PDA

View Full Version : More CNC porn



Doc Nickel
01-30-2010, 06:30 AM
This time, how about a "billet" motorcross helmet, complete with vents, visor and graphics.

www.gaskrank.tv (http://www.gaskrank.tv/tv/motorrad-fun/36-kg-schwerer-alu-daishin-cro-10963.htm)

What is that thing, a seven-axis?

Doc.

John Stevenson
01-30-2010, 06:52 AM
God knows but that is some serious porn. I'm wondering if that could even be done manually to a specified drawing as opposed to it being freehand finished.

5 /7 years ago this would have been next to impossible but there is a chance Xerox had one 30 years ago ;)

Thanks for posting it Doc.

.

oldtiffie
01-30-2010, 06:55 AM
Great post Doc.

Many thanks.

In the lower right corner it said 5 axis.

That's what everyone is up against - from Japan in that case - but there is some top-class stuff in Europe - and I suspect else-where in Asia as well.

John Stevenson
01-30-2010, 07:08 AM
Whilst's it's nice and secretly we would all want one the truth is it's expensive, not so much as in machinery but in software and the training of using it correctly.
When I say expensive as well as $$$ I also mean time and to be honest many people will never manage to get their heads round in it what they have left of their lifetime.

This isn't meant nastily as I know for a fact that I am one of those.

Supporting CNC machines we get asked this 2 1/2D / 3D question every week. Truth is everyone wants to do full 3D shapes, in practice they hardly ever get beyond the simple brackets because of the learning curve and time restraints of what is a hobby.

Hard fact is that 90% of parts made today are still based on 2 1/2D shapes. Anything you make by hand on you mill can be done by a 3 axis CNC.

If it's a simple 3D shape it can be done by automatic CAM programs and still run on a 3 axis CNC mill.

http://www.youtube.com/watch?v=RV8Dq6mslnE

This was generated from a 3D file off SLD's website, put in Cut3D, tools specified and run.
It doesn't seem to be cutting as it's doing a final pass at 90 degrees to the first. It's rough as the step over is too course but I want to prove a point more than make a finished gear.

.

Doc Nickel
01-30-2010, 07:09 AM
How many hours you think it took? :D

I just noticed- While i knew it was a demo/sample model (50th anniversary of something) I figured they were going to fit it with conventional padding. Nope, it's a display only- note how they milled what usually would have been cloth-covered padding around the face opening.

Kind of a shame, I'd love to see some rider actually wear it. Though I'll bet it cost about a hundred grand, counting machine time and writing/verifying the software.

Doc.

DR
01-30-2010, 07:38 AM
A good portion of this multi-axis (3+) has to do with orienting the cutter for optimum feed speed and metal removal.

Most times the work is done with ball end type cutters. For best performance you don't want to cut near the dead zone at the tip. That's one reason you see the heads/work gyrating around at odd angles. You want the cutter to be cutting out at the perimeter if possible.

Peter N
01-30-2010, 07:38 AM
God knows but that is some serious porn. I'm wondering if that could even be done manually to a specified drawing as opposed to it being freehand finished.

5 /7 years ago this would have been next to impossible but there is a chance Xerox had one 30 years ago ;)

Thanks for posting it Doc.

.

It's hard enough to even design in 3D, let alone machine it :eek:
I'm trying to do a full-face 3D crash helmet at the moment, and it's got multiple compound curves in all axes, and it's nearly impossible to draw it with all the surfaces and get them to blend correctly. Lots of work and I still can't get it right :mad:

Peter

Tony Ennis
01-30-2010, 09:25 AM
If the item being modeled can't be described mathematically and you don't have a sculpted item to measure, modeling an organic shape can be pretty tough.

Peter N
01-30-2010, 09:40 AM
Tell me something I don't know. As much as I love and know Solidworks, it can't do Class A surfaces as the curvature continuity is too poor.
Pro E is better and Alias better still, but I'm stuck with what I've got. :D

mochinist
01-30-2010, 09:47 AM
Whilst's it's nice and secretly we would all want one the truth is it's expensive, not so much as in machinery but in software and the training of using it correctly.
When I say expensive as well as $$$ I also mean time and to be honest many people will never manage to get their heads round in it what they have left of their lifetime.

This isn't meant nastily as I know for a fact that I am one of those.

Supporting CNC machines we get asked this 2 1/2D / 3D question every week. Truth is everyone wants to do full 3D shapes, in practice they hardly ever get beyond the simple brackets because of the learning curve and time restraints of what is a hobby.

Hard fact is that 90% of parts made today are still based on 2 1/2D shapes. Anything you make by hand on you mill can be done by a 3 axis CNC.

If it's a simple 3D shape it can be done by automatic CAM programs and still run on a 3 axis CNC mill.

http://www.youtube.com/watch?v=RV8Dq6mslnE

This was generated from a 3D file off SLD's website, put in Cut3D, tools specified and run.
It doesn't seem to be cutting as it's doing a final pass at 90 degrees to the first. It's rough as the step over is too course but I want to prove a point more than make a finished gear.

.Googling SLD's website gave me to many choices that didnt fit the description, can you post the link please?

JoeFin
01-30-2010, 09:48 AM
In the lower right corner it said 5 axis.

That's what everyone is up against - from Japan in that case - but there is some top-class stuff in Europe - and I suspect else-where in Asia as well.

See what you can do when your government doesn't give away your industries to outsourcing

MrSleepy
01-30-2010, 09:53 AM
Great post Doc.

Many thanks.

In the lower right corner it said 5 axis.

That's what everyone is up against - from Japan in that case - but there is some top-class stuff in Europe - and I suspect else-where in Asia as well.

When did Deckel Maho defect to Japan...last time I looked they were German....and are "very top-class stuff from Europe" :)..

japcas
01-30-2010, 10:04 AM
If the item being modeled can't be described mathematically and you don't have a sculpted item to measure, modeling an organic shape can be pretty tough.


I'd say that is why a lot of designs start out as scuplted pieces of clay and then backplotted to 3D cad to help generate the code. Even with a really good sculptor the price to pay them to scupt two or three of those helmets from scratch would be nothing compared to drawing it up out of thin air. Of course I know the helmet was probably backplotted from an identical production helmet or at least one that has been modified but the sculpting part I'm talking about is for one off parts that have no piece to backplot from.

John Stevenson
01-30-2010, 11:00 AM
Googling SLD's website gave me to many choices that didnt fit the description, can you post the link please?

mochinist,

I can't find the damn thing, in fact I can't now find any stl's of spiral bevels, I'm sure it was SLD web site but now not sure but can't find any on other sites.

It was a free 3D download from one of the gear company sites.
Problem is a lot of these sites download a file as 1223345.zip so searching on an old hard drive is hard.
I'll try to look though as I'd like to do a better one for a sample.
.

plastikosmd
01-30-2010, 11:38 AM
man, and I am happy when the new v's on my fab'ed aloris toolholders fit

pressurerelief
01-30-2010, 11:45 AM
Would it be posiible to scan an existing helmet and then tweak the scan as opposed to starting from raw?

japcas
01-30-2010, 11:50 AM
Would it be posiible to scan an existing helmet and then tweak the scan as opposed to starting from raw?

Yes. You could scan a helmet and then modifiy it in cad to what you want. That is what I was talking about above. If there isn't an existing object to work from you could either draw it up from scratch in a 3d modeling program or have someone model one in foam or clay and then backplot it with a cnc to get the required points into the cad software and then into the cam file.

lazlo
01-30-2010, 11:51 AM
Would it be posiible to scan an existing helmet and then tweak the scan as opposed to starting from raw?

I'm pretty sure that's what they did. The machining process even copied the decals on the surface of the helmet! Amazing!

barts
01-30-2010, 11:56 AM
Would it be posiible to scan an existing helmet and then tweak the scan as opposed to starting from raw?

For at least 20 years, this has been done; capture points w/ touch probe and then import data into CAD system, fit surfaces, and generate tool paths....
I helped write software to do this at Valisys....

- Bart

lazlo
01-30-2010, 11:58 AM
Bart, I think they did it with optical image recognition -- I don't think they would have that level of detail with a 3D touch probe, especially not the decals, the interior sections of the vents, the padding, etc.

My Son had a custom helmet made for his head when he was six months old -- they sat him on a chair, and had a set of cameras in stacks of 3 on four sides. They captured images of his head for about 30 seconds, and then set a program running which generated an extremely detailed 3D model of his head by correlating the camera views. They ship the 3D model off to a CNC machine somewhere, and 2 days later a custom helmet arrives.

This is a process that, until recently, was done with a plaster mold, but an infant is terrorized when you wrap their head in wet plaster.

John Stevenson
01-30-2010, 12:17 PM
This is a process that, until recently, was done with a plaster mould, but an infant is terrorized when you wrap their head in wet plaster.

Sounds a good system to me, then only release the mould when they are mature enough :D :rolleyes:

DR
01-30-2010, 01:09 PM
Check out

www.wallawallafoundry.com

To see how large scale "art" is made these days.

I found an article mentioning them in the Wall Street Journal a couple years ago. It was something about guys wanting to laser scan Michaelangelo's David and reproduce it. As I recall the museum would not allow the scanning.

The type of work the foundry can do brings art counterfeiting to a new level.

dp
01-30-2010, 01:57 PM
The first one was expensive. The next 100,000 not so much. The cost of the last one would be the run-time cost of the machine.

I've no doubt that machine would be considered a munitions in this country and would need to be registered as such as it could likely be used for machining the critical components of "nukular" WMD's.

http://ezinearticles.com/?Keeping-Your-Equipment-ITAR-Compliant&id=3131508

sansbury
01-30-2010, 09:03 PM
See what you can do when your government doesn't give away your industries to outsourcing

You're kidding, right? Japan is by most estimates the #1 foreign investor in China.

In other news, Japan also has the lowest birthrate and highest suicide rate in the developed world. Worth keeping in mind as one considers how happy life there is on average.

Doc Nickel
01-30-2010, 09:34 PM
You're kidding, right? Japan is by most estimates the #1 foreign investor in China.

-If I'm recalling an article I read right, if Wal-Mart were a country, it'd be China's sixth largest trading partner.

Doc.

mlucek
01-31-2010, 12:32 AM
This time, how about a "billet" motorcross helmet, complete with vents, visor and graphics.

www.gaskrank.tv (http://www.gaskrank.tv/tv/motorrad-fun/36-kg-schwerer-alu-daishin-cro-10963.htm)

What is that thing, a seven-axis?

Doc.
Damn, think I need a cigarette now and I don't even smoke :D:rolleyes:

barts
01-31-2010, 03:10 AM
Damn, think I need a cigarette now and I don't even smoke :D:rolleyes:

If one smokes after sex one is going too fast .... :p

barts
01-31-2010, 03:14 AM
Bart, I think they did it with optical image recognition -- I don't think they would have that level of detail with a 3D touch probe, especially not the decals, the interior sections of the vents, the padding, etc.


Structured light works well, and the improvement in camera resolution over the last 20 years certainly would help.... as has the three or four orders of magnitude improvement in processing power to aid in calibration, etc.

- Bart

Doc Nickel
01-31-2010, 03:15 AM
If one smokes after sex one is going too fast ....

-You're supposed to use lube, not rosin. :D

Doc.

Bguns
01-31-2010, 04:51 AM
Pressure coolant works better than drip lube :)

Production is the aim...