Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended
	Jul. 31, 2015	Jul. 31, 2014
Income Statement [Abstract]
Revenues	$ 7,337,682	$ 7,725,037
Costs and expenses:
Cost of sales	5,934,477	6,476,232
Engineering	53,958	165,555
Selling, general and administrative	1,191,432	1,639,492
Stock based compensation expense	212,834	4,716
Total costs and expenses	7,392,701	8,285,995
Loss from operations	(55,019)	(560,958)
Other income (expense):
Interest expense, net	(62,644)	(193,687)
Currency gain (loss)	408	(2,272)
Total other expense, net	(62,236)	(195,959)
Loss before income taxes	$ (117,255)	(756,917)
Income tax expense		2,850
Net loss	$ (117,255)	$ (759,767)
Less preferred stock dividends	62,660
Net loss allocated to common shareholders	$ (179,915)	$ (759,767)
Net loss per share of common stock
Basic	$ (.06)	$ (.32)
Diluted	$ (.06)	$ (.32)