New Base finished

spudrick · #1 14-01-2007, 10:21 AM

For a while i have been thinking to replace the pretty ordinary chipboard base on my 12" GSO. After reading up on the "Push-To" system using large diameter setting circle on the base and a inclinometer on the tube i decided to try it and make the new base at the same time.
I adjusted the size of the setting circle to be 61cm diameter and got it printed and laminated.
I used a sheet of 18mm plywood and used the mount as a template, i also modified the base from the triangle ground board to 2 circles like the Skywatcher which suits the setting circle placement better.
Having not had experience with a router to cut out large (63cm) circles before it was probably the hardest part of the job. I made an adjustable guide for the router and to my surprise it worked really well.
I added a full circle of laminex to the base and fitted new thicker Teflon bearings. I aslo added side braces for strength. I changed the handle to a aluminium one and painted the side hardware silver. For the setting circle i cut a semi-circle out of the top board to see the scale. I made screw adjustable feet and inserted a bubble level into the base.
For the Inclinometer i made a timber dovetail and fitted it to the finderscope base.
As my scope was the standard model i also updated it by fitting a fan and added Bob`s Knobs.
By doing this i have found it is easy to make a lot of mistakes timber is not very forgiving but i am happy with the finished job now i just need to test the working of the "Push-To"

Shawn · #2 14-01-2007, 10:24 AM

Exceptional Carpentry Skills, Very nice

Good Work

Shawn

...

Astroman (Andrew Wall) · #3 14-01-2007, 10:51 AM

Nice one Terry, a work of art. Where do I get one of those digital protractors

Starkler (Geoff) · #4 14-01-2007, 12:11 PM

Really nice, and how all gso dob bases should be made

I would be interested to know if the plywood version is lighter or heavier, and if those side ribs have added much to the rigidity of the base.
I really notice with my scope a bit of flexure in the base in the azimuth plane.

rmcpb (Rob) · #5 16-01-2007, 04:19 PM

Great looking job, its how they all should come from the factory but then we would have to pay more and not be personalised.

Where did you get the digital protractor??

cristian abarca · #6 16-01-2007, 05:05 PM

They are not cheap Rob about $US90 plus delivery

Regards cristian

jjjnettie (Jeanette) · #7 16-01-2007, 05:30 PM

That looks really good Terry. How will you finish it? Paint or varnish?
I really like the idea of the digital protractor. How easy is it to read at night?

spudrick · #8 16-01-2007, 07:07 PM

Thanks guys the base is much better than the Factory issue but as has been pointed out we all want to keep the costs down.
The mount is not really as nice as yours Rob

but i have a another project to start, it will be a Truss dob (small one) hopefully i can make it better.
jjjnettie the plywood is just finished in 3 Clear coats and i am just now making Red LED for the base scale and the inclinometer to read at night (had to find out about resistors and things

)
Geoff the base is quite a bit lighter but pretty strong i joined the panels with Dowels, Glue and screws. The side braces hold the rear section to the base and provide good anti-flexing at the top.
I picked up the Digital Inclinometer while in China in December it was US$40

spudrick · #9 22-01-2007, 08:24 PM

OK ready to light it up...
Finally got around to working out resistor values for LED`s. I wanted to keep the light as close to the scale as possible and so by using the plastic handle that was supplied with the old base i could see that the handle had a natural 45 degree shape, so i drilled a hole from the inner part of the handle just big enough to have the dome of the LED poke through and a larger hole almost all the way down to allow the LED to full seat in the hole. I then drilled a hole parallel to the bolt hole to tread the wires through to the inside of the box. I wire it to a 12V DC socket and you can see from the photo its right on target.

chunkylad (David) · #10 01-02-2007, 08:38 AM

Great Job!

I like your innovative approach. Well done!

Dave W

stephenmcnelley · #11 01-02-2007, 10:13 AM

Nice terry, a million times better than the old base i am sure, with a good stable base diameter too.
Looks sweet!

I found the stock GSO fan to be very qiuet, one night i left it going after a quick unsuccessfull session, only to find the battery flat next day. An inline flashing red led from DSE mounted to the fan housing cured the risk of not noticing the fan still running.