Emco Compact 5 PC auto tool changer

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14 Jun 2014 03:00 #47960 by krlynn

OK,

Well to cut right through.

It is normally powered by a DC motor (which you don't have) and an extremely inventive system which uses the motor and a board (which you don't have).

You have a stepper motor and hopefully a plan to attach it, thereafter you are back with the Boxford scenario, which is equally workable

When you get it turning, come on back


Thanks.

NO plan. :blush: Just grand intentions.

The motor is attached. I know where I can get the board, but don't know what good that would do me. I suppose I could make a run at configuring the thing with an external power source and some kind of manually activated switch. That might not turn out to be very elegant but would suit my purposes. I'd rather find a way to control it with linuxcnc. Would be entirely content, however, to manually advance it within a program.

But I suppose the answer remains that there's no sensible way to stick with the Emco motor and inventive system and somehow control it with linuxcnc?

How would the Boxford scenario (in the absence of reverse current as described) work with the Emco ratchet-and-pawl system to eliminate play in the turret?

Here's a photo of what I have (except the seller actually included a second Nema 17 stepper). One of another Emco ATC follows it showing the ratchet-and-pawl mechanism (with a broken pawl).



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14 Jun 2014 15:25 - 14 Jun 2014 15:28 #47962 by ArcEye

Here's a photo of what I have (except the seller actually included a second Nema 17 stepper).


OK, we have been a cross purposes.

Until now, you have not actually said that you have an ATC complete with original motor AND a Nema 17 stepper.

I could not work out why you were taking so much interest in a board to operate a motor you didn't have. :laugh:

But I suppose the answer remains that there's no sensible way to stick with the Emco motor and inventive system and somehow control it with linuxcnc?


So long as you have details of what the inputs and outputs do, it will be possible to control it with linuxcnc.
I am surprised there are no sensors and it would no be beyond the wit of man to add at least one, to mark Tool 1 position at least.

But worst case scenario would be that the operator tells the component what the current tool is at startup and it can work out the rest from there.

regards
Last edit: 14 Jun 2014 15:28 by ArcEye.
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16 Jun 2014 08:03 #47996 by krlynn

OK, we have been a cross purposes.

Until now, you have not actually said that you have an ATC complete with original motor AND a Nema 17 stepper.

I could not work out why you were taking so much interest in a board to operate a motor you didn't have.


Yeah, I should have been more clear at the start.

About 80% of the info I pasted in regarding the board went completely over my head. I included mostly because I thought it might turn out to be of interest to others.

So long as you have details of what the inputs and outputs do, it will be possible to control it with linuxcnc.
I am surprised there are no sensors and it would no be beyond the wit of man to add at least one, to mark Tool 1 position at least.

But worst case scenario would be that the operator tells the component what the current tool is at startup and it can work out the rest from there.


I think I have the details. Just don't know how to use them yet and have no present urgency. I was just hoping someone would reply and say it's already been done.

FWIW, I found examples of EC5 ATCs that had sensors added, but I think all of them also had a stepper.

I'll come back to this and report any progress after I get further with the basics.

Thanks for the replies.

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21 Jun 2014 07:42 #48151 by tenaja
My concern for using a stepper would be consistency and holding force. The DC gear motor uses full reverse power to stall the changer against the pawl. A nema 17 motor most likely will not have the same holding torque, since it is not geared down. On top of that, the stepper will only have maximum holding torque at its fixed step position. If you try to stall the stepper against the pawl, most likely it will not be ideally aligned with that fixed step position, so it will be in a weakened torque position--and might even bounce back a full step. OTOH, maybe the worm gear makes it moot, as long as you can align it adequately.
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23 Jun 2014 18:50 #48197 by andypugh

But worst case scenario would be that the operator tells the component what the current tool is at startup and it can work out the rest from there.

It looks like it would be easy to also add a proximity sensor to detect the pawl position, which would be much better than a simple time-delay.

The most likely scenario for pawl-breakage is the cutting tool hitting the chuck, or some other overload scenario. I would consider it a useful mechanical fuse and resist strengthening it.

it occurs to me that all toolchanger sequences are made up of a set of standard behaviours in various orders. The typical toolchanger is a state machine running a hard-coded sequence.
I wonder how hard it would be to define the set of all states, and allow someone to "loadrt toolchanger sequence=acbabdf"
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02 Oct 2014 23:45 #51731 by uli12us
krlynn. is it possible to make a high resolution Picture from the Toolchanger Board front and back.
I have a C5CNC with the newest Software and want a toolchanger for it. For that purpose I bought a small dividinghead
which I want drive with a DC motor and a self build adapter board.
But, if you have all, what you need, why don't you use it. The toolchanging of the C5 has nothing to do with the toolsparametres. The user must give as much toolchange pulses, like the changer should switch. Thats always a short time the motor runs with full power until its over the stopper. Until that the motor runs continuously with very reduced power against the stopper.
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03 Oct 2014 16:48 - 03 Oct 2014 16:52 #51748 by cncbasher
this is exactly the same as the orac
although i dont see any positional opto's by the picture , although thats hidden at the other end
and the bottom plate , if their fitted

the holding torq is the fact that it reverses against the stop pawl , so the force is not taken by the motor
the only down side is the toolchanger can only rotate one way through positions
controlling the motor is easy with a few relays for run and forward /rev and to run a full wave rectifier in forward and a half bridge in reverse , crude but it works
Last edit: 03 Oct 2014 16:52 by cncbasher.
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28 Apr 2015 14:09 #58182 by gschoep
Any news on this thread? Did you get it working?

Seems like an h-bridge with one direction pwm'd down a bit would be ideal. Depends on the current of the motor of course.

Just starting a project to CNC a Compact 5 myself using the original components. I want to get a tool changer working too.
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25 May 2015 20:59 - 25 May 2015 21:00 #59011 by krlynn

krlynn. is it possible to make a high resolution Picture from the Toolchanger Board front and back.
I have a C5CNC with the newest Software and want a toolchanger for it. For that purpose I bought a small dividinghead
which I want drive with a DC motor and a self build adapter board.


Sorry, I lost track of this thread. Do you still want this? I'll try to take a high resolution photo if you or someone can identify the tool-changer board for me.

Any news on this thread? Did you get it working?

Seems like an h-bridge with one direction pwm'd down a bit would be ideal. Depends on the current of the motor of course.

Just starting a project to CNC a Compact 5 myself using the original components. I want to get a tool changer working too.


No, I did not. I stalled out first and then decided my needs are probably better served by the flexibility of drop-in tool-changers. Also the hands-on control.
Last edit: 25 May 2015 21:00 by krlynn.

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09 Feb 2016 16:26 - 09 Feb 2016 16:30 #69858 by Iron-Man
Krlynn did you ever get your tool changer to function?
Do you know what the approximate center height is?
Would you be willing to sell it in its current configuration?


Thanks,

Iron-Man
Last edit: 09 Feb 2016 16:30 by Iron-Man. Reason: Additional Info.

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