CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended		6 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2015	Oct. 31, 2014
CONSOLIDATED STATEMENTS OF OPERATIONS
Net sales	$ 4,155,000	$ 3,101,000	$ 8,209,000	$ 5,796,000
Cost of goods sold	2,672,000	2,009,000	5,436,000	3,866,000
Gross profit	1,483,000	1,092,000	2,773,000	1,930,000
Operating expenses:
Engineering	188,000	177,000	377,000	354,000
Selling, general and administrative	908,000	780,000	1,903,000	1,621,000
Operating Expenses	1,096,000	957,000	2,280,000	1,975,000
Earnings from operations	387,000	135,000	493,000	(45,000)
Other expense (income):
Interest expense, net	7,000	7,000	13,000	14,000
Earnings (loss) before provision for income taxes	380,000	128,000	480,000	(59,000)
Provision (benefit) for income taxes	146,000	49,000	185,000	(23,000)
Net earnings (loss)	$ 234,000	$ 79,000	$ 295,000	$ (36,000)
Basic earnings per share	$ 0.04	$ 0.01	$ 0.05	$ (0.01)