Cutting Head Connection-Details Required.

[lightl]

Can someone give complete information regarding cutting head connection alarm of the machine(AMADA F0M2). Why it happens, how to avoid it, does it have to do anything with the way we program? Also if the machine has nearly 1600 cutting head connection alarms in a span of 5 months, What are the probable consequences?

 

[LASERNINJA]

Wow. Are you serious...

I don't know a lot about the system but I will tell you what I do know.

Air pressure is supplied to three ports ( maybe more or less ). When the head is where it should be the ports are sealed and air pressure is maintained. When the head breaks away, the pressure drops and a pressure switch is triggered generating an alarm.

If the mating surface is damaged, if the orings are missing, the ports leak air, and the pressure switch may be activated without an actual crash. One time I did see where the switch was out of adjustment. Changed the settings and the problem went away.

In my opinion, there is no way programming one way or another can cause the alarm unless you are crashing the head a lot.

The only other thing I can think of is if the nozzle gap, stand off, is too small. You would have to check pierce gap, edge gap approach gap and cutting gap. The smallest I go is 0.020 If the gap is too small the nozzle can drag causing the head to pull one way or the other.

 

[lightl]

@LASERNINJA

One reason is because of part tilting. The tilted part is hitting the head. One of our machines is "burning up" and the company is attributing the same to the number of head connections that has occurred. The same is due to improper programming as sometimes part gets tilted and hits the head. Kindly advise whether this can be controlled from a programmers perspective or is it purely a machine problem. Also how often in a day ,if you're running jobs, will you get cutting head alarm? Whether so many alarms have come due to part tilting, the same cannot be proven.

 

[TheLaserburns]

I used to have a big issue with parts tilting as we primarily cut round rings. I over came this by disigning my own rests for the bed so they ran both horizontally and vertically across the bed. So what I was left with was 50mm squares that the parts couldn't fall down into. I also closed the gap between the points of the rests to be closer together. The gap before with old rests was 50mm point to point new ones are 10mm point to point. Only issue with doing this is it fills with dross quickly and is a bugger to clean. You may not have to go that small but it's an option.

 

[LASERNINJA]

Okay. Let's take it from the top.

Any cut piece of metal smaller than 6" in the x direction should have a 0.05" tab.

The cutting head should never traverse over a part that has been cut. Amada calls it "cut avoidance" in the programming software. Sygmanest has something similar.

The laser operator need to set the last column on the right of the cutting conditions page to "standard". This should bring the head up 1" after every cut.

Yes, these steps make the machine move slower. But no slower than clearing cutting head connection alarms 20 times a shift.

Last. No amount of head connection alarms is acceptable. To answer your question, zero per day.

 

[lightl]

Many lenses have been burnt recently.(from the bottom side) Could this be a possible reason(cutting head)? Also the lens gets heated while cutting higher thickness( above 8mm thick Mild Steel) Digital meter reads 50-60 degree celsius on the lens holder. The root cause is not found.@ Laser Ninja... why else this might happen.
1. Lens is cleaned.
2. Nozzle centering is ok.
3. Bellows have been checked and replaced.
4. Mirrors have been replaced.

 

[LASERNINJA]

Every time the cutting head has a crash, nozzle center should be checked. If the beam is off, it can melt the nozzle, and cause it to get plugged. Once that happens, the lens is almost certain to burn. Along similar lines, if the nozzle gap is too small, the orifice will get plugged.

Another thing. The output coupler, and rear mirror are two of the most important optics in the machine. They should be replaced every 6,000 hours. Also, they have to be from a reputable company and installed by someone qualified.

The FOM2 is a fantastic machine. I am sorry to hear that you are having so much trouble.

 

[LASERNINJA]

To clarify:

Causes for lens fire.
1. No assist gas
2. Assist gas pressure to low.
3. Plugged nozzle.
4. Pre focused beam (dirty mirrors)
5. Inadiquit lens cooling.
Shop air is too hot or a line is plugged.
6. The laser loses it's cut but the program keeps running.

 

[evans1089]

We have the F0M machine, 4222NT infact.
Cutting Head Connections are when a part tilts up whilst the head is moving in the direction. If the head touches the part thats tilted, it will move the alignment and also cause damange to the nozzle.
You will need to replace the nozzle every time and also adjust the nozzles center again.

We've also had it become when it does scrap cut. If the lead in as broken, leaving the part loose, or the skeleton has risen or dropped from being flat.

To help prevent it. Use thicker tags on parts. And if using scrap cut, make sure you tag the parts where the scrap cut goes.
In major cases, it can snap the aluminium heads. Which are approx £1200 to replace.

 

[jetrep]

I'm not sure if the FO M2 head system is the same as the FO3015NT. If it is there are three tiny switches that get activated when the head hits an object. I believe all three switches are in the closed (pressed in) position. If the head/cone strikes something that causes it to tilt then one of the switches opens. When any one switch opens you get the cutting head connection alarm.

These switches go bad. Over ten years we've had the switches replaced by Amada a few times. This is dated information so it may no longer be the latest but the Amada part number is 71392220. We bought them for half the price from mouser:

http://www.mouser.com/ProductDetail/NKK-Switches/FB15ANEP2/?qs=tJRqkAIQG4yzXUuaWK1GIg==

When a switch was failing or had failed we would experience lots of head connection alarms under normal operation. Replacement is somewhat tedious so replace all three when in there.

 

[evans1089]

I've never seen them on our F0M4222 you mention @jetrep.
The sensor head is a sealed unit. They are made to be the weakest point and break if a part tilts to protect more expensive parts further up. They say more expensive, when a head is £1100!!
This obviously is an extreme example of the scenario, when most of the time with a cutting head connection, it means a new nozzle and to re-center the beam.

 

[LaserSpyder]

yes check switches only if laser stops for no reason in the middle of a traverse and if you are crashing into parts your programmer is at fault. Even if I knew every single part would flip I could set up nest to avoid flipped parts, and all parts that do flip should be tabbed for the next go around and should still be avoided even if tabbed, its "Nesting common sense"

 

[Len21]

They say it all, to avoid those error or hitting the tilted parts, try to stay on the machine and watch every cut, or insert m180 in the end of M104.

 

[evans1089]

A large tag on each part is the way to go. Long thin parts want them on each end and in the middle. The more experience you have watching and using different materials will help you when it comes to programming for each part/material thickness.