CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($)	9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities:
Net income (loss)	$ 62,200	$ (2,600)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Gain on sale of investments	(3,200)	0
Loss on asset disposal	0	2,700
Depreciation and amortization	276,500	319,100
Deferred income tax expense	(7,400)	(43,600)
Stock-based compensation	1,300	11,200
Changes in operating assets and liabilities:
Accounts receivable	(95,800)	364,600
Inventories	206,200	(1,461,200)
Prepaid expenses and other current assets	(25,900)	13,800
Accounts payable	700	194,700
Customer advances	107,900	191,400
Accrued expenses	(317,700)	195,000
Total adjustments	142,600	(212,300)
Net cash provided by (used in) operating activities	204,800	(214,900)
Investing activities:
Redemption of investment securities, available-for-sale	11,100	0
Purchase of investment securities, available-for-sale	(18,700)	(2,700)
Capital expenditures	(18,200)	(45,100)
Purchase of other intangible assets	(12,800)	(7,400)
Net cash used in investing activities	(38,600)	(55,200)
Financing activities:
Line of credit proceeds	250,000	970,000
Line of credit repayments	(250,000)	0
Cash dividend declared and paid	(44,500)	0
Payments of contingent consideration	(166,100)	(100,900)
Proceeds from exercise of stock options	15,500	0
Principal payments on note payable	(4,800)	0
Net cash provided by financing activities	(199,900)	869,100
Net increase (decrease) in cash and cash equivalents	(33,700)	599,000
Cash and cash equivalents, beginning of year	1,245,000	482,000
Cash and cash equivalents, end of period	1,211,300	1,081,000
Cash paid during the period for:
Income Taxes	213,500	35,500
Interest	$ 22,000	$ 27,200