Messages

781

General Mach Discussion / Re: Possible to re-label axes in Mach Mill?

« on: May 24, 2010, 12:49:22 PM »

As Jeff mentioned, Mach has a software 'swapaxis' function that accomplishes what you want to do. It must be called from a macro. I just posted an example macro again here (post #205). You can peek at the macros and see how the function is used:

http://www.machsupport.com/forum/index.php/topic,11422.205.html

Definately check out this little utility:

http://www.cncwrapper.com

From 2D Gcode to this for only $20:  (rotary work starts 40 seconds into the video)

http://www.youtube.com/watch?v=sC2urdg_bqg

782

General Mach Discussion / Re: Need Guru input on an idea: Using Mach as dynamic balancer

« on: May 24, 2010, 12:37:28 PM »

   I like this thread, and hope your idea works.

No question about it working with the components that I purchased as they already work together.

A Guru was need for intefacing an accellerometer to Mach. Unfortunately, this task was apparently beyond the available Gurus, so no balancer with Mach  .

783

General Mach Discussion / Re: Activating a solenoid using Mach 3

« on: May 24, 2010, 12:17:49 PM »

I made my own Solid state relay for high current devices (a big solenoid coincidentally);



but for run-of-the-mill stuff I have several of these little guys:

http://www.cnc4pc.com/Store/osc/product_info.php?cPath=24&products_id=133

Solid state. Fast, silent, work great with MACH. For 8 bucks, it's not worth getting out the soldering iron . .

Just watch your current draw and make sure you use something that can handle it.

They have a nice selection of BOBs as well. I use their C1G . . .  love the status LEDs on each pin!

784

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: May 24, 2010, 11:58:39 AM »

Quick update: Servo drives are sold.

Curmudgeon; In a nutshell, MACH does not run any axis continuously, but it does have an interesting ability to swap the axis around and this can be used to make MACH treat your 4th axis is if it were a spindle . .  by 'swapping' the A axis and the Spindle (which for this purpose is treated as an 'axis')

I wrote macros to do this and posted them. I will post them here again. Note that 950 and 951 are not special numbers. You can use any non-reserved number you like.

In order to not be tied exclusively to a MACH specific feature, I developed the 'swapaxis' capability in hardware (the little board).



A side benefit of this method for MACH is that it works with the smoothstepper board. The swapaxis hardware board simply takes Mach's step and directions outputs from two axis and routs them to two drives. It can then, on command,(any Mach Output) swap the signals to each drive. It is extremely fast and is transparent to Mach (and the smoothstepper).

As I made more macros, things got confusing, so I standardized on Mxx1 to turn something ON and Mxx0 to turn it OFF.

 

785

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: May 24, 2010, 03:22:31 AM »

Another Update:  I've been collecting parts and materials for mill modifications, and as usual, I've gone way overboard to the point where it is no longer really a 'modification' but building a whole new mill.

And of course also a whole new control box to go along with it. My current box is a mess becuase it has been changed and added to so many times.

The result of this is that I am selling two more DUGONG drives (in the bargain basement) and I am also considering selling the existing milll rather than 'modifying' it to such an extreme. Just two photos here. If interested, send me a PM or e-mail and we can discuss.

I have two more projects to finish and then I will be building up the new mill and 4th axis trunnion table. Probably two weeks out.

786

General Mach Discussion / Re: Need Guru input on an idea: Using Mach as dynamic balancer

« on: May 21, 2010, 11:48:43 AM »

While the topic of balancing is interesting to discuss, the thread was intended to be specific to exploring the possibility of using Mach facilities to perform some rudimentary balancing, for the benefit of all MACH users.

I have purchased an accelerometer, programmable controller and strobe that can do the job autonomously. That is how I will proceed from here.

Thanks for the contributions.

787

General Mach Discussion / Re: Need Guru input on an idea: Using Mach as dynamic balancer

« on: May 20, 2010, 02:41:58 PM »

The spindle should be balanced as a unit, thus it would include the disc brake.

We are talking about balancing in-place, so the entire rotating assembly would be balanced by default. If the imbalance is too far from the center, then you would need to a true dynamic, which is sort of beyond what I am talking about in this instance.

The 4 jaw chuck can be balanced, but then as soon as you put something into it there goes everything  to poop again.

I was talking about a 4 inch chuck, not 4 jaw

From a practical viewpoint, lets use consider what we do instinctively on say a lathe. If the lathe starts to get some vibration while we are trying to turn
something mounted off center, we slow it down and take cuts to make things symmetrical and at some some point we crank up the speed and do more finishing to the piece.

You make a valid point, but limited to something that should be and eventually will be symmetrical. I was thinking in terms of a workpiece (or assembly) of some odd shape that will have a monstrous imbalance before during and after the cut. Cutting such a part in extreme slow motion is one solution, but often that will result in an intolerably low SFM or intolerably high production time.

You would agree, methinks, that the closer you can bring the part into balance, even a very rough balance for example by bolting a bob weight to a rotating fixture or even just a face plate, the faster you can spin it for the needed operation. That's all I was talking about, in practical terms. I would tell a story about huge eccentric hinge pins, but I see my time is up...

788

General Mach Discussion / Re: Need Guru input on an idea: Using Mach as dynamic balancer

« on: May 20, 2010, 02:03:14 PM »

Just wondering what kind of bearings do you have on your mill spindle and how is it cooled to run at 8500RPM?

No hijacking, naughty boy.

Start a new thread on medium speed spindle cooling and perhaps I will participate.

789

General Mach Discussion / Re: Need Guru input on an idea: Using Mach as dynamic balancer

« on: May 20, 2010, 06:04:21 AM »

I was assuming the R8 or 5 spindles would be used in your 4th axis you have been working on.

Yes, the R8 is the mill spindle and runs 8,500 RPM max. The 5C is the 4th axis and would only run in the 4,000 RPM neighborhood (hopefully), but it has a 4" steel disc brake on it that is not balanced, so even with the lower RPM, it is a larger problem.

I have had the mill spindle over 7,000 RPM so far and while it is smooth enough for most of the range, it has some harmonics at certain RPM, so there are some 'illegal speeds' that I would like to eliminate. Only yesterday I finally was able to get the 4th axis spindle up to about 3,000 (estimate). It has no harmonics, and is pretty smooth, but if you slap a 4" 3 jaw chuck on there you get quite a vibration. I could send chucks out to be balanced, but I have lots of other uses for balancing capability, so I still need a solution.

There are two other reasons that I am persuing this capability; One is that if the spindles are well balanced and I have some form of rudimentary 'in place' or 'field balancing' capability, I would then be able to balance (within reason) any part that I made on either spindle.   Second is for production purposes; if a badly unbalanced part, say a casting for example, needs to be turned, it can be done much faster if a counterbalance weight is added to the fixture.

As I mentioned earlier, for my own purposes, I believe I have a solution in hand with a particular programable USB scope. However this is still a very interesting topic to discuss and it would benefit a lot of Mach users if an inexpensive and reasonably effective solution was developed that utilized the CNC PC and MACH software that's sitting there already.



 

790

General Mach Discussion / Re: Need Guru input on an idea: Using Mach as dynamic balancer

« on: May 20, 2010, 05:40:20 AM »

Ok, lets make some "Assumptions", since your not providing what you want to use.

Scott, I am not providing what I want to use because I don't know what to use. I don't know enough about electronics to make an informed decision on the best way to proceed. So I ask questions that hopefully are not terribly stupid and leave it to experienced people like yourself who offer up ideas that perhaps would have never occurred to me.

Cheaper solutions may be that you purchase a: M1/M12 from CNC4PC (M12 has 4, 8 bit analog inputs), OR, you can purchase Peter Holmans ModIO device he also has Analog input capability. But since those devices dont not have "Programable" space on them, you would need to do your calculations in VB script in the Macropump, OR, in Brians, or perhaps a combination thereof, or a plugin.

Here is a good example of what I just mentioned. The solution you outlined with the PLC would be too complicated and expensive for a layman, certainly for me, but this looks like a palatable alternative and gives me another idea. I have seen some accelerometers that are already installed on boards with some controls built in. Some are pre-assembled and some are in 'science kit' form. Perhaps that would be a place to look to get the sensitivity adjustment needed.