I got a BSLAPP board DBK2JP.
it works so far but some settings dont.
especially framing speed, no matter what i set it to it seems to default to around 2000 or something.
also tickle signal for co2 doesnt work.
see settings, i made 5 dots and recorded the pwm signal. its missing the tickle signal.
Is this an RF metal tube co2 with a galvo?
yep, homemade engraver with a synrad j48-1 10watts with a raylase galvo head.
good for cutting stencils and engraving glass/wood.
Congrats… 
diy stuff.
I’m looking back at your pwm control. I have to assume your source is a typical interface with power and pwm for control. I don’t have one, so I’ve made these inferences as a question of your scopes pwm trace.
I assume your control board doesn’t have negative supplies and uses standard period pwm. I’d expect a 0 to 5V ttl as this is what most of them use. Not an amplitude modulated signal like yours appears to me. It also goes negative, unless your zero voltage line isn’t.
The yellow on this is 40% pwm from the Ruida controller Purple is laser enable and is active low. Blue is the voltage across my mA meter, only occurs when the tube conducts.
Note the pwm is a TTL voltage pwm.. I think mines 50 micro seconds (20kHz) period.
Nah its just a noisy signal on my scope, those spikes going negative are nothing to worry about.
its plain old PWM, 0v off, 5v on at 5 to 20khz coming out of the controller. just what the laser wants according to its datasheet.
its just to illustrate what happens inbetween the lasing phases, where the tickle pulses should be.
the laser is working fine, power regulation etc. works.
when theres no tickle, the tube takes about 1..2 seconds before it reaches resonance and full power. like a drag race…but with the engines turned off at start.
and it may even damage it or the RF generator.
i could add a external tickle generator using a 555 thats running all the time, but id rather have it working in the controller.
interessting current spikes you have there.
looks like your horizontal div is 500µs, one cycle per two divisions, so your pwm frequency is 1khz not 20.
It’s possible that I did not have the normal period for the pwm. I was changing so much it’s difficult to put in the file name.
I know the 1kHz is about the bottom for a consistent current through the tube.
I would think an RF machine would lase in the micro seconds, as a glass tube is in the mili seconds.
Is there insufficient power on the exciter to dump this much power into it?
Never having one but I have looked into them, I understand the purpose on how it works but have never had one to scope out, so to speak.
Probably enough information to get someone from the Lightburn staff that knows more about these that I.
Maybe @NicholasL can assist, I know he has a glass tube. I’m not really sure who has a metal tube machine.
Hmm, try using the stock factory ‘BSLAPP’ software to set the tickle and see if there is a difference.
What is your ‘Frame Speed’ and ‘Max Speed’ set to? and what is the max speed of the galvo?
Hello Nicholas
my max. speed was set to 12k, the galvo has no problems working at 10 to 15k, its quite a speedy one.
changing the frame speed doesnt do anything, its allways the same speed.
The galvo works at higher speeds when i hit start to engrave, its just the preview framing speed that doesnt seem to get sent to the board.
i just installed the BSLAPP (its horrible) and enabled tickle
it works, unless im in F1 preview mode.
This is F2 works as intended.
interesstingly, when i launch Lightburn afterwards, the tickle signal keeps working
there is 50ms of tickle when i hit start, then comes the PWM. no idea where to set the pre-delay.
theres also a tickle signal when the preview panel is closed
just when the preview panel is open, there is none.
when i turn the bsl board off and back on, its gone. tickle stops working again. its a temporary flag/register that bslapp seems to set.
I tried capturing the USB traffic to the BSL board using usbpcap and wireshark
when hitting Start (F2) it sends the settings to the board using URB_bulk out endpoint 0x02 in packages 0x11 and 0x17, in the second package (0x17) the third byte, bit one is set when tickle is on. cleared when off.
bit2 is set when power ramp up/down is enabled or not. and so on
lightburn only sends out the 0x11 when settings changed and 0x41 controlbut never 0x17.
and no idea where the speed gets sent, i change red pointer / framing speed in bslapp but it dont see it in the capture.
Interesting, and great investigation on your part!
Did you check if the same issue exists with version 1.7.08? (just incase it’s an uncaught regression from a recent update)
Or maybe your particular BSL board model behaves differently?..we may need more information about the board - is there a revision number on it also?
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