Explore Scientific 305mm (12") Ultra Light Dobsonian

[russ.will]

I think I've probably hijacked Tom's (earth titan) thread enough. So I thought I'd post some piccies, along with my trials and tribulations of owning this scope.  For the moment, lets do the pictures:

The bearings. Two Teflon pads support the alt bearing, with three larger versions of the same for the az bearing. On both axis, these bear against aluminium that has been heavily textured with a rounded and random pattern - Like kitchen worktop on steroids. In the case of the alt pads, they project inward by 3-4mm to prevent the mirror box grinding against the rocker box. Only time will tell if this is satisfactory.

The mirror box has garnered much attention, not least because of the ability to collimate from the front, something only possible in a Newt with an open structure. In reality, it's pretty much a bog standard nine point mirror cell, but the collimation bolts sit toward the outside of the cell support sub-frame and the bolts have been turned through 180deg. Collimation is so easy after almost any other scope, it's not funny, although that doesn't mean I haven't had other collimation issues. More on this later.

There has also been much talk of the mirror restraint, which is just a couple of plastic rollers bearing against the bottome edge and a bit of padded felt at the top to stop it banging against the mirror box. Three webbing straps are glued to the periphery of the mirror and screwed to the supporting frame to restrain the mirror, should the mirror box be inverted and the mirror fall out. More on both the rollers and straps at a later date.

The R&P focuser seems to have lost it's initial slight notchiness and is lovely and smooth and could probably support as much weight as you want. However, with no vertical adjustment of the secondary mirror available, the only way I was able to center the secondary under the focuser was to use a couple of 0.5mm thick washers to tilt the focuser slightly.

Secondary cage. Confirmed - It is a cage and it has a secondary.

Out on the lawn and ready for use this eveing. Note the temporary structure to gain a crucial few inches of height, in order to compensate for the ridiculous focuser position. Even with an additional 6-7"of masonry in the equation, the EP is still 2-3" below my eye-line when standing. Below the ecliptic, it's too low for my ironing stool, so my next job is to rotate the cage 45deg to where it should be.

Russell

[SnakeyJ]

Great pictures Russ and interesting thoughts on future fettling.   Looks nice with the Right angle finder added, how has this affected the balance.

Main point I guess for most of us will be the quality of the optics - look forward to hearing more on this as the you and Tom get more use of these dobs.

[John]

It's great to see some detailed photos of one of these scopes Russell. So much more interesting than the company supplied "stock" photos. Thanks for posting them 

[baggywrinkle]

Thank's for posting Russell, as John says above good to see some detail missing from the advertising material.

[russ.will]

Great pictures Russ and interesting thoughts on future fettling.   Looks nice with the Right angle finder added, how has this affected the balance.

Main point I guess for most of us will be the quality of the optics - look forward to hearing more on this as the you and Tom get more use of these dobs.

On the basis of a mere four nights back-to-back viewing, I'd say the mirrors are par for the course in terms of Meade, Skywatcher, et al. Mars, which for some reason I've never had much success with, has ponied up more detail than I've ever seen before. The polar cap and Syrtis Major (I think - I'm not really into planetary, so stand to be corrected!) where clearly visible when the atmosphere allowed. I've also had some nice banding and cloud detail on Jupiter. However, my SW 300p Dob, which I never really loved, managed some awesome planetary detail on the rare nights that support it - One night in particular, etched detail on Jupiter in my retina, so close was it to the stacked images of the imaging boys. And yet with DSOs it was ho hum.

So I wouldn't give the ES Dob a thumbs up or down in optical terms just yet. It's why I'm never really that fussed about first light "reports". Of course people want to know whether something is good or not early doors, but I can't claim to give an honest opinion until I've had a full winter out of a scope.

No; for me at this stage, it's more about mechanical competence or not and this scope has both in equal measure.

Russell

[alan potts]

Russell,

Nice reports and superb photos.

Alan

[Beulah]

Great images. I like the design of the hinged mirror box lid; not seen that before.

[Peter Drew]

I had the pleasure last night of sharing a first light with one of these that was brought up to the Centre by one of our members. It needed collimating initially which was easy and convenient with the supplied adjusting system. The optics seemed well corrected with a very small amount of asigmatism which did not seem to affect the images of Jupiter or Mars, both showing good detail and contrast. The great view of M13 showed that the stray light screen opposite the focuser was doing a good job, a shroud, in the windy conditions would probably have made a good wind sail. The focuser was smooth in operation but had to be fully extended to reach focus with low power eyepieces. You needed a prayer mat for observing low objects but overhead ones were comfortably reached. The RDF is an early candidate for replacement!. Overall, a great telescope for the price.    

[russ.will]

I've held off mentioning the issues I've had with this scope, as I felt it sensible to let ES EU respond to a detailed email I sent them nearly a week ago. I'm still awaiting that response, but I did PM what I found to the fellow owners of both the 12" and 16" scopes on this forum so they could check out their examples - Some of my issues were/are quite serious, albeit all easily solvable if you don't mind a bit of DIY. It should be mentioned that none of the other owners suffered any of the damage I have and in turn, I believe that all of it was done in transit, although certain design weaknesses exacerbated the damage.

Upon unpacking the scope, all of the threads in the plates through which the secondary collimation screws pass, were stripped. The secondary was holding on by the skin of it's teeth, swinging around on the one screw that hadn't fallen out into the bottom of the box. Fortunately, it was well wrapped in layers of soft tissue paper and was undamaged.

Also fortuitous, the three screws that clamp the plates to the spider vanes are exactly the same thread size as the secondary adjustment screws. To solve the issue, I simply inverted the plates and utilized the three undamaged holes for the secondary adjusters and used M4x12mm bolts and nuts to clamp the vanes through the damaged holes. I also applied a dab of grease to the secondary adjusters, as steel through aluminium is a potential corrosion nightmare and never results in a smooth turning screw. They now adjust with a very light touch.

I thought that was the end of my woes, but once under the stars I seemed either to have completely forgotten how to collimate a Newtonian, or the collimation system was ineffective - maybe the collimation screws were at the end of their travel, etc? It seemed to wander off collimation every time I pointed the scope somewhere significantly different in altitude, so I resolved to wait until daylight to sort it out and do some photos for this thread. that was when the real trouble started.

Whilst looking at one of the photos, I noticed a hole where what looked like a a rivet or screw should be in the plate supporting one of the primary roller bearings. Then I noticed that there was nearly 10mm of clearance between that roller and the edge of the primary, whilst there was none at the other roller. A prod of a finger showed that the roller and it's plate could move back and forth, which was clearly not right, so the mirror had to come out. Here is what greeted me.

Both of the rivets holding the plate to the sub-frame had sheered allowing it to rock back and forth and in fact, the two rivets holding the other plate were loose too. A pair of skinny ali rivets, are clearly not up to the task of supporting the secondary if the whole package gets a good hard knock in transit. Steve, in his 16" thread, checked his rivets to find no issues, but also to note that the larger scope has four rivets per plate. The solution was to drill out all of the rivets to 4mm and use some of those short, wide self tappers you get for securing cupboard doors into chipboard/MDF. They are very good a biting into softer materials securely, as they spread their load over a large area.

Another issue I noted whilst meddling, was that the nine point flotation cell plates were screwed down hard to the sub-frame. Thus, the mirror was supported on only the six outer pads. Backing off the main supports screw, plus the ones designed to stop the plate rotating by no more than half a turn, allowed everything to float as it should. Steve found this to be the case with his 16" scope too, so I'd suggest that all ES Dobs may currently be suffering, although how much difference it actually makes may be debatable, especially on the smaller scope.

Yet another issue surrounded the roller bearings, which don't roll. The machine screw on which they rotate and it's securing nut, are tightened too hard as standard making it rigid. Now, as the roller is very hard plastic, the mirror may expand and contract without stiction across the surface anyway, but why make a roller if it's not to rotate? Again, half a turn backed everything off into free play.

Finally, without traditional mirror clips, the mirror is restrained by three fabric straps that secure via thumbscrews too the sub-frame. These are nigh on impossible to access with adult hands, but fortunately the mastic used to stick the other end of the strap to the mirror was so sloppily applied, they just pull off anyway! I'm feeling brave and have left mine off, for the time being.

I joked in Tom's (Earth Titan) thread that I'd wait for him to have problems with his scope, prior to spending my own hard earned on one. Karma has seen fit to visit upon me, all of the sorts of issues I'd hoped to avoid through the misfortune of others. The other irony (that is currently ringing in my ears) is that I am fore-sworn never to buy another Skywatcher product, precisely because I hate half baked manufacture, requiring the end user to execute modifications to make a product work as advertised. My HEQ5 was so sloppy, they might as well have sent me a bag of unassembled parts, rather than commit the sins of assembly they did and my FlexTube 300p Goto, should have been banned under trade descriptions.

No matter, you can't expect a budget scope (and this IS a budget scope) to be perfect and fundamentally the basic design and some of the novel features are very clever indeed. It's a case of some cut corners being found out by the rigors of courier delivery and only time will tell if ES EU take this on board and make the changes required. I hope they do, because it would be very 'Meade' of them if they spoiled a great product for the want of a ha'porth of tar.

Now it's sorted, the collimate-from-front-with-stick is brilliant, the structure is far better damped than I imagined and the stock focuser is one of the best I've used. The views I've had so far, have been impeded by the mirror support issues, but when collimated have been very crisp indeed. I'm awaiting a night that isn't drenched in moisture to give the now sorted Dob a good run out and it will be going up The Lakes with me in a couple of weeks - Hope springs eternal, but packed down, it takes up less space than the base alone of my old 300p FlexTube. With that scope, you tended to make darn sure the weather was forecast to be good, in order to make sure it was worth leaving a heap of other niceties behind to fit it in the car. No quandaries like that with the ES.

[Dreadz]

Glad you got yr scope sorted. I know what you mean though, you kind of expect that you'll end up making some modifications or adjustments to a "budget" scope but major repairs or alterations just to make a scope work as it should are another thing entirely! Did the packages show any evidence of being thrown around in transit when they arrived? I'd like to think it would've taken some impact to shear rivets and cause the issues you've experienced but that surely would've damaged the boxes significantly!

Sent from my GT-I9300 using Tapatalk

[russ.will]

Not if it was dropped flat on it's side, or knocked over having been stood upright. To be fair, the outer box looked scraped around a bit, but it was whole and the inner cartons everything is actually packed in, were pristine.

Russell

[SnakeyJ]

More a case of poor packaging design in this case.

Excellent report Russ and well measured. Hope ES come back with a considered response.

typed on my mobile with Tapatalk

[Ant]

Looks like a nice scope. These truss tube scopes do look really good.

However all the issues that you've had and having to fix them all yourself, with not even a response from the supplier - tells me never to buy anything from ES.

That level of customer service is appalling.

[vlebo]

I wouldn't touch one with a barge pole !!  If my scope arrived in that condition and I had no response for a week from ES I would send it back and demand a refund .  Regardless of what you pay for a scope these flaws would , for me,  be unnacceptable. Outrageous !!!

[Dude_with_the_tube]

i really hope that ES are going through the same phase what other scope manufacturers had when they first released a new scope and all these issues what Russ has mentioned are just initial teething problems and will be sorted out ASAP.But it does make me worry that there are quite a few major problems with scope what means that quality control is very low or non existing before the scope is actually packed and shipped out.Hope that improves very soon as i like the idea of compact truss design scope.

Looking forward to your first light and other reports on this scope.

Clear skies. 

[russ.will]

I do know that ES EU are in the process of moving their entire warehouse inventory, which no doubt is somewhat time consuming, but I will be expecting a response. It took them a week to respond to my initial sales inquiry, which caused them to loose an ED80 sale to a US dealer.

I stated in my email, that I was not looking for a refund, as I was likely to mod the scope anyway, but that my experience should be used by them to ensure others don't suffer similar. It is in their response to that aspect alone that they should be judged.

i also think it's a bit knee jerk and short sighted to summarily dismiss all ES products on the basis of what looks like the faults of one unlucky example. I'm sure there is at least one example of one bodged sales/technical issue from all of the main manufacturers and yet people would not be so quick to dash off Skywatcher who must number many more. They took SIX MONTHS to source me a tiny GOTO motherboard for my FlexTube 300p that would have fitted in a very small jiffy bag. I'll not damn ES after one week.

Russell

[Ant]

Based on the customer service you have received I would write off that company NOT the manufacturer (unless they are of course the same).

I needed a replacement leg for my HEQ5. ONE email and about two days wait I had a new leg in the post. This was cracking customer service from the retailer - I doubt Skywatcher or OVL ever even knew about the request.

Poor customer service will be from the RETAILER not the manufacturer. If your retailer of Skywatcher made you wait 6 months for a part - then you should be moving your purchase away from that RETAILER, not avoiding Skywatcher.

I would damn any retailer after hearing nothing for a week. If they came back and said "Sorry to hear of your issues, we are moving but will get it sorted in X days (regardless of how long X days is)" then that IMO is fair customer service - but to be ignored... that's treating customers with disdain and taking them for granted.

Ant

[GuillermoBarrancos]

Based on the customer service you have received I would write off that company NOT the manufacturer (unless they are of course the same).

I needed a replacement leg for my HEQ5. ONE email and about two days wait I had a new leg in the post. This was cracking customer service from the retailer - I doubt Skywatcher or OVL ever even knew about the request.

Poor customer service will be from the RETAILER not the manufacturer. If your retailer of Skywatcher made you wait 6 months for a part - then you should be moving your purchase away from that RETAILER, not avoiding Skywatcher.

I would damn any retailer after hearing nothing for a week. If they came back and said "Sorry to hear of your issues, we are moving but will get it sorted in X days (regardless of how long X days is)" then that IMO is fair customer service - but to be ignored... that's treating customers with disdain and taking them for granted.

Ant

Well said! And sadly, I have heard just one too many of these reports when it comes to Explore Scientific! Hence, why I avoid them like the plague.

Especially when you, like in my situation, having to import everything, deal with customs, import fees and high shipping rates. I depend on dealing with a retailer that has good customer service.

[IanWatkins]

Hi Russell,

Sorry to hear you have had problems (actually, that's all pretty bad).

It is still a great looking scope though, have you had a good observing session with it yet and can you give a rough report on optical performance?

Telescope House confirmed to me today they could get these for UK customers. My only concern would be whether they would be able to help with these types of technical issues or whether they would simply act as middlemen (plus their cut).

I'm still very tempted (I'm happy to tweak myself) as it has always been a dream of mine to have a big dob that I can drop in the car.

Cheers

Ian

[russ.will]

Poor customer service will be from the RETAILER not the manufacturer. If your retailer of Skywatcher made you wait 6 months for a part - then you should be moving your purchase away from that RETAILER, not avoiding Skywatcher.

it was OVL that failed to get the part.

They sold me it direct, but I had to wait for it to be loaded on a container, along with their quarterly stock order. I couldn't get any dealer interested, including FLO.

Thank you also for the customer service 101. As the UK customer support for an American loudspeaker manufacturer, working via the Norwegian importer into the EU, I'm fairly up to speed on this stuff. I personally hold at least two of every consumable item (drivers, crossovers, plate amplifiers, etc) for every one of our products, which being fairly high end, sell in far lower quantities than most telescopes. If I can manage that, I don't see why OVL can't hold a handful of dirt cheap electronic boards that are common across an entire range of telescopes and doubtless most of their other Alt/az products too. 

Maybe you were just lucky and they disassembled a damaged unit to get you your leg. Like i said, for every negative customer service tale, there is a positive one for most manufacturers. I'm not saying ES are good, nor that I believe a sample population of our opposing experiences is representative, but I don't buy that most of the rest (at these prices) are any better, under the wrong circumstances.

Customer service in this hobby outside of the high end, seems to stop with off the shelf replacements. In that regard, it lags behind the similarly specialist brands of consumer electronics IMHO.

Russell

[russ.will]

Hi Russell,

Sorry to hear you have had problems (actually, that's all pretty bad).

It is still a great looking scope though, have you had a good observing session with it yet and can you give a rough report on optical performance?

Telescope House confirmed to me today they could get these for UK customers. My only concern would be whether they would be able to help with these types of technical issues or whether they would simply act as middlemen (plus their cut).

I'm still very tempted (I'm happy to tweak myself) as it has always been a dream of mine to have a big dob that I can drop in the car.

Cheers

Ian

it only had brief use under less than great conditions, not to mention it was pretty much full moon. Initial impressions was that optically, it's pretty much par for the course, but that session was marred by the collimation issues, where I spent most of my time staring at airy rings as I collimated. They seemed quite nice though!

Ever since, it's been cloudy/hazy and I did waste a couple of decent nights with the ED80 triplet that arrived at about the same time, but I didn't want to used the 305 Dob until I'd sorted it. Indeed, I may take the opportunity to turn the secondary cage through 45deg - The focuser position is the only design decision that I can really gripe about - It just doesn't make any sense.

Russell

[IanWatkins]

Thanks Russell,

Hopefully you'll get a good clear night to test it in anger soon (weather willing).

Despite all the problems I would love to hear that its great to observe with, after all that is what's it all about.

I'm also confused about the focuser location, both the side it's on and the fact it's horizontal rather than the more traditional 45degrees.

Stick with it.

Cheers

Ian

[dodgerm37]

Many thanks to the Pathfinders for leading the way. I placed an order for a 12" last week. Being in the states, ES has taken their time getting the truss tubes over here. I'm wondering if solid aircraft rivets would provide a stronger connection than the hollow pop rivets that seem to be used. Hopefully the problems you have encountered will be addressed and future customers will be spared any greif. Many thanks and clear skies, Bob

[dodgerm37]

Now the bad news, expected shipping date mid to late June, at least for now. Oh well, now I've got time to locate the rivet drivers and bucking bars. I hate to wait! Bob

[russ.will]

I had a response from Tassilo over my issues which, as ever, was enormously satisfactory.

He pretty much offered a replacement straight off the bat, or parts to achieve the same result. As it's only really the primary cell/box that is the issue, I've accepted that. He also mentioned some other items, which I'm just awaiting a clarification on, that will be of interest to all current owners, as well as attaching a PDF of the English instruction manual. If you haven't received one via email, PM me you email address and I'll forward my copy.

Interesting was that the manual includes the specs for all of the ES Dobs current and planned. The 12 & 16" are a given and we knew about a projected 20", but has anybody mentioned the 10"?

Russell