Messages

181

Mach4 General Discussion / Re: I don't see the "SIMULATOR" tab

« on: March 13, 2023, 10:19:53 PM »

Hi,
not exactly sure what you mean. Mach4 does have a Simulation Device but you don't need a license, and you don't need to download it, its part of every
Mach4 build....its already there.

Craig

182

Mach4 General Discussion / Re: Is there a trick to updating registers? what am I doing wrong

« on: March 11, 2023, 07:24:09 PM »

Hi,
sorry the excerpt from the SigLib table is not a screen shot but rather a text file.

Craig

183

Mach4 General Discussion / Re: Is there a trick to updating registers? what am I doing wrong

« on: March 11, 2023, 07:22:50 PM »

Hi,
I have attached a couple of screen shots from my machine. The first are entries in the SigLib  table where a given input, a servo alarm for instance, will cause an Estop
but also write to a register. The second shot is of the Register Diagnostics. Note that the servo alarms are so seldom, if ever, triggered are not especially interesting,
but the AXIS1, AXIS2 reflect the status of the axis select switch on my pendant, which in turn informs Mach of the axis to jog and puts that in another register
just call AXIS and has a number, 0,1 or 2 depending on the axis to be jogged. Note that these values are live, that is to say whenever I flick the three position toggle
switch to select an axis to jog the registers update. I've been using this scheme for months and it works perfectly. If the registers were misbehaving then my pendant would be
misbehaving also,yet it is not.

Craig

184

Mach4 General Discussion / Re: Mach4+ESS / Homing Error- Motor Not Enabled

« on: March 11, 2023, 04:27:13 PM »

Hi,

Craig, my switches are all proximity sensors... are there advantages to using mechanical switches?

For Home switches I believe there are advantages, for Limits, no.

For a Limit switch all that you really care about is that the switch operates when the axis is adjacent the switch. It does not especially matter if it operates +-0.1mm
nor does it particularly matter when the switch deactivates when you back up.

Home switches are different. Recall that Mach references the machine coordinate of an axis to zero (or Home Offset if so programmed) not when the switch activates but when it deactivates.
The axis will advance towards the Home switch until the switch activates and then decelerate to a stop. Then the axis will back up and the machine coordinate zeroed as the switch deactivates.
There is a premium here on exactly when a switch activates and when it deactivates. Snap action micro switches are very good at repeatably activating at exactly the same spot again and again.
The Omron switches I use have a precisely defined and repeatable hysteresis, ie a given travel before the switch deactivates.

With proximity switches and to a certain extent optical switches there is a minor variation not only when the switch operates but most importantly when the switch decativates when the axis reverses.
Its for this reason that I prefer snap action microswitches for Home switches.

Having told you the reason that I like mechanical switches there will be many to say the contrary and with experience to back the claim. I suspect in truth both solutions are adequate.

If you really want accurate homing then you'd use Index Homing. Given that I have servos on all my axes and the the servo drives have an auxiliary encoder output including an Index signal
I could invoke Index Homing easily. It would require an extra input to Mach for each axis of course, so four currently and five coming.

I made my own breakout board for my new mill. It has an eight wire plug for each of the six axes, four wires for differential Step/Dir signalling, one for an Enable, one for a Reset,
one for a servo Alarm and the last one is a 0V Return. I could I suppose redesign to have say a 10 wire plug which would allow at least one extra wire for Index Homing....but really do I need it?
I can Home or Reference my linear axes to within 0.02mm just with snap action microswitches....is that not good enough? I could with Index Homing do better, to within 1um....but is that
really a big advantage of just skiting? Once I fully develop my fourth and fifth axes I may have to revisit this decision, I really need to Home or Reference my rotary axes within say 15 arc secs,
and I suspect that Index Homing may be the only way to get that sort of accuracy. If that were the case then I would retrofit just the fourth and fifth axis with Index encoders rather than redesign
my breakout board.

Craig

185

Mach4 General Discussion / Re: Is there a trick to updating registers? what am I doing wrong

« on: March 11, 2023, 02:48:45 PM »

Hi,

Are the registers (iRegs, etc...) actually also simply entries in a LUA table as well?  Or are they global variables?

They are certainly global variables and the only way to export data from one Lua chunk to another chunk. What I cannot tell you is whether they are a fixed location,
I suspect they are. As you know most Lua variables are dynamically allocated and throughout a session will be created and destroyed many times. As such the
'handle' for a given variable will vary, however my guess is that registers are fixed.

Craig

186

SmoothStepper USB / Re: Is this potentially an ESS Smoothstepper problem?

« on: March 07, 2023, 09:23:03 PM »

Hi,
I'm dubious that is the ESS, if there were a fault it would show up again and again. Remember the ESS sees a stream of numeric position data in 1 millisecond slices, It does not
know or care about whether its cutting a W or any other letter.

I would guess its the code rather than  the machine, an electronic or mechanical problem would show up at other times.

Craig

187

Mach4 General Discussion / Re: Tru Cut MACH3 Profile

« on: March 07, 2023, 09:05:40 PM »

Hi,
I'm not a plasma user, although a mighty great plasma torch would make short work of the garden.......but I'm sure plasma users would appreciate a conversational style
Gcode generator.

There is one feature that Hypertherm make a big thing out of, and me be even patented, called 'True Hole'. They claim that if you cut something like a bolt hole in a piece of plate
using True Hole results in the roundest most accurate hole God ever put breath into. I'm very sure if mach users had the opportunity to generate code which mimiced True Hole
they would be very happy.

Craig

188

Mach4 General Discussion / Re: Mach4+ESS / Homing Error- Motor Not Enabled

« on: March 07, 2023, 04:18:49 PM »

Hi,
are you familiar with the placement of the switches inside the machine?

It was very common and still is, to have two limit switches per axis, naturally enough one at each end of the axis, and to use one of those switches as a Home switch
when homing but otherwise as a limit switch. This is perfectly acceptable even if it does not really go 'whole hog' such as I described on my machine.

I do reiterate the point that the most valuable use of switch is not  Limits, but rather Home switches. If you religiously Home your machine at startup and enable SoftLimits
then your machine will never cross over the boundary of your machine, ie the Limit switches will never be triggered.

My first mini-mill was like that, I had three Home switches only and thereafter relied on SoftLimits. It worked extremely well. I had three crashes in seven years and in every
instance it was my own fault. I always meant to get around to fitting Limit switches but never did. My new build mill is much bigger ans very much faster, 25m/min rapids,
and so I determined that I needed not only SoftLimits but Limit switches as well.

The reason I mention this is because Home switch can be anywhere in the machines envelope. Limits switches all but have to be at the extreme of travel, but not so Home switches.
Having said that its common to fit them near to one end of an axis, but not strictly required. For example my Home switches are about 10mm 'inside' the boundary. When the machine is Homed
the machine coordinate is usually set to zero at the Home switch position, but optionally can be set at a 'Home Offset'. In my case I make the Home Offest 10. So when the machine
is homed to the Home switch Mach knows that the actual boundary is a further 10mm away.

Being able to locate Home switches at any convenient location may often mean an easier placement, out of harms way, out of the coolant stream or whatever. It may also give you the oppurtunity
to design your Home switch installation that they not be damaged by over-run.

I use Omron roller plunger snap action microswitches for both Homes and Limits. They are high quality and have highly repeatable hysteresis, another matter where  I 'hop up and down a bit'.
I Home or Reference my machine (without the complication of Index Homing) within 0.02mm which is entirely adequate for most things.

https://nz.element14.com/omron-industrial-automation/z-15gq22-b/micro-sw-roller-plunger-spdt-15a/dp/1500340

Craig

189

Mach4 General Discussion / Re: Mach4+ESS / Homing Error- Motor Not Enabled

« on: March 07, 2023, 03:35:23 PM »

Hi,

I have three Home switches, one for each axis, each on their own ESS input. I have 6 Limit switches, two per axis for all three axes, there again each on their own input,
for a total of nine inputs. Then Mach knows exactly which switch operated and what that portends.

I hasten to point out that I have been described as 'anal retentive over this matter'....which I think is rather unfair....I just like hopping up and down on the spot a lot!
I'm not drunk, I'm just holding up this lampost if you really want to know' (not original but a misquote of Tom Waits)

Craig

190

Mach4 General Discussion / Re: Is there a trick to updating registers? what am I doing wrong

« on: March 07, 2023, 03:14:17 PM »

Hi,
I hope I'm not belabouring the point or trying to 'teach my Grandmother to suck eggs' but we have a perfect example of one of Lua's strengths right here.

All Lua variables are a table. The syntax for addressing a table is the name of the table followed by a period followed by the name of the entry in that table.

I'm more familiar with FORTRAN and C and the elements of an array are sequentially numbered integers 0,1,2, etc. In Lua however an entry name may be a number or
a string and any mixture thereof.

As an example:

mc = the name of the table
X_AXIS = Name of an entry in the table
mcJogSetRate() = Name of an entry in the table.

Note the one entry, namely X_AXIS equates to just a number. in this case 0. The other entry, namely mcJogSetRate() is a function. Thus the entries in any given table
my be a mixture of strings, numbers or functions. Compare that to C where all elements in the array must be of the same type, say float.

This is a perfect example of the principle of 'a function as a first class value', that is to say a function can be bandied about as if its just a number.....extremely handy
and much of Lua's flexibility comes from use and re-use of that property.

The 'mc' table must be huge. Think of all the APIs like mc.mcJogSetRate() and the many hundreds like it, mc.X_AXIS and many dozens of other numeric assignments
including mc.ISIG_INPUT43 for example.

Again apologies for hijacking the thread but this property of Lua intrigues me greatly.

Craig