cutting poplar and ..

[Marc Pod]

Hi,

I have few Q.

1. Is cutting 4mm poplar plywood AB/B quality at 45 speed and 68% power(21mA on ampmeter) with SPT 90W tube bad or good or....
2. I just saw there is strange bubble in tube see pic
3. Tube is SPT TR90 with integrated red dot pointer. Red dot is suddenly scattered all over the place. Befor it was small red dot along whole path from mirror 1 to out of tne nozzle. Now it is see pic but it still comes out of the nozzle like it is supposed to
Thanx

[Michael Henriksen]

Speed/power sounds about right. I cut a lot of 3mm and 5mm poplar and your settings are app. in between the settings I use.

[Robert Bonenfant]

Hey Mark,

Your speeds and power settings are great if your getting successful cuts. We have 100 watt machines and cut 3mm Baltic Birch at about 35/mms - 70 Power, We can go faster but our machines tend to not cut all the way through on some parts so we keep them under 40 speed. Plywoods quality can also make a big difference, our baltic birch has a solid birch core which makes it a little harder to cut than lets say Homedepots MDF cores.

As far as the bubble in the laser tube, its bad but can easily be fixed. Try to tilt your tube carefully until the bubble moves to the output pipe, Big bubbles are what you need to worry about the most because they can cause a tube to fail rather quickly. If your still getting alot of bubbles, change the water and make sure to use Distilled water and not tap water. When you have large bubbles it can create a heat spot and very shortly can cause a tube to fail - Lesson learned the hard way four years ago :-( $895 for a tube and overnight shipping.