Consolidated Statements of Operations (USD $)	3 Months Ended
	Jul. 31, 2011	Jul. 31, 2010
Net sales	$ 2,548,000	$ 2,494,000
Cost of goods sold	1,908,000	1,597,000
Gross profit	640,000	897,000
Operating expenses:
Engineering	166,000	69,000
Selling, general and administrative	721,000	606,000
Operating expenses	887,000	675,000
Earnings (loss) from operations	(247,000)	222,000
Other expense (income):
Interest expense	12,000	10,000
Interest income	0	(3,000)
Interest income (expense)	12,000	7,000
Earnings (loss) before provision for income taxes	(259,000)	215,000
Provision for income taxes	0	0
Net earnings (loss)	$ (259,000)	$ 215,000
Basic earnings (loss) per share	$ (0.05)	$ 0.04