Tool Length Measuring

[James Lovell]

I have an old Thermwood 80ES with the 91/9100 controller. We are just now starting to test the machine since we purchased it used. I have noticed in the manual that there seems to be some kind of measurment stand that I do not have, to measure the tool length while it is inside the tool holder clamp. When I have typicaly measured tools on other routers, I would do a table touchoff. This machine seems to just want a variable plugged in as the length into the controller. My exact question is, where do I measure from to get the exact measurement of the tool. You start from the tip of the tool to where? The collet possibly, or maybe even the edge of the tool holder itself.

[Keith Neal]

We has the same issue when we first got our machine,I might be wrong but isn't tool length the total cutting length of the tool,for example we have a 3/8" onsrud bit total length is 3 5/8" including shaft but only 1 1/2" is actually used for cutting (I use a scale rule to measure by hand)so tool length is 1 1/2".

[James Lovell]

My issue is I'm going to be putting a tool in for the first time, and I want to make sure my "Z" Zero would be correct. I have yet to figure how to configure my "Z" Zero.

[Paul Ford]

James,
In the tool manager, is it asking for a daylight value? Our machine here is 5 years old so I'm not 100% sure that the configuration is the same. The daylight value is from the tip of the tool to the top of the spoil board so doing a touch off should do the trick for you if you record your Z value to the spoil board.

[Dennis Englert]

Paul,
You can contact Support at Thermwood 800-533-6901 or support@thermwood.com.

On the older systems, for 3 axis machines the tools length was daylight value, which is the distance from the tip of the tool to the surface of the table. On 5 axis machines, this length was used differently. The Model 80 predates my experiences, so someone in Support may be able to research this issue.

I thought I had posted a response to this yesterday, but was unable to locate it. I believe you had a question about a fixture, also. The fixture was used to set a router bit to the same length consistently, therefore the daylight value would be consistent from one router bit to another. Usefull for machines not equipped with a tool changer and tool length sensor.


Dennis

[Brad McIntosh]

James,

The "DAYLIGHT" settings for each tool is the distance from Machine Absolute Z0 (HOME) to the top of your table or spoilboard. This is found by mounting the tool in the head, teaching the end down to the table/spoilboard surface and recording the ABSOLUTE Z position off the screen into the Tool Parameter Table entry for the assigned tool number. ("DAYLIGHT" = "The amount of <light> between the tip of the tool and the table/spoilboard when the head is at Z-HOME.)

The "Tool Pre-Set Measuring Stand" was regularly used prior to the development of the "Automatic Tool Length Sensor". This measuring device is used to record a "STANDARD" or reference measurement with the colleted tool and holder in the stand. This was usually done once the "DAYLIGHT" was found for it on the machine. This "STANDARD" or reference value is then used whenever you change-out that tool so that the new one is returned to the exact same "length". By doing so, you will not have remeasure the "new" tool to the table/spoilboard since the relation ship of the tool to the holder is exactly the same as that which was used for the original "DAYLIGHT" measurement.

Some people would attempt to set ALL the tools to the same reference height, therefore reducing the number of times they have to measure daylight values. Others would group the tools into similar lengths - long, medium, short - allowing them to work with a three (3) "STANDARDS" and therefore only three (3) "DAYLIGHT" values on the machine.

I hope this helps.