Legend TT Focus

[Pete Thomas(UK)]

When using the Epilog I usually have the red dot pointer on. I have noticed that some times it appears in a different part of the mirror on the end of the x axis bar. Thought nothing about again until tonight it seemed way off. I had been cutting 5 mm acrylic at 4% speed and 100 power.

Switched off. Went to pick up the kids came back and set about checking focus. No adjustment was necessary. Started to work again and slowly over time the red dot moved off centre again.

As I was checking things out I noticed how warm/hot the inner casing was where the lased tube is attached. The aluminium fins on the laser tube were nearly too hot to touch. With little pressure applied to the inner casing by the tube I could move the red dot pointer reflection quite significantly in the mirror.

It would appear that as the laser is worked hard it gets hotter so much that the body is distorting sufficient to cause the laser to go out of line.

Any one else had similar problems? Any suggettions. I do have a good extractor attached and running.

How hot would you expect the casing to get?


A little concerned.:confused:

[Dave Johnson29]

How hot would you expect the casing to get?


Hi Pete,

You could check the manual and see the max. operating temp for the tube. I suspect it is around 45C. The casing should be cooler than that. If not then you may have dust or swarf caught inside the airways somewhere. I'd be pulling covers off and checking fans. maybe one fan has stopped working.

Too hot to touch is well above a desired operating temp.

[Joe Pelonio]

I have a legend also, and have never seen the red dot problem. I don't think I have ever touched the tube when hot, but I have often run it 10 to even 24 hours at full power speed 6 cutting 6mm acrylic and don't remember feeling any major heat. Are you sure your fan has enough power, and there are no clogs in the exhaust? I clean mine out annually and find the inside diameter reduced by the debris. Also, a long run diminishes the flow. If you hold a sheet of paper up to the front vents with the fan on it should stay there, held by the suction. One other thing that could help is leaving a nearby window open slightly to allow air to be drawn in. In a small room with the door closed it has to suck it from under the door and doesn't flow as well.

[Peck Sidara]

Pete,

Received your email as well. The Legend TT utilizes the exhaust blower to cool the laser source. The stronger the exhaust, the better off you'll be.

The amount of air-flow/pull is dependent on the specs of the blower as well as your plumbing. Your blower may be rated higher than the specification but if you're plumbing is many meters long w/ multiple bends and leaks, this will significantly drop the amount of air you're drawing. Have this checked out.

Room temperature or in the range of 40-80 degrees F is the operating temperature range for your laser. If it's getting hot to the touch, there's not enough flow or there's a significant amount of dirt/dust build up on the laser. Clean it off using a brush and vacuum being careful about static electricity and make sure the machine is unplugged.

If the red-dot pointer is wandering over time and as heat builds up, it's possible one of your optics is defective, causing it to absorb heat and heating up the o-ring behind the mirror causing the alignment to go off.

Identify UK and/or our tech support group should be contacted to further trouble-shoot.

HTH,