CONSOLIDATED STATEMENTS OF CASHFLOWS - USD ($)	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Cash flows from operating activities:
Net income	$ 714,000	$ 642,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Stock compensation cost amortized	108,000	108,000
Depreciation	367,000	353,000
Deferred income taxes		34,000
Changes in operating assets and liabilities:
Trade receivables	486,000	(397,000)
Contract assets	144,000	(1,002,000)
Inventories	(502,000)	(692,000)
Prepaid expenses and other assets	(134,000)	109,000
Operating lease right-of-use assets	259,000
Trade accounts payable	288,000	580,000
Accrued liabilities	281,000	7,000
Current and long-term operating lease liabilities	(199,000)
Customer deposits	(8,000)	(195,000)
Net cash provided by (used in) operating activities	1,804,000	(453,000)
Cash flows from investing activities:
Capital expenditures	(508,000)	(152,000)
Proceeds from disposal of equipment	1,000	2,000
Net cash used in investing activities	(507,000)	(150,000)
Cash flows from financing activities:
Principal payments on long-term debt	(33,000)	(1,677,000)
Principal payments under capital and financing lease obligations	(71,000)	(71,000)
Payments on line of credit	(13,399,000)	(4,581,000)
Proceeds from line of credit	12,426,000	5,556,000
Proceeds from long-term debt	1,985,000	859,000
Net cash provided by financing activities	908,000	86,000
Net increase (decrease) in cash	2,205,000	(517,000)
Cash, beginning of period	58,000	575,000
Cash, end of period	2,263,000	58,000
Cash paid during the period for:
Interest	99,000	108,000
Income taxes	70,750
Non-cash investing and financing activities:
Tax credit reclassified from deferred tax asset to a receivable	34,000
Property held for sale reclassified as property, plant and equipment		$ 694,000
Capital leases reclassified from long-term debt to finance lease liabilities	98,000
Deferred rent reclassified from accrued liabilities to operating lease right-of-use assets	206,000
Equipment financed through accounts payable	$ 20,000