hz mains frequency. This would simply need counting for 50x60x60x24 to produce action every 24 hours. The action would consist of creating sufficient stepper motor steps to rotate the cams one revolution. The 50Hz input would use interrupts to avoid the stepper code from causing missed counts from the 50Hz. Of course, the Arduino sketch would need synchronising with real time so that the calendar advance occurs at midnight. A simple push button pressed just once at midnight one day could do this.

I guess it's time I described how the 31 days is converted into the day-of-month in terms of two decimal digits and how the weekday and month are driven The basic principle uses gears with missing teeth where no motion is to be transferred to a pinion on the drum. eg. for the units the counting is one-to-one until we get to the end of the month at day 31 and the units show "1" but the next position corresponds to the first day of the next month so instead of going from "1" to "2" it needs to stay at "1" so the tooth that would turn the pinion is missed out and the units drum stays showing "1". For the tens digit of the day-of-month, the drum wants to show zero or a space until the day reaches 10 when the tens digit wants advancing to show a "1". So no teeth for 1-9 then a tooth at 10 turns the tens drum one digit. From 11-19, again the drum must stay at "1" but a tooth at 20 moves it on to display "2". Same again from 21-29, no teeth, but one at 30 to move the drum on to show "3". Finally, when the date goes from 31 to 1 the tens drum needs moving onwards to show "0" or a space so here we have a tooth. To advance the month, one single tooth where the date goes from 31 to 1 engages with a pinion on the month drum to advance it to the next month. The months drum pinion has 12 teeth for the 12 months in the year. The units of date has 10 teeth (no surprise there) but the tens doesn't have 4, it has 8 because a 4 tooth pinion would not work - the tens drum has two sets of 0123 and 8 positions. The day-of week drum has a ratchet with 7 teeth. Here's a collection of photos and diagrams that show the principle and test rigs. These also show that where no teeth are required the "gear" can be reduced to just what's needed to carry the wanted teeth.

To go off at a bit of a tangent, I've been thinking of much easier alternatives, interesting though this purely mechanical perpetual calendar might be. The original thinking was as part of a mechanical clock with the only modern workings being auto-winding. In that aspect this made perfect sense. But if I'm driving the calendar off an RTC with all its facilities, maybe it's daft to just use the change of date to trigger the mechanism. All the "clever stuff" of differing numbers of days in months could be handled in code quite easily. I could make the mechanical perpetual calendar part of another clock project with just the simplest electronics. For example, the 50Hz mains frequency could be used to time an Arduino which would then drive a stepper motor at a constant speed. Since the mains supply is maintained to the accuracy of an atomic clock over a 24hr period the clock would keep perfect time - even better than using an RTC or quartz crystal. It would be possible to make maximum use of an RTC and reduce the mechanical parts to a minimum even with a mechanical display. The reason for wanting a mechanical display is to provide a large and easily seen display under all normal lighting conditions from full sunlight to electric light in the evening. The best/easiest way of doing this seems to be to use drums with numbers and letters glued on. In the past I have investigated and experimented with various types of display and the drum approach won out. The minimal mechanical approach would be to use stepper motors to drive each drum, which means four of them. Next would probably be to use the layshaft as in this project but driven directly (through gearing) by a single stepper motor, plus another for the day-of-week. This relies on the special type gears used to turn the drums correctly. I shall explain this shortly as I realise I have not done so yet. The layshaft gearing has 31 teeth per revolution and is simply advanced one tooth at each midnight, except at the end of the month when it needs to be moved on extra notches for all months without 31 days.

The end-of-month pawl (purple) wants a better shaped tip to fit the tooth.

More parts mounted and the opportunity to test the date advance. Note - there is some distortion due to wide angle lens.

Some of the parts mounted on an acrylic sheet. The combined hanging levers as springs may not work. The main date drive bar one certainly doesn't work - there's far too much movement for that length. The month drive one might work but I'm not at that stage yet.

This is as far as I could go without being able to mount things and check for clashes.

There's been a delay in the delivery of the picture frame and until I get it I can't establish the exact dimensions of the box sides or back so since I think I currently have more chance of success in proceeding with this project than with the longcase clock and I want a working calendar to use, I shall make use of the old acrylic sheets and the framework to further this project at the expense of the longcase clock. I already have my moon globe clock so the longcase can wait. I think I've gone as far as I can without fastening things to a solid base and using bolts to carry wheels etc.

Latest photo of the parts I've designed and printed so far (not including the display drums). It's not an easy project but I'm gradually getting there

Here's a new calendar diagram showing the cams and link bars etc. The months advance bar will cross in front of the date wheel ending in a pawl to drive the months wheel and a hanger link. I may make the latter a spring rather than a free rotating lever.