masjstovel

On 08/03/2020 at 12:52, spillage said:

I forgot to mention. I tip for putting it all back together. If you can get hold of something like trimmer wire cut yourself of about 6", fold it in half and put it through your belt. When you put the housing back on put the two ends through the hole and pull them through the bracket with the guide wheels, bolt the housing into place and you can then pull the string/wire through gently and it will pull the belt with it.

Ah thx. Ive just used a long unbrako (hex key) to push the belt between the plastic wheels. Works fine for me after i found the technique. 

Question: could the huge backlash in DEC effect tye varies in RA guiding as well?

I mean; could the RA guiding get better after ive now fixed the DEC backlash or are they completely separate guiding-wise?

Thx again @spillage. I wasnt wiggling so much but im fairly sure its tight now!

ah, yes - about the spacers. I did the measuring and my result was a negative value : -0.015. Not sure what to do about that.. also the 3 dec bearings (minus the cone shaped - 2 on the brass and 1 on the housing. It sounds like they switch up with braking. The axis spins but not the bearing in some positions. On all 3 - maybe. I thought it was just the lower one as it is visible through the polar scope outer opening. The bearings are noe tight to spin around - so i think its just happening when theres total balance and not force on the bearings - so what this does to the guiding - i dont know?

1 minute ago, spillage said:

the gap between the belt cog and housing should be 1mm.

It is. The problem that im portraying is the play in the cog itself. I think the setscrew thats on the flat part wasnt properly fitted/had loosened, so there was play in the cog. 

And the braking sounds.... The outer edge of the bearing moves along with it.
Would it work with some loc-tite on the outside to make it sit properly in its slot?

Ta-daa. Think i found whats causing the backlash...

On 05/03/2020 at 20:55, spillage said:

Just as a thought. Try slackening off the dec worm housing bolts and backing out the grub screws. This should allow you to move the dec housing around slightly.

Tighten up the grub screw opposite the worm just until you feel some slight resistance. Then just take up the slack in  the opposite grub screw and tighten up the housing bolts then try slewing.

 

This is what i have done. Ill try to work a bit more with the hoising and set screws, but MANY hours have gone to that with same backlash so.

 I plan to remove the housing and check the setscrew on the cog on the worm if its tight!

Also i noticed dec is perfect clockwise, but counter clockwise it is more braking, even though its slightly. Dont know what this tells me

1 hour ago, spillage said:

In PHD if you click on the brain the first page will show you the location of the stored file. Normally users/user-name/PHD2. This file will give everyone the info they need to check you guiding. A new one is created each time you start PHD2 and guide.

If you slacken off the dec worm housing you really should be feeling some backlash. What if you slacken off the four bolts and wind out both grub screws?

 

I can check again tonight but with both screws all the way out plus housing bolts slightly loosened there are a couple of millimeters backlash tops if any and with alot of force, if i recall correctly.

I was going to remove the housing as well yesterday, but i couldnt get the DEC motor out because it was stuck in the belt like the belt. There was tight space to get the cog in there so i dont think theres anything wrong with the belt. Slewing works and everything, but i cant get off the dec housing with the belt in place on the motor. 

32 minutes ago, alacant said:

I wonder if the OP is adjusting the grub screws without first loosening these?

¿?

No their loosened slightly before playing with the setscrews if thats what you mean? The 4 screws on dec housing

Neat trick on checking balance in PHD btw, i will try that:)

2 hours ago, alacant said:

Hi

- Slotted nut to take up the worm endfloat (remove the round cover with the two holes to reveal it): make sure it's not too tight. With the clutch tight, rotate dec and with the cover off, loosen the nut until you can feel movement. Now tighten until the enfloat just disappears.

- You may now have the worm too close to the brass gear causing it to bind. Slacken the north grub 1/8 of a turn, tighten the south by the same amount.

- phd2: do a ga run of at least 2 minutes, then guide somewhere high in the sky for as long as you can bear it.

- post the guide log

Thanks, I will post my phd-log. 

Yes, I've done the procedure,  but in RA axis i easily feel the backlash when working with the set-screws, so  its much easier to know when im on the right spot as the backlash disappears. In DEC i dont feel any backlash when working with the setscrews, thats the problem. So my only reference in DEC is when the setscrew meets resistance. 

1 hour ago, spillage said:

sorry if I have read this wrong.

The dec cone adjustment it to take up the slack of the axix bar and stop movement up and down (between the weight bar and dovetail clamp).

The worm gear will need the four bolts slackening on the worm housing then you can move the grub screws, re-tighten the worm housing bolts and test for back lash and run the mount to check for binding. As you have already taken out the slack on the actual worm before assembly you should not really need to play with the ring bolt (inside the black cap).

Getting the scope balanced is really important with the belt mod and I run PHD with the target to help me with this. If RA keeps hitting west then I adjust the weights and check the target again. This is just my way and may not be right.

Thx @spillage. Yes i am aware that it takes up slack. My DEC is easier to spin around the more loose it is so i worked with this too as it was too tight. I did the deassembly to check my bearings in relation to the slight braking sound when DEC tightens.

The easiness in the axies now is close to perfect. And i was happy with my balancing yesterday. 

But guiding is far from perfect. I get 31000ms on DEC backlash even if DEC is no backlash i can feel physically. 

This i dont understand. Also the phd2-graph is oscillating heavily on bot axies. Dec wants to stay on the bottom side of the graph.

This is why i start wondering if theres something i need to program. Like in phd2 or in ascom, regarding tracking speed or something. I dont know?

Worth mentioning is whst i told @alacant is that i "never" feel backlash in DEC, so that its hard to know how the worm is on my brassgear

2nd picture was before guiding assistant yesterday and a bot strange. Havent seen RA and DEC acting with identic trends before

Ok. Desembled DEC again. Worked alot on the coned bearing on the weightshaft end. Couldnt really see any wrong there so just reassembled again. Had the weightshaft even looser than last time before i tightened the 3 lockingscrews.  Both axis is much smoother now. 

But.. guiding still sucks. Basically the same as yesterday.

I dont understand this. Guiding also is everywhere. 
Is there supposed to be new/other ASCOM drivers for belt modded mount? Its like the guiding and motor movement (from phd2-graph) are so radical and steep. 

Also I dont feel any backlash in DEC physically still. When i loosened the weight-bar nut a bit and the 2 set screws, theres still no backlash. This makes it hard to adjust the setscrews for the worm placement correctly. It's like i get no feedback from what i do except feeling the set-screw tighten when the worm meets the brass wheel. Where do i go from here?

2 hours ago, 1parsec said:

The belt does not need to be very tight.  Apply just enough tension to remove any slack from the belt.  Usually light finger pressure pushing on the motor is enough.

If using a screwdriver it is easy to apply too high tension. Be careful if using a screw driver as a lever.

 

Then i think the belt tension is as it is. But the motors arent supposed to be very tightly screwed down? I dont understand why this is

20 minutes ago, spillage said:

if you put the mount on the bench upside down and then place the bottom of the mount down onto to RA axis I find it easier to remove refit. If it gets tight just gently rock the mount to feel where it lose and then gently lift it up a few mm and then let it down again. You have to have the bearing very square to the axis or it binds going down. Hard to explain but a bit of a balancing act.

I just use a screwdriver between the motor and housing and just apply a small amount of pressure.

The cone shaped bearing need to be carefully tightened. So take up the slack rotate a few times, tighten a bit more rotate and repeat until hand tight.

The picture starts to get clearer for me now. So tightening the coneshaped bearing; you screw the holding ring on polarscope to tighten it in place, right? So screw, rotate, screw and so on? And as it is tight and in place for sure, then slacken a bit? 

Also for DEC; screw, rotate , screw rotate on the weight-shaft end?

Smart tip with the screwdriver. So the motor is screwed not too tight in place, but the belts are as tight as possible?

And again the extra washer/spacer is needed even when there are spacer there already?:) 

There are some slight "braking" sounds when the axies go tighter so a misialigned coneshaped bearibg sounds plausible.

@alacant that washer really works well?:)

11 minutes ago, spillage said:

Mine was also tight but adding an exta spacer on the opposite side of the teeth on the gear improved it. The setting circle now has allot of clearance but this is fine for me.

The super tune measures the spacing below the teeth on the gear and makes sure that the worm and gear are aligned as well as can be.

The worm housing adjustment you did is the same as me and yes I meant taking sideways movement out of the worm gear before fixing into place.

I seem to find that when putting the RA back together having the mount sat upside down helps. When fitting the RA tapered bearing I like to rotate the bottom of the mount a few times and slightly undo and then redo up to make sure it is in evenly. I just normally do this up as tight as I can by hand.

 

Hope this makes a bit more sense.  

 

Thanks alot! Ive been needing this help!

There is 1 or 2 (was 2 one place, but dont remember where) spacer on the top side already. You mean one extra on top of this/these?

And to clarify; the tightening of the motors. I am not sure how tight/lose you mean. Is it in relation to the belts? I kept the motors in tension on the belt with "moderate" strength with 2 fingers when tightening the screws for the motors. These i tighted pretty good. 

I struggled very much in reassembling the RA axis (read; plastic hammer, blood and tears). You mean the cone shaped bearing on the bottom? That could be the issue yes! Thanks again. And sorry for question-bombing:)

56 minutes ago, spillage said:

I will start with the tightness. Take just the RA back out and put an extra spacer on top of the brass gear (to early to rember it's name). This will remove any tightness around the top area. 

When putting the worm gear back together I ignore the tip on astrobaby's site and adjust the worm gear before fitting it back together. Take the play out of the RA by going to tight then back of a bit by bit.

Have you gone through the supertune setup?

Do the same with the DEC and do not over tighten the motors, just apply some pressure before tightening.

Even balance is I find crucial with the belt mod and of course good PA,.

Thank you!!

I did astro-babys guide as backup to Martin Pyotts youtube videos on supertuning neq6, if thats what ypu mean by supertune setup?

What i didnt do was calculating spacers, as they were all in good shape and i left them where they were on disassembly. The result: ~1mm space between setting circles and mount on both RA and DEC. Didnt think too much about it since the axies were tight and had no play. Thoughts on this? In my head this space = too many/high spacers? 

When you say "on top of brass gear" you mean on the opposite side of the teeth?

Also i am not sure how you mean adjust the worm gear before assembly? You mean the lockrings for the worm? (I did that before assembly making sure the worm had no play and and not tightening more) or do you mean the adjustment of the worm distance to brass wheel with the 2 setting screws?

Update:

So, finally I had clear skies and eventually got to test the mount first time since supertuning it.

And the result:
It was a total disaster!

I almost had tears in my eyes after all that work with the mount.

So now i need some help diagnosing the problem.

The guiding was terrible as you could see from the attached pictures.
I am wondering what could be the issue.

What i am experiencing is as mentioned earlier, that the axis has some "tight" areas. a little bit on RA , but especially on DEC, so it makes the setup hard to balance, especially in DEC.

Other factors than the mount-supertuning that might have caused issues:

• I really dont know the reason for this, except the tightness in DEC, but i balanced my rig after fully equipped and after the "session" I saw that DEC was somewhere between slightly and moderately not in balance. More slightly than moderately. 
• At some times when slewing to targets the power light on the mount started blinking. Only at full speed, not in guiding. I used 12v 5A power supply plugged in the wall.I am in the process of rearranging cables - a power "hub" for everything and a pole with fuses. I did some tests just now with this new power supply (not the one i used yesterday) and i saw that the voltage dropped from 12.10V which its set to, down to 11.80V when slewing full speed. The light started flashing again after some time slewing. Ampere AC was steady-ish at 5A. and Ampere DC was going from 1.45 not slewing to 1.41-1.42 when slewing.
• I dont have vision south so i calibrated in PHD2 in a west, at maybe 30degrees height.

First photo is after calibrating (cleared calibration data before session)

Second photo: Running PHD2 guiding assistant. This is during uncorrected guiding. RA was dropping but going up and down like the tendensies you can see in the start. Dropped to -16" but bumping alot up and down.

3rd photo: Results after going through the guiding assistant. Note the DEC backlash. There is no noticable backlash physically in DEC. There is slight noticable in RA, but not in DEC and this number is huge. I watched several times for tangeled equipment, but didnt notice any.

4th photo: backlash-graph. Insane.

5th photo: Guiding after guiding assistant.

Other info: Did polaralignment with SharpCap and got excellent result (00.00.00 actually)

So what im trying to find out here; Does the issues i've mentioned about the power and balance effect guiding this way, or is it likely there is something with the supertuning?

Could anyone please help me troubleshooting on this? 

7 hours ago, Juicy6 said:

I have the 7 m cable too. It will reach the exact same speed as the 15 m variant, so maybe the line amplifiers are limiting speed to 60+ MB/s. 70 MB/s or 400 MB/s would not improve anything. With my cables it feels fully transparent, no delays, no lags. 

You think its for that brand in particular, and maybe other brands could deliver better or? 60mb/s will work for me now, but just wandering for the future sollutions i could bump into

11 hours ago, whipdry said:

FYI, an NUC will run without issues on a 12v supply. 

Which one? I find some but they run 20v:/

17 hours ago, symmetal said:

4) You would use a short male-A to male-A USB3 cable as James mentioned to join your Orico hub to the socket on the active extension cable at your tripod leg.

Alan

Probably stupid question, but there is no problem using the male end on active usb in hub, and then the male to male from active female to laptop? The other way around in other words. Then i can plug in the active's power supply indoors. I have rearranged so i have 1 power supply feeding everything on the rig and dont want to go back to the cabledrum mess i had:) Thats also the reason i dont want a mini pc, since my one powersupply is 12v for all the gear.

Also, if 60mb/s is for a 15m cable: I need only 5m or 7m cable. I wonder how that will affect the speed? I see its alot of "depends", but are we talking 70mb/s or 400mb/s logically speaking with this much smaller length? 

Thanks alot for many good replies guys! 

This Raspberry PI and Astroberry... Is astroberry a software? How does it work? 
I still do my imaging from my inside laptop? Using SGP pro and PHD2 as usual and all that? 

I dont know much about this subject as probably shines through by now, but my frames take 32mb each. This means 60mb/s will be just fine or? does other things "take data" from the USB other than downloading frames? 
If i put a external SSD with USB3 on the rig connected to the USB-hub as @Juicy6 mentions, that will be placed "before" the long active/repeater USB cable that goes to my laptop inside. Does this then not effect the potential speed-loss or..? 

9 hours ago, JamesF said:

1) Probably not.  I have three or four of the seven-port Orico USB3 hubs and  they have been very reliable so far.  The 10Gbps USB3.1 model might be a bit excessive -- you'd probably get by just fine with the USB3.0 version, but if you're happier going for the faster model then I see no obvious issue with it.

2) I don't think you should see problems.  I have once in a while found a USB2 device that didn't want to talk to one USB3 hub but happily connected to another.  It seems to be quite rare though.

3) The issue with cable length is that the USB spec. requires that a signal get from one end of a cable to the other in a maximum time.  If the cable length is more than 3m then that limit is likely to be exceeded.  It's possible that the USB hardware at either end of the cable might be more tolerant, but it doesn't have to be and you may find that sometimes it works and then sometimes it doesn't.  Or it works for a while and then stops working.  Some people have said that if you use very high quality cables you stand more chance of it working, but I've not tried pushing things that far at all.  Otherwise if you want to go more than 3m then you need an "active" cable, which is really just a normal cable with a built-in USB hub at the end powered from the USB connection itself.  That shouldn't really be more than 3m long either.  You may get away with "daisy-changing" active cables to get the length you need, but if the hub in the cables draws too much current then the one at the end of the line might not work reliably.  I think there's a limit to how many USB hubs you can chain together too, and obviously you'll have two at the telescope.  Possibly the only way to find out is to try it.  The other thing you can do is use a pair of converters that take a USB signal and retransmit it over a cat5e cable.  I've never used one, but people have posted here that it works well.  If you are using USB3.0 active cables then using the USB3.1 hub is almost certainly not going to give you any benefit over the USB3.0 model.

4) https://www.amazon.co.uk/dp/B01KRO8D20 is a male type A to male type A USB3 cable by the looks of it.

I would probably solve this a completely different way.  I'd have something like a Raspberry Pi (ideally an RPi4, though I'm not completely up-to-date on how well the software works with those at the moment) on the mount and run Astroberry or StellarMate or something like that, connect the USB3 hub to that and then run a cat5e network cable back to the house and control all the kit via the RPi over the network.  It may even be possible to power the RPi from the USB3 hub.  You need to be happy enough configuring up the RPi end though.  There are a few people on SGL who do exactly this.

In fact I do something similar in my observatory, but I have a lightweight Intel-based PC on the pier and because the warm room isn't very far I run USB and HDMI cables from the PC to the warm room.  I run the same software as Astroberry and StellarMate use though, so I could operate everything remotely from the house if I wished to.

James

Thanks alot for a fast and throughougly reply @JamesF, appreciate it alot! 

Regarding 1):

Reason for not going for the 3.0 version was that its not powered (from what i can see on the 4-port version), while the 3.1 is powered 12V and i can put that in my power supply that feeds the whole rig. I am on thin ice now, but i imagined it would be more reliable if its a powered HUB?

Regarding 2):
Nice!

Regarding 3):

Im probably using the terms repeater/active wrong, but i think we're talking about the same thing.

Most of them ive looked up are also powered externally 5V DC it seems.

You're saying these active USB's should not be more than 3m in length? I am asking because most of these products i find are minimum 5m, but many up to 25m long or even more.

https://www.amazon.com/SIIG-Active-Repeater-15-Meters-JU-CB0711-S1/dp/B0053YLXVS/ref=sr_1_9?keywords=repeater+usb+3.0&qid=1583023723&s=electronics&sr=1-9

Regarding 4): 
What i meant here was male to male active cable. 

Could you maybe pretend I was 5 years old and try explaining me what a Raspberry PI , and Astroberry is?:) 
Is it like a DIY ASIAIR kind of? 

I have the rig on my porch and cables through the door opening, where i sit and freeze my butt off as of now, because of the 3m maxmimum issue. There is WiFi signal on the porch so maybe I would be just better of with a mini-pc (Lenovo thinkcentre etc) if what your saying about the cable length for active USB is true. Problem then is that its not 12V as the rest of the setup, so i would have to go around the one power supply that feeds the rig now.

Hi,

Doing some cable re-management on my AP-rig, and decided i want a USB-hub regarding this. 

I dont want a mini-PC or a ASIAIR or simular. 

Some questions pop up regarding this, and i hope i can get some help from you guys!

1. Is there any reason NOT to go for this, except that it has only 4 slots?
https://www.amazon.com/ORICO-Powered-Aluminum-SuperSpeed-Splitter/dp/B07XHL5399/ref=sr_1_3?keywords=orico+usb+3.1&qid=1583018558&sr=8-3

2. Should i expect issues with having already "hubbed" equipment connected to the hub or wont that be a problem? Meaning, I have an ASI 1600MM camera with two USB 2.0 slots which the EFW (filterwheel) and EAF (autofocuser) are connected to. So when i connect the ASI1600 to the hub, the EFW and EAF will already be connected to ASI1600 - so it gets sort of "hub to hub to computer" 

3. Ive read many places that USB 3.0 should be max 3m long or it will lose its power or something. So i plan to solve this with having all gear connected to the hub on i.e the tripod leg, and then have a USB 3.0 repeater cable 10m long from tripod to inside where my computer will be. USB 3.0 Repeater cable is new to me, but as I understand it it sorts the length problem? 

4. Lastly, the HUB need USB 3.0 male in its main input, and my computer needs male input, so i then need a USB 3.0 repeater male to male. I cant seem to find this - only male to female. Then i would need a short normal USB 3.0male to male from the repeater to my computer? I just think it will be kind of a strange sollution; ASI1600 as a hub, goes through a USB hub with a USB repeater which connects to a normal usb 3.0 that goes to the computer. It just seems cumbersome and messy in my opinion. How would you go about this? 
 

On 17/02/2020 at 15:54, david_taurus83 said:

So far, I have watched some basic levels and curves videos and managed to come up with this. 240 x 60s at ISO1600. Just levels and curves and a bit of denoise. There is more to be had and plenty of dust to try and tease out further. Looking back, PI wasnt as straight forward when I started. Even with this data, I'm struggling with ABE in PI to remove a bad gradient on the right hand side of the image without damaging it too much whereas the trial of Gradientxterminator in PS dealt with it relatively easily?!

That's just a lovely composition btw! 

On 23/02/2020 at 07:52, Craig123 said:

The Zwo filters are well known for causing bad halos. Baader are better but I still get them on very bright stars using the narrowband set. 

ZWO has fixed this issue and provides new filters now. I have the new ones, 1.25", and have not seen haloing. Then again I'm new to AP and havent got tons of data to back it up. 
From ZWO on the new filters, with comparison to the old ones:

https://astronomy-imaging-camera.com/product/zwo-new-narrowband-1-25-filter

Quote: "Form 2018, ZWO Made a progress on narrowband filters with the new standard, provide better performance."