force stem direction

[erichexter]

I am trying to experiment with writing drum set music, is there a way to force the stem direction? In this example I would want to force the F/5 step up.
http://imgur.com/J3Vv0E7

[erichexter]

Here is an example of how drum set notation is typically written http://musescore.org/en/handbook/drum-notation

[gssjr]

Not sure when this was introduced but you can now do this with the "voice" keyword, e.g.

vextab
tabstave notation=true tablature=false clef=percussion
voice
    notes G-G-G-G/5
voice
    notes F-F-F-F/4