tool change problems, still

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Robert Glenn
Junior Member
Posts: 85
Joined: Tue, Jun 07 2005, 8:24AM

tool change problems, still

Post by Robert Glenn »

All

We have been running our router for about 5 years; up until about 4 years it was problem free then we started having tool change problems where the NC would stall in the middle of a tool change. It mysteriously went away as mysteriously as it showed up, and it is back with a vengeance. I have been working with Thermwood on cleaning tools, sensor replacements and adjustments with little success. Most recently my operator pushed the “green” tool release button during one of the stalls in desperation to do something, and the air cylinder kicked on and the draw bar closed and the program proceeded. This was obviously a surprise because I thought the “green” tool release button was inactive unless the tool lockout was on.

I would appreciate hearing from any one having similar problems and solutions they have implemented. My core business is based on time to cut a sheet and this problem has significantly impacted that time and cut into what little margin we have.

Thanks

Rob
True Line Cabinetry
Carl Jones
Thermwood Team
Posts: 46
Joined: Fri, Mar 16 2007, 7:46AM

Re: tool change problems, still

Post by Carl Jones »

Hello Robert, It sounds like you may either have a bad wiring connection on the front of the router, or a possible bad router cartridge. If the operator pressed the green button while in the middle of a tool change macro, the machine was probably waiting for the down input to make. The air cylinder was already on trying to release the tool. When the down input was made, the machine proceeded to finish the tool change. The green button is disabled by the plc unless the output 34 is manually turned on, or the tooling lockout switch input is off. The next time it stalls, I would double check what input it is looking for and work from there. In the end, you may need to replace the router spindle. Also, for safety reasons, I would instruct your operator to press the emergency stop and try to send the machine home before trying to "wiggle" or press any buttons when it stops. If they do not, if the input is made it will continue its routine.
Thermwood Technician
Robert Glenn
Junior Member
Posts: 85
Joined: Tue, Jun 07 2005, 8:24AM

Re: tool change problems, still

Post by Robert Glenn »

Thanks Carl,

As it turns out the green button solution may have just been a coincidence. It stopped numerous times yesterday and pressing the green button did nothing. There are times when it just stalls then eventually picks the tool and I suspect the “successful” green button solution was one of those.

Most of the time it will do it when picking up a tool and it gets stuck waiting for input 2. There are occasions though when it gets stuck depositing a tool.

I have most recently been focused on the situation where it is picking the tool and input 2 is not getting a signal.

Some one at Thornwood sent me a picture of a green router motor with the sensor #’s and locations. Can you tell me it the sensor numbers match the input switch numbers for example does sensor 2 match input 2 in the controller? And can you tell me what each sensor does?

Thanks
Carl Jones
Thermwood Team
Posts: 46
Joined: Fri, Mar 16 2007, 7:46AM

Re: tool change problems, still

Post by Carl Jones »

Hey Robert, The switch #'s on the spindle and the inputs on the control are swapped. The #2 input is controlled by the switch #1 on the router. That is the "up" drawbar input. That senses if there is a tool in the spindle and/or if it is locked in correctly. The the input #1 is controlled by the switch#2 on the router. That is the "down" drawbar input. This is sensing if the drawbar is fully extended during the ejection of the tool. Thanks
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Rob Davis
Guru Member
Posts: 351
Joined: Mon, May 23 2005, 5:43PM
Location: Indiana
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Re: tool change problems, still

Post by Rob Davis »

Robert,
Perhaps this is stating the obvious, but the only troubles we have had with tool changes are when air pressure drops or is interrupted. When our air drier went out, we had water in the lines which casued havoc with sensors and flow and such. Maybe you have done it already but make certain the air flow to the head is not obstructed or dirt in lines. This can cause come and go problems too. Hope you get this solved!
Robert Glenn
Junior Member
Posts: 85
Joined: Tue, Jun 07 2005, 8:24AM

Re: tool change problems, still

Post by Robert Glenn »

All,

Thanks for the ideas.

Short version – we believe we have isolated the problem to the primary air solenoid

Long version – After many hours of adjusting sensors, cleaning tools, talking to Thermwood, and HSD technical service in between jobs I finally dedicated this entire day to finding the solution. I wrote a program that changed tools about 20 times in a row, went to the input registry in the maintenance tab and ran the machine over and over watching the inputs go on and off and listening and watching for any anomalies. What I recognized is that input 2 came on “after” I heard the primary air solenoid cycle and when the tool change stalled I didn’t hear the solenoid cycle and consequently input 2 did not close. This makes me believe input 2 won’t close if the draw bar doesn’t engage. So I wasn’t getting the sensor 2 input because of a faulty or poorly calibrated sensor it was because the draw bar wasn’t closing. While running through my tool change program if it stalled I simply rapped on the solenoid body with the back of a screw driver, the solenoid would cycle, input 2 would close and the tool change would proceed. I was 10 for 10 in executing this “fix” so I’m pretty confident this is it.

So tomorrow I spend some time talking to Thermwood about wiring or replacement in the mean time I’ll keep the screw driver handy.

I wanted to add this detail just so others can learn from this experience and I would appreciate comment from Thermwood that the scenario described above is valid or there is some flaw in my logic and for some reason I just got lucky 10 out of 10 times.

Rob
Carl Jones
Thermwood Team
Posts: 46
Joined: Fri, Mar 16 2007, 7:46AM

Re: tool change problems, still

Post by Carl Jones »

Hi Rob, that sounds like you have found the problem. The input #2 will not close if the solenoid won't turn off and release the pressure. Give me a call today and we can make sure that there isn't anything else going on there. 800-221-3865 X 250 Thanks
Thermwood Technician
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