Tool to Square Z-Axis

[terryd]

Mike, How do you read the dial indicator when its spinning? and how many rpm's do you set it for? Never be afraid to state the obvious....... ;-). Hehehehe!!! sorry just couldn't help myself..

Terry

[gerald_d]

With strobe light when it is spinning, and a mirror when it faces the other way. Set rpm's to strobe frequency. Isn't that obvious?

[richards]

So, Terry, you caught the motion blur in the photo. Good eyes. It's a good thing that I have a spindle with totally adjustable speeds.

Gerald, the shutter in my Nikon only syncs to 1/120th of a second, which is the limiting factor governing the shaft RPM and the bank of strobes. I haven't gotten around the problem caused by light fall-off in the mirrored sections (inverse square light fall-off law), so the photos of the mirrored sections are much too dark. I quess I could attach a servo to the aperature ring on the camera, but I think that the ID3004 servo that I have on the test bench might be a little awkward to attach (10-1/2 inch long, 10-15 lbs.).

Of course the only two things turned on in the shop is the vacuum, to pull the mdf platten/spoil board tightly against the support boards, and the lights. The spindle shaft is turned by hand with a few seconds pause at each position, with my hands off the table top, to let the needle totally settle.

If you want to see something interesting, just give any axis a light thump with your finger tip as you watch the dial indicator. You'll be surprised how much movement you'll see. It makes me wonder just how much jitter there is in each cut caused by the vibrations caused from a spinning spindle, cutter chopping through the wood, V-wheels chattering along the V-rails, steppers clogging through their steps, etc. Has anyone ever proved that this Shopbot machine actually works?

[harryball]

Shopbot machines are only experimental based on theory. No real practical application is known. Fortunately for me, I'm only a theory too so we get along great.

I did hear once that some guy tried to make a sign with one, can't imagine what he was thinking.

Robert

[mikejohn]

Mike
Does the inverse square law apply to circular motion?
Maybe your problem is more with the Gurney Mott theory of the formation of the latent image.

.........Mike

[richards]

Mike J.

You've brought up an excellent point - one worthy of more discussuion. Honestly, I hadn't even considered the Gurney-Mott theory, which is:

THE GURNEY-MOTT THEORY

When a photon of light of energy greater than a certain minimum value (that is, of wavelength less than a certain maximum) is absorbed in a silver bromide crystal, it releases an electron from a bromide (Br-) ion. The ion, having lost its excess negative charge, is changed to a bromine atom. The liberated electron is free to wander about the crystal (see the figure below). As it does, it may encounter a latent image site and be "trapped" there, giving the latent-image site a negative electrical charge. This first stage of latent-image formation--involving as it does transfer of electrical charges by means of moving electrons--is the electronic conduction stage.

What do you think, is it even applicable in digital photography, and, if so, is it more applicable than the inverse square fall-off law?

[harryball]

Of course you realize if you go to this level you won't be able to be in the room watching the bot during the alignment process. The Heisenberg Uncertainty Principle states the act of observing a shopbot during alignment will change the alignment of the system... or is that you can't know the alignment and the XYZ position at the same time... hmmm.... perhaps you could construct a Heisenberg compensator and install it first.

Robert

[richards]

Robert,

Now we're getting somewhere. The Heisenbery Uncertainty Principle is defined as:

In quantum physics, the Heisenberg uncertainty principle or the Heisenberg indeterminacy principle — the latter name given to it by Niels Bohr — states that one cannot measure values (with arbitrary precision) of certain conjugate quantities, which are pairs of observables of a single elementary particle. The most familiar of these pairs is the position and momentum.

I'm beginning to finally understand why no machine can ever be expected to work.

[3d_danny]

Here is a ready made spindle square.

http://www.penntoolco.com/catalog/pr...ategoryID=6153

not a bad deal for $139


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[mountie1808]

I'm really in the wrong ballpark now. How are you able to make such fine adjustments???? I've only been working on the bot since march but am taking it upon myself to get this thing to really make some money. I'm having to tweak things, even resetting the router to the top of the unistrust for added clearance. What I haven't been able to do effectively is perfectly level it. I still get a slight (a wee bit more than slight) downhill edge on the cut with a 1/2" endroute bit. The only method that I know if is to use a bullet level and tinker back and forth hoping to fall into place but have yet to get it to disappear. Are there fine adjustment screws somewhere to do exactly what I need to do and I'm just missing them??

Mike