There is a way using your own freighters. Freighters from a civilian line can't pick up parts the last time I looked.
On the screen where you give orders to your fleet (F12) select a fleet with a freighter in it. Order it to the planet you want to pick the parts up from. On the order list is the order "Load Ship Component" When you select that order a list of available parts will pop up adjacent and you need to click on the selected part, and then click on the "Add Move" button. Order the fleet to the destination and then use the command to either unload a specific component, or unload all installations which will empty the ship of all parts/installations.
A couple of warnings to go with this. There is no automatic checking if the size of the component is to large for the freighter. Most will not be a problem, but check the tonnage on the ship design screen and compare to the total cargo capacity of a single ship. You can't have the part split between ships so be aware of this.
Good Luck
Brian
