New here myself.
My first attempts at cutting plex ,from Home Depot BTW, were pathetic.
I was using a Demel with Dremel bits. Basically just melted the stuff and wasted bits.
If you can smell the plex while cutting then you might as well shut the job down because it will not end well.
I think the Dremel is too fast and the bits have way too many flutes on them.
I am currently using this Zen spindle running at 24V:http://www.zentoolworks.com/product_info.php?cPath=16&products_id=135
and these bits from ebay:http://www.ebay.com/itm/380411420374?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_1516wt_832http://www.ebay.com/itm/150763700037?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_1500wt_832
The plex now cuts beautifully. No issues at all. Very smooth finish.
The trick seems to be to slow down the rotation and always use a bit with two flutes or less.
My experience anyway. The bit needs to push the plex shavings out of the way before it starts melting from friction.
Too many flutes and the plex shavings are really small and just sit there and melt.