Test the conversion

you can use any G-code sender to manually test the conversion: moving x and y axis, homing direction and laser function. CNCjs and UGS a good g-code senders  (Click here to goto cncjs dowload page) but any other will do too e.g. LightBurn, T2 Laser, LaserWeb.

The default behavior of Mini Gerbil when powered up is to energise the motors in hold position (aka layman’s terms “lock up”). The reason for this is to increase accuracy so the gantry never loose it’s position.

When the Door switch is used (wired up to the controller) you need to clear the controller alarm via a command “$X”. The Inkscape plugins do that clear command by default when streaming the g-code files. After issuing a “$X” you can issue a g-code command like “G0 X1 Y1” t’o move the gantry or issue a “$H” to home the machine to its zero coordinates (Left Top corner same a stock K40). Command “S100” turns the laser on where the number stands for the power e.g. 100 equals 1mA. (Depending how you set the power range e.g. $30=2000 equals 20mA).


G1 X1 Y1 S100 F800


stands for: M4 laser on, Goto coordinates X,Y (1,1) at 800mm/min with the tool (laser beam) powered at 1mA and switch it off (M5). G0 is a move without any tools enabled.

You can also home the machine via the $H command. If the machine does not home correctly then it can be that the axis motor connector needs to be swapped around (180 degrees, when homing away from zero) or the end stops don’t work.

Note: You can test the limit switches via CNCJS. The status command “?” (yes, just type a question mark in the black box area called console in the G-code sender) provides status information back so you can see if they work when you push the gantry in the zero position. (Top left corner, set $1=100 so motors don’t lock while in rest. Later on revert back to 255 to keep the Gantry aligned and into the correct position). Some of the status line information might be hidden so expand the status message box. The limit switch information is at the end of the status line. If the limit switch is not triggered then there is no information. If triggered then you see something like <Idle|MPOS:0.000,0.000|Bf:0,255|Fs:0,0|Pn:X,Y>