go to your applications folder.
open up apple script editor
type in the following code:
on idle
tell application "System Events"
key code 87
end tell
return 2
end idle
hit compile.
save as an "application" and name it like "auto alcher"
go to system preferences which is located on your dock
click "accessibility"
Click enable mouse keys
Now open start the auto alcher script u just made. 2 seconds should be perfet for auto alching.