CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended
	Jul. 31, 2019	Jul. 31, 2018
CONSOLIDATED STATEMENTS OF OPERATIONS
Net sales	$ 6,346,000	$ 4,473,000
Cost of goods sold	3,953,000	2,994,000
Gross profit	2,393,000	1,479,000
Operating expenses:
Engineering	388,000	302,000
Selling, general and administrative	1,423,000	1,211,000
Operating expenses	1,811,000	1,513,000
Income (loss) from operations	582,000	(34,000)
Other expense:
Interest expense, net	27,000	24,000
Income (loss) before income tax expense	555,000	(58,000)
Income tax expense (benefit)	111,000	(15,000)
Net income (loss)	$ 444,000	$ (43,000)
Basic earnings (loss) per share	$ 0.07	$ (0.01)