Jump to content

1912116577_Solarchallenge2022banner.jpg.913a200cf105ddeae9f37765cb1d0c73.jpg

Explore Scientific 16" dob


Recommended Posts

Hi Russell,

Double-sided tape (actually thin strips of carpet tape, as that's what I already had) & cable ties. The tape is not 100% secure, but prevents lateral movement; the cable ties add security, but would not stop lateral movement. Once I'm sure I'm happy with its location (*), I'll replace the tape & ties with some 3M mounting tape (sticks like -- er -- chewing-gum -- to a Break-pile).

(*) Still undecided about the conventional finderscope. It's only a 50mm. I'm going to make an 80mm, which I think might be more useful with a Telrad on a scope of this size.

How are your quick-release mods coming on?

Also, have you received the upgrade stuff (battery box, etc) from ES yet? -- I haven't.

Link to comment
Share on other sites

Thanks Steve.

I was figuring that as the next job is to turn the secondary cage by 30-40 degrees, I didn't want to commit to a permanent mounting solution just yet. The Telrad base has two strips of tape on the bottom, but despite the fact that the finder and riser weigh nothing, a square centimetre at each corner would be a bit finger tips for my liking. i thought I could see tie-wraps in your pictures and that will do for the moment. I may, as aluminium taps with steel screws quite nicely, go for something more permanent once I've turned the cage. If I mess it up, I figure Tassilo may have at least one spare cage! ;)

Conventional, or at least RA finderscopes are leaving me a bit non-plussed at the moment. I bought an Altair 12x60 RA which I thought was quite nice, but felt the standard illuminated reticule EP was a bit weak. However, dropping the MV 24mm SWA in (supplied EP is 26mm) just created an astigmatic mess in the outer 30% of the FOV. Dropping the 20mm in brought the edges more under control, but the TFOV isn't much better than the supplied EP.

Then, on a grape induced whim, I bought an 8x50 Williams Optics RA finder and rings to fit my ES ED80 Apo, because the AA 12x60 won't fit in the Apo flight case. To say that it has blown me away, would be an understatement as the illuminated reticule EP from the AA and any 1.25" MV I care to drop in it, are pretty much sharp edge to edge. I ain't quite as bright, but by compensation it doesn't hide fuzzies in edge of field mush. I think I may make the trade of the AA for a (weird - why did ES re-invent the finder shoe) ES/Meade finder shoe, pocket the difference and enjoy the balance benefits of a much lighter finder.

I haven't done anything on the quick release front. I put that on hold pending a primary box that worked. Come pay day, I think I will spring for the QR levers for the bottom of the truss poles for starters.

The battery pack and extension tube came packed in the recesses of the foam packing for my replacement primary mirror/box. I posted piccies in my ES305 thread and whilst the extension tube is quite cute, the 8x D Cell battery pack is noting to write home about.

Russell

Link to comment
Share on other sites

  • 4 weeks later...

Very interesting thread. I am considering upping my aperture and of the commercially available scopes, this seems like the logical answer to this. (BTW 365 astronomy are now selling this in UK) 

Steve (BinocularSky), I would be very interested if you can find time to list all mods you have done, weather they are in your mind must have or just preferred (IE: Shroud a must have) and the approximate cost of all these mods.

I am very  much a out of the box and use kind of guy, however for the extra 85% OF light gathering available from this scope over my current 12", in this instance I would be prepared to do some modding to get there. 

I have checked the specs against my current 300P and the base is smaller so should be easier to move around and 23.8KG for mirror box is not to difficult to handle so more plus points.

I believe it will open up a whole new cosmos that I dont currently get with the 12". So I am very interested in this scope for this reason. My star hopping skills have improved a lot recently and so the GOTO is no longer a must and I would be prepared to forego this.

regards

Steve aka Baz

Link to comment
Share on other sites

Mods so far (Mod - perceived "desirability" - cost):

Shroud - essential - nothing (I used stuff I had in the kite-making box)

Padded Secondary " drawstring bag" with gauze dessicant pocket - essential (arachnids infest the place I keep my scope) - nothing (used stuff from the scrap box)

Storage cover - essential  (keeps dust, pollen, etc off stored scope)  - nothing (used an old car cover I had)

Truss-pole bag - desirable - as above

Telrad - desirable (the supplied RDF is truly awful) - two cable ties and some 3M mounting tape (£2.99 in Lidl); already had the Telrad base & riser

9x50 Optical Finder - desirable - nothing (I already had it)

Fan reversal - preference - 10 minutes with a screw-driver & spanner

Counterweight - essential (with the amount of stuff I'm hanging off the secondary cage) - nothing (a bit of lead flashing that I already had, bent to shape to hang off the handle on the mirror box)

Colour-coded truss poles (enables them to be put in the same place each time and also to hold the top ends before the secondary cage is on) - desirable - nothing (I have long hair and used old hair elastics (aka "ponytailers"))

In the pipeline:

Eyepiece rack on the side of the rocker box (I have the rack, just need to get round to doing it)

12x80 RA finder (again, I have the bits to make it; just need to do it - it will replace the 9x50)

Proper counterweight system (a couple of rigid "pockets" for covered-lead counterweights

QR levers on truss pole attachments (depending on an upgrade from Tassilo that is supposedly in the pipeline)

Edited by BinocularSky
Link to comment
Share on other sites

Thanks for that buddy, looking at that the only cost to me extra would be cloth for a shroud, RACI viewfinder and a dewshield (I notice you never mentioned one but I am assuming you already made one from some old material you already had ;-) heheh )

Lot of things to consider but I really need to see one first I think. New post coming up

Thanks, Steve

  • Like 1
Link to comment
Share on other sites

dewshield (I notice you never mentioned one but I am assuming you already made one from some old material you already had ;-) heheh )

Actually, no. no dew shield (But I do have the material should I find one to be necessary :grin: ). At the moment, the light shield seems to be adequate in preventing secondary dewing; a combination of shroud and boundary-layer fans protects the primary.

  • Like 1
Link to comment
Share on other sites

  • 1 month later...

OK, the battery pack and focus extension tube arrived yesterday (haven't used either). Battery pack is just a 8-D-cell pack with a long DC lead to fit the fan input, and a nylon bag to put it all in. I'll probably stick with my rechargeable lithium pack unless I decide the populated D-cell pack will make an adequate counterweight.

More to the point is the set of replacement truss-tube mounting blocks to fit on the secondary cage. I had reported to Tassilo that the thread of one of the original (ally) ones had already stripped. The replacements have a threaded steel insert and are a great improvement. The tread is recessed a few mm, which will probably aid solo set-up.

Things take time dealing with ES, but I get the impression that Tassilo is very keen to help solve any problems.

Link to comment
Share on other sites

  • 2 months later...

Hello,

Not sure if there are any other posts you did on this scope. But, may I ask how have you gotten on with it? I am thinking of upgrading my 12" to this 16" and was wondering what the views have been like i.e. Is the mirror good quality?

Also, do you think it would be possible to leave erected and move, say via a trolley/wheels? I'm presuming that the mirror box has to be lifted/slid from the rocker box once the poles are off, if you are packing it away. Further, I'm thinking of how practical it would be to leave these two bits together and then also the secondary cage on the truss poles, and all of it covered for storage, making it more of a traditional dob to setup i.e. scope onto a mount. I view mainly from home and would want to minimise time and disassembly time - don't want to be crashing about packing stuff away at 2 or 3am in the dark with neighbours trying to sleep.

I guess practicality is important to me, or I may as well keep my 12" which is a case of lift mount out, lift scope on, done. 10 -15 mins setup is fine, not hours, or I probably would never use it.

Thanks

John

 

Link to comment
Share on other sites

I've not used it since the spring, although I have done a few mods. With the short nights of summer, I find it much more convenient to cart the big binos to our observing sites, and the new "improved" streetlights have made observing from home unsatisfactory. I expect to have it out again at the next dark of the Moon, weather permitting, and I will give further impressions then.

John, whilst it would be possible to leave the mirror box in the rocker box and "trolley" it, I don't think it would be practical to leave the truss poles and secondary cage assembled - too much torque on attachment blocks that are not designed for it. The last time I did it, transporting the bits 100m from the car, settign up and tweakign collimation took just under half an hour. I'm considering modding the secondary attachment to truss poles to QR levers, which should make the whole process a lot less fiddly, but I want to see what the new attachment blocks (mod sent out by Tasilo) are like in practice in the dark before I do this.

Link to comment
Share on other sites

Hi thanks for that. Look forward to your thoughts when you've used it a bit.

I suppose attaching poles to the secondary would only take a couple of moments once you knew how. Bit worried that doing it a lot would cross thread or strip threads though. However, lifting this large 12" about in the dark especially when the tube is damp, I worry for my back and dropping it.  The 16" truss would save weight, but I'm not sure I'd want to be taking a secondary cage off of 4 poles in the dark when fingers are a bit cold and I'm tired. Lots to think about!  

John

Link to comment
Share on other sites

I've not used it since the spring, although I have done a few mods. With the short nights of summer, I find it much more convenient to cart the big binos to our observing sites, and the new "improved" streetlights have made observing from home unsatisfactory. I expect to have it out again at the next dark of the Moon, weather permitting, and I will give further impressions then.

John, whilst it would be possible to leave the mirror box in the rocker box and "trolley" it, I don't think it would be practical to leave the truss poles and secondary cage assembled - too much torque on attachment blocks that are not designed for it. The last time I did it, transporting the bits 100m from the car, settign up and tweakign collimation took just under half an hour. I'm considering modding the secondary attachment to truss poles to QR levers, which should make the whole process a lot less fiddly, but I want to see what the new attachment blocks (mod sent out by Tasilo) are like in practice in the dark before I do this.

Have you received the attachment blocks yet?

Russell

Link to comment
Share on other sites

Thanks for that. Definitely be easier on the other side as it won't be in the glow of the streetlight in my garden but in the 'dark' patch.

I'm pretty much sold on this scope. I think this scope and 2 or 3 ES 82 deg eyepieces and coma corrector will be a good investment of £2k. After much thought, I'm willing to invest 10 - 15mins assembly time, if it means I don't have to lift and stumble about with a large solid tube as I do at the moment. My back will thank me, and then there is no chance of an accident happening in the dark.

I would have to make a shroud and would also need to cover the secondary and the handles in the mirror box as I don't believe they'd escape the streetlight glow around here. Best get researching sewing skills!

I'm just wondering, how thick would the material need to be to be an effective shroud? Also, any chance of material seeping water through and then dewing up?

John

 

Link to comment
Share on other sites

I'm just wondering, how thick would the material need to be to be an effective shroud? Also, any chance of material seeping water through and then dewing up?

Ideally, shroud material will be hydrophobic (e.g polyester, dacron, etc.) Mine is PU-coated ripstop nylon, approx 50gsm, which is not ideal but it's what I had in my kite-making box (I'll proibably eventually make a dacron one). Avoid cotton, it's hydrophilic and will get very soggy on a dewy night! Sew it with a decent polyester thread like Gutermans. If it's opaque, it will also act as a light guard.

Dew won't be caused by water seeping through; it forms on the mirror when it cools below dew point. The idea of a shroud is to reduce  radiative cooling by masking part of the sky to which the mirror can radiate. Of course, if you have a soggy shroud, you will increase the relative humidity inside the shroud, and hence elevate the dew point. This is one reason I have my shrouds open near the mirror box: it allows a circulation of air. Also, the boundary-layer fans on the ES will keep the air against the mirror from getting too humid.

Link to comment
Share on other sites

Hi,

Thanks again.

Would you recommend coating the shroud in waterproofing stuff, like for tents then? As I know when I had my car cover, if it was waterproofed it didn't get as wet and drenched, as most of it beaded up and dripped off.

John

Link to comment
Share on other sites

Just wondering - is this telescope still being produced? 

I don't see it listed on ES's website (no dobsonians listed):
http://explorescientificusa.com/collections/telescopes
 

And at some point the last week (because I know I did look last week), it has dropped off the canadiantelescopes website:
http://www.canadiantelescopes.com/Shop-By-Type/Dobsonians_2/Explore-Scientific-16-Truss-Tube-Dobsonian_2.html

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.