Project: Skylight F15m (mini): launching at NEAF!

Feeling somewhat inspired, I've decided to take a project that has sat on my back burner for some time and bump it up the to-do list.

The basics of the project is this: Take my 100mm/F15 Skylight Refractor, and shrink it to 60mm aperture proportions. The result will be the same fusion of Victorian design and modern engineering, but in miniature. This 60mm /F15-ish refractor will have the same quality of design and manufacture, and I aim to keep the design and build even more in-house than my 100mm...thanks to recent investment in workshop tooling!

My aim is to show the Skylight F15m (mini) for the first time alongside it's bigger brother(s) at NEAF in April 2011, where I will be presenting. But until then, I will update this thread as the design and build progresses.

Feedback at all stages will be welcome, either on this thread or via pm, and all thoughts and suggestions will be welcomed.

My ultimate goal is to create a refractor that ultimately ticks the box of upholding the standard of design & quality my 100mm has set, and that of a small, affordable package.

Watch this space for more to come...

Hi Richard

I'd like to make a few suggestions, if I may.

First, make the tube 3" diameter. This will ensure the possibility of using the 3" Sky-Watcher tube rings, which will make it easy to mount and put extra accesories on it, should that be desired. A oversized tube wil also be easier to baffle effectively.

Second, use a 2" focuser. A 60mm f/15 with a 2" 40mm widefield eyepiece under a dark sky must be seen to be believed. Ultra pinpoint stars from edge to edge without any field flatteners or the like.

Third, use the 2" Baader Steeltrack on this sweet little thing. We want the best.

Fourth, the Baader Steeltrack uses Zeiss M68 threads to attach the 72mm dovetail to the tube adapter. Put at least a 60mm extension tube between the tube adapter and the M68/72mm dovetail so that the scope can be binoviewer friendly be removing the extension tube. A 60mm extension tube should be enough if the scope is set up to accept a 2" diagonal coming to focus about 40mm out, at least with a Baader Maxbright bino. I am not sure about other binoviewers. Perhaps better make the extension 100mm.

Fifth, the finderscope. A long 25mm or 30mm straight-through would look classic on a small scope such as this. PLEASE make it in brass! Power should be 8x, no higher. 10x is acceptable on a 30mm version.

Sixth, tube color. Personally, I'd like it in white with black lens cell and focuser cell and with brass finderscope with black finderscope rings.

Seventh: Looong dewcap. At least 2x the lens diameter. More like 3x. Same color as the main tube.

Maybe not what you had in mind, but hey, you wanted suggestions!


Clear skies!
Thomas, Denmark

I'll take mine with a Moonlight 3 knob focuser!
Very excited about this project, Richard... f/15's nice! CNC rings would seem to be a must... collimatable cell, as previously suggested.

I think the focal length should be at least 1000mm, although 1200mm would be even better.

I'm thinking in this 60mm it would be easy to be side tracked from the mission objective. So if you make it as a true mini version of the 100mm, I think you have a winner.

I'd like to see the tube leaning towards heavy wall thickness... something that feels like Takahashi quality... powdercoated vs. painted?
Wes

Geez, this thing is quickly going into the unaffordable territory if all the suggestions (which really are great) were to be implemented.

I'll vote for somewhere in between.


John

Geez, this thing is quickly going into the unaffordable territory if all the suggestions (which really are great) were to be implemented.

I'll vote for somewhere in between.


John

I agree...and look forward to some affordable pricing.

I'm thinking in this 60mm it would be easy to be side tracked from the mission objective. So if you make it as a true mini version of the 100mm, I think you have a winner.

I agree with Doug and I hope to see it at NEAF.

Ron

Hey Richard:
Fantastic idea. I recently picked up a Unitron 60mm so I'm into it!
How about offering some lens/cell sets for sale as well, for the most part I'm an ATM type guy and I'll bet you'd do well with ATM sales as well.

Regards,
Jim

Geez, this thing is quickly going into the unaffordable territory if all the suggestions (which really are great) were to be implemented.

I'll vote for somewhere in between.


John

I agree...and look forward to some affordable pricing.

Me too.

Geez, this thing is quickly going into the unaffordable territory if all the suggestions (which really are great) were to be implemented.

I'll vote for somewhere in between.


John

I agree...and look forward to some affordable pricing.

Me too.

Me three.

Hi All:

I agree with John - a balance is good ;-) Since this should be much more affordable than the 100, it should result in a higher volume of sales if priced at the right point. I know if your facility is not set up to do large quantity, then too low a price would not be a good thing for the supplier, but if priced like a Takahashi, it won't be a good thing for the buying community.

This could be likened to my pet peeve on the automakers - especially US: why on earth won't one of the big three give us a car that is styled like a supercar (low, wide, gorgeous curves but not too many) but performs at the 80% point so it could sell for less than $30K? I mean, how much would it hurt the bottom line to make a reasonably priced beautiful sportscar, vs a bunch of me toos? Same thing here - give it the look and feel of a fine vintage refractor of a century past without the stratospheric pricing. How about gloss black or deep red with brass (or gold anodize) cell, focuser, etc.? (There's eough white tube scopes in the world ;-) Just my two cents...

Geez, this thing is quickly going into the unaffordable territory if all the suggestions (which really are great) were to be implemented.

I'll vote for somewhere in between.


John

I for one want the scope to maintain the Victorian look!!

I for one want the scope to maintain the Victorian look!!

Me too.

Ok…there’s some nice balance in the posts here, thanks. I like balance.

First of all, I’d like to open about my schedule…I’m exhibiting at Astrofest in London on Feb 4th & 5th, and am currently working flat-out to get another new refractor ready for then. So work on the F15m will not get underway until the second week of February.

Also (like any other commercial venture) there are restrictions that I will need to work within. Building a 60mm refractor that does absolutely everything for everyone and sells for 4 figures or more is not sensible or practical... see here: The Homer

When designing my refractors, I will unashamedly admit that I build them to look at, as well as through! I think my 100mm is drop dead gorgeous (if I do say so myself :o )…and the F15m will be quite literally a miniaturization of this refractor. I love the way brass looks on black, so the F15m will be black. Out of necessity, I also have to be careful with the use of brass…brass in the modern world is treated (& often priced) like some kind of precious metal, and getting off the shelf parts can be difficult (if not impossible). However, there will definitely be brass on the F15m.

An oversize tube is not really an option for me (sorry Thomas), as the aesthetic result would simply be too lumpish for my tastes. Also, the focuser is one of my tougher decisions, as I’m unconvinced that a Steeltrack or Moonlight is the way to go…but I’ll deal with this when the time comes.

I’m not set up for volume…and I wouldn’t have it any other way! As with the 100mm, each F15m will be a labour of love, and will be unique. However, even with this in mind, affordability remains a key point for me.

At the moment, here are the few thoughts in my head (it’s mostly empty at present).

• Extra long dew shield (Thank you Thomas), made of brass (just like its’ big brother)
• Brass finder (I have some ideas here)
• Long, elegant, slender powdercoated gloss black OTA (just like its’ big brother)
• Collimateable cell
• Focuser…???

More later...

Another reason to come to NEAF 2011 .....Who know's this year it's built your own scope????????

Hi Richard

No need to be sorry! You wanted suggestions and I gave you some. Here are some more:

Focuser: As you're clearly concerned (rightly) about the scope getting too expensive, I'll suggest going for a more economical 1.25" focuser. This will also fit well with the narrower tube you seem to prefer. A good bet (ask Doug!) would seem to be the CrawMach 1.25" crayford focuser, the only 1.25" crayford made for refractors. They can customize them for you, including brass anodizing, which I think will *really* look outstanding with the black tube and yet not be as expensive as a real brass focuser. Coupled with a small brass finderscope and I think you'll have something that really stands out in the crowd!

Oh, I prefer white refractors, being a Zeiss man through and through, but that's just me.


Clear skies!
Thomas, Denmark

I for one am thrilled by the prospect of this and by my equipment list it is clear that I love 60mm achro refractors. I also looked at some of the items on the wish list of posts and the thing that concerns me is that and yes the SkyLight 100 is a gorgeous scope indeed, but I could conceivably see the 60 f/15 being more than the much maligned Parks PRT-46 at $1999.00 That scope has been the brunt of many posts that bash it and its price point. Now don't get me wrong, I know that the SkyLight will be a far superior scope but will it be within the reach of the common man such as myself or will it be elevated to the realm of only those with immense amounts of discretionary income.

I truly believe that there is a resurgence of interest in this genre of telescope and a foray into that market should be wholeheartedly embraced but it should be done so with caution and restraint.

I know that the SkyLight will be a far superior scope but will it be within the reach of the common man such as myself or will it be elevated to the realm of only those with immense amounts of discretionary income.

I don't know the price yet, of course, but the 4" f/15 that Richard makes and sell goes for the equivalent of $2,400 in the UK, so I think it's fair to assume that the 60mm f/15 will be substantially more economical and nowhere near that Parks joke. Heck, the 4" Skylight is just a little more expensive than the 60mm Parks...

My guess will be $400-500. Hey, it will have features no other commercial 60mm has had for more than four decades!


Clear skies!
Thomas, Denmark

Sounds like you're on a darn good path on this one, Richard.

I can see where the focuser will be an issue, though - it certainly doesn't need to be anything as heavy duty as the Baader Steel Track. The suggestion of using a Crawford Machine focuser (single speed) is really a good one, and wouldn't add a whole lot of cost. And .... they're typically black, which would match the black tube (which is a GREAT idea!). The only other version that is easily available is the Antares model, which I would describe as average, mainly because its much stiffer than the Crawford focuser.


John

I know that the SkyLight will be a far superior scope but will it be within the reach of the common man such as myself or will it be elevated to the realm of only those with immense amounts of discretionary income.

I don't know the price yet, of course, but the 4" f/15 that Richard makes and sell goes for the equivalent of $2,400 in the UK, so I think it's fair to assume that the 60mm f/15 will be substantially more economical and nowhere near that Parks joke. Heck, the 4" Skylight is just a little more expensive than the 60mm Parks...

My guess will be $400-500. Hey, it will have features no other commercial 60mm has had for more than four decades!


Clear skies!
Thomas, Denmark

I could do $400-$500

Sounds like you're on a darn good path on this one, Richard.

I can see where the focuser will be an issue, though - it certainly doesn't need to be anything as heavy duty as the Baader Steel Track. The suggestion of using a Crawford Machine focuser (single speed) is really a good one, and wouldn't add a whole lot of cost. And .... they're typically black, which would match the black tube (which is a GREAT idea!). The only other version that is easily available is the Antares model, which I would describe as average, mainly because its much stiffer than the Crawford focuser.


John

I have got the Crawford Machine 1.25" on my Carton 60/1000 and it is an awesome focuser! I think it would be a wonderful compliment to this whole concept.

Here is a thought - make something like a f/20, and supply quality Huygens eyepieces, that are adjustable for spacing between the elements. Now you have a scope where you can dial in the color correction to perfection, and more importantly, each customer's particular definition of perfection. Zeiss-quality customizable eyepieces for your scope. From what I've read, Huygens perform well at those focal ratios, and now, with a fraunhofer objective, you have an optical chain with only 4 elements in it total - compared to at least 6 elements for the apo triplet user with moncentric ep's, and compared to up to 10 or more for those who like the various wide angle ep's and triple or quad glass objectives. You can't compete with the short tubes for FOV, so instead go for where maybe you can outdo them - the best plantetary/binary star scope in 60mm, period. And for those applications, fewer glass is generally believed to be better. Shoot for a scope that not only can stand toe to toe with a TV60 or a Tak 60, but for those two applications, can beat them.

I'm definitely interested, and certainly another reason to get existed about NEAF.

I echo many of the feature requests above (except for the oversize tube, and don't care what color it is ), but here are a couple of my own, in order of importance:

* Please offer the option of custom fit tube rings. I know that custom-sized rings are can be ordered from third parties, but a "made to match" set would look all that much better on a scope like this.

* A wicked-long, felt-lined dew shield. I'm thinking of something sufficient to observe for 3 hours without needing to heat it. A dew shield on the finder would help, too.

* Finder scope, please make it a straight-through, and a 10x30 would work great. I think 30mm should be the minimum size. I would also like to have the finder mounted on high-stalk mountings directly on the top of the tube, rather than left offset. This would make it more convenient for equatorial mount use, and left-offset finder mounts on small scopes are not as friendly to left-eyed observers

* A custom wooden crate would be a nice addition, but I realize that this may send the price too high.

* Focuser: I've heard many good comments from observers who have used the CrawMach focusers, but have never used one myself. I would think this would be ideally suited to a scope like this.I wonder if getting brass knobs for them is feasible? Also, dual speed focusers on f/15 scopes are unnecessary.

• Extra long dew shield (Thank you Thomas), made of brass (just like its’ big brother)
• Brass finder (I have some ideas here)
• Long, elegant, slender powdercoated gloss black OTA (just like its’ big brother)
• Collimateable cell
• Focuser…???

More later...

Richard,

To help spur your thinking...

1. Also consider gloss silver as opposed to chrome as a black and silver accented scope is quite beautiful plus would be neat as the 4" would be the gold standard and the 60mm the silver standard Even with a gloss silver dew shield and finder and *focuser* (see pics) you could still have a few brass accents here and there to add to the elegance even more (like oversized brass focuser knobs, brass screws, etc.).

2. Might want to consider offering it with a multiple ocular holder as this would give it that certain vintage charm also.

3. For the finder, would not scale it smaller but keep it at no smaller than 50mm as small 30mm finders are useless IMO, difficult at best. So would rather see a beefy finder.

4. Focuser...would be nice to see something without another branding on it. Sure the Baader is nice, but would be special to see a brass finished or silver finished focuser as conveys great mechanicals of old. Again, some pics attached.

ps - all pics are from the Post a Pic of your Refractor thread here on CN...