PrimaLuce Lab Guide Rings........Oh dear!

[RayD]

Well I have the Eagle2 Pro, and very impressed.  Seems well built and works with no issues so far, although I will be keeping a close eye on it when using it outside in anger due to a couple of areas where I can see possible issues, but we will see.

As with the above, I got the Sesto Senso focus motor, and again this seems pretty good.  Connected on the the Tak well, calibrated fine and seems to run very well.  However............

Guide rings!!!

The PrimaLuce Lab Plus system is supposed to be fully compatible with all the Plus named components, and part of me using this was the attractive side of having a fully isolated system that I could use in Spain to leave as complete as possible as it is taken down and set up each time.  The guide tube rings are shown in all the promotional information from PimaLuce Lab as connected directly on to the Eagle2, effectively using it as a dovetail.  This is where this system fails I'm afraid, and what they are saying and showing is possible, simply isn't.

The Eagle2 has a series of M5 and M6 tapped holes in the top and bottom to connect all the Plus items, and standard metric dovetails to.  The 80mm tube rings for a guide scope also have 3 x M6 tapped holes and they come with 4 x M6 socket headed machine screws (bolts to you and me).  Well to align them to have double fixings, as it shows in all the promotional videos, you can only use M5 holes in the Eagle2, and then you do not have a flat surface to secure down to, so only have a tiny bit of purchase area, which not only has a tendency to bend the bolt, it will damage the ring and quite frankly is just poor engineering practice:

 

Image below is a screen shot of their own YouTube videos showing the bolts secured on the radius of the ring.

Whilst I am an engineer by trade so check things as I am putting the together to make sure I am happy with the design etc., it really doesn't take an engineer to see this is an extremely poor design.

Alternatively you can line up a single M6 hole on the top plate at various locations, which uses the centre hole on the ring, offering a slightly better contact with the bolt head (although still not flat so not ideal), but this means a fixing through a tapped hole in to a tapped hole, which is simply wrong as far as fastenings go.  If it is connected this way it os highly likely that it will never tighten fully and if used for guiding will be flexing all over the place.

Pic below showing the single M6 aligned position meaning the connection is a tapped hole through tapped hole.

 

Pic below showing the double aligning holes are all M5, meaning using m5 bolts through the M6 tapped holes (bolts not supplied).

 

Whilst I am happy with some of the equipment, and the above issue can be overcome by using an upturned vixen dovetail between the Eagle2 and the rings, I am posting this to highlight to people thinking of using this system as advertised that it cannot be done properly, or at least to a standard reflective of the price paid for the kit and to get decent guiding.

Back to the drawing board on this one I think.

 

[swag72]

I used a dovetail (albeit it not turned upside down) bolted to the rings and then the Eagle bolted through the rings and dovetail with the guide rings on top of the Eagle 2.

[RayD]

9 minutes ago, swag72 said:

I used a dovetail (albeit it not turned upside down) bolted to the rings and then the Eagle bolted through the rings and dovetail with the guide rings on top of the Eagle 2.

Yes the main rings are fine Sara, and I have mine mounted similar to you, but the method of fixing the guide rings to the Eagle2 is flawed.  It must surely lead to flexure.

[swag72]

1 minute ago, RayD said:

Yes the main rings are fine Sara, and I have mine mounted exactly as you say, but the method of fixing the guide rings to the Eagle2 is flawed.  It must surely lead to flexure.

Whether it does or doesn't I can't tell as I've now removed the Eagle from the rings and put it in my tripod legs.... I was getting issues somewhere and it could have been in a number of places (this being one of them) - My issues are fixed but I don't know if it was flexure in the mounting rings.... I'll never know!

[RayD]

Just now, swag72 said:

Whether it does or doesn't I can't tell as I've now removed the Eagle from the rings and put it in my tripod legs.... I was getting issues somewhere and it could have been in a number of places (this being one of them) - My issues are fixed but I don't know if it was flexure in the mounting rings.... I'll never know!

That's a shame to need to do as the mounting position is really the biggest selling point of this unit for me.  All the functions I already have with my Pegasus hub.

Oh well, let's see how it goes 

[LightBucket]

Well i did this with my pegasus hub....along with my rpi3which controls all my kit, and is rock solid, guide rings gon on the top fixed to Losmandy clamps

 

[LightBucket]

I have to say for a piece of quality kit at the price it is, that is a bad design, even if the rings fasten as they should, how solid is the top of the eagle, it must be pretty thick...

I think I would contact them and have a discussion on it, and if you decide to keep put a Losmandy or vixen rail on the top and fix guide rings to that, Losmandy maybe better as it will spread the load more....not that there will be much load, but will eliminate any flexure for sure..

[LightBucket]

??? just looked at the actual price of the Eagle 2.... thought the Pegasus hub was pricey..

[RayD]

4 minutes ago, LightBucket said:

I have to say for a piece of quality kit at the price it is, that is a bad design, even if the rings fasten as they should, how solid is the top of the eagle, it must be pretty thick...

I think I would contact them and have a discussion on it, and if you decide to keep put a Losmandy or vixen rail on the top and fix guide rings to that, Losmandy maybe better as it will spread the load more....not that there will be much load, but will eliminate any flexure for sure..

No it certainly isn't a good bit of design, and at any price point really, not necessarily at this high one.

The unit itself is actually really solid, so I genuinely don't think there will be flexure of the top plate, but I guess you can never say never.

I've been toying with using the Atik OAG on the Tak anyway as it fixes directly to the EFW3, so I will probably go that route now and return the guide rings with a note pointing out what I believe is a genuine flaw considering it is clearly advertised as being used in this way.

[Rusted]

Oh dear, indeed! Totally unforgivable fail on the first day of kindergarten engineering! 

A possible answer is a thick, wedge shaped washer or spacer under each [much longer] hex socket head screw.

Even that would need a radius on the bottom to push the crushing forces [almost] perpendicularly into the ring casting.

But, that wedge-shaped, curved washer would still slip sideways as the screws were tightened!

The screws ought to be much longer and BOLTS to boot. [See below]

As you have pointed out: The ring holes should be plain and not threaded.

 

The manufacturer ought to be providing a complete flat topped, crescent shaped piece to fill the arc for adequate strength.

The lateral [skewed] forces would then balance out. Or they should cast one in with a flat top into the ring!

Or, provide local lugs for the screw heads to rest perpendicularly on the material to be fastened.

A flat surface for a bolt or screw head to rest on is the most basic engineering at early caveman level.

Cheddar Man would have known about the huge skewed forces involved in non-perpendicular bolt fixing beds!

 

Interestingly [?] Orion UK's rolled tube rings suffer from exactly the same, appalling, design geometry.

Advanced CAD blindness one presumes. From somebody who never made anything from scratch in their entire lives.

 

Hint For The Day: Machine screws are threaded almost up to the underside of the head.

Bolts always have a plain length of shank and a shorter thread length. 

The plain shank provides greater tensile strength and offers far better lateral location in correctly sized holes.

Both are measured from the tip to the underside of the head regardless of thread length or head form.

 

Second Edit: Having looked at the design again I have a possible solution.

The manufacturer should have countersunk plain holes and used matching countersunk, socket head, stainless steel screws.

The ring is very thin at these critical attachment points so the ring castings would probably need beefing up.

This is NOT a DIY option because the countersinking tool is attacking the metal at an angle on a radius!

It would need a stiff right angled drive to get the cutting bit inside the small ring!

So it really needs a very special milling machine to do it right.

In summary: I wouldn't start from here. 

[RayD]

I'm going to have a chat with them to come up with a reasonable solution I think.  As I said, it can be overcome with a dovetail, but this is just adding another (expensive) component where their advertising shows it isn't needed. 

[Stu]

Very curious bit of engineering! Now you have highlighted it, you can actually see that the bolts don't sit flush in their promo image but it's not something you would know beforehand.

As said, rings with non threaded holes, plus a shaped insert ie curved on the bottom to fit the ring profile and flat on top, with non threaded holes again would do the trick. Nicely anodised to match of course!

[Rusted]

I can see their design problem.

They want it to look pretty and the rings to remain light in appearance.

They have a problem with ring clearance around fatter guide scopes.

So there isn't much room for added lugs or crescent options.

Ask them for a new set of rings with countersunk non-threaded holes. 

Just to see what they say.  

[RayD]

5 minutes ago, Stu said:

Very curious bit of engineering! Now you have highlighted it, you can actually see that the bolts don't sit flush in their promo image but it's not something you would know beforehand.

As said, rings with non threaded holes, plus a shaped insert ie curved on the bottom to fit the ring profile and flat on top, with non threaded holes again would do the trick. Nicely anodised to match of course!

That's the thing Stu as you say, you don't really look in close detail until you have it in your hands.  I just assumed the basic engineering side of things had been addressed with something like rebated holes, similar to a dovetail.

I think the same as you, a crescent shaped insert, perhaps with countersunk bolts to fix through, although I can't see them supplying them with every set of rings, and it then takes away the tapped holes which would be used if you fit them to a dovetail.  In a way you need 2 different types, with one for dovetail fixing and one for direct fixing.

In all I think it is just the advertising that is wrong more than the rings as it is showing something which isn't right, and instead it should only show them fitted using a dovetail, and the dovetail fixed to the Eagle2, not fixed directly.

Oh well no harm done as I can return them, but I will definitely be letting Filippo know that this is something he should perhaps be looking at in more detail.

[RayD]

1 minute ago, Rusted said:

I can see their design problem.

They want it to look pretty and the rings to remain light in appearance.

They have a problem with ring clearance around fatter guide scopes.

So there isn't much room for added lugs or crescent options.

Ask them for a new set of rings with countersunk non-threaded holes. 

Just to see what they say.  

Yes I think you're spot on.  As I've just written above, it is more likely that will need to produce a dedicated set if rings solely for direct connection to the Eagle2.

[LightBucket]

The bolts not sitting flat is bad enough, but what I really don’t understand, is how they got the rings fastened tight when going through two threaded holes that is just impossible, I can’t believe for a minute they thought that was a good idea, even for someone like me with a non engineering background knows that doesn’t work, yet is shows that on there promotional video, does it actually show them screwing the rings on, as I have not watched it..?

[RayD]

1 minute ago, LightBucket said:

The bolts not sitting flat is bad enough, but what I really don’t understand, is how they got the rings fastened tight when going through two threaded holes that is just impossible, I can’t believe for a minute they thought that was a good idea, even for someone like me with a non engineering background knows that doesn’t work, yet is shows that on there promotional video, does it actually show them screwing the rings on, as I have not watched it..?

I think to screw it on with the 2 fixings they have shown you need to use M5 bolts as the ones which line up with these on the Eagle2 are M5, so they could have screwed through the tapped holes, which then leaves the issue of the poor fitting.  However, to use just the single centre fixing in one of the many M6 holes, you would be screwing threaded hole to threaded hole, which as you rightly say is just wrong.

I have dropped them a line essentially echoing this thread and my concerns to see what their response is.

[LightBucket]

7 minutes ago, RayD said:

I think to screw it on with the 2 fixings they have shown you need to use M5 bolts as the ones which line up with these on the Eagle2 are M5, so they could have screwed through the tapped holes, which then leaves the issue of the poor fitting.  However, to use just the single centre fixing in one of the many M6 holes, you would be screwing threaded hole to threaded hole, which as you rightly say is just wrong.

I have dropped them a line essentially echoing this thread and my concerns to see what their response is.

Ok, so they have used M5 bolts through an M6 threaded hole into the Eagle 2, that makes more sense I guess..

[RayD]

Just now, LightBucket said:

Ok, so they have used M5 bolts through an M6 threaded hole into the Eagle 2, that makes more sense I guess..

Well I assume that's what they've done as that is the only way I would be able to fix it to my Eagle2.  I'm guessing this isn't the intended option though as they are only supplied with M6 bolts.

It's all a mystery to me 

[LightBucket]

8 minutes ago, RayD said:

Well I assume that's what they've done as that is the only way I would be able to fix it to my Eagle2.  I'm guessing this isn't the intended option though as they are only supplied with M6 bolts.

It's all a mystery to me 

Hmmmm, very strange the reply from them will be very interesting, keep us posted..

Apart from these issues, how is the product, it’s look superb although out of my price range, I guess with the inbuilt PC it moves it a step above the Pegasus hub..

[RayD]

Just now, LightBucket said:

Hmmmm, very strange the reply from them will be very interesting, keep us posted..

Apart from these issues, how is the product, it’s look superb although out of my price range, I guess with the inbuilt PC it moves it a step above the Pegasus hub..

Will do as I think there is a few of us on here now with one so small issues like this need addressing.

Yes, so far very good indeed.  Although I haven't tested outside yet, indoors with pretty well everything running it has been faultless and all software is working fine.

I have the Pegasus hub also in my obsy and had it from when it was released, and rate it very highly indeed.  I am keeping that set up the same as I run a desktop in there, and the Pegasus does everything I want it to do and does it very well, as I am sure you are seeing also.

Whether it is worth the premium price???? Who knows, but at the moment it is what I was hoping it would be, so fingers crossed.

[LightBucket]

10 minutes ago, RayD said:

Will do as I think there is a few of us on here now with one so small issues like this need addressing.

Yes, so far very good indeed.  Although I haven't tested outside yet, indoors with pretty well everything running it has been faultless and all software is working fine.

I have the Pegasus hub also in my obsy and had it from when it was released, and rate it very highly indeed.  I am keeping that set up the same as I run a desktop in there, and the Pegasus does everything I want it to do and does it very well, as I am sure you are seeing also.

Whether it is worth the premium price???? Who knows, but at the moment it is what I was hoping it would be, so fingers crossed.

Yes, I am very please with the Pegasus too, but as I have moved away from windows to using Indi on an Raspberry PI3, I am awaiting the release of the Indi driver for the ultimate hub, (a couple of months away) then I will have a complete remote set up using Indi, so no more Serial, USB or Ascom driver issues to worry about, as they became a real nuisance...

I did think about one of those Intel compute sticks with the i3 processor to stick on the side of the Pegasus, but decides against that.....although it was recommended by Evans at Pegasus, as I think that’s what he uses...

[RayD]

5 minutes ago, LightBucket said:

Yes, I am very please with the Pegasus too, but as I have moved away from windows to using Indi on an Raspberry PI3, I am awaiting the release of the Indi driver for the ultimate hub, (a couple of months away) then I will have a complete remote set up using Indi, so no more Serial, USB or Ascom driver issues to worry about, as they became a real nuisance...

I did think about one of those Intel compute sticks with the i3 processor to stick on the side of the Pegasus, but decides against that.....although it was recommended by Evans at Pegasus, as I think that’s what he uses...

Yes I think I am one of the lucky ones in that regard in that I never seem to have USB issues (fingers firmly crossed).  I don't know why specifically, maybe cable type/length, separation, USB board, I'm not really sure.  I am also one of the very few who rates W10 pretty highly, but this may be because I only use Pro or Enterprise versions which give you much more control of what happens and when.

I've not ventured the route of RPI, and if I'm honest almost certainly won't, but I do hear good things about it.  How come you don't have USB issues then?  Doe it not use USB to communicate with the hub?  Excuse my ignorance but I know nothing about it.

Evans is a really good guy.  Many a midnight email exchange has been had as mine was one of the first ones there were a few things that needed to be ironed out, but he got on it straight away and was really grateful for the feedback.  He really seems to know his stuff and his product.

[LightBucket]

2 hours ago, RayD said:

Yes I think I am one of the lucky ones in that regard in that I never seem to have USB issues (fingers firmly crossed).  I don't know why specifically, maybe cable type/length, separation, USB board, I'm not really sure.  I am also one of the very few who rates W10 pretty highly, but this may be because I only use Pro or Enterprise versions which give you much more control of what happens and when.

I've not ventured the route of RPI, and if I'm honest almost certainly won't, but I do hear good things about it.  How come you don't have USB issues then?  Doe it not use USB to communicate with the hub?  Excuse my ignorance but I know nothing about it.

Evans is a really good guy.  Many a midnight email exchange has been had as mine was one of the first ones there were a few things that needed to be ironed out, but he got on it straight away and was really grateful for the feedback.  He really seems to know his stuff and his product.

Yes I do use USB, but it just seems to work every time with no issues, regardless of cable length, brand etc...it was always the USB to serial drivers that caused problems before, but none of them with the rpi3, it’s also the control software that is superb to, its an all in one package of planetarium and image capture software called Kstars, its as good if not better than SG pro in my opinion...and again, it just works..

Does take a bit of learning though, but once you get used to it, i for one would not go back to Ascom on a windows machine for all my equipment control...

He is very helpful, I had an issue with mine, in that the software would not, under any circumstances  connect to the hub, I contacted him and he opened a teamviewre session with me and sorted the issue within minutes, I’d was a development issue in that a driver had not been loaded into the internal memory of the unit, it’s worked flawlessly ever since....supeb after service

 Before I bought the hub, I had there version 2 focus controller, and again super service, cant rate them highly enough

[Sinan]

I know this is an older post but, since I ordered the PrimaLuceLab guide rings, the info in the post worried me. It seems like they have fixed this issue by supplying additional plates that allow the screws to sit flush against the rings. Here's a photo from their site (I will see if they work when they arrive):