10" Newt to Dob Base

[MarkAR]

Whilst I have my imaging mount running my 250P-ds is sitting there redundant. So I thought I'd have a go at building a Dob mount for it and hopefully motorise and add goto eventually.

 

Here's my initial sketch with the bearings running on the sides. 

I wasn't too happy with the drag factor and possible misalignment causing issues so decided on using ball bearings.

 

The second iteration makes it easier to add a worm and wheel to the spindle and the ball bearings can be adjusted for alignment.

 

The final iteration adds some amount of lightness.

 

I'll be making this from acetal sheet with aluminium cross bars.

Base/Azimuth is 550mm diameter x 8mm thick, sides 360mm x 700mm x 10mm.

I should be able to take out some more material from the base depending on where the motor, worm gear and lazy susan bearing fit.

 

[Gina]

Looks good Mark.  👍👍

[MarkAR]

Thanks Gina.

[MarkAR]

Made a start at the weekend, so far I've:

 

1. replaced the dovetail with a 40 x 10mm aluminium bar (plus one the other side)

2. added 20mm stainless axle bars

3. mounted the altitude bearing wheels

 

 

[MarkAR]

Quick vid of skimming the altitude bearings.

[MarkAR]

Next up was gashing the worm wheels. Set up an indexing head on my engraving machine to gash 360 grooves for the tap to sync to.

[MarkAR]

Then on to hobbing the teeth.

[MarkAR]

Using 30mm aluminium for the cross bars, all cut to within 0.01mm in length.

Power tapped ends  M10.

[MarkAR]

Used a router to cut out the side panels.

[MarkAR]

Azimuth base all drilled and used a router to make it round. Just need to do the centre hole 30mm.

[MarkAR]

Made a lot of progress in the last week or so.

 

Used a template to route out for the 30mm spindle and a trial fit of the lazy susan bearing.

Also did a quick test assembly, this proved a little too wobbly with just the aluminium bars so has a rethink.

 

 

[MarkAR]

Decided to add some lightness to the parts.

[MarkAR]

Threaded the spindle M30x1.5mm and made a nut, the centre is M12 for a 20mm extension for the azimuth worm gear

[MarkAR]

Two extra sheets arrived for the from and rear panels.

Added bearings for the altitude wheels to ride on as well. 

[paul]

That's an impressive transformation, thanks for sharing your processes.

(I'm totally envying that workshop too👍)

[Marmot]

Whatever you do for a living, you’re in the wrong trade.......you should be building telescopes for a living!

you have created a quality item.