Choosing a motorised focuser

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MrAstroBen
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Joined: Fri Mar 16, 2018 12:19 pm

Choosing a motorised focuser

#1

Post by MrAstroBen »

I have picked a new to me but older Vixen ed130ss. It is light, fast at f6.6 / 860mm and has a dedicated flattener.

However the single speed focuser needs updating so i am looking at combinations for going motorised while at it. The flattener threads on via the usual Vixen M60 so any focuser needs to support this.

The baader steeldrive has been recommend and they do a motorised unit to match. Has a hand control option as well as PC which would make sense for me. Also still manual hand operation and no need to remove focuser knob (a major plus as i use the telescope for terrestrial also)

My concerns though are operation with Sharpcap and long term compatibility. Assume sharpcap sees all focusers as an Ascom device regardless of make?

But does that mean Ascom updates need to be supported by the manufacturer long term also?

Advice and recommendations appreciated

Thanks Rob
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admin
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Re: Choosing a motorised focuser

#2

Post by admin »

Hi,

SharpCap should see all ASCOM compatible focusers and allow you to use them. I use the word 'should' because sadly not all ASCOM drivers are created equal - some work nicely on all software and some are less compatible. I do my best to work around incompatibilites when I can but it is not always possible.

The biggest issue surrounding long term support for these devices has not been the ASCOM drivers themselves but the drivers for the USB-Serial adapters that are used to allow modern PCs to talk to them. There were some despicable actions taken by the manufacturers of these chipsets a few years ago that basically made it very hard to use older hardware with newer versions of Windows (you had to actually go out and look for older versions of the drivers and manually install them - the manufacturer - 'prolific' - had deliberately stopped the latest versions of the driver working with older chips in Windows 8 and avove). I would therefore suggest that a solution with a serial (RS232) connection and a separate USB-Serial adaptor would be a good choice if all else is equal - at least in that case you can replace the USB-Serial adapter cheaply in future since it is a separate part.

cheers,

Robin
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oopfan
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Re: Choosing a motorised focuser

#3

Post by oopfan »

I find it interesting how advancements in computers sometimes thwart the average guy, much like advancements in automobiles. When I was a young lad I could flip the bonnet of my '66 Triumph Spitfire MkII and literally sit on the front wheel while tinkering with the engine. Fast forward a couple decades and it is no longer true -- there is so much technology under the hood that you need $1000's of diagnostic equipment.

I came across this gem yesterday: "The USB port of the Arduino Uno can be connected to a desktop/laptop. If the connection is enumerated, i.e. the computer recognizes the device, the current supplied to the board is 500mA at 5V. If the connection is not enumerated, 100mA is supplied at 5V." USB Enumeration is the process by which the host computer identifies a device to load the appropriate driver and learns the capabilities of the device. The article went on to explain how you can force Windows to recognize the device.

That. to me, is technology working against you, not with you.

Brian
MrAstroBen
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Joined: Fri Mar 16, 2018 12:19 pm

Re: Choosing a motorised focuser

#4

Post by MrAstroBen »

Brian, afraid commercial applications like windows are more about getting a tighter grip on personal data and wallet than giving a product to serve our needs.

Robin, thanks for the information.

My requirements for a motorised focuser are.
Works well with Sharpcap.

Can be used via a hand controller when on a manual mount and no laptop. Visual for planets at hi mag.

Motor attachment that is not fragile and does not restrict finger focusing. I use the scope as a large telephoto lens for terrestrial also.

Recommendations welcome. Lakeside etc?
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