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Offline jevs

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Putting tools in tool holders
« on: March 08, 2015, 04:58:04 PM »
First off, I am just learning this CNC stuff. I have a little manual experience.
I have a 7 tool changer machine with mach3 on it. I have it working as it should and my tool change macro is working also. It changes to the right tool when I command it manually.
I have BobCAM.
My questions is, how do I load my tools in the tool holders? For example..do I have to precisely measure how deep I put my end mill into the holder? Do I have to precisely measure how deep I put a bit into a chuck?
I am researching all this, but it might be faster to understand if I ask some simple questions one at a time.

In BobCAD you have to tell it your overall lengths and protrusion lengths. Is the overall length the whole length of the tool and holder from the spindle, or the length of the tool before you sink it into the holder?

Frustrating to get going on this.

Offline Hood

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Re: Putting tools in tool holders
« Reply #1 on: March 08, 2015, 06:09:45 PM »
There are many ways to do it and all depends on your setup.

You can choose a tool or a probe for a master tool, call the tool and bring it down to just above the surface and then jog up incrementally until you can slip a feeler gauge in, you then set the DRO to the thickness of the feeler. You can then load another tool , jog down as before then whatever the DRO reads (minus the feeler) is the offset for the tool table.

Others have auto routines with a touch off plate wired into Mach.

I use a height setter that I have hooked into Mach so I can set tools up before they are placed into the tool changer.

Regarding BobCAD, you do not really have to set the tool lengths etc, that is just for simulation purposes, so it is entirely up to you whether you enter values or not. I just tend to enter values if it is a ,onger than standard tool when I have to reach way in somewhere, that way the simulation doesn't show the holder crashing.


Hood

Offline jevs

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Re: Putting tools in tool holders
« Reply #2 on: March 08, 2015, 06:54:13 PM »
So, those numbers are not critical? If I did want to run simulations, I could just set them close to about where my tools will end up in the holder?
I guess drawing my tool holder is not critical either?

I do have an econo-probe touch plate that I wanted to use. I also have an econo-probe setup as a probe.
I am still trying to figure out how to wire both those up.

Do you touch off the face of the part, or off the table?
Does it matter what tool you pick as the master?

Offline Hood

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Re: Putting tools in tool holders
« Reply #3 on: March 08, 2015, 07:04:43 PM »
I would not bother changing any of the lengths in BobCAD unless when you simulate it collides with the stock and you know in real life your tool/holder would not as it is longer.

Normally you will touch off the surface of the material and zero the DRO (or set the feeler gauge distance)   in Mach  or if your material is being totally cut on the surface you may wish to set the top of the material as a slight positive value, all depends on your part I suppose.

I have a Haimer 3D taster set as my master tool, I have set its zero position up in the tool table and I manually insert it into the spindle and call the offset I have it set for, that way once it is at zero on the top of the material I just zero Machs Z DRO and any tool called after that is correct.
 If you have a probe then, depending how it works, you could possibly use that as your master tool or you could even have a spare holder with a drill rod in it that you use as the master, in fact you could even just use the spindle nose as the master if you wanted.

Hood

Offline Hood

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Re: Putting tools in tool holders
« Reply #4 on: March 08, 2015, 07:09:14 PM »
BTW the problem with using, say for example, Tool 1 as a master is if you replace the tool in and do not get it exactly the same position as before,  then all the rest of your offsets are now changed. So much better to use a probe or another known point that never changes.

Hood

Offline jevs

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Re: Putting tools in tool holders
« Reply #5 on: March 08, 2015, 07:15:55 PM »
So I would always have one of my 7 positions occupied by the probe?
I would probe the surface of the part.
Then set that as zero.
Then have all the other tools hit the touch plate?

Does not make sense to me. I wish their was a video of this somewhere. Will have to look.

I would think the touch plate is used for all heights and the probe for edge finding. I don't think you can touch the probe to the plate either because they would both compress.

Offline Hood

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Re: Putting tools in tool holders
« Reply #6 on: March 08, 2015, 07:26:39 PM »
I do not know how your machine works but I can manually operate the drawbar and put a tool in the spindle without using the tool changer, thus I can use all 12 tools in the changer and still use the probe.

As I said I have no idea how your probe works, before I had the haimer I had a home made probe, when it touched the surface of the part the LED on it would go out. There are also other types of probes/edge finders, for example there is the type that complete a circuit through the machine and light up and buzz when contact is made, obviously the material has to be metallic for that type to work.

If you have a touch plate hooked up to Mach you could use one of the macros you should find on the forum to set up the tools.

Personally I like the way I do it, I can set all tools up out of the machine and when I change a worn tool it just takes seconds to reset its new offset. All my height checker consists of is a linear scale and a linear rai. Will post a couple of pics of the two I have made (one for each mill) if I can find the pics ::)

Hood

Offline Hood

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Re: Putting tools in tool holders
« Reply #7 on: March 08, 2015, 07:31:04 PM »
Ok found a couple of pics, the  blue one is the first one I made for my Beaver Mill, the other one is the one I made for the Chiron, it is not quite finished in that pic as I do not have the part that touches the tip of the tool made.
Also if you look in that pic you will see the probe I was talking about that I made that had the LED.

Hood

Offline Hood

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Re: Putting tools in tool holders
« Reply #8 on: March 08, 2015, 07:34:23 PM »
Here is a slightly better pic of the Chiron one, still not finished but it is a better view.

Hood

Offline jevs

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Re: Putting tools in tool holders
« Reply #9 on: March 08, 2015, 07:36:08 PM »
Here is my machine:
https://www.youtube.com/watch?v=Sjc9--rOPrs

The tools are held in a turret with a snap ring. The tool holders have a bearing on them. It grabs the retention knob and pulls them up in there.
The change is purely mechanical. It just moves Z up past the home and that pulls on things to rotate the turret. It is kind of like a ratchet with a rod that pulls to rotate it to the next spot.

I could probably leave a turret hole open and manipulate Z to just grab and ungrab the tools without going high enough to rotate it.
Maybe that gives you some ideas on how I should do it?
I have two of these:
http://wildhorse-innovations.com/index.php?_a=viewProd&productId=80
One is setup as a probe and the other as the touch plate.