52 replies to this topic

[gus1989]

BTW the extra weight of the battery actually helps balance the s50 in eq mode. The s50 is about a pound out of balance when used in eq mode. I use a 20,000 mAh battery and it works pretty good. A heavier battery would improve the balance and increase imaging time. My s50 uses the battery charge first then uses the scope's battery. It runs all night.

I don't have an S50 yet, but was wondering what location you velcro the battery to achieve the  balance you mention.  A picture would do a lot to help me understand.

[sanford12]

I don't have an S50 yet, but was wondering what location you velcro the battery to achieve the  balance you mention.  A picture would do a lot to help me understand.

Just don't cover the vent holes at the top.

 

Album: Sanford12

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Edited by sanford12, 14 June 2025 - 10:42 AM.

[gus1989]

 

Just don't cover the vent holes at the top.

 

 

 

 

 

Thanks for the picture.  Please help me understand how that location helps with balance as compared to other locations.

[sanford12]

Thanks for the picture.  Please help me understand how that location helps with balance as compared to other locations.

Can't answer to the weight adding any benefit. My battery pack only weighs 7.5 ounces. Did have a battery pack that weighed 3 pounds but I thought it was way too heavy, didn't seem to affect the scope negatively. The pack you see will last 7 hours with the dew heater on. Which is enough for most nights without getting into the scopes battery which isn't a big deal if it does.

Edited by sanford12, 15 June 2025 - 06:36 AM.

[former lurker]

That's the correct place to mount the battery. The reason to mount it there is because the tripod mounting point is not centered on the bottom of the camera. It doesn't matter in alt-az but in eq mode it makes a big fifference.

Look at the bottom of the s50. It's obvious.

Edited by former lurker, 15 June 2025 - 10:32 AM.

[former lurker]

This is an image obthe base of the s50. The tripod mount is most definitely NOT at the scope's balance point.

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[gus1989]

Gotcha -- thanks for the picture!

[sanford12]

This is an image obthe base of the s50. The tripod mount is most definitely NOT at the scope's balance point.

Did you try balancing it at the attachment point to find out? Maybe it was offset to balance the scope. 

[former lurker]

I did check the balance point... I used a pencil across the tripod threads in several directions and can confirm that the s50 does not balance at the tripod mount location. It's not even close.

A 3/8"x2"x4" steel plate velcroed just above the power button balances the s50 pretty good. Not perfectly but it works well.

[lsjones]

I did check the balance point... I used a pencil across the tripod threads in several directions and can confirm that the s50 does not balance at the tripod mount location. It's not even close.

A 3/8"x2"x4" steel plate velcroed just above the power button balances the s50 pretty good. Not perfectly but it works well.

To calculate the weight of a 3/8" x 2" x 4" steel plate, we need to determine its volume and multiply by the density of steel.
Dimensions and Volume:
Thickness: 3/8 inch = 0.375 inches

Width: 2 inches

Length: 4 inches

Volume = Thickness × Width × Length = 0.375 × 2 × 4 = 3 cubic inches

Density of Steel:
The density of steel is approximately 0.283 pounds per cubic inch (based on mild steel; this can vary slightly depending on the alloy).

Weight Calculation:
Weight = Volume × Density = 3 cubic inches × 0.283 pounds/cubic inch = 0.849 pounds

Therefore, a 3/8" x 2" x 4" steel plate weighs approximately 0.85 pounds.

 

Courtesy of GROK.

[gus1989]

So, if you attach an external battery with the Velcro just above the power button, to obtain optimal balance you would need about 13oz. Battery pack. 

[former lurker]

Or just ask what it weighs. 15.44 oz. That includes the approximate inaccuracy of the measurements, the paint, and the weight of a 2"x4" piece of hook side industrial velcro. Not included is the weight of the 2"x4" loop side of the velcro on the s50.

The dimensions may be slightly off but the weight is accurate.

That's a very good calculation of the weight given the unknown variables!

[former lurker]

BTW my 20000 mAh battery weighs 8.16 oz. It works very well. A heavier battery would probably work better.

I use the battery instead of the steel weight and balance is not an issue with my s50 in eq mode. Being able to track through the zenith is a hugh plus for me.

[gus1989]

I know this is getting a little off-topic, but with this battery placement and a more balanced scope, does that have any affect on dropped frames? Have you done any tests that might support that?  Just curious. 

[former lurker]

I don't know how to make a test to determine fewer dropped frames. But, I have taken images of over 120 thirty second subs and only dropped 3 or 4 sub frames.

To drag this back on topic... We have to put our batteries somewhere to extend imaging time so we might as well eliminate the possibility of cable twist and improve eq balance at the same time.

[Digital Don]

Considering mounting a battery on the Seestar itself?  You might want to take a look at this post on the ZWO Seestar Forum. 

 

While they don't mention external batteries specifically, they do say that the device was not designed to carry extra payloads. 

 

Food for thought...

 

Don

[AhBok]

I should give my little anecdote here. I mounted a 10K lithium to my S50 in eq mode. At first, I was happy not having to deal with cable wrap. However, when trying to image M13 recently with live view off, I discovered about every 5th or 6th frame to have a double image which I recognized from my imaging experience to be skips that I’ve mostly seen by balance issues. I tried other parts of the sky with no issues, but the problem with M13 as well as other nearby targets including M92 was quite repeatable on multiple nights. I removed the external battery and the problem went away. I’m now convinced that for me, a better solution is a combination of a magnetic coupling and only plugging in the external power after acquiring the target. The external battery is now mounted to a tripod leg.

This may not be an issue for others, but I post this for another data point.

[gus1989]

Interesting!  I hope more chime in with there feedback on this. 
 

[former lurker]

Hmmm... Double imaging. I haven't had THAT problem.

Maybe play in the gears? Perhaps in a certain part of the sky gear lash happens when the s50 is almost exactly balanced. Try adding MORE weight?

Ahha! That may be why zwo has deliberately put the tripod mount point off balance. That would compensate for gear lash. Maybe???

And why live view off?

[sanford12]

Considering mounting a battery on the Seestar itself?  You might want to take a look at this post on the ZWO Seestar Forum. 

 

While they don't mention external batteries specifically, they do say that the device was not designed to carry extra payloads. 

 

Food for thought...

 

Don

That was for mounting a camera on the arm itself not putting a battery on the body. Doesn't really apply

[AhBok]

Hmmm... Double imaging. I haven't had THAT problem.

Maybe play in the gears? Perhaps in a certain part of the sky gear lash happens when the s50 is almost exactly balanced. Try adding MORE weight?

Ahha! That may be why zwo has deliberately put the tripod mount point off balance. That would compensate for gear lash. Maybe???

And why live view off?

With live view turned off, all frames are saved. If live view is on, bad frames are rejected and not saved. At least, that is my understanding. 

[AhBok]

Hmmm... Double imaging. I haven't had THAT problem.

Maybe play in the gears? Perhaps in a certain part of the sky gear lash happens when the s50 is almost exactly balanced. Try adding MORE weight?

Ahha! That may be why zwo has deliberately put the tripod mount point off balance. That would compensate for gear lash. Maybe???

And why live view off?

Gear backlash is definitely a problem imagers must deal with. I suspect the plastic worm and worm gear in the S50 have more eccentricity than well machined (and more expensive) brass gears. For RA, backlash is more of a problem a few degrees before and past the zenith as play is taken up on the west side of zenith (N hemi). For the DEC axis, backlash shows up when any unbalance causes slight shifting of the OTA in positions where the balance point is shifted. The S50 lacks easy ways to balance in various positions. GEMs are well suited for this, but even they require autoguiding for dealing with backlash and eccentricity. 
 

But heh, short focal lengths are pretty forgiving and $500 for a complete package are nice trade offs for a bit lower yield on sub exposures compared to modest imaging rigs costing a few thousand more.

[marvindj]

With live view turned off, all frames are saved. If live view is on, bad frames are rejected and not saved. At least, that is my understanding. 

But for some reason when using a Plan, Live View is forced on. I can't seem to keep it off. Perhaps my issue.....

[Pegasus55]

Just 3D print the external battery holder for the Seestar. It rides on the telescope and rotates with it. Never have to worry about cord wrap being an issue with this!

that works great in alt/az , how well does it work in EQ? 

[PFJs Customs]

that works great in alt/az , how well does it work in EQ? 

That's a great question Pegasus55, I have not tried out the new EQ mode with my Seestar as I do not have a mount for this yet.

 

But if anything I think that by using some velcro I can make the battery holder and battery stay in place and work even in EQ mode.