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Well as long as you two are happy that's really all that matters. The rest of us will muddle thru although I have few wants in regards to my equipment. Getting the observatory finished with chart racks and corner storage etc. Motorization of the roof etc. New painting and CD changer and wired for XM radio etc. Mike

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Shut..p maan.... Your OB is as sweet as it gets........now it's got a motorized roof....

I'm green.....

Rob

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That's a big mount Rob! Lookin good as far as I can tell. Though that is hardly an endorsement since I'm ignorant of mechanical stuff and easily impressed (grin).

There was earlier discussion of ball bearings for big mounts. Not exactly new tech, but of course brass bearings have served well even longer, at least since the age of steam.

Since I don't know nothin about the topic and would like to learn... Am curious what factors made you decide to use brass bearings with grease fittings, rather than ball bearings? Seems either would work fine. Just curious about design reasoning in this application.

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Well several reasons. One reason is I can get more surface area contact with brass/bronze bearings. If machined to very fine tolerances...these bearings work exceptionally well. Second...Roller bearings require you to engineer the mount a bit bigger to accomodate the bearing outer dimeter.

Ball bearings are best for axis that are moving at speed, and when low friction is paramount. In my application, brass bearings are the ticket. And I am making the top bearing part of the *housing* and can use the mass of the bearing structure to be *part* of the upper support.

Lastly...this is for a mount generally designed and intended for visual use. Still the tolerances are close, and movement will be smooth and slop free.

I hope there will be enough room for greese......

OH...and it was the *easiest* to machine.

Rob(I am not a skilled machinist)

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What mill/lathe is that, and can I ask how much it cost you? How do you like it?

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I believe it is from Central Machining. It's an older model that was liquidated. It went for around $700...I got this one for $500. It does everything I want it to do, and it is precise enough to do the job well. I love the combo set-up. I have a small shop so it fits my needs well.

Rob

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Providing a great place for amateur astronomers, and ATM's to come and enjoy their hobby.

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Rob, will yours do threading?

I was looking at a similar medium-sized combo at a good enough price at Harbor Freight, pretty good swing and length, but that particular item didn't have threading capability. Of course having enough skill to make accurate matching threads at arbitrary size is another issue altogether (grin).

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Actually I never thought about that issue. It does have a pass through of 7/8"..but I am sure you could do it.

There are accessories for that application. Personally I won't be making threaded things this way.

The current HF models don't looks as *hefty* as this model...so I don't know their capability.

As for my uses it is a great machine. For the money.

Rob

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www.goldmtobservingcenter.com
Providing a great place for amateur astronomers, and ATM's to come and enjoy their hobby.

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Lookin good! That's awfully big. Impressive.

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Well it is for a 13"-15" Haven't decided..... Newt.

I try not to throw anything away.....So I use what I have.

Thanks for looking in on my project...

Rob

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Providing a great place for amateur astronomers, and ATM's to come and enjoy their hobby.

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Ha Rob, Looking really nice. I like the feature of being able to swivel the column around a bit to align to north precicely...

Great us of old iron

What kind of gears are you using for the drive? Teeth look beefy...

Keep the pictures coming.

Regards,

Preston

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The drive gears are some old ones I had off an old mount. the ring gear is 4". I wanted to use larger 7" Beyer's but found these to be adequate for the job. Plus I had them already. No money spent..

I'm scrounging up the metal for the fork now.

I have to machine a few nylon washers too, and then get to work on the Newt going on this mount.

Rob

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www.goldmtobservingcenter.com
Providing a great place for amateur astronomers, and ATM's to come and enjoy their hobby.

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