Dual Speed Focuser or DC Focuser motor?

[lonebod]

I'm looking at Focuser upgrades for my Sw 200p Dob. Was wondering if should got for a dual speed Focuser, or a DC motor? Would they give similar results bearing in mind I have the stock focuser at the moment? Isothermal actually a motor upgrade for the stock motor?

G

[nightfisher]

Tempted to suggest a dual speed focuser upgrade as a dob is primarily for observing rather than imaging

[lonebod]

I was wondering is the dc motor could give the same fine control with out buying the new focuser?

[Peter Drew]

Given the same focuser I still think you can manually adjust the focus just as critically for visual use as you can with a motorfocus system. The advantage of a motor of course is that you don't have to touch the telescope.     

[ronl]

This upgrade to the stock focuser is a much cheaper way, and does the

job very well, and is easy to fit and adjust, well worth a look.

http://www.365astronomy.com/dual-speed-110-microfocus-upgrade-kit-for-skywatcher-crayford-focusers-p-2484.html

[lonebod]

Thant might just do the job. Thanks.

[lonebod]

Although.... Reading this, I kind of suggests is also does the same thing but also gives me a route to automating things which I like the idea of.....

http://www.365astronomy.com/skywatcher-electric-dualspeed-autofocuser-p-2119.html

[christhebrit]

That second link is very interesting.

Just unfortunate that it runs off a battery.

I made a battery box to run my GoTo from, along with other devices.

I might just look into a way of wiring it straight in.

[spaceboy]

I would say it depends on how close the focus is between your eyepieces. If they are parfocal then go for the auto focuser but be aware that when the motor is fitted you no longer have manual control and become reliant on the batteries being able to power the focuser. There is a mod to slow down focusing even further to allow micro adjustments.

If you have several turns of the focuser knob between eyepiece changes then I would look into replacing the whole focuser for a better one. Yes you can bolt on a 10:1 focuser knob but for £70 pound but personally I think you'd be better off just spending that little bit more on a better focuser similar to the Revelation/ GSO offerings and selling your standard focuser to re-coupe some of the additional cost.

[lonebod]

I've got the Hyperion Zoom where there is hardly anything between mags. I'm also wanting to use if to fine adjustment on prime focus ap.

[spaceboy]

Then the auto focuser seems the winner.

[Gazabone]

Personally I would go with the dual control rather than motorised on any of my scopes, but particularly if I'm using my (completely manual, non powered) Dob. I have a spare motor kit kicking around the house but regard it as just something else to hook up to a battery, another wire to keep an eye on when walking around the mount or slewing the scope and another contol box to find in the dark rather than a simple knob which is always in exactly the same place relative to the telescope. Also, the motorised version takes far longer to find focus if the scope is way out of focus to start with!!! Perhaps I'll change my mind if/when I really start getting into AP.

[ollypenrice]

Using electric focus for visual observing has always driven me to the brink of distraction. I wouldn't do it!

Olly

[lonebod]

Doing it. Loving it..... For now.

Also bought this. http://www.firstlightoptics.com/astronomy-cables-leads-accessories/hitecastro-dc-focus-controller.html

Now I can control it form my laptop along with my camera and got mount. Glad I got this rather than the dual speed focuser. The laptop control gives even finer control.

The hitecastro dc focuser also means I don't need a batter pack.

[ollypenrice]

Sorry, in your post you said this was for a Dob so I think most people assumed you were talking about visual observing. With a camera, sure, electric focus is good.

Olly