You need a 240 plug. This is one that fit the outlet in my garage. (I assume it used to be a dryer, but there's no line for a matching washing machine.)

https://www.amazon.com/gp/product/B07X9Z5CX5/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Just cut off the end of the cord and attach the new plug.

Optional: A 120 to 240 adapter.

https://www.amazon.com/gp/product/B01LBYK04O/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

This lets you use your Shopsmith with a regular 120 outlet. (I only use the 240 outlet when using the dado set.)

Extension cord.

https://www.amazon.com/gp/product/B06W563YSZ/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

This is rated for welders, so it's more than enough for a Shopsmith. But it's heavy and a tripping hazard, so again, normally I use the 120 adapter.