This post is for those needing a hatch idea for balsa builds
So the hatch work is really straight forward. Start with thin sewing pins and you will insert them from the inside of the fuselage. The corners of the hatch are great but you cannot always get to them easily so I just use to for each side of the hatch. You can see in this image that I colored the inside edge of the hatch stringer with a black marker to better differentiate the hatch stringer from the fuselage stringer. Just insert the pins between them carefully. Pins between the ply plates will be more difficult to insert but push gently with something metal and they will go in and not kill your fingers.
The pointy ends will stick through and now you have perfect guides for a straight edge to cut.
And here you can see the faint pencil lines. I use a heavy vinyl measuring tape from our sewing kit to lay across the curved part and make a straight line. Heavy card stock will do just as well. Now remove the pins. Some tweezers can be helpful so you are not killing your fingers. I push on the pointy end to back them out and then grab the heads from below with my tweezers.
Now is the scary part. You have to TRUST that the pins did their job and they always have for me. Cut very carefully along the lines you made using a #11 blade. You want #11 so you do not get heavy handed and have better precision. Just score the balsa on the first pass. This is not a race. Make a few passes until you feel the skin give way and when you go over the stringer you can feel some resistance. Once all the skin is cut as you see below, then go back and cut the main stringer free giving you a hatch. You may have to pop some glue joints as some may seep if you use thin CA. You can see the skin lifting here, That was intentional.
With the hatch out, clean up your edges with a sanding bar and use some additional CA in spots that may need it.
Put your focus on the hatch again. Glue the skin all around and then check your fit in the hole. DO NOT SAND THE HATCH FIRST. Check the fit of the hatch after you have sanded the hole. You may not need any additional sanding work on the hatch. If the fit is not great, THEN sand the hatch.
Closure will be two hinges on one side and a couple of magnets. I'll do that later but any questions on this... feel free to ask. BTW, this took about 10 minutes to do. STUPID easy and makes quick work of something the first time, every time.