Adjusting tt speed on the cheap:any tricks?

I have a Michell table with HR power supply which has speed adjusting screw on its back.I don't want to spend $100-150 to buy a strobe disc with a strobe light so i'm trying to adjust speed on the cheap.I did some adjusting using a camcorder with a built in stop watch and counted if the table did 33 1/2 turns in a minute.Any other ways to save a buck?Thanks in advance.
you can get a free strobe disc here:

No Stobe light is needed, simply use it under a normal incandescant lamp (60hz - use the corresponding disc)
To reinforce what Bdgregory has stated, you might try a flourescent light--they tend to "strobe" better than incandescent lamps (or at least they did when I used them for this very purpose several years ago). Try to knock down the ambient lighting as well.