Gento's scanner safety board

[sbk]

Anyone could clearly and loudly explain me the exact function and the effects of these Tr1 to Tr4 potentiometer?? I'm trying to adjust these since two hours and I think I'll go mad soon!

I can see some change when I turn Size Pot, but it's inconsistent. And I see absolutely no change on the projected image when I change the Offset Pot... Well, I think the user manual isn't clear at all, I think even the worst I ever saw (not the translation which is great, but the explanations of the functions, etc).

[greenalien]

1) Make sure you are displaying the correct test image Test 3 -- square inside larger square.
2) Your objective is to blank out the inner square, while leaving the outer square visible. Ensure you have followed the zone setup instructions for the PC software - Set the slider for X-Min and YMin
to 2%, X-max and Y-Max to 98% and make sure the zone setup is transferred OK - and set the pots to their initial setup value (Turn Tr1 and Tr2 clockwise until you reach the end position (approx. 25
turns)
3) As you make adjustments to the blanking, you will probably find that one of the inner lines disappears. Now adjust the offset until it reappears - adjusting the offset a bit more will make the opposite line disappear, so readjust until both lines are visible again, then add a bit more blanking. Keep repeating until 2 opposite lines just disappear. Then repeat for the other axis.
Hope this helps!

[sbk]

Thanks for the explanation!

But I still have no success adjusting the board I can see some strange change when I turn the Tr1 or Tr2 pot, sometimes the image disappear, but I can't manage to make it reapper by turning Offset pot.

Also, when I turn the pot full clockwise, the scanners go crazy and makes a hard noise!! Maybe I have something wrong in my connections, but I do not see what, I carefuly followed a star ground schematic... I have DT25 scanners (or Litrack from JMLaser).

[mccarrot]

You have something really wrong there, the 4 pots on the scanfail should have no effect on you galvos

Where did you get your feedback signal from? this should be a connection on you driver somewhere and not the galvo.

Please explain step by step how and where you have connected everything.

Also keep in mind you can get a groundloop if you connect the feedback ground toghether with the 24V ground, but this depends on how you projector is build up.

[sbk]

I get the feedback from the single driver board of the Litrack scanner, I pick only the X and Y output feedback signal and go to the 3 pin feedback input connector of the safety board, on X and Y input.

The Gnd isn't connected on the 3 pin input of the safety, I have only the Gnd from its power supply connector going to the central grounding point of the projector. I power the safety with +24/-24V.

The X+/- and Y+/- input signal of the scanner driver are connected to the DB25 X+/- and Y+/-, the ground isn't connected. The DB25 ground is going to the central ground of the projector.

The only weird point I noticed is there's a sort of connection between the scanner's head and the Gnd. Not 0 Ohm, but 5-10 Ohm, maybe it's a coil's side connected to the ground?? Seems strange. Don't know if it's normal or not, but I have two scanners sets and it's the same on the two.

Maybe I should isolate the scanners from the base plate, even if the optical base plate is already isolated from the electrical base plate (by the antishock system). But I have a very stable projected image, I think I have not really an issue with a ground loop...

So far, the security board is sort of working, for example if I project a single beam it is blanked when I reach the protected area, but it's inconsistent, so not really secure for the moment.

[specialbart]

Where's the best place to buy a ScanFail kit? The web site for the software doesn't say where one can be purchased.

[mccarrot]

I have them on stock

[specialbart]

I have them on stock

i can't find it at you store.. what's the price?

[mccarrot]

PM send.

I have 2 in stock for reduced price.

[sbk]

BTW Maurice, did you found a way to fix the over sensibility of the safety board? I had some frames being cut, although not a dangerous effect, just a decreased size...