PDA

View Full Version : Educate me on 4th axis



jacampb2
10-04-2009, 12:07 AM
I have a BP S2 CNC machine I have had up and running for almost 2 years now w/ leadshine drives and Mach 3/ PC controls.

When I bought the machine it came with a 14" (IIRC) rotary table also stepper driven. The controls were originally setup to unplug the Y axis and plug in the rotary axis and still have only three axis control. I will still need a fourth drive, but other than that, I have everything to put the rotary axis back in place.

From the research I am doing, I know that the CAM software has to support rotary machining, and that most packages in reach of the average hobbiest only allow for 3 axis at one time. I don't really have anything specific in mind for the rotary table, but I would like to get it up and running over the winter. I am thinking mostly I will be using it for cylindrical milling, but I have it in the back of my head that it might be nice to be able to use it for machining multiple faces and entry points into a part. It seems to me that the latter would require all four axis to be usable at the same time.

So, my questions are, is Mach3 capable of running more than three axis simultaneously? Their software description says it can run 6, it has been a long time since I read the manual, but I was thinking it was still limited to only running three axis at one time... Then, my next question, is what am I looking at in CAM packages? I have played with the Vcarve demo, and Artcam Pro, both of which I believe will do cylindrical milling with a fixed Y, what would I need to get into to allow full 4 axis control?

Any explanations or pointers on more reading material would be great. I am not finding much info in my online searches, and CNCzone keeps locking up my browser on my work PC here...

Thanks,
Jason

djc
10-04-2009, 04:00 AM
So, my questions are, is Mach3 capable of running more than three axis simultaneously?

Yes.


Then, my next question, is what am I looking at in CAM packages?

Have a look at Dolphin Partmaster. That supports 4th axis.


I am thinking mostly I will be using it for cylindrical milling, but I have it in the back of my head that it might be nice to be able to use it for machining multiple faces and entry points into a part

If you think a little about what you are doing, you can generally get away without true 4-axis unless you are doing something really complex. For cylindrical milling, where you might only be moving X- and A- together, a bit of Excel, enhanced by HuntnPeckCAM works well.

For multiple faces, use your standard CAM package for each face and then FingerCAM to link them together and change offsets as necessary.

macona
10-06-2009, 09:24 PM
Mach will do 6 axis at one time.

The cam is where its going to get you. 3 Axis is pretty reasonable in price, add a 4th axis and the price goes up big time. On my machine I just figure the item as flat and replace Y with A and go for it. But that has its limits.

14" rotary table. That a lot of weight for that table.

jacampb2
10-10-2009, 08:45 AM
Thanks guys, that is kind of what I figured I was going to hear. I am not sure that I will ever use the 4th for anything but artsy stuff. I have a friend who wants a ring and I have some ideas for cylindrical engravings. Most likely A,X,Z will be fine, but it seems if I am going to go to the expense of another drive I ought to investigate all the options. If I stick with 3, I can just go with a quick connect on the Y like B'port did from the factory and save $130 on the 4th drive.

Any suggestions on more advanced CAM packages that do full 4 axis? Do any of them have trials or demos that can be DL'ed and tried to get the feel and see if I like it?


14" rotary table. That a lot of weight for that table.

The table was a factory add on to the series 2. I have the serial numbered manuals that show it came with the machine. The S2 is probably 1.5x-2x's beefier than a series one in the base casting. I am sure I'll have to re-tune the axis to account for the weight, but I don't think it will be to much for the machine.

Thanks!
Jason

macona
10-10-2009, 01:51 PM
No free software that I know of, not even cheap ones.

jacampb2
10-10-2009, 05:15 PM
Yeah, not looking for free or cheap, just a demo, even one that doesn't produce code, just to see how easy it is to learn.

Ill keep searching, thanks!
Jason

macona
10-11-2009, 12:33 AM
Mastercam does it. Havnt figured out how yet.

Michael Moore
10-11-2009, 02:42 AM
The full version of Visual Mill from mescoft.com does 4, and I think an indexable 5th. You can download demos from their website. I've got the full version but I've yet to try doing anything with a 4th axis.

http://www.mecsoft.com/DownloadDemosb.shtml

cheers,
Michael

John Stevenson
10-11-2009, 06:23 AM
Dolphin which is a reasonable cheap program will do 4th axis work quite easily.

You draw out in the flat with the Y axis equal to Pi x D

http://www.stevenson-engineers.co.uk/files/rotary%20cams1.BMP


You then select the profiles you want to cut and bracket them in the operations list with > Start 4th axis and < End 4th axis

Anything inside these brackets then gets automatically transferred to X and A moves.
You also designate the OD of the work so it can accurately work out the correct feed rate from linear to rotary.

http://www.stevenson-engineers.co.uk/files/rotary%20cams.jpg

Finished job.

Dolphin has a very active office in the US at www.dolphincadcamusa.com

.

pressurerelief
10-31-2009, 11:43 AM
What is the cost of these programs? Looking at VisualTurn and VIsualMill versus the dolphin products? I have a legal seat to alibre.

I never see pricing and hate to call because if it is way out of my range I will never here the end from the sales guys.

P/R

John Stevenson
10-31-2009, 12:04 PM
Dolphin does have pricing on their site, not sure if standard runs 4th axis or pro you will need to ask but they do hobby pricing.
Not published as they probably don't want to get pro shop trying to save a buck.

There is a form to fill in and it has an additional info box where you can ask about 4th axis.

I'm running an old copy V9.0 ] of the full version so mine does 4th axis but I don't know what the differences are in the various versions of V10

pressurerelief
11-06-2009, 11:35 AM
John,

Spoke with Dolphin Cam today and as you said they do a pretty deep discount for the HSM'ers. Nice people to deal with. Thanks for the lead.

P/R

Prototyper
12-22-2009, 07:30 AM
I too am in the market for a CAM package within the reach of the home shop.

Care to share the quote you received from Dolphin?

Thanks

sansbury
12-25-2009, 02:31 PM
A year ago I looked at BobCad and Dolphin for CAD-CAM. I ended up going with the dreaded BobCAD because they offered more 3D functionality for the price. Version 23 includes 4th axis wrapping and indexing which I think is the same as Dolphin.

BobCAD as a company is a pain in the ass to deal with. They love the hard sell but they will wheel and deal if you push back as hard as they lay it on. Dolphin is certainly a nicer organization and I got the sense that the software did less but might be a bit more mature and stable. So it is a "pick your poison" situation.

The worst thing about BobCAD is that the documentation they include is crap. The training videos are OK, but they make you pay for them, and they are just now starting to sell a user's manual which may be better for some. You can piece a lot together from forums and other sources. I think it's foolish of them since I think they make a lot of enemies of users who don't pay for training and then have a lot of trouble with the software.

Mark Hockett
12-27-2009, 02:56 AM
There is no need for a 4-5 axis CAM system to program for a 4th axis. I have worked on 4 axis VMC's since 1995 and have never run a program on a 4 axis machine that needed all 4 axis running at the same time. On a 5 axis machine you have a need to run 4 to 5 axis simultaneously but on a 4 axis machine you usually only run 2 to 3 axis simultaneously. When machining with a 4th axis the cutter is usually positioned at the spindle centerline (Y axis) so the only axis movement is in the X, A, and Z directions. If movement is needed in the Y axis then chances are there will be no movement in one of the other axis. Many 3 axis CAM systems allow for wrapping of a 2D drawing, This will substitute the X or Y axis for the A axis. There are also programs available to wrap drawings. Here is one,
http://d2nc.com/
http://www.d2nc.com/D2nc_4th_Axis.swf
http://www.d2nc.com/index.html

This is the 4 axis mill I currently own,
http://i24.photobucket.com/albums/c10/mahockett/fad1-1.jpg

I had a high dollar multi axis CAM system for many years but got tired of paying the high maintenance fees for something I never used. So when I upgraded to Mastercam X4 I didn't get the multi axis option and have not missed it.

John Stevenson
12-27-2009, 10:24 AM
Interesting piece of software mark, just downloaded it for a further look. Thanks.

.