ATM dob mount for newtonian tube

Wanna make a scope? Or better still, grind a mirror yourself. Or, you have some good tips in making a really useful accessory? This is the place to show what your hands can do...
Post Reply
User avatar
Kamikazer
Posts: 131
Joined: Wed Oct 08, 2003 3:35 pm
Location: Hinamizawa

ATM dob mount for newtonian tube

Post by Kamikazer »

Hi guys,

We are making a dob mount for an intes MN61 and i need advice about on construction

The scope weighs 9kg...With accessories should be about 10kg
How thick should my plywood be?
Is number of plys very important?

--------------------------------------------------------------------------------------

Altitude bearings:

Material: teflon pads and ??? aluminium ???

Diameter of bearing?
Larger bearings should give better control but it may add bulk.

Angular separation between bearing surfaces?
Larger angular separation should cause the weight of the scope to exert a larger natural "clamping force" or friction.
Too small and the scope might tilt when changing eyepieces, etc.

--------------------------------------------------------------------------------------

Azimuth bearing:

Material: a suitable pair is teflon and plastic laminate (from what i read)

Diameter of bearing? The larger it is, the more stable. but can add bulk also.

--------------------------------------------------------------------------------------

And also...
Where do i buy plywood, teflon pads and plastic laminate?

Thank you
K.L. Lee
User avatar
chrisyeo
Posts: 1186
Joined: Wed Oct 08, 2003 9:11 pm

Post by chrisyeo »

Hi Kun Loong,

May I know which club is building this? :)

I think there are too many questions here... Have you all decided on which plans you all are going to use for the mount yet? There are many plans on the internet and they will guide you to what materials and substitutes you can use for a dob mount.

For a start, furnitute slides and vinyl discs make viable substitutes for teflon pads and plastic laminate. Plywood can be cut and bought from woodworking shops found in the yellow pages. You can get a good deal if you call and ask around.

Cheers,
Chris
Traveler
Posts: 291
Joined: Sun Oct 12, 2003 2:20 pm

Post by Traveler »

Hi, perhaps you could give the diameter of the tube too? And since it's a mak-newt, i suppose most of the weight is distributed evenly and not at the rear of the OTA?

You can try borrowing this book from most libraries:
Making and Enjoying Telescopes by Robert Miller and Kenneth Wilson
http://www.amazon.com/Making-Enjoying-T ... 0806912782
There're a couple of dobsonian projects listed in the book so u can get some ideas from there.

I'm sure there're a couple of ATM gurus out here. Hope to get some advice from you :)


Cheers
User avatar
Kamikazer
Posts: 131
Joined: Wed Oct 08, 2003 3:35 pm
Location: Hinamizawa

Post by Kamikazer »

hi, chris,
SP astronomers are building them.

sometimes the internet is quite useless.
it is very easy to find specific plans and designs but nothing general, which is what we need.

i will post a drawing of our preliminary design as soon as we can so you guys can give feedback on it.

thanks
K.L. Lee
User avatar
chrisyeo
Posts: 1186
Joined: Wed Oct 08, 2003 9:11 pm

Post by chrisyeo »

The San Francisco Sidewalk Astronomers have good plans and explanations on materials, tools, sources, etc. I found them quite helpful:
http://members.aol.com/sfsidewalk/cdobplans.htm

Cheers,
Chris
User avatar
Kamikazer
Posts: 131
Joined: Wed Oct 08, 2003 3:35 pm
Location: Hinamizawa

Post by Kamikazer »

hi,
thanks for the link.

i came up with something like this:
Image
and this:
Image

Next is to source for material and refine to design for easy fabrication.
K.L. Lee
Post Reply