Note 7 - Product Warranties - Changes In Product Warranty Liability (Details) - USD ($)	3 Months Ended
Dec. 31, 2016	Jan. 02, 2016
Accrued liability at beginning of period	$ 306,488	$ 291,980
Increase in reserve	26,034	42,352
Repairs and replacements	(26,974)	(47,406)
Accrued liability at end of period	$ 305,548	$ 286,926

Carrying value as of the balance sheet date of obligations incurred through that date and payable for estimated claims under standard and extended warranty protection rights granted to customers.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)(5)
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15(5))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of decrease in the standard and extended product warranty accrual from payments made in cash or in kind to satisfy claims under the terms of the standard and extended product warranty.

+ References

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Balance Type:	debit
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- Definition

Amount of increase (decrease) in the standard and extended product warranty accrual from changes in estimates attributable to preexisting product warranties.

+ References

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration