*UPDATE 20*
8 December 1997 - 6 am Monday Morning
I interrupt this regularly scheduled update (24 December) to inject some info that many seem to want. The new animation on the index page is a VERY reduced animation study of a 3 to one ratio geared race, and I came up with some interesting numbers! Nearly 1,000 downloads of my humble animation (4 times the index calls for the same period, several someone's are linking in my graphics!), in only a couple days on the net!
The center gear and orbitals are 24 teeth, the race has a total of 108 variable sized teeth, and the nose teeth are 3 times the size and spacing of the tail teeth (high spin end). For one orbit of each orbital, it takes 5.5 revolutions of the center gear (constant rate), each orbital spins 3.5 times per orbit (at variable rate), with 4.5 contact revs per orbit.
NOW it gets interesting! Within 1.4 percent of actual measurements, I chose the nearest rational number, and guess what? The nose orbital is only traveling TWICE the velocity of the tail, with 2/3 the spin rate! I didn't expect that! So there you have the numbers for your calculations!
The tail spin is 150% of the nose spin, just HALF the nose orbital's race velocity! COOL! Although I was expecting something closer to 3 times race velocity (easy mistake to make isn't it?) the whole numbers (or rational anyway) make for nice plug ins of mass and orbit rate (center gear rate anyway). Have fun the rest of the year, 1998 is nearly here!
OOh! OOh! Before I forget, one man reported 2 meters per second and still accelerating on a mini GIT in a toy boat, before it broke apart on the opposite bank of his test pond! WOW! If I can get it verified, that looks to me to be flight quality thrust (with wings anyway)! He stated that he used friction tape as his race and wheel surfaces. I surely want pictures and a video if he can get it repaired and retested (Please Mark?), so stay tuned!
I'm having a BUNCH of fun getting insulted and flamed in the science and space newsgroups, seems that ridicule and "knowing" that something is impossible, and refusing to consider that they might be wrong is good science! Sheeesh!
Still planning on the first for a good rewrite, I'm sneaking in a few graphics that will dress the new "gitplain.htm" an effort to lay out the pertinent information in a less confusing manner, so please be patient, good things coming! OH! One of my readers (from Finnland) said he had heard of my GIT from the lips of !* Arthur C. Clarke *! on a future theme show! If anyone else saw it (think he said the discovery channel) PLEASE let me know these things! How come I'm sometimes the last to know? Well this was just supposed to be a few lines, so I'll let you get back to the formerly current update! 12:30 pm 24 Dec 97 - DvC
First off, I'd like to say (after several GIT attempts on my own part) that it's much easier to make a bad GIT than one that works, and to complicate matters worse, a single orbital bad GIT will do the friction surface shuffle, all any borderline doubter needs to say "Ah HA! I KNEW it wouldn't work!".
First and formost, the traction surface on the race must be a rather "live" substance that is just short of glue, having a very low slip factor, and a good pressure on the orbitals is needed as well. If the orbitals just whip right up into the high orbit rates, it's quite probable that it's slipping in the race.
I received word from a successful GIT Builder that another man had spent thousands on constructing a GIT, and it didn't work (and never told ME about it either!), a sad tale that I'm sure is being repeated out there (I only get a small percentage of folks that will talk with me on this subject). Luckily a successful demo re-energized our silent brother in GITdom, and he will be able to try and find a surface that won't peel right off on the first go-round (the "Dip It" stuff for tool handles won't stay put), Let's see if we can correct that!
The forces that make a GIT go are not easily won. First, we need to make the orbital do something un-natural in it's motion, and the traction needed (gears are SO much nicer here!) to do the spin translations is rather high.
Many have speculated (myself included) that once the centrifugal force gets up high enough, it will force a much stronger traction with the race, and that has NOT proven to be the case! While the centrifugal force is a squared force (in relation to the orbit rate), the spin inertia of the orbital, and the acceleration and deceleration (and reluctance to do so) are also squared, strong slip desiring forces to be reckoned with!
In other words, if it slips at low orbit rates, you can spin it up into the danger zone without improving your chances of obtaining inertial thrust, so make it right the first time! (An exception may be A H Forge's double conic with a neoprene like cellular cushion that seemed to grip better as the speed increased on his knurled cones).
SO!, Have a strongly "grippy" surface on your race! I've had pretty good success with rubber cement more than an hour dried, but less than a week old (when it gathers dust and starts to get shiney, paint it again). A good cushion on your drive wheel will make up for little bumps and valleys in your race, and apply a strong pressure against the race to insure SOLID ROLLING TRACTION. Another means is to use a dual wheel that is spring tensioned, embracing the orbitals in a pinch that allows for variables also.
Of course all that added cushion just makes for large elastic energy losses in the machine, which properly shouldn't be added in when calculating pure thrust generation, and should only be applied to that specific construct. I wish I had a gear cutting mill table for sure!
If you've made a failed GIT, take a close look at getting it to operate properly with a good wheel pressure and a better traction race surface, try it again!
Now, for my next concern, many still can't see that the spin does in fact increase and decrease about the race in a friction drive variant of the GIT. It seems intuitive that since the wheel is in full contact with the orbitals equally, that they should all spin at the same rate all around the race, and that's just not true!
The orbitals at the tail have a certain amount of drive wheel surface pass their centers in any given time period, while the same time period for the nose orbital has the orbital traveling in the direction of the wheel, so less spin is the result at the nose, since less surface is passing it's center of spin.
I'm working on a geared GIT animation, doing several things with each frame generated, including measurements of race movement distance, spin amount, angle traveled, etc., for each time segment (one half tooth of the drive gear), putting together a graphic analysis so I can do a reitterative sum of forces on this version.
Already it's apparent that the orbitals undergo an inverse conversion of movement profiles. In the 3 to one race I modeled, the nose orbital is traveling 3 times faster in the race than the tail orbitals, but the spin is 1/3 the amount of tail spin. Animating with gears makes for rather exact temporal placements! If that doesn't convince you, then trust me, a Center wheel drive GIT DOES have spin translations!
Quite a few folks have contacted me letting me know they are in the process of GIT building, and experiments are going on around the world, some of them tell me about it. One man now has his own GIT page in the works, give a big welcome to Dann McCreary! His GIT page on the net is:
http://www.geocities.com/Athens/Delphi/8777/git.html
Because of the large number of communications I receive, I can't include them all in my updates, and hopefully my return letters will address most needs for my readers. I tend to pick out examples that address the most concerns and repeated queries for this technology, so if your letter is not included here, let me assure you that what you send me is being read and helping us all get closer to the stars.
I'm working on a new page to help clarify some of the concepts that are difficult to grasp immediately, the gif animation to the left is just one of several I've put together working on a "gitplain" document. When dealing with multiple angular energy transfers, it helps to break them down into bite sized concepts. Hopefully when I get it finished, my grade school readers will be going "Ah HA!" See, I told you it works!
I still haven't secured another site, and I ran into an automatic limit program on my server when I tried to do an update earlier, so I have removed James Hurl's rendered animation (1 third my site limit!) to free up room enough for me to keep talking here. I will still mail it to interested folks, just ask!
'Tis the season (HO HO HUMBUG!) for my annual depression, with my sardonic and flip personality getting the better of me at times, so I'm intentionally keeping my communications small so I don't get into too much trouble. If my normally loquacious letters seem terse and clipped to you, it's because they are! When the sun comes back and the perpetual grey skies of Oregon again shine with sunlight, I'll be in a much better mood!
I'd like to welcome the team from South Africa into the GIT world! Colin and two others at his company are now interested in the GIT, and are seriously considering building one. Given the fact that they work with inertial guidance systems, and precision is second nature to them, I hope they do go on to make one (or more)!
How come none of the US companies are not talking with me? WHAT, you think silence equals a head start? NA! Given the fact that it's rather easy to make a bad GIT, it's likely that many who don't collaborate with me will likely NOT be very successful, unless they read my site (and all the megabytes of words spread now across over 130 files!) VERY CAREFULLY.
Sorry! I'm working on getting the site more compact and meaningful, but it will be a while yet before I have it to a point where I can get it on line. Currently I'm working on visuals that will help convey the ideas that most folks seem to miss initially. When I have to repeat myself in my mail a bunch, it's a sure indication that the points need addressed publicly, and right up front where it can be found.
Thank you all for watching, it's not going NEAR fast enough for me, and for those wanting more, better, bigger, NOW!, all I can say is ME TOO!
The next update will likely be the end of the year, a New Year's rewrite that I'm taking my time on. I hope by then to have a lot more room also, so the animations I've had to remove from the net can be reinstalled for retrieval, and new ones added as well.
Again, if something just can't wait for a new update, I'll tack it into this page. I'm still answering my mail (less wordy as it is) so do write, I really enjoy hearing from folks, even the repeated advice I get from those not too deep into the site yet (I get to point to the relevant pages), and occasionally a real treasure is found in the mail.
You know, the US Post Office and the fraud division of the Justice Departmant are not quite as prevalent in my stats this month, (they were REALLY interested in my site the last couple of months), so I'm kinda glad my no sales or shares policy kept me from being TOO interesting to those kind of folks! Not until a flying GIT (no question what-so-ever) is operational will I even consider the capitalization of this idea under my watch.
The GIT DOES work, but having my own experiences (and failures) with 2 inch and 3 inch micro versions, I can see how there may be many out there that just won't get it for some time yet, but keep plugging away at your own constructions, once it actually works, it's worth the time to have a whole new paradigm created by your own hands!
Enough for now, Merry Christmas Everyone (try anyway, mumble, grump!), talk with you later!
8 am Monday morning, 8 December 1997
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