How to union this or fill or weld?

I’m new, but learning fast, but i made this joint, and it looks great on screen and till I 3D printed it i did not realize I had a space, that i cannot figure out how to weld, or union it in Shapr3d… again I am new to any design 3D cad, my son was helping me design what I needed, till he got cancer…and prefer to let him rest and i had to learn from ground zero… I really enjoy it and look forward everyday when I wake to get to work on it!

I’m posting some pictures, on the joints… I prefer not to show the whole design if thats ok, unless someone can help me personally.

Thank you!

Those two blocks need to be combined in that circle, the space between the blocks are suppose to be there. one block is skiiny one fat, and needs to be joined to the right hand sided curve…

I think the replace face tool is what you need if I correctly understood what you want to do :grinning:

The problem is it does not show up like your video in Shapr so it does not seem to work for me… it looks filled yet when i do a sty it is not… Your video shows a blank space and mine does not. so some reason it is not joining…and it will not give me that option to join…