Line of credit (Details) - USD ($)	3 Months Ended					6 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Jun. 29, 2018	Dec. 29, 2016
Line of Credit Facility [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding	$ 201,575		$ 165,000			$ 201,575
Line of Credit Facility, Periodic Payment, Interest	3,035			$ 10,175		9,616	$ 20,511
Repayments of Lines of Credit		$ 201,575
Interest paid		$ 39,070			$ 17,355
Accrued expenses	$ 736,417		874,421			$ 736,417
Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity									$ 250,000
Line of Credit Facility, Current Borrowing Capacity			$ 250,000
Line of Credit Facility, Maximum Borrowing Capacity, as a Percentage of Inventory			50.00%
Debt Instrument, Closing Fee, Percent		1.00%
Line of Credit Facility, Renewal Fee, Percent		1.00%
Line of Credit Facility, Collateral Monitoring Fee, Percent		8.50%	0.70%
Line of Credit Facility, Collateral Monitoring Fee in Event of Default, Percent		1.00%
Repayments of Lines of Credit		$ 165,000
Interest paid		2,579
General and Administrative Expense		1,000
Line Of Credit Facility, Prime Plus Fee		$ 1,895
Accrued expenses			$ 28,797
Prime Rate [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Delinquent Payments, Basis Spread on Variable Rate		5.00%
Minimum [Member] | Prime Rate [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate During Period		5.00%
Notes Payable to Banks [Member]
Line of Credit Facility [Line Items]
Notes Payable to Bank								$ 250,000
Debt Instrument, Interest Rate, Stated Percentage								5.00%
Debt Instrument, Basis Spread on Variable Rate		74.00%
Debt Instrument, Interest Rate During Period		5.74%
Line of Credit Facility, Collateral Fees, Amount		$ 250,000