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Old Feb 18, 2013, 06:38 AM
The wheels touch down FIRST??
BJ64's Avatar
Australia, VIC, Melbourne
Joined Jun 2009
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Um... could you repeat that?

You mean that no matter where your axes are, if you punch in G0 X0 Y0 Z(home height) in the MDI screen, it will always go home automatically?

If so, how does it know exactly where 'home' is?

Is that something you have preset somewhere first?

Forgive me for sounding dumb - but setting home and getting it to always go there regardless of where each axis is when I turn the machine on is exactly what I'm trying to do...

BJ
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Old Feb 18, 2013, 10:48 PM
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South - Africa
Joined Nov 2007
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Are you trying to get the machine to home on start up without home switches? Usually you can only initiate a homing sequence if you have home switches on your machine, other wise you have to jog the machine manually to where you want home and set that position as home. the machine can then be returned to that set home while it has not been switched of.

My machine usually returns to home after a cut, I makes sure its home before i switch it of so I could just set home and continue work on next start up.
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Old Feb 19, 2013, 05:50 AM
The wheels touch down FIRST??
BJ64's Avatar
Australia, VIC, Melbourne
Joined Jun 2009
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Ahhhh.... thanks!

That's what I've been trying to work out - if it needs switches to be able to "go home" when you start the machine up the next time.

I was hoping that there was some way to set some kind of reference point that the axes would all be able to go back to by hitting "ref all home" - in between turning the machine on and off.

I kinda makes sense that it can't (without switches) - in a way - I guess.

Coz you could always bump/move any axis while the machine was turned off, and it would have no way of knowing that you had done that.

Still - it would be good if you could do a "ref all home", and the software would write that info away to a file somewhere. And when you shut-down properly, it could also write the co-ords of where everything was at that point in time off to another file somwhere.

Next time you start it all up, the software could assume that the axes are at exactly the same position they were when you shut it down last time. Hence, it would still know where 'home' was relative to where it is right now.

The two basic assumptions here are:

1. Nothing has manually moved an axis from where it was at shut-down.
2. You haven't had any lost steps between the 'ref all home' calibration and where it was at shut-down.

After all, the whole CNC things works by internally counting the number of steps on any axis in any given direction, no?

Hmmm... food for thought...

BJ
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Old Feb 24, 2013, 05:52 AM
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Quote:
Originally Posted by BJ64 View Post
Um... could you repeat that?

You mean that no matter where your axes are, if you punch in G0 X0 Y0 Z(home height) in the MDI screen, it will always go home automatically?

If so, how does it know exactly where 'home' is?

Is that something you have preset somewhere first?

Forgive me for sounding dumb - but setting home and getting it to always go there regardless of where each axis is when I turn the machine on is exactly what I'm trying to do...

BJ
Correct ever time you use the machine you need to define 0,0,0. Which is normally where you switched it off. Ie when you finish send the machine home. Its not really a big deal to reset the origin on start up. The only other option is home switches.
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Old Feb 24, 2013, 06:40 AM
The wheels touch down FIRST??
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Yah...but on a 4-axis, it'd be nice to know that X/Y & A/B all go back nice and square for the next time you power-up...

BJ
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Old Feb 26, 2013, 06:33 AM
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so mdi g0 x0 y0 z0 a0

or if you have used a/b

g0 x0 y0 a0 b0
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Old Feb 26, 2013, 09:08 PM
The wheels touch down FIRST??
BJ64's Avatar
Australia, VIC, Melbourne
Joined Jun 2009
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Yes...

But if I issue mdi g0 x0 a0 b0 a0, where exactly is it going to go to?

From what I understand so far, it won't know where "0" is once I turn the machine off - unless I have limiting stwitches... ?

BJ
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Old Feb 26, 2013, 10:40 PM
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All the CNC machines I used you need the machine to find x,y and z limits. And they all have limit switches. This was done every time you turned the machine on. This verifys machines health and the amount of travel the machine has.

You can select where the tool starts and stops. So is this the zero you want?
If so, this is what you need to figure out where your tool start and stop should be and forget about the limit switches. The starts and stops are nearby the work. So keep your work within the limits of the machine.
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Old Feb 27, 2013, 04:03 AM
The wheels touch down FIRST??
BJ64's Avatar
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Thx P901 - but it's a bit different on a 4-axis foam-cutter.

I need the wire to be square and level in '4' dimensions - X&Y + A&B - if that makes any sense i.e. wherever X&Y are in finite space, A&B have to be exactly parallel and start/end at exactly the same spot.

I'm thinking that without limit switches, I'll probably make a little 'template' right-angled block and have some aluminium strips on the base board where I can ensure the block will always locate into the exact same position when I place it there.

Then all I'd need to do is jog the X/Y & A/B axes until my hot-wire is parallel to the top near edge in both length and height and I should have a common right-angled and square starting point +/- half a mm or or so...

BJ
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Old Feb 27, 2013, 11:14 AM
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Denmark
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559 Posts
Hi BJ64

My Foam cutter doesn´t have limit switches or homing switches either. Works fine without them because of the slow speeds (100-200mm/minute). My CNC Router has limit switches and they have saved the machine several times. Things happen very fast when jogging at 8000mm/minute!!!
Here´s how I do it:
You only have to set up your machine once. When you´re satisfied with the position of the wire, zero all axis. I use the 4 axis Foam screen set for Mach 3 and then use the jog both axis buttons to jog the x-axis/a-axis simultaniously. Same with y-axis and b-axis. I then jog the wire to the starting position based on the G-code generated by DevFusFoam and the block of foam. I then hit Ref-all and the DRO´s all reset to zero. Now I´m ready to cut.
After the cutting is done I hit Goto-Z and all the axis´ return to the position where I pressed Ref-all. That´s it. No need to have a fixed home. Just make sure you jog the axis´ together or use the command line to enter G-code commands like G00 X100 Y0 A100 B0 etc.

Happy CNC cutting, BJ

- Michael Hammer
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Old Apr 02, 2013, 07:35 PM
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Italy
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Originally Posted by BJ64 View Post
Second that!

Stefano (author of Dev*, Profili etc.) is without doubt a genius. If only he could explain in easy-to-understand English how his software works, his products would be much more of a pleasure to use. Que sera...
I'm the devXXX series and Profili developer, but really not a genius

It isn't so easy to write a good help file for devFus (foam) for me.
Every different shape requires different tricks.
Generally I give some hint to the users that contact me by email.
If some of you has the time-will to write more about the use of devFus, I can then add those text to the official help file as Users Hints.
To make it possible I should get a TXT or doc file for each help page where you like to add your comments.
May be that could help a lot new users...

Actually I'm very busy with releasing the first release of devWing, for ribbed wings (take a look at it the www.devcad.com web site if you like)

But may be we can do something to improve the devFus Help file (I'm italian mother tongue, so not very fluent with english )

Anyway I'm very happy when I see users able to get the best from my applications. I really don't get rich with them, so this is part of the fun...
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Old Apr 02, 2013, 08:59 PM
The wheels touch down FIRST??
BJ64's Avatar
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Hi Stefano

Maybe we could start a Wiki on it?

BJ
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Old Apr 03, 2013, 03:21 AM
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Italy
Joined Jan 2003
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Originally Posted by BJ64 View Post
Hi Stefano

Maybe we could start a Wiki on it?

BJ
Yes, if you know the way it works!

Edit: I took a look at wikipedia rules, and they doesn't like article about manuals, FAQ and so on.

I think I could open a new forum about my main products:
- Profili
- devCad
- devFus
- devFus Foam
- devWing
- devFoam

With different topics grouped by application.
This is not to try to make a big forum and and fight against RCGroup or RCUniverse, but to help the users of my application to find evaluable info and skilled users.
The forum will be somehow moderated to keep spammers away.
Some of you can then be the moderator of some Topic
The Forum will be linked to my web pages www.profili2.com and www.devcad.com

What do you think about this idea?
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Old Apr 03, 2013, 06:38 AM
EDF rules... :)
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Joined Nov 1999
13,586 Posts
Stefano,

I like Devfusefoam, it is a great product and you have done us a great service. Thank you.
I look forward to aquiring Devwing in the next month or so. I downloaded it last night and learned how it worked to a point and am happy with its abilities. I have not explored what the options of plotting and cutting yet but will eventually when I buy the software.

I will participate in the forum and add what I know to the wiki when you get it up and running.

Cheers,
Eric B.
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Old Apr 03, 2013, 06:51 AM
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Italy
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Originally Posted by AirX View Post
Stefano,

I like Devfusefoam, it is a great product and you have done us a great service. Thank you.
......

I will participate in the forum and add what I know to the wiki when you get it up and running.

Cheers,
Eric B.
You can find here the forum: http://devcad.forumfree.it/
It's also listed in Profili and devCad web site main menu now.
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