Note 4 - Revenue Disaggregation - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Revenue	$ 4,034,408	$ 3,718,884	$ 7,400,268	$ 9,755,244
Transferred over Time [Member]
Net Revenue	1,788,000	888,000	3,533,000	2,774,000
Transferred at Point in Time [Member]
Net Revenue	2,246,000	2,831,000	3,867,000	6,981,000
Aerospace [Member]
Net Revenue	774,000	1,833,000	1,489,000	5,183,000
Aerospace [Member] | Transferred over Time [Member]
Net Revenue	197,000	134,000	386,000	1,299,000
Aerospace [Member] | Transferred at Point in Time [Member]
Net Revenue	577,000	1,699,000	1,103,000	3,884,000
Industrial [Member]
Net Revenue	2,519,000	882,000	4,563,000	1,870,000
Industrial [Member] | Transferred over Time [Member]
Net Revenue	1,226,000	259,000	2,595,000	386,000
Industrial [Member] | Transferred at Point in Time [Member]
Net Revenue	1,293,000	623,000	1,968,000	1,484,000
Research [Member]
Net Revenue	741,000	1,004,000	1,348,000	2,702,000
Research [Member] | Transferred over Time [Member]
Net Revenue	365,000	495,000	552,000	1,089,000
Research [Member] | Transferred at Point in Time [Member]
Net Revenue	$ 376,000	$ 509,000	$ 796,000	$ 1,613,000