Hello, when u cut woods for scratch build, how do you cut small notches in bulkheads so it comes out nice and square. Sometimes these notches are so small that it can't be cut with band saw or scroll saw. If u want to cut bunch of them with Xacto knife it's going to be a pain and takes a while. what is the best way to do these cuts. Thank you

I have never scratch built anything that had notches that were too small for a bandsaw. I do all notching this way.

Let me explain it this way, when u cut into wood with a saw U can't change the direction of the cutting blade 90' to make a right angle cut. A square notch with sides smaller than width of the cutting blad can't be cut. I just remember U can do it with a rotary tool using Diamond burr bits.
I just wonder if there is any better way? thanks

you can try making a couple of relief cuts. Start by cutting on the line up until the 90 degree corner and then back up and start sawing more cuts in the notch and break or cut out all the little pieces. Or if there is enough room start coming in from the other side of the 90 degree angle so that you to cuts come together at a clean 90 degree

There's a nice short article on scratch building in the current AMA mag.    I have cut into the wood with scorll saw across the grain just shy of the lines.. then an exact make short work of the parallel grain cut.  a sanding block of hardwood spar type cleans it up nice..</p>

Actually, if you have one, some scroll saws accept spiral cut blades. These blades cut on all sides and from every angle. You can feed your work in to where you want to make your 90 degree corner and immediateluy push your wood at a 90 degree angle to what you were cutting. The blade cuts from any angle.

I should have my wood for my next build in hand sometime this week. My plan is to do a short thread of cutting your own kit, AKA scratch building. I use the scroll saw most the time but for this demo I will also be using a band saw. To remove the notch you just cut from one corners top mark to the lower corner mark after cutting into the bottom of notches sides. This gives you room to get the blade angled to cut out the notch. In balsa wood you just keep making relief cuts from the outside to the inside line and the wood sort of pops out. I will be posting in the kit building forum with a lot of photos. It's really easy to do but I hope I have the language to explain what I'm doing. I figure a lot of photos will hide my lack of vocabulary.

Well I don't have a band saw or scroll saw but the band saw I was cutting with at work

could not change the direction of the cut at right angle. I'll Look into that spiral cut blades. Thks

Thanks to all of you for inputs.

Thanks, that's great I'll be looking forward to it.

The spiral blade only works on the scroll saw. Well, the ones I have seen. I have never seen one for a band saw but that doesn't mean someone doesn't make one. I don't have one for my scroll saw I have at home but I think there are some at the shop of my wood working club. On this build I plan on doing the kit cutting at the clubs shop to cut down on dust in my own shop. We have a number of band saw blades in different sizes/widths. When I start cutting I will be using a 1/8 or 1/4 inch wide band saw blade. I use the clubs band saw for a lot of small projects and the narrower blade makes turns and small cuts a lot easier. If the club is out of the scroll saw spiral blades I may go in search for some for my own saw to show how easy they are for notch cutting. I should be posting up at least by early next week. My wood was mailed yesterday and I'm ready to start making saw dust and strange looking boogers!!!

I have used spiral blades on a few projects, not for airplane parts but for other craft projects. They work ok but I try to keep their usage down to a minimum if I can. They dont last anywhere near as long as regular precion ground blades and I generally cant cut as fast with them. But for certain cases they do serve a purpose.

spiral blades for a band saw don't exhist !....... they wouldn't do the thrust bearings or guide blocks/bearings any good at all !!!......
one method with a band saw is to make a cut on the lines into the piece and then to clear out material between by making several cuts not quite up to the 90 degree depthline. if you stop the plunge cuts close enough to the depthline that there is less material left than the depth of the teeth on your band, you can then jentlydrag the piece across the band using the teeth as a nibler to clean up to thedepth line. goes pretty quick, once you get the hang of it. if your doing several of the same pieces as in spars onribsor stringers offrames,set up a stop to stop your piece at the depth line. then, just plunge away and drag the piece across with itsliding on the stop for your depth.
it's best done with a fine tooth metal cutting blade, about the only blade i use on my 14 inch saw is a 1/4 inch- 14 tooth metal cutting blade, they work fine for just abouteverything but resawing over 1-1/2. just remember that the band has set in the teeth and it will cut wider than the appearant body of the blade, so start your plunge cutting well inside the lines and work out to the lines. once the two outside cuts have been made and the width of the notch is established, the smooth sides of the blade will hit the shoulders( side cuts)of your notch , so the notchit won't get any wider when you do the drag cut..

I used to do the saw thing for notches, just like everyone above has mentioned. But lately I have started using a tool made by Midwest and sold by Tower called an "Easy Cutter". It is simply a hand shear. Sears and several other retail outlets carry them, also. I use the easy cutter to cut the depth of the notch. 1 cut for each side. After all these are made, i use a sharp chisel of the appropriate width to cut across the notch, finishing the notch with sharp square corners. You can do this with about any thickness balsa and up to 1/8" plywood with ease. I find this a lot easier and quicker than messing with a saw for notches.

I make my own notching tools. I epoxy two short pieces of a fine hacksaw blade to a strip of bass wood. the basswood is cut so the wood plus blades give the correct width and epoxying the blades to the side of the basswood allows for the correct depth. once made correctly saves a lot of time but I still use an xacto knife for the crosscut. I use about three inches of blade for a smooth stroke and leave the basswood longer for a handle.
Only problem I have encountered with these tools are the strips of wood I buy vary dimensionly from order to order.

Ronward's comment is post 12 above are so very good. I use the same technique with great success. I'll second the suggestion to use the metal cutting blade in your band saw as it gives excellent results on soft wood such as balsa yet works just as well on the plywoods.

I understand. I never change the direction of the cutting blade 90 deg. Cut the sides of the notch first. The bottom of the cut, the "U" is made by cutting a series of parallel cuts (parallel to the sides) into the notch. Skew the workpiece slightly and you will nip off these "ribbons". The bottom of the notch will now look jagged as heck. Run the bottom of the notch sideways across the blade and rake it clean. It is very fast and easy. If you were here I could show you how to do this on a bandsaw in about 5 seconds. A metal blade is also a good idea to make cleaner cuts. I've been doing it this way for years.

Hi!
I do the same using my band saw (works with every saw)...first two cuts...then several parallell cuts inside! Never ever think of doing 90 degree bends...does not work!

I use band saw and clean up with X-acto and sandpaper strip glued to stick that is same size (actually, slightly undersized) as stringer to be used. I have a set of square punches to cut holes in parts, too.

Hi, I read all ur comments. Some of them I had to read many times trying to undrestand them.
Thanks alot for ur help. So far my favorite (easy for me) is to cut with a Xacto knife or a sharp knife for soft balsa and use burr bits with rotory tool for had wood such as ply and clean it with a file. Thank you all again.

I have a set of chisels ground to various widths down to 1/8. I simply make the two cuts to the prescribed depth, and then knock out the notch with a chisel. Very easy and quick.

i wouldnt try this with ply , it would take too long, but just put a strip of sticky back sandpaper on one side of a 1/4 x1/4
hardwood stick and sand it into the balsa former , it works great.