Messages

111

General Mach Discussion / Re: x & Y speed requirements

« on: December 03, 2012, 06:24:25 PM »

Gerr & Rich

Gerr,
The specs on the steppers remain top-secret.  The seller/builder can’t seem to get me the information nor can he provide a tracking number.  Gotta love eBay!  It is rumored that the machine will arrive Tuesday.  Hopefully the mystery will end there.  The picture of what I believe I bought shows rack and pinion on all three axis. No specs on their ratios either.  Arguably, it will have larger steppers than what we are messing with.  The power supply is 36V.

Rich,
You are correct we will do both, live with what we have or will soon have and define what we require then seek it out.  Remember the goal is to learn motion control to prep for a re-control.  I don’t really need a plasma table but it looked fun.

I have made a few attempts to re-control a router but bailed out from the frustration.  The last attempt was in 2002 with a brand name control that never worked.  In follow-up with the manufacturer a week ago I learned that:

1) The system was incomplete and therefore will never work

2) It was registered to a company that is not mine

3) The person who it is registered to is an employee of manufacturer that I bought it from

How’s that for a scam?  It also explains why support (the same employee) blamed us for its failure and, well, wasn't very supportive.

If I really have a need for a machine I just buy it.  In this case, while banging about the net, I saw a plasma table sans its control for sale.  I bought it.  May as well learn to control it, right?  I have a zippity-doo-dah-whiz-bang plasma cutter that has 5 minutes use on it. The cutter even has a machine torch and switch gear of some sort.  It all seemed like a marriage made in paradise.  All we need is some motion.

112

General Mach Discussion / Re: x & Y speed requirements

« on: December 03, 2012, 12:05:51 PM »

Thanks Rich.  I must be missing something.  As I said, I understand the drivetrain math and physics relating to acceleration. So whether the mass, friction, and resistance are large or small doesn't matter to the torch as long as the desired acceleration can be achieved.  What I don't know is how fast the torch should accelerate to provide a pleasing and eye-catching cut. Can you tell me from experience what the starting/target acceleration number should be for Mach while cutting thin sheet metal.  If I had that number then the math of acceleration would be of use. 

113

General Mach Discussion / Re: x & Y speed requirements

« on: December 02, 2012, 08:18:02 PM »

We shall see on Tuesday!

114

General Mach Discussion / Re: Help with setup & controler

« on: December 02, 2012, 08:15:41 PM »

The TB6560 is history.  Ger21 is correct, current is the issue regarding heat.  We reduced the current and heat was reduced accordingly.  We determined there was no error in connections or the resistor sizing.  The Gecko only saw a 20 F rise with the higher current and no rise with low current while the stepper saw a 90 F rise.  This is all for education.  When the final selections and assembly are made we will balance the current and ventilate the enclosures as required.  I assume too that the machine will act somewhat as a sink for the stepper.  The stepper did run noticeably better at the higher current . . . the truth is always in the middle.

115

General Mach Discussion / Re: x & Y speed requirements

« on: December 02, 2012, 05:37:31 PM »

Thanks, I just started twisting a small NEMA 23 with Mach and a Gecko G540.  Very slow it is--thus causing the question.  I have in transit a 2x2 table with NEMA 23s but the manufacturer can’t or won’t provide the specs.  I will know when it gets here. The table looks okay otherwise.

Where would I start to calc a more proper sized stepper?  Hopefully, one that will work with the G540.  I understand the drivetrain math and just the theory of acceleration.  An acceleration number for Mach would be appreciated.  I am really lost on determining the RPM of a given stepper.

116

General Mach Discussion / x & Y speed requirements

« on: December 02, 2012, 04:27:55 PM »

What are the target x&y speeds for a plasma table?  I know . . . it depends.  But what is a ballpark top speed required in IPM for cutting light gauge sheet metal?  Maintaining a NEMA 23 stepper, what is the useful upper rpm limit?

117

General Mach Discussion / Re: Help with setup & controler

« on: December 01, 2012, 02:03:17 AM »

I am now able to twist the stepper.  The solution was, as you all noted, to place the TB6560 in the garbage can and replace it with a proper control.  I purchased a Gecko Drive G540 and power supply from “danmauch” via eBay.  I spent several days attempting to resolve the TB6560 with out success.  I have 2 hours invested in the Gecko including a drive to town to acquire resistors and soldering the connections.  I am sure I am not home free just yet, but the thing moves.   Thanks for the sage advice.

The stepper does seem a bit hot after just a few minutes of twisting with no load . . .145 F and climbing.  Any thoughts on that?  The Gecko is hovering at 108 F.  That’s just a 20 F rise from ambient. 

118

General Mach Discussion / Re: Help with setup & controler

« on: November 25, 2012, 05:29:44 PM »

ger21

Screenshot 2010 is well done and, in my opinion, very intuitive. Your zero feature would have saved me many frustrating hour while using the Wadkin.  Just enough of a problem to be irritating but not some much as to toss more money at it.  The cost feature ratio on cnc has certainly changed over the decade.

119

General Mach Discussion / Re: Help with setup & controler

« on: November 25, 2012, 04:02:48 PM »

Ger21

Is the 2010 screen your work?

120

General Mach Discussion / Re: Help with setup & controler

« on: November 25, 2012, 02:42:32 PM »

Ger21

Candcnc may not be far from the dollar mark if you consider the THC and software bundle.  The upside is that the pros will have done it.  The downside is that we still won’t be able to fix our own machine.  I will break out the calculator and delve.  In part the project is to enlighten a young teenager.  He is top of the class and claims to be headed for civil engineering.  Based on his actions I think he would enjoy mechanical or electrical.  Just want to expose him to something other than the books.  The plasma is for use on the NASA moonbuggy competition build. They hand-jive the parts now and complain about second ops to clean the shake out of the part.