Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Share data	3 Months Ended		6 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Condensed Consolidated Statements of Operations [Abstract]
Net sales	$ 17,880	$ 15,106	$ 36,128	$ 31,646
Cost of sales	9,921	8,930	20,785	19,337
Gross profit	7,959	6,176	15,343	12,309
Selling, general, and administrative expenses	3,851	3,517	7,755	6,591
Engineering expense	2,063	1,299	4,348	2,855
Relocation expense				211
Operating income	2,045	1,360	3,240	2,652
Interest expense	102	170	236	383
Other expense - net	20	81	50	145
Income before incomes taxes	1,923	1,109	2,954	2,124
Income tax provision	808	466	1,241	892
Net income	$ 1,115	$ 643	$ 1,713	$ 1,232
Earnings per common share:
Basic net income per share	$ 0.12	$ 0.07	$ 0.18	$ 0.13
Diluted net income per share	$ 0.12	$ 0.07	$ 0.18	$ 0.13
Weighted-average basic shares outstanding	9,470,000	9,400,000	9,457,000	9,398,000
Weighted-average diluted shares outstanding	9,628,000	9,412,000	9,596,000	9,412,000