Coupling the SharpSky motor, or any other motor, depends on several factors. Obviously, the scope focuser design and how handy you happen to be mechanically. If you are considering the upgrade but not too sure about the mechanical aspects I can send you a SharpSky bracket as fitted to the motor.
The bracket is adjustable length ways so once a suitable mounting point has been identified aligning the motor drive with the respective focuser drive shaft should prove relatively straight forward.
Looking at your focuser you appear to have a couple of mounting screw points either side of the knurled lock/tension adjustment. You also have a large flat surface (the blue face) which could be used as a fixing point.
If you would like a bracket in the flesh, so to speak, please let me know
Shaft diameter :
If you let me know the diameter of the focuser drive shaft I can customize the flexible aluminium coupler to any shaft
size equal to or in excess of 3mm.
Coupling the SharpSky motor, or any other motor, depends on several factors. Obviously, the scope focuser design and how handy you happen to be mechanically. If you are considering the upgrade but not too sure about the mechanical aspects I can send you a SharpSky bracket as fitted to the motor.
The bracket is adjustable length ways so once a suitable mounting point has been identified aligning the motor drive with the respective focuser drive shaft should prove relatively straight forward.
Looking at your focuser you appear to have a couple of mounting screw points either side of the knurled lock/tension adjustment. You also have a large flat surface (the blue face) which could be used as a fixing point.
If you would like a bracket in the flesh, so to speak, please let me know
Shaft diameter :
If you let me know the diameter of the focuser drive shaft I can customize the flexible aluminium coupler to any shaft
size equal to or in excess of 3mm.
Cheers & clear skies (wall to wall cloud here),
Dave
that is true but i have no idea how the existing focus motor works - not sure if the second part is a gearbox? not that mechanically minded but i can hack and break anything
Yes, I suspect you are correct and there is a gear box between the motor and the drive shaft.
Are there any mounting points on the ML focuser, specifically on the black aluminium body of the focuser ? I have seen images of motors bolted to this part of the focuser body.
I will try and get hold of the ML focuser and have a look for a suitable solution.
Yes I think you are correct with the top mount idea. As you have pointed out the GSO style focuser has the two grub screws which are just present to stop dust & muck getting into the focuser barrel. Once removed will provide a very secure anchoring point for a top bracket.
The top bracket could either be curved or flat mounted into two small aluminum blocks which have been profiled to sit flush onto the curved barrel - custom stand-offs if you like.
I think I have a GSO style focuser on an old Newt so will see if mine has similar anchor points.
I meant to mention (I'm sure you already know Phil) the SharpSky Pro bracket is bolted to the base of the motor enclosure using M3 bolts. The Aluminium case is tapped M3 to receive said bolts. Therefore, you can remove the bracket - nothing is going to fall off inside the motor enclosure.
You'll need a 2mm allen key to remove the black knob from the fine focus shaft and a good quality philips head screwdriver of the correct size to remove the "bearing sled" (let's call it that) mounting screws (they were quite tight on mine); I'd remove one screw at a time and make sure there is some pressure on the drawtube from the fucusser to ensure the "sled' stays aligned correctly.
Pic 1 shows the Sharpsky fit to the shaft, note that for the purpose of illustration that the orientation of the sharpsky is 90 degrees out.
Pic 2 shows the correct orientation and the standard sharpsky brackets.
Pic 3 shows the one of the two screws that hold the "bearing sled" and the perfect orientation with the centreline of the sharpsky bracket.
Pic 4 Phil's fickle finger of fate points to the right mounting (looking from the rear) screw.
Pic 5 shows the LHS screw.
pic 6 shows a rough approximation of how the bracket needs to be bent. Bunnings should have some suitable flat aluminium.
Pic 7 shows a Stainless cap screw that will replace the couuntersunk item(s) and attach the bracket.
Dave H, PM me with your address and I'll send you a kit, bracket and screws.
Remind me never to get stuck on a desert island with you....
Last edited by acropolite; 17-12-2013 at 10:03 PM.
oh the shim sounds great - cant thank you enough Phil (and Dave) will this be Phil's secret GSO fit up kit? mechanically not there but you know i would have a trailer load of spares
Yes, I suspect you are correct and there is a gear box between the motor and the drive shaft.
Are there any mounting points on the ML focuser, specifically on the black aluminium body of the focuser ? I have seen images of motors bolted to this part of the focuser body.
I will try and get hold of the ML focuser and have a look for a suitable solution.
Cheers,
Dave
I will take some more photos soon of the focuser. be good to see the other focuser mountings
Sorry for the delay, work keep asking me to do things while I'm trying to think about important astro-stuff ..... really is most inconvenient
Here is a image of a ML focuser showing some possible mounting points - do they exist on the model you have ?
yes i know what that is like this is some more of the moonlite i have - i don't seem to have those "holes" the two holes you do see for one of the two focus brackets was stripped when the scope fell off my mount not long after i fitted the focuser. snapped it straight off and there is a bit of bolt still in one hole - scope is fine - wow that was a few years ago now at ISSAC?
Shame, because if you could use the two holes and the flat that would give you a nice solid mounting point.
Can you remove the bolt from the inside, or drill it out and re-tap the holes ?
This is always the headache with brackets, there are so many focusers and variants on the market it's impossible to come up with a one bracket fits all solution. Making the SharpSky bracket adjustable does make things much easier but it still takes a bit of head scratching.
Probably the simplest focusers are the SkyWatcher models as they generally have a flat surface base and four fixing bolts that can be replaced with hex stand-off bolts the bracket being attached to the female side of the stand-off.
OK Dave h0ugh, here is your bracket (shortly to be in the mail) and fitting instructions.
The bracket isn't entirely flex free, but I'd say its as solid as the stock brackets and so should be OK.
1. Remove existing sharpsky bracket from focus motor, note that there are 4 washers underneath the bracket, take it off somewhere safe in case the washers try to run away and hide (as mine did)...
2. Fit the new bracket to the motor, re-use the washers between the motor and bracket. Leave the screws loose until after the bracket is fastened to the focusser. Note the screws have a very fine thread and are easily cross threaded or stripped so be careful. @ Dave T, it wouldn't hurt to use slightly bigger screws, I can't see the threads lasting if motors are transferred between mounts in this manner.
4. Take out the two countersunk screws holding the bearing assemblyon the focuser, make sure there is some pressure on the focusser so that the assembly doesn't move.
5. Slide the focus motor on to the shaft, allowing a little clearance between the coupler and the coarse focus wheel. Using the 2 dome headed screws secure the bracket which should be close to perfectly aligned, if not you may need to make some small bendy type adjustments. After the two bolts are tightened on the focusser, you can then carefully tighten the screws on the motor, not too much pressure as mentioned before. Once you're satisfied with the alignment tighten the coupler screws, there is one black allen bolt and 2 grubscrews).
OK Dave h0ugh, here is your bracket (shortly to be in the mail) and fitting instructions.
1. Remove existing sharpsky bracket from focus motor, note that there are 4 washers underneath the bracket, take it off somewhere safe in case the washers try to run away and hide (as mine did)...
2. Fit the new bracket to the motor, re-use the washers between the motor and bracket. Leave the screws loose until after the bracket is fastened to the focusser. Note the screws have a very fine thread and are easily cross threaded or stripped so be careful. @ Dave T, it wouldn't hurt to use slightly bigger screws, I can't see the threads lasting if motors are transferred between mounts in this manner.
4. Take out the two countersunk screws holding the bearing assemblyon the focuser, make sure there is some pressure on the focusser so that the assembly doesn't move.
5. Slide the focus motor on to the shaft, allowing a little clearance between the coupler and the coarse focus wheel. Using the 2 dome headed screws secure the bracket which should be close to perfectly aligned, if not you may need to make some small bendy type adjustments. After the two bolts are tightened on the focusser, you can then carefully tighten the screws on the motor, not too much pressure as mentioned before. Once you're satisfied with the alignment tighten the coupler screws, there is one black allen bolt and 2 grubscrews).
