Messages

1131

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

« on: June 15, 2009, 07:30:54 AM »

That is very cool!  And just think how much money you can save by making all your own bolts from now on!  :-)

Regards,
Ray L.

This is one of the parts I had in mind to make when I was messig with code to make the 'bolt' . The latest iteration of the 4th axis made these with a single program and one setup, including tapered NPT threads, hex flats, the thru hole and cutoff. It's coming along . . . .

1132

General Mach Discussion / Re: couple of things I have noticed with mach /g83 problem

« on: June 15, 2009, 07:20:42 AM »

no big deal on the decimal point thing , if this were my project I would welcome constructive advice on how to better things, I get the impression that alot of folks would rather get defensive and explain things away than be open minded and consider another viewpoint  , my apologies for even bringing it up.

FWIW, I agree with your assessment. 'Fanboy' mentality is always a detriment to progress on any product. In my brief experience here, the authors of the software seem very interested in constructive criticism, which is really what matters. It makes perfact sense to improve Mach's compatibility with commercial software by doing something as simple as including a decimal in numbers, which should have been there already.

Non-programmers may not understand how lines get parsed or how numbers get interpreted. G-code is interpreted, so each line gets parsed as text. The parser is looking for the decimal in any numeric value. If there is not trap for the absence of a decimal (and why would there be?) then the parser faults. No software has a trap for every conceivable entry error, including Mach, which has no traps for obvious basic errors in calling external subroutines. So faulting other software for not having traps that it really should not need anyway, makes no sense to me. But that's just my opinion others may disagree. 

I vote that your suggestion was valid, constructive and well worth a look see from the authors if they seek to step up their game.

1133

General Mach Discussion / Re: Moving off Limit switch

« on: June 14, 2009, 07:35:59 PM »

Yes, you definately cannot directly connect 12V or 24V to your BOB!

You need a transitor inteface. The 12v or 24v triggers the transistor which then directs the BOBs own 5v back to the limit switch pin on the BOB.   Simple, but neccessary.


If the estop is being triggered by the limit switches, then yes, you can indrease the debounce, but if you are still having that problem then it didn't go away.


There may be other things that debounce applies to but one more experienced than I would need to chime in on that.

1134

General Mach Discussion / Re: Moving off Limit switch

« on: June 11, 2009, 06:44:20 AM »

Two things you can do to clear erratic limit switch behavior are:

1) increase the voltage of the limit switches to 12v or 24v which will also scale the immunity.

2) replace the mechanical switches with photointerruptors which are not effected by the machines vibrations.


FWIW, my initial problems with limit switches triggering e-stops was swarf getting between the switch contacts and the grounded machine parts. Putting heat shrink eliminated most of the false stops, but still tiny pices could get in there. I eventually covered the contacts with 'liquid electrical tape' and that finally sealed them up. You might check that also.

I now have two of my 4 axis to photointerruptors and they are dead on accurate in homing and so far have not triggered any false e-stops. I'll convert the other two axis  when I get time.

1135

General Mach Discussion / Re: Is this backlash or missed steps????

« on: June 11, 2009, 06:34:17 AM »

I get about 1/28" error over the 8 foot table using only 2 decimal places for the steps per inch vs 10

Mach can probably accept (and actually use) more than twp decimal places in the steps.

I'm in agreement with using simpler ratios, but when that's not possible, can't you just enter enough places until you get to the accuracy you need.

1136

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

« on: June 11, 2009, 06:13:06 AM »

Viper servo drive is on order. Should allow me to use the full power and speed of the servo motor with the 1,800 line encoder.

Design is finalized after about 3 iterations. Here are the first final parts: the motor mount and the belt tensioner.





With the Viper and permanent motor mounting and belt drive, I'll stop and do some more testing and post another video.

Then it will be on to making the permanent spindle head.

1137

General Mach Discussion / Re: XY and Z zero

« on: June 10, 2009, 08:04:53 PM »

If he had a drawbar, he'd be able to use holders.

It seems he is using a router head or something similar, so it would likely be a collet of some type.

1138

General Mach Discussion / Re: XY and Z zero

« on: June 09, 2009, 03:54:29 PM »

Im building a larger router and I use the Kress spindle. I dont think there is a tool holder for Kress, but I could weld some kind of stop on all my tools and messure the lenght from there.

If there is no quick change available for your spindle (or if is stupid expensive), and your tools don't bottom in the collets (or however you hold them) you can still get a repeatable reference length by just putting a collar on each tool so that it installs in he same place each time you use it.

That will have the same effect as an end mill holder realtive to your tool change proceedure. You measure the tool once and tell Mach how long it is and then when you change tools, you just tell Mach which tool you are going to use and it looks up the length of that tool and 're-zeros' for you  . . . is one way to view it.

The tool tables and fixtures can be a big elephant to eat for a newbee, but take it a bite at a time and you'll get it. It's worth the effort and you will wonder how you every got along without it, once you figure out how convienient it is and how much time it saves.

1139

General Mach Discussion / Re: First Post - Help with setup issue?

« on: June 08, 2009, 01:17:31 PM »

Brian will be looking at the backlash code once Turn and Plasma have been done and that is after mill has been done
Hood

Sounds reasonable to me . . .  compensating for backlash in software, in my opinion anyway, should not be a high priority item, considering there are much better ways to eat that particular elephant.

1140

General Mach Discussion / Re: First Post - Help with setup issue?

« on: June 08, 2009, 01:09:06 PM »

I fooled with backlash for hours. Nothing i can explain will give that experience.

I hear you. I only played with it long enough to determine that although it has a comp speed setting, that setting is ignored. Actually I'm not too keen on the whole concept of backlash compensation, so it was never a big deal for me anyway, I just commented on what I found when I played with it.

Frankly, I'm more and more impressed with Mach the more I dig into the macro capability, and I haven't even touched on the brain facility yet. Mach looks to me like a WIP and it doesn't cost $5,000 so in my opinion, it is an impressive piece of work all things considered.

I was not impressed with the single index threading as I could not see how it would ever work and I said so on the forum and quickly found that pointing out Machs shortcomings is not popular around here    However, now there is quite an effort going on to improve threading with many counts per rev, so I was obviously not alone in my assessment.   The CV has some issues, the tool comp is a bit bizarre and as we discussed, the backlash comp is out to lunch basically.

In the plus column is that these issues (at least those important to me) are being worked over for the new version of Mach which is very exciting.