Consolidated Statement of Operations (USD $)	3 Months Ended		6 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
Net sales	$ 2,988,000	$ 2,711,000	$ 5,900,000	$ 5,259,000
Cost of goods sold	1,727,000	1,840,000	3,757,000	3,748,000
Gross profit	1,261,000	871,000	2,143,000	1,511,000
Engineering	145,000	180,000	298,000	346,000
Selling, general and administrative	610,000	551,000	1,188,000	1,272,000
Operating Expenses	755,000	731,000	1,486,000	1,618,000
Earnings from operations	506,000	140,000	657,000	(107,000)
Interest expense, net	11,000	12,000	22,000	24,000
Earnings before provision for income taxes	495,000	128,000	635,000	(131,000)
Income Tax Expense (Benefit)	198,000	0	254,000	0
Net Income (Loss) Attributable to Parent	$ 297,000	$ 128,000	$ 381,000	$ (131,000)
Earnings Per Share, Basic	$ 0.05	$ 0.02	$ 0.07	$ (0.03)