Messages

591

Screen designer tips and tutorials / Re: Small changes to jog flyout

« on: August 29, 2013, 09:03:32 PM »

I should have responded by thanking you for the solution a long time ago!  You were correct that did it.  Another post here reminded me that I would like to make another change.  I don't like cycling through the step sizes in the jog flyout.  Is there a way to make separate buttons for each step distance? That would be so much more convenient.

Thanks,

Gary H. Lucas

592

General Mach Discussion / Re: USB Motion Card and not cutting to right size!

« on: August 28, 2013, 10:49:33 PM »

Mike,
I have one of those cards, and I was having trouble with parts not being the right size too.  I swapped cables and determined that it was just the Y axis mechanically and not an electrical issue. THEN I found the loose coupling on the Y axis screw!!  The other two were a little loose as well.  Since then it has always cut accurately.  My machine is rather small but has 800 in/oz steppers running on a 68 volt power supply driving 20mm ball screws.  Lots of power so I haven't had any problem loosing steps at all.  I suggest you use a dial indicator on each axis and run it back and forth at various speeds to see if you are in fact losing steps. Very easy to tell, if you actually find a problem switch the axis cables if you can and see if the problem stays or moves.

Gary H. Lucas

593

Third party software and hardware support forums. / Re: Just got BOBCAD and here are my initial thoughts.

« on: August 24, 2013, 09:19:19 PM »

Hood,
Just wondering, have you ever tried CamBam?  I am using CamBan for milling right now, but I a very impressed with how it works for a very inexpensive program.

Gary H. Lucas

594

General Mach Discussion / Re: Proximity sensor help required

« on: August 20, 2013, 08:38:04 PM »

Well since no one else is jumping in here!  It sounds like you need a pull up resistor to the plus voltage source.  You probably need a couple of milliamps of current at your source voltage.  Use ohms law here: E (voltage) = I (current in amps, a milliamp is 0.001 amps) x R (resistance in ohms)  You can move the terms around so that R=E/I  so for 24 volts and 5 milliamps you'd have 24/0.005 = 4800 ohms or a 5K resistor. Plug in your numbers and flavor as needed!

Gary H. Lucas

595

General Mach Discussion / Re: Anybody got a lead on where I can buy some Neoprene (rubber) sheets??

« on: August 09, 2013, 11:31:00 PM »

Brett,
Unfortunately you can't walk through the building looking.  It is however over 600,000 sq. ft. of 36 foot ceilings!  At one time my brothers father in law had a business where he got all the returns from McMaster Carr, two 40 to 53 foot trailers each week.  His place was on my way to work and I'd stop most mornings and he'd let me look through the stuff before anyone else.  I got about 10 Mitutoyo digital calipers for $25 to $35 each, open box but still in the sealed bags! I still have a 4" 6" 8" and 12", gave the others as presents.  I used to buy all kinds of stuff for the shop where I worked, the owner was my best friend.  He was forced out of business by a frivolous lawsuit. He told me that I had gotten so many good deals on all kinds of stuff that he actaully had a profit when he sold off the the shop equipment! I recently pulled out my collection of milling cutters that I got back then, it's a small fortune worth that I paid pennies on the dollar for.

Gary H. Lucas

596

General Mach Discussion / Re: Anybody got a lead on where I can buy some Neoprene (rubber) sheets??

« on: August 09, 2013, 09:35:19 PM »

If McMaster doesn't have it you probably don't need it. They have the best online catalog I have ever used as well. They also have bellows Scott.

Brett

The best part is that I live 5 miles from their east coast warehouse, so I can call it in an pick it up an hour later!

597

Third party software and hardware support forums. / Re: CAD CAM Software Advice

« on: August 07, 2013, 12:57:51 PM »

I just started using CamBam and I am very pleased with how it works. Down load the demo and use it up to 40 times before buying it. Surprisingly powerful for the money and the methodology seems to be very easy to grasp.

598

General Mach Discussion / Not getting how to use tool length offsets

« on: July 23, 2013, 09:14:59 PM »

I've used tool length offsets extensively in the past on a Fadal and also an old Bandit controller.  However I am just not getting it with Mach 3!  I crashed a drill into a part destroying it after I thought I understood from a test run. What I wanted to do was use my edge finder as a touch off tool to find edges and the top of a part.  So I was going to call that tool zero and always leave it setup.  I have tool height setter with an LED and 0.200 overtravel that is 2" tall. So I was going to pick a spot on the table and always place it there. Once all the tools are set on the presetter I should be able to pick up the sides and top of the part in the fixture using tool zero and set all axes to zero. Then tool changes that call tools 1 and up should get positioned correctly.

Issues that I see:

I see where there is a tool change position X=0 Y=0 Z=5", but a tool change called in g-code from Cambam does not move to a tool change position.  The move appears to be enabled on the settings page. What else controls this?  What code makes it do the move? Does the tool length offset get applied first after the tool change, moving the Z so the tip of the new tool is at 5"? I think if the machine doesn't move to the tool change  position then everything else pretty much fails.

Thanks,

Gary H. Lucas

599

Tangent Corner / Re: Ballscrew End Machining

« on: July 16, 2013, 10:46:09 PM »

It makes sense that the od is not concentric. Its metal that pushed up when the rollers pressed the grooves into the shaft.

600

General Mach Discussion / Re: using variables

« on: July 13, 2013, 09:02:00 AM »

Yes you can substitute a variable for the Q parameter.  I have not found anything weird in the #var  , the exception being it does NOT recognise a stated negative value such as -#100  , You have to convert the value to a _value by -1* or 0- before MAch3 will recognise it as such.

BUT the Q does not control hole depth it controls the peck distance.

In your case you would not see any advantage to using the #var you have to change the location values for each hole and when you do just specify a new Q value.

G83 X0 Y0 Z-1 Q.010 R.050 F10
X1 Q.020
X2 Q.030
etc,etc

(;-) TP

TP,
I was just using Q as an example, couldn't remember what it controlled. I used to program for a couple of Fadals and I had a variable I called Z Safe.  At the beginning of every program I'd set it to like 6" which would let the operator run the program in the air above the part, and clear all the clamps and such.  Once he had everything correct he just changed it to a safe but fast number.

I also used variables to pass data into sub routines. In your example the locations only get used one time. I would put all the hole locations in a sub routine.  Then I'd spot drill using a 90 degree point drill to a depth equal to the radius of the finished hole. Since the tip is slightly flat you get a nice chamfer. Then I'd drill it, calling the same sub routine with variables set outside the sub. Then I might drill it again, using the same sub, changing the variables again.

Which brings up another question. You mention using Q=0-1 to get a negative value. Does that imply that Mach also does some math functions in addition to add, subtract, and multiply? I once wrote a short 50 line program that cut a 15 degree tapered pocket 12" x 18" x 7" deep with corners rounded out to clear a square cornered insert using variables and some trig.  We tested it with a tiny ball mill on a small block of aluminum, then changed the variables and ran the big block. 200 passes to rough with a shell mill, 700 passes to finish with a ball mill!

I'm very rusty at this point and trying to get back up to speed with my home built machine.

Gary H. Lucas