Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net income	$ 1,904,445	$ 1,455,905
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	919,392	943,595
(Gain) Loss from disposal of equipment	(1,782)	17,485
Deferred income taxes	100,000	(40,000)
Changes in operating assets and liabilities:
Accounts receivable	(457,954)	(232,484)
Inventories	(266,082)	298,422
Other current assets	183,385	15,489
Accounts payable	354,223	349,057
Accrued wages and salaries	335,212	308,406
Other accrued expenses	11,179	(69,726)
Unearned revenue and customer deposits	(194,796)	158,822
Net cash provided by operating activities	2,887,222	3,204,971
Cash flows from investing activities:
Capital expenditures	(1,782,886)	(1,339,044)
Proceeds from the sale of equipment	3,122	4,869
Proceeds from certificates of deposit	4,731,000	5,560,000
Purchases of certificates of deposit	(4,980,000)	(5,818,000)
Net cash used in investing activities	(2,028,764)	(1,592,175)
Cash flows from financing activities:
Cash dividends paid	(763,245)	(763,245)
Net cash used in financing activities	(763,245)	(763,245)
Net increase in cash and cash equivalents	95,213	849,551
Cash and cash equivalents at beginning of period	800,894	231,252
Cash and cash equivalents at end of period	896,107	1,080,803
Supplemental schedule of non-cash investing activities:
Capital expenditures in accounts payable	$ 0	$ 3,073