CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended
	Jul. 31, 2016	Jul. 31, 2015
CONSOLIDATED STATEMENTS OF OPERATIONS
Net sales	$ 4,091,000	$ 4,054,000
Cost of goods sold	2,555,000	2,764,000
Gross profit	1,536,000	1,290,000
Operating expenses:
Engineering	207,000	189,000
Selling, general and administrative	1,112,000	995,000
Operating expenses	1,319,000	1,184,000
Earnings from operations	217,000	106,000
Other expense:
Interest expense, net	6,000	6,000
Earnings before provision for income taxes	211,000	100,000
Provision for income taxes	86,000	39,000
Net earnings	$ 125,000	$ 61,000
Basic earnings per share	$ 0.02	$ 0.01