Bolt On Generic Electric focuser ?

[TechnoBill]

Hi All,
I have been searching but cant seem to find what I thought would be relatively common given how clever amateurs are at making inexpensive but useful things.

Thanks to a new part manufactured by one of the local members of the local astronomy club, I now have everything working together on my Eon 110 F/6 refractor. The Adaptive optics, with the Flattener/reducer and the QSI583wsg. I can now get it all into focus, so I am really happy on that point. Thanks Les.

The last thing I want to achieve is adding some sort of electric focuser (without replacing the excellent rack and pinion focuser that is already on the scope).

I am sure I have seen somewhere, electric focusers that bolt or clamp on to an existing focuser and attach to the fine focus knob either by belt or some other means? But I cant seem to find any now that I want one :confused2:.

Is someone able to point me in the right direction?
I could probably make one myself as I have a 3D Printer and have a basic understanding of Arduino's but I am sure simple ones exist.

Thanks
TechnoBill

[wasyoungonce]

I'd recommend a Sharpsky Pro unit ( (http://www.iceinspace.com.au/forum/showthread.php?t=112059&highlight=sharpsky)also with inbuilt dew controller) based on PIC controller. Works a treat and is fully ASCOM compliant or use standalone software. If you didn't want that then maybe the earlier version of sharpsky focuser (http://www.iceinspace.com.au/forum/showthread.php?t=91023&highlight=sharpsky). A neat small package PIC controller also fully ASCOM compliant.

[raymo]

Have a look at the Skywatcher one that is in the Bintel online
catalogue. It comes with two different mounting brackets, and has a flexible coupling should it be needed.[my scope didn't need it]. I would think if neither bracket was right for your focuser, it wouldn't be hard to make one. Incidentally, it connects
directly to the focuser's shaft, not to a knob. Anyway, worth a look at $89.95 + postage. I have no connection to Bintel.
raymo

[Nico13]

Hi Bill,
I'm in the middle of putting an ASCOM complient ARDUINO unit together at the moment using an ARDUINO UNO board and Easydriver stepper driver board.
Look at "SGL Observatory Automation" on Yahoo groups as they have the Sketch for the Arduino and also the ASCOM links as well as a stand alone gui which is good.
You will have to join the group to get it though.
Hope this helps.

[Merlin66]

I use the SW electronic motor on my TS102.
A small toothed pulley fitted to the motor shaft and the toothed belt just runs on the 10:1 knob.
I used the SW mounting plates with a 6mm spacer.
Photos available if needed.
(I can control it from the laptop via the Shoestring FCUSB...majic!)
http://www.store.shoestringastronomy.com/index.htm

[TechnoBill]

Thanks everyone,
For now I have decided to go with the sky watcher one as it is in stock and I can pick it up from the store.

After watching some vids, it does not look like it would be too difficult to adapt it to my Eon 110 focuser if it does not fit out of the box. I am into 3D printing so I can print my own couplers and/or stand off brackets if necessary to get it in the right spot.

Not having seen one yet, I dont think it will work on the 10:1 side though. I assume I will have to fit it on the opposite side. Not knowing how the 10 to 1 works inside the focuser.

Thanks Again.
I will let people know how it goes.
Bill D

[raymo]

Hi again Bill. I think you could make the SW one work on the 10:1 side,
but You probably don't need to, as quick taps on the button move the
focuser a very tiny amount; also, even at maximum speed, the focuser
movement would be too slow, and would become frustrating.
raymo

[TechnoBill]

Thanks Raymo
I will report back once I have it installed or attempted to :P

Bill D

[TechnoBill]

Well,
I managed to install the Sky Watcher focuser on the Orion Eon 110 with some work. As expected, the included brackets were not compatible with the Eon's focuser. However, I was able to design an alternate custom made one and print it out on my 3D printer. After fitting it and testing it, I then realised that the Scope will no longer fit in the case with this electric focuser mounted. So back to the drawing board (CAD Program) and I redesigned it so it is a removable system.
I can now attach the focuser when required and remove it at the end of the night for storage in the case.

I have to say, that the SW Electric focuser on just copes when I have all my gear on the scope and pointing straight up. I will have to find out whether the motor can work on 12V rather than 9V. Maybe that will give it a little more torque. Otherwise I might have to upgrade to the Arduino version suggested by Nico13

TechnoBill

[raymo]

Sorry about the lack of torque. Mine lifts my DSLR set up for EP projection, so I'm guessing your setup is heavier.
raymo

[TechnoBill]

Not to worry yet. its coping. Just surprised me a little when at first it could not lift the gear I reduced the tension on the focuser as now the electric motor can apply resistance and that seems to have helped. I just wish the clouds would clear so I can play some more instead of spending money hehe.. I just added the shoestring FCUSB controller so I can control the focuser from the PC.


TechnoBill

[raymo]

Sorry about the tardiness. The motor seems to exert significant
resistance, so I have almost completely slackened off the tensioner. The motor holds the focuser still until I've nipped up the focuser lock. This,
I hope will make sure that the motor has a long happy life, and maybe the batteries will last a bit longer. Actually I was wondering how long I can expect to get out of the battery.
raymo

[TechnoBill]

Hi Raymo,
No worries in regards to the tardiness. I have lots going on too (non astronomy related) so I forget to check forums regularly.
However I have been playing around with controlling the focuser through the PC using the shoestring focus controller to drive it.
It works quite well but the software is pretty ordinary. I have been searching and trying different software. Focus max is my preference as it supports backlash compensation, but its manual focus controls are primitive. I considered writing my own software for the Shoestring controller, but I have not found any info on how to interface to it.

Bill D

[raymo]

I haven't thought about PC controlling mine. I just have the hand
controller sitting on the table alongside my laptop. Mine was faulty, so
I had to return it, and am awaiting it's replacement. There was current flowing all the time, so it flattened the battery in 4 hrs.
Glad yours seems to be o.k.
raymo

[TechnoBill]

Hmm Interesting my battery was flat the next morning even if the cables were unplugged from the Controller, which is one of the reasons I switched to the shoestring, at least it gets power from the USB so no battery. Maybe that problem is a common fault.

Bill D

[Terry B]

For comparison, I have had one of these focusers on my scope for many years and have never changed the battery.
Terry

[TechnoBill]

Thanks for the info Terry. It does not worry me much as I wont be using it now that I have the shoestring but it is interesting to note that this fault exists for others that may find battery life forbiddingly short if they have a faulty one like me.

Bill D

[TechnoBill]

Hi Nico13,
Thanks for pointing me in the right direction. I joined the group an using the software there I now have an Arduino Controlled stepper based focuser working through Ascom. Much more torque and it is strong enough to lock the scopes focuser in place with all my gear on it.:thumbsup:

TechnoBill

[raymo]

Continuing the saga of my battery eating focuser: I put my meter on mine, and it showed a small current flow all the time the battery was
installed. Disconnecting the cable to the motor made no difference, so the problem was in the hand controller. The retailer replaced it, but said that
they could find no fault with it. The second one did the same thing, but the current flow was smaller, so it took a bit longer to eat the battery.
Not wanting to spend even more on postage, and possibly get a third
faulty one, [assuming that the retailer would send another one, that is],
I installed an on/off rocker switch into the circuit, and placed it to the
left of the speed control knob where it is easily operated by my thumb.
I know that the retailer doubted me, and said he had sold many of them
without any complaint, so I'm glad [from my point of view] someone
else has had the same problem. Anyway, problem solved, but SW need
to fix this fault.
You should see if you can return yours Technobill.
raymo

[Eden]

Hi Raymo,

I purchased one of these a few months ago and fitted it to my Skywatcher Black Diamond 120 refractor.

I have exactly the same problem with the supplied hand controller in that it drains the battery even when it is not plugged in to the motor. To make matters worse, the 9V battery connector inside the controller is reluctant...putting it lightly...to come away from the battery when it comes time to change it. I ended up getting a Shoestring FCUSB controller and ran it from that instead.

I am not familiar with the mechanics of your focuser, but the first time I fitted this motor to my scope I ran into a few issues but some of them are related to the focuser on my particular OTA. The motor provides plenty of torque and with some modifications to my focuser I was able to get it to lift a couple of kilograms worth of equipment. The trick was getting the roller-to-drawtube tension so that the load did not cause the drawtube to slip but not overly tight to the point where the motor could not turn the roller.

In any case, I could not find a suitable configuration that would allow the motor to operate at anything less than half of it's full-speed RPM.

[raymo]

Hi Brett; I was wondering if there were any more people out there
other than Technobill that have this problem. Putting the switch into the circuit fixed the problem, and the rechargeable 9v battery I put in it is still
going strong some months later. I might call Bintel and have another word with them on the subject. No problems fitting mine to the scope,
done in 15 mins. They said they could find nothing wrong with mine when
I returned it, but they sent me another one eventually, and that had the same fault. I didn't think they would be happy to send me a third one, so
put the switch in it.
Happy focusing
raymo