So, now you have the disk with spoke lines drawn on it. What you want to do next is drill radial 1/8 holes along the side of the disk towards the center.
Sounds complicated, but it really isn't. Piece of cake actually (mmmm cake...) You just need to make a simple jig.
- Drill a 1/4 " hole (or one the same diameter as your axle hole) in a board that is wider than your disk.
- Put a piece of the correct size dowel in the hole, pop your disk on to the dowel and then turn the board on its side so that your disk will be parallel to your drill bit.
- Secure your new jig to your workbench or drill press. You want your drill bit to be centered on the thickness of your disk and be directly in line with the center of your dowel (which will be used as a pivot for your disk.)
The drill bit needs to be centered on the pivot dowel.
The bit needs to centered on the thickness of the disk as well.
Now the easy part. Using a 1/8" drill bit, line up one of your spoke marks and drill your first hole into the disk. You want to be sure that it will be at least as deep as you want your rim to be wide. Also not so deep that you'll leave holes in the hub of your wheel if you use the inside of this disk to make the hub. For this example, I drilled between 1/4 and 1/2" deep.
After you drill your first hole, simply rotate your disk until you line up your next spoke line. Drill that hole and repeat rotating and drilling until you have all six holes drilled.
Okay, entering the homestretch. Your next jig is simple as well. This is what going to allow you to cut out the rim with a minimum of hassle.
- Use your hole saw to cut a hole in a board the same thickness as your blank disk. (This gives you another wheel blank as well.)
- Trim the board up so that you have about 1/2" on the top and bottom of the hole but enough wood left and right of the hole so that you will have plenty of clamping space.
- Draw a line directly though the center of the hole and then turn you jig on its side.
- Drill a hole just slightly larger than 1/8 (3/16, 5/32 etc depending on what you have on hand) on the top of your jig, lined up with the center line you drew and all the way through the 1/2" margin of wood. Repeat this for the bottom.
- Place the disk with the drilled spoke holes into your jig and then use 1/8" dowels through the top and bottom to secure it to your jig. (Because the holes in the jig are just a little bigger it will be easy to move the dowels in and out of the jig but they will seat firmly into the disk.)
- Put your smaller diameter hole saw (for me 1 1/2") into your drill. Line up your jig so that the pilot bit on your hole saw lines up directly with the hole in the center of your disk and clamp it securely. (The hole is slightly larger than your disk so you have the ability to adjust it slightly up and down to line up correctly.)
- After you are lined up, drill half way through disk. flip the jig over, line it up and secure it again and then finish your cut.
Lined up for your first cut. Keep your hands away from holding anything near the hole saw. The dowels keep the blank from spinning in place.
Flip it, line it up, secure it and finsh the cut. Let the blade cool before touching it.
What you end up with. The perspective is a little off on this photo but the rim is actually 3/16ths all the way around.