Tracking woes

[Pitch Black Skies]

3 hours ago, alacant said:

A separate power supply is always a good idea. 

I can't find any potential external interferences. I'm going try a separate power supply if my adjustments to the idler have made no difference.

Edited May 8, 2022 by Pitch Black Skies

[Pitch Black Skies]

No improvement to the RA graph after adjusting the idlers and using a separate power supply to the mount.

I've tried various aggressiveness settings and they are not improving it much.

I decided to strip the mount down to have an inspection. My RA worm mesh is very tight again. I wonder if the mesh is too tight, is it capable of causing striction? ie causing the worm to jam for a split second and then release when tracking.

Anyway, I managed to inspect the bearings. There is a slight lateral play between the races on the larger ones. The smaller ones for the worm carrier have greater play. Is that that to be expected? Also when turning the worm in the carrier, I can feel very slight notches or bumps within the smaller bearings. It's hard to feel it but it is there.  I think this could be the source of the problem. I cancelled my new bearings order but might re-order just the 4 worm bearings.

[alacant]

2 hours ago, Pitch Black Skies said:

re-order just the 4 worm bearings

Hi

Skateboard shops have them. 689Z.

[Clarkey]

FWIW I have just finished stripping down and replacing all the bearings on my HEQ5. The small worm bearings were very rough (although this might be because I had over-tightened the end float). Whether this will improve the performance significantly is a question that will need to be answered when there is some darkness to work with. I was getting some quite bad guiding spikes similar to yours - but not as regular. My overall RMS was well below 1" but I would like to get it < 0.5 if possible.

[Pitch Black Skies]

5 minutes ago, Clarkey said:

The small worm bearings were very rough

Did you get a chance to compare them to the new ones? Mine had a bit of lateral play. I'm wondering how much lateral play new ones might have if any?

Did you source yours through R&M BEARINGS?

Can you drop a line here after you've had a chance to test guiding to see if there's any improvement?

[Clarkey]

Neither set of bearings had any obvious lateral movement - new or old. But the old bearings in the worm carrier were pretty awful when turning the drive wheel. Lots of stiction and very uneven. The rest of the bearings did not seem too bad, but as I had pre-purchased a complete set I was intending to change them all. If there is no improvement I would be very surprised. I also found the belts to be a bit loose which would also affect performance. The performance of my HEQ5 had definitely dropped off from new and I am hoping this will make a significant difference.

Yes, the bearings were from R&M. The worm bearings are actually ceramic - not because it is necessary but it was what they had in stock.

It may be a while before I get to test them as I have put all my gear away for the summer now - no astro darkness here until the end of August.

Edited May 12, 2022 by Clarkey

[Pitch Black Skies]

1 hour ago, Clarkey said:

But the old bearings in the worm carrier were pretty awful when turning the drive wheel

Mine are a bit notchy too despite the mount only being a couple of months old. They might not be best quality to begin with.

I think I'm just going to do the worm carrier ones. They are cheap and besides, all of the others seem fine.

[Pitch Black Skies]

I think I might have just found the source of the problem...

I found some play in the worm when rocking the mount from side to side looking for backlash in the RA. I couldn't hear the play and it was barely even perceivable, but after tightening one of the fasteners on the end of the worm the mount now feels more solid.

If the numbers are still poor, those worm bearings are the next to go 

[Pitch Black Skies]

So just had a chance to test guiding again..

A definite improvement since tightening the worm carrier nut/fastener.

I'm consistently getting a total RMS of less than an arc second now. This is great considering my image scale is 1.19"/pixel.

However, there is still the odd dip in the RA graph but it isn't as aggressive. I'm putting it down to those notchy worm carrier bearings. I will be replacing them soon and will be back with a further update.

It is great relief to have gotten to the bottom of it 🥳

Thanks for everyone's help

Edited May 18, 2022 by Pitch Black Skies

[vlaiv]

@Pitch Black Skies

Just noticed that you guide with 0.5s guide exposure. That is very fast and will often result in chasing the seeing.

Maybe try next time at say 2-4s just to see what soft of guiding you get?

[Pitch Black Skies]

20 minutes ago, vlaiv said:

@Pitch Black Skies

Just noticed that you guide with 0.5s guide exposure. That is very fast and will often result in chasing the seeing.

Maybe try next time at say 2-4s just to see what soft of guiding you get?

Hey, na that's just the tracking rate at x.50. I have it set to 2s exposures. You can see it on the bottom right of the images. The layout is a bit different on ASIair compared to PHD2. It's not as sophisticated but it works 😅, sometimes.

[Clarkey]

Looks much better. Looking at the DEC adjustments it does seem to be under-reacting to the drift (having to make multiple adjustments). Might be worth increasing the aggression or the guide rate.

I think my guiding on the HEQ5 was in the region of 0.7" RMS so this looks similar.👍

Edited May 19, 2022 by Clarkey

[Pitch Black Skies]

I've just replaced all of the bearings.

The new ones are a bit stiffer.

I'm really surprised that I got good guiding numbers last night. When I had the RA worm carrier off, I rotated the shaft in the housing and it was extremely notchy this time since tightening the nut/fastener.

With the new ones in, it rotates silky smooth.

Just need some clear skies to compare results.

Edited May 20, 2022 by Pitch Black Skies

[Pitch Black Skies]

These are the bearings if anyone decides to replace their own sometime;

 

2 × 30205M Timken Roller Bearing

6 × 6006-2RS C3 FAG Deep Groove Ball Bearing 30×55×13

4 × 689 2RS Ceramic Hybrid Ball Bearing 9×17×5

 

And I would recommend to at least  consider replacing the worm carrier bearings. They are the cheapest and make the most difference as the stock ones are simply junk IMO.

Edited May 20, 2022 by Pitch Black Skies

[alacant]

10 hours ago, Pitch Black Skies said:

just replaced all of the bearings

Hi

Well done. It looks like you've solved it.

Question: We use heq5 and eq6. Now you've got yours running by process of elimination, would you recommend this method? Any preference of order in which to substitute? 

Normally for each mount we receive/visitor brings along/WHY, new or old, it's pulled apart, cleaned, lubricated and necessary or not, bearings replaced. Thinking: just the worm shaft bearings may be all that is needed.

We genuinely don't know which is best; full substitution or the a-bit-at-a-time method. The latter could save us a load of time.

Cheers

[Pitch Black Skies]

2 hours ago, alacant said:

would you recommend this method?

Hey,

I think for my mount, I could have just gotten away with replacing the worm carrier bearings. All of the others seemed fine. I have seen someone on YouTube complain about the their HEQ5's worm carrier bearings too. I don't think they are the best quality.

Something I have learned about bearings too from this is that the 2RS in the model number stands for 2 rubber seals. They're assumed superior to the zz or 2z.

"What is the difference between 2RS and ZZ bearings? The 2RS are sealed for life bearings i.e. the grease within the bearing cannot get out or contaminants get into the bearing and damage it. The ZZ are just a metal shield to stop larger contaminants damaging the bearing."

I think your method is fine, especially for a business. A full strip down, re-grease and all bearings replaced gives peace of mind to both yourself and the customer, and it rules out any potential problems if guiding errors still persist.

I think the clean and re-grease is important and while that's being done it doesn't take a whole lot to swap out the bearings too.

If you are finding it too demanding though, it might be interesting to trial just replacing the worm carrier ones.

Or even better, get me a flight over.. I could do with a few days in the 🌞

😅

Cheers

[Clarkey]

13 hours ago, Pitch Black Skies said:

2 × 30205M Timken Roller Bearing

6 × 6006-2RS C3 FAG Deep Groove Ball Bearing 30×55×13

4 × 689 2RS Ceramic Hybrid Ball Bearing 9×17×5

I think this is exactly the same as I have used. I'll find out in September if it has improved the mount.

With regards to the question above, I would say the the worm carriers certainly seem to be the main issue. I replaced all the bearings because I had already brought them. However the larger bearings felt absolutely fine and will have less impact on guiding unless excessively worn. I think the most important issue is getting the end float right. Even with the rather poor bearing I removed, the performance was not that bad - but that was because I had over tightened the end float. If you get this spot on (along with the worm carrier) it should give good results. I have now made a tool to adjust this so it is a simple job to set up.

[Pitch Black Skies]

I've just tested guiding with the new bearings. I'm now averaging around .60 total RMS.

At one stage I was going steady at .37!

Huge improvement.

Just to note, it did take some tweaking and fine adjustments even after the new bearings were installed.

The 1s exp is the main cam. The guide cam was set at 2s exp.

Edited May 21, 2022 by Pitch Black Skies