Cutting sheet at 45 degrees? Fixture?

[Scott Shepherd]

If I had a LOT more time on my hands I'd happily post about the need to keep tubes at a keen level to the first mirror or why semi focussed beams scatter but being hand on heart truthful the time involved would be colossal, maybe if I retire early I'll post a lot more in depth stuff but for now I'll just do what I can in the time I have.
Please please don't think I'm being smug or elitist but the subject matter is mind warpingly complex involving quite a few first principles that even when you understand them cause headaches.

Or.......you could mock one up, put it in, push start, prove it works, and avoid all that wasted time

[Dave Sheldrake]

A nuclear device will also crack wallnuts Scotty

[Scott Shepherd]

Prove it

[Kev Williams]

Keith I predict some enterprising business either US or Chinese will copy your idea and there will be one on the market in a few months. I don't think its able to be Patented however because you posted on a public forum.

Who gets a patent isn't necessarily determined by who gets to the patent office first, it's typically determined by who can prove they had the idea first. Posting an idea on a public forum is actually proof of the idea, and its date.

[Paul Phillips]

A nuclear device will also crack wallnuts Scotty

See Dave, this is why I appreciate your incredible level of knowledge, every tidbit you share with us mere humans is savored and digested with the utmost appreciation of being able to further our knowledge of the mysterious complex inner workings of the laws of physics how lasers do their thing! Thank you for the time that you do take to throw some crumbs from the masters table!

[Scott Shepherd]

Who gets a patent isn't necessarily determined by who gets to the patent office first, it's typically determined by who can prove they had the idea first. Posting an idea on a public forum is actually proof of the idea, and its date.

Sorry Kev, that's dead wrong. Posting your idea on a public forum will not provide you ANY protection at all. If you want to invent something, you should NEVER post it anywhere until you have filed for the patent.

The U.S. Patent system is a "First to File" system, not a "First to prove anything" system.

[Dan Hintz]

Who gets a patent isn't necessarily determined by who gets to the patent office first, it's typically determined by who can prove they had the idea first. Posting an idea on a public forum is actually proof of the idea, and its date.

Proving you invented something first (but not disclosing it to the public), was the way it used to work (up until about two years ago). Now, it's whomever files first.

[Dave Sheldrake]

See Dave, this is why I appreciate your incredible level of knowledge, every tidbit you share with us mere humans is savored and digested with the utmost appreciation of being able to further our knowledge of the mysterious complex inner workings of the laws of physics how lasers do their thing! Thank you for the time that you do take to throw some crumbs from the masters table!

My life would be a lot easier if I didn't post at all Paul no gain or loss to me either way

[Rich Harman]

My life would be a lot easier if I didn't post at all Paul no gain or loss to me either way

What bothers me Dave, is that you are a self proclaimed expert on lasers, indeed many other proclaim your expertise too. Yet, you post things that are not true, have it pointed out that they are not true, then evade.

I will cite post 140 of the Chinese laser tips and tricks thread where you tell someone that their problem with not being able to get a good alignment is that their tube is not level - which is hogwash. Eventually in that thread you sort of admit that you were dumbing it down. In this thread you make a reference to the importance of the tube being level, maybe because I questioned your advise there too.

Then in this thread you tell someone that their idea won't work - yet they prove it does. Then you talk about mind warpingly complex ideas that you don't have the time to explain to us, that we should just trust you and not question.

As an expert and an authority you have the responsibility (IMO) to make sure that you are sharing information that is not only correct, but applicable.

[Rich Harman]

My life would be a lot easier if I didn't post at all Paul no gain or loss to me either way .... Poof! and just like magic the shop keeper dissappeared

How can I interpret that in a non-negative way?

I do not think I am unique when I say that I contribute to a forum in order to share what I have learned and to learn things myself. I enjoy learning (that's a gain for me), and I enjoy helping others (another gain for me). Sometimes people are impressed that I know some things (that gains me some sort of status, and strokes my ego), other times they may think I am a dolt (loss of status, not good for ego).

If someone truly gains nothing by participating, or loses nothing by not participating, what is the point of participating? I can't speak to what Dave feels he gained but I am certain that his participation at the very least has gained him status in this forum an an expert.

If his sig line is true, I guess Dave's life just got a lot easier. So that is something positive.

[Dan Hintz]

What bothers me Dave, is that you are a self proclaimed expert on lasers, indeed many other proclaim your expertise too. Yet, you post things that are not true...

Even the best people get things wrong at times (I know I do). The trick is to use logic and work through the scenario... more often than not the correct answer comes out at the other end. I try to admit when I'm wrong, but I stick to my guns when I think I'm right (until proven wrong). It's not a comfortable feeling realizing someone had the answer and it wasn't you, but we all deal with it in different ways.

[Scott Shepherd]

I certainly hope Dave hasn't disappeared. He's contributed more to this forum in a short time than anyone else I can remember. I also know, first hand, how willing he is to help offline. He gladly gives out contact information and offers help. He's got more time behind a laser than 99% of the people on here. Small lasers, big lasers, Galvo's, Gantry's, and everything in between. Dismissing his knowledge because you don't agree with something he said in 2 posts is silly. I don't see where he said anything incorrect in this post. What He said was the beam would scatter. I suspect that's a fact. What Rich seems to be reading that as, as proof Dave was wrong. However, what Dave did not say was that a beam that is scattered can still cut just fine, it's just not the ideal beam structure, which is probably 100% true by anyone's standards.

To take that sort of nitpicking and try to run someone off because of it is a real disservice to this forum, in my opinion.

[Dave Sheldrake]

As an expert and an authority you have the responsibility (IMO) to make sure that you are sharing information that is not only correct, but applicable.

A valid point Rich and I can see what you mean but a couple of things that leaves out,

The reason for a tube being level to the plane of the beam is important, the problem is the explanation of why it is important is at point C, if the person asking is at point A then that requires explaining point B before going to point C, that's where time comes in.
In the thread you mention it is far easier to just let somebody stick the tube in at an angle as while there are problems associated with it the chances are they are unlikely in the real world to cause any safety issues or readable benefits. This thread itself has issues with using semi profiled beams onto a reflective surface, it will cause scatter (I have a 4 inch long scar on my chest as testament to that) but in reality the risks associated with it are small. It comes down to chosing between what people can get away with safely and a long technical explanation of what is and isn't correct when the benefits of 4 hours writing still achieve the same thing.

Take Michelle (I think it was) asked about metal cutting machines, thankfully she seems to have taken it at face value that the chinese metal cutters are dangerous without needing a long explanation of the different parts of the chinese machines that won't pass safety inspections and the intrinsic electrical problems associated with using exothermic gasses in machines not really designed for them.
In effect I said that the machines are a fire or explosion risk and in essence that's true, all it will take though is somebody to pop along and say "But Oxygen isn't flammable" and they would be right so calling into question the entire statement that Oxy assist machines present a big fire / explosion hazard.

Getting back to the angular settings on a tube, there are issues with it, do I have 4 or 5 hours to write up the issues and the why of those issues when in reality it won't make a lot of difference to the end user unless an unlikely set of conditions is met? probably not.

As to being an expert....not me....X is an unknown factor, Spurt is a drip under pressure. I don't list professional qualifications, I don't list the machinery I have or use and with good reason, I don't want anybody to accept something at face value because it's me or because I seem to have a lot of machines. What I want more than anything is people to be safe, happy and get what they want done when they want to do it without making some of the mistakes I have in the past.
You are quite correct, I do dumb down answers sometimes simply because an answer somebody doesn't understand is pointless and achieves very little and certainly doesn't help them.

I'd love to spend 8 to 10 hours a day on this and my own forums answering questions and posting data, the reality of life means I simply don't have that sort of time if I want to stay married, keep my job running and have a social life so I'll try to help as many people as possible in the time I have spare. I'm no smarter than anybody else (hell I know as much about woodwork as most people know about nuclear cross sections) and my social skills are limited (I'm autistic) so if I come across as cold or arrogant or eliteist I apologise, it's not intentional.

cheers

Dave

[Rich Harman]

In the thread you mention it is far easier to just let somebody stick the tube in at an angle as while there are problems associated with it the chances are they are unlikely in the real world to cause any safety issues or readable benefits.

This is the problem. You say that it is important, too complicated to explain why, but then admit that it wouldn't make any difference. I say that, even if in the most technical way it is correct, it is not applicable. In that thread about the tube being level you tell me to model it in 3D and I would see why it wouldn't work. The thing is, modeling it in 3D shows that it does work. Which makes what you said wrong. But you maintain that it is right, and that you don't have the time to teach me why.

May I suggest that if you don't have time to explain these things that maybe you could provide some keywords on the concepts you are referring to so that we can Google the matter on our own, or better yet provide a link. Certainly this knowledge (if correct) can be extracted from other places.

I do dumb down answers sometimes simply because an answer somebody doesn't understand is pointless and achieves very little and certainly doesn't help them.

Having someone spend time making certain their tube is perfectly level, when it does't actually matter, does not help them. They may have a job and family too, time is valuable to many people.

You shot down Keith's idea saying this:

Going the above pictured route will cause a LOT of abberations Keith, the spot will end up being scattered to blazes. When redirecting a beam it MUST be worked on while in the incident phase and not the focal phase.

To me that sounds like you didn't think it could work and were citing reasons why. Someone less motivated may have read that and given up on the idea. After all, those words came from someone with an understanding of the mind warpingly complex field of lasers. What was the point of that comment if not to discourage him from wasting time on the idea?

I think I will not say any more about this. Most likely it will only serve to make me look (more?) like a hair splitter or "nitpicker". I've made my point as best as I can. At the very least maybe some additional care will be taken in the future with regards to expert advice.

[Paul Phillips]

My life would be a lot easier if I didn't post at all Paul no gain or loss to me either way

Dave, I hope that I did not come across as disrespectful, I was trying to use humor, but was absolutely serious about being very appreciative of your help and I for one have learned much from your posts and hope you will continue to share your knowledge because it would be our loss if you didn't.