Note 13 - Income Taxes (Details) - Deferred Tax Assets and Liabilities (USD $)	Mar. 31, 2014	Mar. 31, 2013
Deferred Tax Assets and Liabilities [Abstract]
Inventory reserves	$ 279,000	$ 296,000
Accrued vacation	237,000	227,000
Stock option compensation	150,000	360,000
Warranty reserve	88,000	78,000
Accounts and notes receivable reserve	57,000	25,000
Net operating loss carryforwards	91,000
Federal credits	69,000
Other	17,000	16,000
Gross deferred tax assets	988,000	1,002,000
Prepaid expenses	(616,000)	(232,000)
Property and equipment	(1,004,000)	(429,000)
Gross deferred tax liabilities	(1,620,000)	(661,000)
Net deferred tax (liability) asset	$ (632,000)	$ 341,000