CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS - USD ($)	12 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
CONSOLIDATED STATEMENTS OF OPERATIONS
Net sales	$ 18,396,000	$ 16,302,000
Cost of goods sold	13,615,000	11,047,000
Gross profit	4,781,000	5,255,000
Operating expenses:
Engineering	1,082,000	906,000
Selling, general and administrative	4,967,000	4,738,000
Operating expenses	6,049,000	5,644,000
Loss from operations	(1,268,000)	(389,000)
Other expense:
Interest expense, net	74,000	24,000
Gain on asset disposal	(8,000)
Loss before provision (credit) for income taxes	(1,334,000)	(413,000)
Provision (benefit) for income taxes	681,000	(152,000)
Net loss	$ (2,015,000)	$ (261,000)
Basic loss per share	$ (0.38)	$ (0.05)