Consolidated Statement of Operations (USD $)	3 Months Ended		6 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Net sales	$ 3,101,000	$ 3,381,000	$ 5,796,000	$ 6,866,000
Cost of goods sold	2,009,000	2,087,000	3,866,000	4,265,000
Gross profit	1,092,000	1,294,000	1,930,000	2,601,000
Engineering	177,000	140,000	354,000	287,000
Selling, general and administrative	780,000	893,000	1,621,000	1,765,000
Operating Expenses	957,000	1,033,000	1,975,000	2,052,000
Earnings from operations	135,000	261,000	(45,000)	549,000
Interest expense, net	7,000	9,000	14,000	18,000
Earnings before provision for income taxes	128,000	252,000	(59,000)	531,000
Income Tax Expense (Benefit)	49,000	96,000	(23,000)	203,000
Net Income (Loss) Attributable to Parent		156,000	(36,000)	328,000
Common Stock [Member]
Net Income (Loss) Attributable to Parent	$ 79,000	$ 156,000	$ (36,000)	$ 328,000
Earnings Per Share, Basic	$ 0.01	$ 0.03	$ (0.01)	$ 0.06