cuivenion

Hi David, message received. I wasn’t going to disassemble the battery, I’m not that brave. The battery seems to have a fairly standard jack connecter, so I was just going to put a buck converter between the battery and the mount using a wired connection. I will double check that the battery has a management system inside before trying it out though.

The hoover is a Shark IZ251UK, bought from a uk retailer. I’ve added a couple of images of the battery if anyone’s curious.

Good point, I would imagine it has, unless the managment circuitry is somehow included in the hoover and not in the battery. When you use the hoover it just cuts out when the battery runs out. It doesn't get gradually slower like I suspect it would if there was no management system and the voltage was getting lower and lower. The batteries are lithium ion.

I think I'll give it a go at some point then. That E-bike battery sounds good!

Hi, I recently got a cordless hoover with two lithium-ion batteries. I'm wondering if there's any reason I can't use a buck converter and use the batteries to power my mount? The batteries are 2350 Mah DC, 25.2v, 59.22 watt hours. They won't last that long I imagine, 4-5 hours per battery with a HEQ5 if I'm lucky but that would be enough for me.

Good luck, post some images for us!

Just came across this at Starizona. The new version of the ED50 flattener can be used with DSLR's. It has 55mm backfocus.

https://starizona.com/products/evoff-field-flattener-for-skywatcher-evoguide-50ed?_pos=3&_sid=ed9902717&_ss=r

Thought it might be of interest for ED50 owners.

I usually do at least three iterations when using Sharpcap.

I'm using an oncooled ZWO ASI224 for DSO imaging. I did make a cooling system for it but it ended up misting the coma corrector so I've decided not to use it while imaging. I've decided to get as much image time as possible by using the cooling system to do darks later, but I have a fairly wide range of temperature for the uncooled light frames.

Obviously it would be best to get as close as possible in temperature for each light but pre processing would be much easier if the darks were within 0.5c of the lights, would this temperature difference be a bad idea?

Hi, yes I meant the main gear that meshes with the worm. vlaiv gave a good explanation in an earlier post.

You can still get backlash from the worm and the main gear. If the main gear isn’t perfectly round it will bind at some points and be too slack at others.

Well I did a star test but the results wouldnt be helpful as I realised that the coma corrector/camera was tilted after I took them. The stars were better after I corrected this but still not right.

The day before imaging I realigned the focuser using astrosheds video as a guide and also shimmed the bearing plate on the focuser to try and fix the tilt in the focuser tube. I also redid the collimation.  It all looked good until the focuser tube stated to tilt again the day after. Looks like this is going to be an ongoing process.

6 minutes ago, Spile said:

What is the result of a star test?

Just finishing up another collimation attempt. I'l hopfully do a star test tonight and show you an image.

Just now, bottletopburly said:

Astap has a ccd inspector for measuring tilt built into its tools menu 

Nice, I didn't know that. I'll check it out.

brilliant thanks.

Don't think they do it for the HEQ5 though unfortunately, so I'll be watching this thread with interest.

16 minutes ago, Craig a said:

I can see the rotation error just by looking at the pic you posted of the view through the focuser, it’s laying left up right down in the view, hard to judge which way it’s rotated from the pic but I’m 99.9% certain there is a error there it’s not a circle but more oblong indicating a rotation 

Just to be sure is area A or B you're looking at? Thanks for your help.

3 hours ago, Craig a said:

To me it looks like you have some rotational error in your secondary Mirror that will cause some problems, to set the focuser tilt properly you need to take the whole secondary assembly out and mark the point directly opposite the centre of the focuser hole in the tube it’s easier to take the whole focuser off aswell. Bit of a faff but once done it shouldn’t need doing again. Re the rotation error in your secondary can be sorted with a good Cheshire 

Hi, how did you recognise the rotational error? I do have a cheshire which one of the images above is from but I'm not sure whats indicating the rotational error.

2 hours ago, CraigT82 said:

Your stars look a bit triangular to me, indicating the primary mirror might be being pinched by the clips.

Edit: could also be the secondary mirror if it isn't attached to its holder properly.

Hi, the stars are triangular in the second image but not the first and I've been careful with the primary mirror clips because I've made that mistake before. I think you're both right and the secondary is out. I'm not sure what you mean by not attached properly though.

Thanks for the replies.

I use Sharpcap and it's great. You usually use it with a guidescope and a cam like an ZWO asi224 or similar to get the right FOV, but you can use your main imaging scope and camera as long as it's supported and has the right FOV. 

You might find that depending on how good your mount is that unguided exposures won't be much longer than the 30 seconds you're already getting, even with very good polar alignment.

Some of the images aren't showing.

Hi, I've been struggling with the stock focuser on the 130PDS for a while. The main problem is the tilt on the focuser tube.

I ended up with stars like this:

There doesn't seem to be anyway I can find to get rid of the tilt in the focuser tube. Nothing is overtightened if I loosen the four shaft bolts it doesn't make a difference. The tilt only goes away when the focuser is completely slack

After re collimation and adjusting the tilt adjusters on the focuser I got this.

This is a iphone picture of the collimation:

I'm just wondering what to do from here. The collimation looks pretty near to me. Using the tilt adjusters on the focuser don't seem to be helping that much and only one is accessible while using the focuser anyway. Very much open to ideas.

On 02/02/2021 at 01:31, Jiggy 67 said:

I would never go back to OO after they allegedly serviced my SW reflector, I’m convinced they never touched it......oh and his parting words when I picked it up....”maybe we’ll see you again with a real scope “....

Said something similer to me when I made an inquiry about my 130p reflector too. Can't comment on the quality of their products as I've never used them.

1 hour ago, alberto91 said:

Cool.

A shame that the Takahashi Epsilon 180ED costs 5,000 dollars.

Yeah that's the extreme end of the spectrum, but there are much cheaper alternatives. I can get a good representation of the brighter messiers though my F5 newtonians and an uncooled ASI224 in a fairly light polluted area using 4-8 second exposures. It would be great to see what is achievable with some of the more recent cooled astrocams and a more reasonably priced newtonian with a suitable corrector reducer like this:

https://www.apm-telescopes.de/en/optical-accessories/flattener-reducer-correctors/ts-optics-2-newtonian-coma-corrector-0.73x-reducer-astrophotography

Camera, scope and corrector should be about 1/2 what the takashi costs.

If you have good PA in Sharpcap you should be fine. I look through the polar scope and make adjustments until I get Polaris roughly in the center of the FOV, then I use Sharpcap to get good polar alignment.

Because I'm just using the polar scope to just get in the ball park it doesn't need to be aligned super accurately, but if you were using the polar scope as your only method of PA you'd obviously have to make more of an effort to make sure the polar scope is aligned to the RA of the mount.