Note 5 - Product Warranties - Changes in Accrual for Product Warranties (Details) - USD ($)	9 Months Ended
	Jul. 31, 2018	Jul. 31, 2017
Balance at beginning of period	$ 180,000	$ 70,000
Liabilities accrued for warranties issued during the period	165,269	176,113
Warranty claims and costs paid during the period	(157,377)	(93,565)
Changes in liability for pre-existing warranties during the period	(22,892)	2,452
Balance at end of period	$ 165,000	$ 155,000