John,
Use an amp meter and ensure that the amps do not go over the motor capacity. If they do, use a blast gate in front of the cyclone and with your most open air configuration, slowly close that gate watching the amp meter until the amps are less than the motor rating. If you had this problem with a filter which is not the case with your venting outside, you would retest after about 3-4 filter cleanings. At that point the filter resistance would increase from the particles that get trapped in the filter matrix allowing you to readjust the blast gate to be more open.
Remember that failing to move enough air means the dust you miss should be addressed with regular thorough shop cleanings and use of a good dual cartridge respirator mask.
Hope this helps..