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Post by Ron Walker on Jun 13, 2022 14:36:02 GMT -7
Posted by: Philostopher1 Feb 10 2018, 07:47 PM Project update February 10 2018 SW Oregon has had unusually nice weather this last week which has made it pleasant to work outside in my little tin shed-shop. During the prior weeks while fighting with Seasonal Depression, I managed to settle a few things. First, is after months of research and deliberation my light source is a single cree xq-e hi led through a MIAO Lab super fisheye lens per starball\hemisphere. I believe it is the best source for point size intensity and color balance. So that has prompted the development of an occultation system which I wasn't planning other than the projector stand area. I attached a picture of the "eyelids" below. There are two per lamp. The eyelids roll over one another so when the projector is pointing up a single 1/4 sphere folds back below the lamp\lens. As the projector rotates the cups will move out and form a complete hemispherical cup when the projector is pointing down etc. I'll post the mechanics once their done. These are made from Cinefoil that was formed in a plastic 3" "bath ball" ornament thing. The next pictures are the fork. It's not done either but I am making good progress. Considering, most of the pieces were cut with a saber saw it's turning out ok. I'll fix visual Aesthetics later with ABS slurry and paint. Finally, for this update, I have decided to just drill the aluminum hemispheres I have. I tried multiple times to produce a carbon fiber hemisphere and it just becomes a frustrating mess. There is a real art to carbon fiber. It needs to be pre impregnated and vacuum formed to get the beautiful quality. I don't have the set-up or experience to pull it off. I had an "A-ha!" moment regarding drilling stars for fun, efficiency and accuracy. Maybe, I read something like this here many years ago and it percolated up through the noise in my consciousness. First, there is a celestial sphere available here that can be made into a paper model. It was spherically mapped based on Hipparcos (I think). Anyway, you can select the magnitude you want up to sixth. Labels, gore numbers etc. here: www.suopte.com/en/apps/stellasphaera.phpI am going to approach it this way. 1. Download the Stellaspaera pdf. I am going with 6th magnitude, 36 longitudinal sections with 18 latitude. This is the highest resolution offered. These get imported into photoshop, scaled for my hemisphere and then reversed. The sections will then get wallpapered to the outside of my hemispheres. Now I have a drilling template. 2. The same process is done again for the inside of the hemispheres with non reversed charts. The charts are then laid over cinefoil and tacked down with repositionable adhesive (3M Super 75). Now the foil can be punched through with a needle or drilled holding a pin vise with the tiny drill bits. 3. The hemispheres will have some orientation markers scribed into the aluminum inside and out so that the outside and inside are geometrically aligned. Now one section of the cinefoil pinholes can be aligned and affixed inside the hemispheres thereby properly aligning through the larger holes outside. I have been discussing this quite a bit (no pun). I want to get away from dealing with drilling #80-ish holes through 1\8" hemispheres. Been there and done that and it was very frustrating. Rather the smallest holes will be 2mm through the aluminum. In the situations where there are a few very close stars there will simply be a larger hole with the cinefoil pinholes behind it. In most cases, particularly for 1mm pin holes there will be a small standoff tube pressed into that hole, acting as a stub for lenses. This will continue down through 4th magnitude wherein a "bugel bead" will be pressed and affixed in place. I want to have the freedom to install lenses on lower magnitude stars. I am looking into optical injection molding companies that can make a 3mmx 250mm fl lens. I'll leave it here for now.
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Post by Ron Walker on Jun 13, 2022 14:36:36 GMT -7
Posted by: Philostopher1 Feb 10 2018, 07:55 PM QUOTE(Ron Walker @ Nov 26 2017, 10:48 PM) * So the timing belt will be glued down with the teeth facing out. Will you run a larger belt around that one or just drive with a smaller metal gear?
Since I hate almost anything computer controlled I will wish you luck. My solution would be to incorporate the 23.5 degrees in the mechanics of the projector. Then just simple motor control. With this drive you must drive the 23.5 degree motor with the diurnal drive. Nothing will work if the computer goes down. But that's just me as all that stuff is beyond me.
Warning! Warning! Warning! Will Robinson!
I have to rebuild the diurnal hub. Damn. I learned the hard way that one can not simply reverse a belt and drive it with another belt. At least not with an HTD 3m. It seemed like a good idea but the drive belt teeth wont mesh as the drive belt curves in, and the sprocket belt curves out. DUH! More credits in the School of Hard Knocks towards my Planetarium Science degree.
So I bought three new matched belt and pulley sets from BB Manufacturing. I am going with GT3 profile. It is the kind of profile that is used in precision CNC machines...
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Post by Ron Walker on Jun 13, 2022 14:37:25 GMT -7
Posted by: Ron Walker Feb 10 2018, 09:08 PM QUOTE(Philostopher1 @ Feb 10 2018, 07:47 PM) * Project update February 10 2018 SW Oregon has had unusually nice weather this last week which has made it pleasant to work outside in my little tin shed-shop. During the prior weeks while fighting with Seasonal Depression, I managed to settle a few things. First, is after months of research and deliberation my light source is a single cree xq-e hi led through a MIAO Lab super fisheye lens per starball\hemisphere. I believe it is the best source for point size intensity and color balance. So that has prompted the development of an occultation system which I wasn't planning other than the projector stand area. I attached a picture of the "eyelids" below. There are two per lamp. The eyelids roll over one another so when the projector is pointing up a single 1/4 sphere folds back below the lamp\lens. As the projector rotates the cups will move out and form a complete hemispherical cup when the projector is pointing down etc. I'll post the mechanics once their done. These are made from Cinefoil that was formed in a plastic 3" "bath ball" ornament thing. The next pictures are the fork. It's not done either but I am making good progress. Considering, most of the pieces were cut with a saber saw it's turning out ok. I'll fix visual Aesthetics later with ABS slurry and paint. Finally, for this update, I have decided to just drill the aluminum hemispheres I have. I tried multiple times to produce a carbon fiber hemisphere and it just becomes a frustrating mess. There is a real art to carbon fiber. It needs to be pre impregnated and vacuum formed to get the beautiful quality. I don't have the set-up or experience to pull it off. I had an "A-ha!" moment regarding drilling stars for fun, efficiency and accuracy. Maybe, I read something like this here many years ago and it percolated up through the noise in my consciousness. First, there is a celestial sphere available here that can be made into a paper model. It was spherically mapped based on Hipparcos (I think). Anyway, you can select the magnitude you want up to sixth. Labels, gore numbers etc. here: www.suopte.com/en/apps/stellasphaera.phpI am going to approach it this way. 1. Download the Stellaspaera pdf. I am going with 6th magnitude, 36 longitudinal sections with 18 latitude. This is the highest resolution offered. These get imported into photoshop, scaled for my hemisphere and then reversed. The sections will then get wallpapered to the outside of my hemispheres. Now I have a drilling template. 2. The same process is done again for the inside of the hemispheres with non reversed charts. The charts are then laid over cinefoil and tacked down with repositionable adhesive (3M Super 75). Now the foil can be punched through with a needle or drilled holding a pin vise with the tiny drill bits. 3. The hemispheres will have some orientation markers scribed into the aluminum inside and out so that the outside and inside are geometrically aligned. Now one section of the cinefoil pinholes can be aligned and affixed inside the hemispheres thereby properly aligning through the larger holes outside. I have been discussing this quite a bit (no pun). I want to get away from dealing with drilling #80-ish holes through 1\8" hemispheres. Been there and done that and it was very frustrating. Rather the smallest holes will be 2mm through the aluminum. In the situations where there are a few very close stars there will simply be a larger hole with the cinefoil pinholes behind it. In most cases, particularly for 1mm pin holes there will be a small standoff tube pressed into that hole, acting as a stub for lenses. This will continue down through 4th magnitude wherein a "bugel bead" will be pressed and affixed in place. I want to have the freedom to install lenses on lower magnitude stars. I am looking into optical injection molding companies that can make a 3mmx 250mm fl lens. I'll leave it here for now. I never thought that a LED would be small enough but that one is 1.6mm x 1.6mm which is fairly small. Then placing it in a fisheye lens would make it smaller. From looking at the lens I wonder if it will be viewable a full 180 degrees. The thing that is unique to the Spitz fisheye is that the lens literally has a deep depression into which the bulb is placed and one can see the arc gap or the filament well past the 180 degree point. That will be an interesting experiment. As for drilling the small holes, It might be interesting to seeif you can use a drill stop on an 1/8 inch drill and go 3/32nds of an inch and then finish off with the #80. Actually probably the drill stop at 1/16th as the tip of the drill is tapered and will go a bit further. The #80 will tend to drop to the bottom of the tapered hole and align properly without any problem. You could even put in clear colored gels in the 1/8 inch part if you wanted to color the stars. I am just having a problem with trusting the alignment of the cinefoil behind the holes glued to the curved surface of the globe. Also you might look into lenses that are more like 1/4 to 3/8 in diameter as they will be easier to form and thus cheaper and much easier to align. Remember that Sirius will be at least 1/4 inch in diameter behind the lens.
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Post by Ron Walker on Jun 13, 2022 14:37:55 GMT -7
Posted by: Ron Walker Feb 10 2018, 09:21 PM QUOTE(Philostopher1 @ Feb 10 2018, 07:55 PM) * Warning! Warning! Warning! Will Robinson! I have to rebuild the diurnal hub. Damn. I learned the hard way that one can not simply reverse a belt and drive it with another belt. At least not with an HTD 3m. It seemed like a good idea but the drive belt teeth wont mesh as the drive belt curves in, and the sprocket belt curves out. DUH! More credits in the School of Hard Knocks towards my Planetarium Science degree. So I bought three new matched belt and pulley sets from BB Manufacturing. I am going with GT3 profile. It is the kind of profile that is used in precision CNC machines... Since I am the "overkill king" I would go with this as your main drive pulley: www.bbman.com/catalog/product/72-5P09-6A5 But that is just me and this is your main drive. The big diameter will engage a lot of teeth and not pop out or off. For your drive pulley you can make any size you like just get one with flanges to hold the belt in line.
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Post by Ron Walker on Jun 13, 2022 14:38:14 GMT -7
Posted by: Ron Walker Feb 10 2018, 09:36 PM QUOTE(moonmagic @ Nov 28 2017, 08:09 AM) * Just so you know others are still following along and find it all very interesting. 99.9% is above my head, but none the less I am so impressed with the level of workmanship. I'm glad Ron is able to grasp all of this. I think Ron can make anything work! mm
You give me much to much credit Mr. Moon.
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Post by Ron Walker on Jun 13, 2022 14:39:16 GMT -7
Posted by: Philostopher1 Feb 10 2018, 10:24 PM QUOTE(Ron Walker @ Feb 10 2018, 09:08 PM) * I never thought that a LED would be small enough but that one is 1.6mm x 1.6mm which is fairly small. Then placing it in a fisheye lens would make it smaller. From looking at the lens I wonder if it will be viewable a full 180 degrees. The thing that is unique to the Spitz fisheye is that the lens literally has a deep depression into which the bulb is placed and one can see the arc gap or the filament well past the 180 degree point. That will be an interesting experiment. As for drilling the small holes, It might be interesting to seeif you can use a drill stop on an 1/8 inch drill and go 3/32nds of an inch and then finish off with the #80. Actually probably the drill stop at 1/16th as the tip of the drill is tapered and will go a bit further. The #80 will tend to drop to the bottom of the tapered hole and align properly without any problem. You could even put in clear colored gels in the 1/8 inch part if you wanted to color the stars. I am just having a problem with trusting the alignment of the cinefoil behind the holes glued to the curved surface of the globe. Also you might look into lenses that are more like 1/4 to 3/8 in diameter as they will be easier to form and thus cheaper and much easier to align. Remember that Sirius will be at least 1/4 inch in diameter behind the lens. Hi Ron! Ihadn't thought about the drill stop idea... I am going to give this some thought. Maybe if I get a flexi shaft dremel and a small chuck or collet for it for the #80, 85, and 87 bits, I could hold it like a pencil It would be much easier than having to build a jig. There would be a more direct light touch feel too. Hmmm. Bits smaller than #80 run about $7- bucks each. Perhaps the foil would be a good candidate for these 5.5-6th magnitude stars. Great idea! I think I might run with it! In regards to the lenses, the 3mm lenses I mentioned are for 1mm holes and smaller. At the moment I have 50- 10mm x 250mm PCX lenses, and 35- 9mm x 250mm PCX lenses. The fisheye I mentioned is 238 degrees. I believe that ASH Enterprises is using a very similar lens for their LED drop in lamps for the Spitz A3P, 512, and 1024. Also, as of this moment the Cree XQ-E is the smallest and highest luminous intensity available. The great thing is that point source light sources are highly desirable so there will be smaller brighter leds coming along. There are single wavelength side emitting leds that emit from a .623mm emitter, but they are only about 30 lumens. The cree led is capable of nearly 300 if over driven. Interesting to note that the Spitz model B Sylvania zirconium arc lamp only put out 25 lumens! Must have been a long dark adaptation for the audience pre show. blink.gif The Ash lamp assy
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Post by Ron Walker on Jun 13, 2022 14:42:14 GMT -7
Posted by: mrgare5050 Feb 11 2018, 03:16 PM Question for you Jamie - we are trying to figure out how to get more posters like YOU to participate in Observatory Central (its a long story why its called this) .. question.. how did YOU find OC? If you take part in this survey, Ron will send you a free gift. Maybe.
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Post by Ron Walker on Jun 13, 2022 14:42:42 GMT -7
Posted by: Philostopher1 Apr 1 2018, 12:05 PM April 1st 2018
Project update
The weather has been pleasant enough to spend more time in my tin shed\shop so I got a little more done.
shop
Earlier, I posted some progress on the fork, and found that I had to rebuild my diurnal axis hub due to an error in judgment. That was mistakenly assuming I could use one timing belt turned inside out as a pulley on the hub. The teeth on the belt when turned inside out increase their angle, while the belt with the teeth on the inside form a narrower angle, thus they don't mesh together. Live and learn.
The new diurnal hub and the latitude hub:
The yaw hub turns the entire projector from the base of the fork. I used 4" abs 2-4" adapters and cut and sanded them down as needed. The pulleys are off the shelf GT3 timing pulleys often used in CNC applications. Getting the abs parts concentrically centered wasn't easy. They may be off by as much as 200 microns. Doing all this with a cheap drill press with runout isn't easy. The pulleys were carefully marked and the abs parts got some fast drying epoxy and were set, positioned and centered over the pulleys with stainless steel nails for support pins. Fortunately, when the pulleys were machined very fine concentric tooling marks were left to measure and align to. Then I potted them with epoxy resin.
Here's the fork with all the parts mentioned. The carbon Fiber is on but not finished. There is one more session of sanding, one more epoxy coat and one final (hopefully) sanding and finishing run. So far there are six layers of epoxy...
And here's the beginning of the carbon fiber
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Post by Ron Walker on Jun 13, 2022 14:43:00 GMT -7
Posted by: Strgzr Apr 1 2018, 12:33 PM WOW! Beautiful Work!
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Post by Ron Walker on Jun 13, 2022 14:43:22 GMT -7
Posted by: Philostopher1 Apr 1 2018, 07:37 PM QUOTE(Strgzr @ Apr 1 2018, 11:33 AM) * WOW! Beautiful Work!
Thank you! It's challenging with simple tools. I have a "Bob's CNC" but I don't have room for it in the shed. Also, it needs an epoxy or varathane coating to tolerate the radical temperature changes in my shed. Aside from those excuses, there is the "old dog new tricks" psychology at play.
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Post by Ron Walker on Jun 13, 2022 14:43:40 GMT -7
Posted by: Ron Walker Apr 2 2018, 12:58 PM Looking good. Just can't wait to see what you do with the planet projectors.
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Post by Ron Walker on Jun 13, 2022 14:43:57 GMT -7
Posted by: moonmagic Apr 2 2018, 03:10 PM Still "lurking about" and continue to be fascinated with your skills. Enjoy every picture and post. mm
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Post by Ron Walker on Jun 13, 2022 14:44:14 GMT -7
Posted by: Philostopher1 Apr 7 2018, 08:11 PM Update
April 7 2018
It's been a productive week.
I got the central hub cut out, and fitted for the lattitude axis.
It was tricky getting all this squared and centered. My drill press has about 0.5-1mm of run out depending on the weather or it's mood that day. So throughout this there is this bit of persistent error. I really should have bought a simple lathe for this. Oh well.
All this will get painted of course.
Here's the hub with the bearing tubes before being jigged squared and drilled.
The hub with the parts jigged and drilled
The latitude extension tubes with the bearings on. That aluminum disk holds one side of the diurnal bearing, and provides the slip rings mounting surface.
Here's the diurnal slip rings with the plate and cut outs for the wires.
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Post by Ron Walker on Jun 13, 2022 14:44:32 GMT -7
Posted by: Philostopher1 Apr 7 2018, 08:24 PM QUOTE(Ron Walker @ Apr 2 2018, 11:58 AM) * Looking good. Just can't wait to see what you do with the planet projectors.
Thanks!
I am planning to set them up around the main projector like RSA Cosmos, and the newer designs. My project is very much oriented around the RSA Cosmos systems. Basically individual projectors like little moving light heads in synch with some protocol TBD.
Here is one of theirs
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Post by Ron Walker on Jun 13, 2022 14:44:49 GMT -7
Posted by: Ron Walker Apr 8 2018, 12:47 PM That is more then fantastic work!
What are you using for brushes on the slip rings, and how did you make the? We love details and close up picture.
This is some superb work. Also, I would not worry about that 1mm out of round problem. If you were making a jet engine that rotated at 20K rpm I could see a worry. The nice thing about planetariums is they move very slowly and any shifting will be absorbed by the timing belts. This will work fine.
The "protocol TBD" is what terrifies me. Trusting computers has never been a strong point with me. I wish you luck on that one.
Otherwise exemplary work!!! Keep at it!
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