Gina

The fork.

I have a 10mm steel rod that came out of a 3D printer that would be suitable as an RA axle. The Dec axle is simply cylindrical ends to the 3D printed clamp for the cameras.

The axle is 1" OD in that version. I already have a selection of ball bearings much smaller than those huge pillow block ones and I'm planning to use these smaller/lighter ones - they are quite adequate for the payload of the dual widefield imaging rig. I can design a 3D printed carrier which I think will be quite adequate. Thanks for the link.

Here is an initial design for the camera clamp and Dec rotation wheel for use with the fork mount. A hole through the clamp between the cameras will take a bolt and nut to clamp the cameras. The camera holes are just a clearance fit on the body of the cameras. The end parts will go into ball bearings housed in the ends of the fork of the fork mount. I've shown a complete disc for the Dec wheel but the Dec axis will only move a maximum of 129° - from Polaris to the southern horizon. Dec drive will be by either a belt or friction drive. With good polar alignment the Dec axis would only be used for pointing the rig at the start of an imaging run. All movement would be in the RA axis as this is an equatorial mount.

Collected together the metal parts of the fork mount and they weigh over 8Kg. For a payload of around 4-5Kg this seems OTT. And this is not including some of the heavy aluminium plates or the fork itself. It's mainly the pillow block ball bearings. I think this mount would be more suitable for the Esprit 80ED scope. OTOH I guess it could do for both the Esprit scope and widefield rig.

My warm room is far larger than I need or even want. In fact I'm considering converting it to a summerhouse, making it dual purpose ? When I built the observatory several years ago many things were different. Nowadays, I control everything (except the roof) from indoors and the astro control has gone from desktop PC to laptop and now to Raspberry Pi on the pier. Only the main power supply and backup battery remain in the warm room and they could be moved to the scope room if I wanted - onto a shelf. ATM the warm room is just another place to collect rubbish ?

Good luck James ? I thought my observatory site was steep but yours is worse! Mine is much the same size though the warm room takes more of the area. Mine is also on 6 concrete blocks. With hindsight (wonderful thing!) I should have built my scope room bigger with two piers (or more). Swapping heavy scopes is a nuisance. But my widefield imaging is moving outside the main observatory onto a Skywatcher Pillar Mount with DIY fork mount and DIY 3D printed mini dome. So I too am building a new observatory but on a tiny scale ?

Sorry, I missed this before. You already know from our conversations but for the benefit of others, it's SketchUp Make 2018. This is the "free for personal use" version of the software.

It was going fine well past halfway and getting very late so I went to bed and left it running as I often do. This is not supposed to happen (the mess on the narrow part) ??

I think I shall be combining the micro dome (or it might be a clamshell) and DIY fork mount with this thread as I think the entire dual widefield imaging rig would be best combined into one blog.

With medical problems out of the way and now having my "GinaRep Giant Mk2 3D Printer" virtually finished and working pretty well I am now looking at getting back to sorting out a dual widefield imaging system. The bigger 3D printer means I can design and build a bigger micro dome capable of accommodating a larger imaging rig (well that's what I'm hoping). This dual rig will go on my DIY fork mount on my second pier - Skywatcher Pillar Mount. The EQ8 in my main observatory will be used for telescopes only.

Resurrecting this thread because I now have my "GinaRep Giant Mk2 3D Printer" virtually finished and working pretty well so planning a bigger micro dome maybe to take a dual widefield imaging rig as I have the equipment for that so should use it ? A dual rig will weigh nearly twice as much as a single rig so I may stick to aluminium for this mount for the weight carrying parts. They're already made too. I may get back to astro imaging again yet!! ?

That print came off the bed at around 40mm. So I've added some ABS slurry to the aluminium bed and kept the bed at 120°C. I also opened a sealed bag of unbranded ABS filament so no chance of moisture absorption and so perfectly dry filament. This print has now reached 70mm without failing.

Now attempting to print with some very cheap ABS that I've had in stock for several years. 25mm/s and hotend at 320°C to melt fast extruding filament. Print bed at 120°C for first layer then 110°C. Bed heater will also heat cabinet to help with warping. With higher temperature and slightly lower speed I'm hoping this print run will work. Layer height is 1mm with the 2mm nozzle. Extrusion multiplier at 1.3 and extrusion width set at 2mm. That should help with inter layer adhesion.

This will do.

Strangely the bed level has gone way off now whereas last time it didn't make much difference. Bed temperature of 110°C. Of course calibration needs to be done at working temperature rather than cold so I'll adjust it to give the automatic compensation less to do.

Duet WiFi board is fine :) Changed some wiring to add more tolerance and shortened some wires where excess length was catching up. XYZ moves now working properly. I'm now going to try a print run with ABS - the large trumpet shape but taller. With the new bed supports it needed re-levelling and here is the cold bed automatic calibration results.

Just done a quick test by moving the working motor connector to the other driver and the motor drivers are working - PHEW - looks like the £150 worth of board is alright.

Found a wire broken on one of the connectors. That would certainly stop the motor working, just hope it hasn't caused the driver to fail

If it's not one thing it's another - means leave it - tomorrow is another day!!

Now I have another problem - the Duet WiFi control board is reporting :- I'll look into that tomorrow in daylight - I can't see anything wrong ATM. 

I've given up on brackets for now and added 40mm M5 screws in each of the four corners of the aluminium bed plate to space it away from the sheet of OSB I'm using as a base.

I have a problem with the supports for the print bed when set at 120°C for printing ABS - they're softening and the bed is sinking I used PETG and that doesn't take the temperature. I'll try ABS or maybe Nylon

Fume duct from other side.

The finished ABS trumpet and new fume vent duct with fittings and hole in the wall into the broom cupboard in the kitchen.