This fall, I decided that it was time to stop reading up on things and start doing things.  My completion of that constant travel down to Texas, Evan’s full time job, and Erin’s full-time student-ship means that I now can make the spare time to do whatever I had previously been dreaming of.  Since that time I have, in no particular order, done all of the following:
1)    Scraped the popcorn off the kitchen ceiling.
2)    Re-skimmed it.
3)    Put in recessed lighting.
4)    Bought under-cabinet lighting.
5)    Scraped, skimmed, and painted the laundry room and hallway ceilings.
6)    Cut a set of Catan pieces on the FabLab laser cutter.
7)    Made a second set of those as a gift.
8)    Made a wooden box for the above.
9)    Made a laser-cut shape sorting box as a toy-making experiment.
10)    Bought and assembled a Stirling engine.
11)    Made a laser-cut dust cover for it.
12)    Designed some laser-cut Christmas ornaments.
13)    Also drew up the gears and other pieces for another orrery.
14)    Bought the rough cherry lumber for a queen sized bed that will go into Evan’s old room.
15)    Completed a chip separator for my shop vac to make any further woodworking easier to clean up after.
16)    Aquired several miscellaneous woodworking tools and learned to sharpen all my edged tools.
Things are moving along nicely.

Advertisements

This is a tale of a father-daughter project. Like most projects that you design from scratch, it took longer than originally anticipated but it was worth doing in many ways. You’d think that as a scientist and engineer who has done nothing but research and development for my entire career, I’d be used to this by now and I guess I am; I don’t get upset when projects run on and on. But I never have learned to estimate the timeline of one either.

Anyway… As soon as I joined the Tulsa FabLab, Erin immediately envisioned making her own set of custom game pieces for Catan. She wanted to cut them out of wood and maybe make a box to put them in. I started immediately; she would have also if she hadn’t been taking 18 hours this semester in engineering so she can be excused for not doing most of the work herself.

I found the basic shapes on thingiverse.com and made some modifications. She took that file and made some refinements of her own and I then took it back and made sure the line widths were what they should be to make the laser cut or engrave.

I designed a gift box for them all to be stored in and she came up with some initials to be engraved on the top. Then, the day before Thanksgiving, we went to the FabLab where I had reserved two hours and cut it all out.

I really enjoy these collaborations; there are a fairly limited number of things that dads and daughters can both really enjoy doing together and this is one that works for us since we’re both engineers.

As to the woodworking aspects of the project, there is much to say. The game pieces are flat which makes this the perfect project for a scroll-saw or laser cutter. In fact, one day when laser cutters become the same price as scroll saws, they will take over that market because they not only do the same job but do it perfectly as well as offering the option of engraving (by burning only the surface).

The gift box is another matter. Because the laser cutter is basically a high-tech scroll saw, the project either has to be made out of only flat pieces or require some work with other tools after the pieces are cut. The latter is nothing new to woodworkers, in fact all real projects are like that. For the propeller-head crowd that flock to laser cutters, that is a bit of alien thought. I was on a timeline and really didn’t want to bother with creating a groove that the box bottom could slide into so I just cut the bottom to the real outside dimension of the box and glued it on. It’s plywood so that should be OK.

But first, a word on plywood. I bought a sheet of stuff at Lowe’s and it is the crappiest piece of material I have ever encountered. The 4×8 sheet was flat when I bought it (and, after all, isn’t that what plywood is engineered to be?) but as soon as I cut it into laser-cutter-sized pieces, they warped a bit. HOW CAN PLYWOOD WARP? That’s the one thing it is NOT supposed to do!

Anyway, I put the piece on the cutter and forged ahead. The first pass is usually the engraving pass where the laser head goes back and forth over the wood in a raster pattern and burns the top surface at low power. Some wood is vaporized and so there is definitely a change in thickness that you can feel but mostly the burning turns the wood black and makes an image. In my particular piece of crappy plywood, the veneer was so thin that it just burned through to the next layer. Strangely, the thickness was just enough to burn off the veneer but not char the next layer (which the guys up at the FabLab had never seen happen) and as such, it looked a bit weird. The second layer had some sort of light-dark pattern in it (like spalting) which showed through in the images and made them look completely strange. I did not have enough time to run it again since somebody was waiting to use the machine after me so I just took them home and decided to stain them.

So we took them home and applied some stain. I used whatever I had laying around from my last project and we brushed it on pretty thick and immediately tried to sort-of squeegee it off the top surface and leave it in the engraved parts to make them really dark and enhance the contrast. This mostly worked.

As to the joints, finger joints are a natural for the laser cutter and I very much like not having to have my fingers so near the cutter like you do when making these on a table saw. And, since the thing is so precise, they fit perfectly. At least in the finger-width dimension. The design assumed a full ¼” of plywood and of course it was less than that so the fingers were too deep, leaving some of the finger sticking out beyond the box. This is easily remedied by a disk sander but my daughter decided that it was fine the way it was. She does not have the typical woodworker’s aversion to this sort of thing and so I agreed to leave it.

This is where a ‘parametric’ design tool would be handy (the high-end CAD systems are like this). You would tie that dimension to a user input and, after measuring the material with a caliper, you would enter this and the design would adapt accordingly. But I didn’t have that software.
Another interesting phenomenon that I did not expect was the smoke marks on the “exit” side of the laser beam. The material sits on a metal honeycomb and air is pulled downwards through the machine to pull the smoke out as well as hold the material firmly in place. In my case, since the plywood was warped, as soon as one piece was cut out, there was no more partial vacuum to hold the piece flat and it warped upwards which let the smoke swirl around a bit underneath the material. This left smoke marks on the underside. Again, this is easily sanded out which we did.

This plywood took stain very strangely. One side blotched worse than anything I had ever seen. The “good” side would blotch in long lines that must have corresponded to something underneath the veneer but was most annoying. But it was not annoying to my daughter; she was totally happy with the result and therefore so was I. My alternative was to start over. We had put a sealer coat of shellac on the game pieces before the stain but for some reason I forgot to do the box pieces.

Again, my daughter was satisfied. Together we bought some brass hinges and a latch and installed these. I let her do most of this and one of the hinges ended up really crooked. We thought about it and decided to let this stay as it was and not try to fix it – mostly because she was returning to the university and wanted to check the project off her list. This is a gift so she needs to have it done and wrapped very soon.

After a number of coats of blond shellac, it looks pretty darned good – even in spite of the lousy plywood. And a good time was had by all. So, shop time, daughter time, and something completed. Check, check, and check. That’s something to be thankful for – and on the Thanksgiving holiday too!

20121126-131730.jpg

Mel is mentally gearing up to start a new job and wanted to take one more little short getaway before she goes into a situation where she has no time off for the foreseeable future.  So we went to Branson.
If you can’t think of anything to do, you can always go to Branson or (if you’re addicted to losing your money) Las Vegas.  I wasn’t terribly enthused about it but that’s because I have no vision.  We actually had a very good time.
Mel found a nice place called “Still Waters” resort where we could have spent all our time without ever leaving the property.  But the package came with tickets to both Dixie Stampede and Silver Dollar City so we actually spent very little time at the resort.
I have been to Silver Dollar City many times; mostly as a kid.  My enthusiasm for it was at a low ebb since all my memories were of running from one scary ride to another (both when I was a kid and with my own kids).  I’m done with rides – I just don’t care any more.  They don’t interest me at all.  But a coworker mentioned that there is a lot to do there that doesn’t involved riding anything.  I had forgotten about all the craftsmen.  And, as it turned out, it was the “Harvest Festival” during which they bring in even more craftspeople for you to watch.
I thoroughly enjoyed the day. I got to watch and talk to three blacksmiths, three woodcarvers, and a guy who took trees and made them into square beams for building houses.  Not sure what that guy’s description is.  There was also a guy there with a strange little sugar-cane-squeezing mill turned by a mule walking in a circle which was good for a few minutes of entertainment.  The day passed very quickly.
We also went to the Titanic Museum which was pretty fun as well.
When it came time to return home we decided to go home another way.  I had read a couple of years ago about the Ozark Medieval Fortress, a castle under construction using medieval-period techniques but I should have done my homework: they are closed – probably forever due to lack of funds.  We drove up to the entrance but two trees were barricading the road.
I quickly reset the GPS to take me to Eureka Springs.  We made it there in time for lunch and then strolled around a bit until our parking meter ran out of time.  Then I called the number for Old Street Tool; two guys who make wooden handplanes for use in making moldings the old fashioned way.  They don’t really have a storefront; just a shop in the basement of Larry’s home.  They apparently feel that if anybody is interested enough to seek them out, then they probably will enjoy talking to them so he invited me over.  He even volunteered to come downtown and lead me over to his house.  I managed to find it by myself but not without calling him a second time to make sure I was headed down the right track.
It was really fun chatting with a master on the subject of his mastery and I would have paid money for the time I spent with them but they gave me their time freely.  I even got a bit of tutoring on proper technique.
So after littering their floor with shavings, we then headed out – back towards highway 412 which leads homeward.  We got back at 6:30 and Erin arrived soon afterwards for her fall break.  It was a pleasant way to spend a few days.

Last Tuesday I went into the ophthalmologists office for a YAG Laser Capsulotomy.  That’s the thing where, after cataract surgery, you develop another cataract on the rear surface of the lens capsule.  This happens about 80% of the time; I have no idea why proteins would decide to condense on a surface where they never did before but that’s what happens.  The YAG laser just burns a hole in the capsule so you can see through it.  This was quick and painless although I did have to actually go to the hospital to have it done.
The doctor told me earlier in the year that they had a laser in his office and would do this procedure there but apparently in the intervening months they were told that in order to work with Medicare, they had to do every procedure in a “real” hospital so I had to go there.  I don’t think the total experience was any different.  It literally took 30 seconds.  I could see better by the next day.
My follow-up was yesterday and I was told that although I had a slight astigmatism in my right eye, it was not really worth doing more surgery on.  All necessary procedures are included in the price that I’ve already paid so I can legitimately insist on it but my vision tests out at 20/20 and I’m not sure it’s worth it.  He is totally willing to go ahead with it but I’m going to let it ride for awhile and see what I think in six months when I have another follow-up.
So I guess that’s all over.  For awhile there, my vision was seemingly getting a bit worse but about a month before my last follow-up, I began to see noticeably better and that has remained.  After the YAG laser, I can see noticeably better still. I still don’t think it’s as good as I used to be able to see with glasses. Maybe it’s because I can only focus at two places – the doc says that this should improve with time.  Somehow (perhaps wishful thinking) I had the idea that my brain would figure out how to focus at all distances in about two weeks but the doc says it can take a long time.  As in a year or more.  Still, that makes me hopeful.  Last week while looking at displays in a museum I had to either get right up on a placard to read it or stand 10 feet away or so.  But I’m pretty much back in the saddle, optically speaking.

I’m going to attempt to describe what it’s like to go through cataract surgery and be as detailed as possible.  Most people seem to just have the surgery and tell others “Yeah, I can see great!”  I’ve talked to some of these folks and when you dig hard, I’ve found that their vision was not so great at first and that it took about two weeks to return to normal.  So I have to conclude that most people try to put it all behind them and talk in vague generalities.
Well, I’m going to try and remember everything.  Plus, I read some personal testimonials at various websites and a large number of those are poorly written or obviously written by somebody who had a bad experience and was angry about it.  Lots of posts were written in all-caps; I always discount those.  Nothing was terribly useful to me so here is my experience.
I got an IOL called the “Tecnis Multifocal”.  There are several different models but I don’t know what the differences are.  I have a wallet card that I’m supposed to carry for some reason but it says that the prescription is about +20 diopters.  The diopter is the reciprocal of the focal length of the lens.  I’ve always wondered why optometrists use the term diopter rather than focal length like the rest of the optics world.  If one is the reciprocal of the other it seems that one would be as useful as the other. I’ve since learned that you can get contact lenses like this.
Right after the surgery, things were simply blurry – simply out of focus like what you see if you look through binoculars that aren’t focused yet.  After a few days, things were still blurry but seemed to be more focused.  At that point I could discern another aberration: around most images I could see six other images slightly offset from the real one.  They are faint but they are there.  These are mostly noticeable at night when looking at lights such as streetlights, traffic lights, oncoming cars, etc.  The aberrations aren’t all that distracting but they’re noticeable and generally contribute to the feeling that the eyes aren’t yet working right.  This effect has subsided with time.  I think this must be the “halo” that the literature describes.  I’m not sure If these ‘extra’ images are due to astigmatism or some other effect.  It will be interesting to see if they eventually go away.  I suspect they will not since one of the things I read somewhere mentioned that these IOLs are not recommended for truck drivers or anybody who drives a lot at night.  Another interesting aberration is that some lights (not sure which type – they almost always are bluish and I see them in parking lots) have many concentric rings around them.  More rings that my lenses have.
Up close is interesting.  There is a point at 12” away from my face (I measured it) where everything comes into sharp focus.  This was pretty blurry at first but was apparently due to the general blurriness I described above.  The image is pretty sharp but does seem to be a bit diffuse at the edges of sharply defined letters and numbers.  Photographs of things with lots of small things like leaves on trees seem to be never quite in sharp focus although I can definitely see what they are.  Printed text is easier to read than things like computer monitors that illuminate themselves.
The region in between 12 inches and about 10 feet is pretty blurry.  The surgeon says that with time, all this area will come into sharper focus and then the healing will be complete.  Or more like the brain training will be complete.
It’s interesting to try and study the images up close.  If I concentrate on a text document on the computer, some blurriness around the edges of things seems to come and go.  I don’t know if this sort of thing always occurs even in healthy eyes and you just don’t notice it or if this is my brain training itself to ignore things that are not known characters or to ignore a secondary image coming from the other focal point.  I think some of this may still be due to the other aberrations that are working themselves out because I can use a magnifying lens and get things into nice sharp focus.
I can at times see the rings in the lens or perhaps it is the shadow of the rings.  I notice that if there is a light source above my head, sometimes there will be a glint off my eyelashes and this point source that is very close to my eye will show me a pattern of rings which exactly matches that of the IOL.  I can reproduce this by sitting near an off=axis light source (such as sunlight through a window) and holding a length of ball-chain up very near to my eye (at about eyelash distance).  The glints from the little balls will each produce an image of rings that exactly match the diagram of the Tecnis that I downloaded from Abbot’s website.  Again, this is pretty rare and is not distracting but it is interesting.
Wednesday: Can read tail number perfectly on the left – can’t really make it out on the right.
Thursday: Tail number on A/C across taxiway is perfectly sharp on the left.  Can barely make it out on the right.
Friday 17 February 2012: Noticeably better as it is every day.  Again, left eye normal at infinity, right eye slightly blurry.  Traffic lights still with multiple ghost images but they seem closer to the real image today.  Merged with the real image so that I can only see half the ghost – unlike earlier in the week where I could see six individual ghost images around the center (real) image of the traffic light.  Today, streetlights have multiple faint halos – maybe three or four. Other lights do not. One porchlight in my neighborhood generates a nice ring pattern but only that one light.  Today, I can read the tail number off the plane across the taxiway perfectly with the left eye – I can easily make it out with the right but it isn’t sharp.  Also ocular migraine this morning – sometimes called a migraine aura or scintillating scotoma.  That brings the total to four altogether.  I can’t seem to correlate them to anything that might cause them.
Monday 5 March 2012: Just got back from two weeks in Greenville.  I had to just go on as normal and stop analyzing my own vision since I had to drive a lot and them work at a variety of distances.  While talking about it at work, I was accused of overthinking things and this may be a valid comment.  I should probably just get on with life and let my brain train itself.  Still, I’m back at it now.
Working in the optics lab, I went and got a pinhole.  It was the smallest I could find in the monochromator’s set (.25 mm).  I held this up to my eye until my eyelashes were touching it and put a flashlight right up to it.  This has the effect of allowing you to see things like floaters in your eye and, in my case, the lens implant itself and its concentric rings.  Pretty cool actually.  Nothing else of interest though.
At this point, I feel my left eye is back to normal at distances.  The right is still not in focus and I don’t think it will get there.  I downloaded an iPhone app that measures visual acuity and it still says I’m 20/20 in the left and 20/25 on the right.
Right before I left on my trip, I had a visit to the opthalmologist’s (the surgeon actually) and this is what he measured my acuity at.  Visual acuity is not everything though.  You can be tested at some value and still not think you can see as well as you used to.  I’m not sure how that translates into something you can test though.  The iPhone app seems to indicate that I have some astigmatism in my right eye.  This can be corrected and apparently is included in my treatment plan.  He also said I have the beginnings of a capsular cataract which is a common occurance after cataract surgery where some gunk condenses on the rear surface of the lens capsule.  This can be treated quickly with a laser and will be done – probably in May when my next appointment is.  He wants me to wait this long for everything to stabilize before deciding what to do next.  I can’t wait.
Finally, looking at computer monitors is still the hardest.  Oddly, when I first sit down, everything is blurry at the standard 18 inch distance but if I just look and try to read, the characters soon become focused.  If I move my head at all, the image goes blurry again and I have to concentrate awhile to make it focus again. I’m not sure why that happens except that the brain is most likely doing something cool.  At the last appointment, the surgeon again told me pointedly to just get on with life and not to give up and buy those “cheater” glasses at Walgreen’s.  I need to give the brain time to deal with its inputs.
Night driving is pretty annoying though.  Every light has either rings, a blur of blobs around it or it looks like a star with radiating lines coming from it.  Plus for lights that are off to the side, there is an annoying internal reflection or something that turns into a large diffuse blob of light.  But I don’t drive at night that much so I can deal with that.

Well, after a quick post-op today (at the 6 day point for the second eye), I’m 20/20 on the left and 20/25 on the right.  Pretty good.

I saw the surgeon briefly and he said I should read as much as possible and force my brain to learn how to see the images it’s getting.  The right eye is still blurry but should improve during the week and then it’s just a matter of practicing; kind of like how you have to flex a new knee joint after a replacement surgery. 

Things are pretty sharp at 12 inches but anything else is blurry.  He said that my zone of focus will enlarge with time.  Pretty crazy how the brain can figure all that out.

My eyesight has never been good for as long as I can remember but it’s always been correctable to perfection.  So I know what the world is supposed to look like – nice and sharp.

I guess that’s why I’m so impatient right now; I’ve made an investment in the sort of lens implants that allow me to focus at infinity and also up close at reading distances.  That’s something I haven’t been able to do without glasses in a very long time and even then not without the effort of carefully aiming the bifocals.  I’ve been very much looking forward to seeing well, particularly after having put up with a cataract on one side for quite awhile lately.

I realize it’s only been a bit over two days since my surgery but I want to see perfectly now.  On the left, I can see at infinity very well although perhaps not perfectly.  On the right, it’s still pretty blurry.  The left side can focus at about 12 inches but anything inside of that or outside of it out to about 15 feet is pretty blurry. 

I guess I just have to wait.  What’s annoying about my situation now is that there isn’t anything that will improve things.  I have no crutch like reading glasses – I just have to wait until the internal swelling or whatever it is settles down.

I’m still struck by how much more blue the world looks.  Everything that is white looks like something out of a Tide commercial.