Consolidated Statement of Operations (USD $)	3 Months Ended		9 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012
Net sales	$ 2,976,000	$ 2,826,000	$ 8,876,000	$ 8,085,000
Cost of goods sold	2,035,000	2,024,000	5,792,000	5,773,000
Gross profit	941,000	802,000	3,084,000	2,312,000
Engineering	129,000	165,000	427,000	510,000
Selling, general and administrative	692,000	595,000	1,880,000	1,867,000
Operating Expenses	821,000	760,000	2,307,000	2,377,000
Earnings from operations	120,000	42,000	777,000	(65,000)
Interest expense, net	10,000	12,000	32,000	36,000
Earnings before provision for income taxes	110,000	30,000	745,000	(101,000)
Income Tax Expense (Benefit)	44,000	0	298,000	0
Net Income (Loss) Attributable to Parent	$ 66,000	$ 30,000	$ 447,000	$ (101,000)
Earnings Per Share, Basic	$ 0.01	$ 0.01	$ 0.08	$ (0.02)