Maybe this is not the best way. Perhaps using a brad type drill would be better and only drilling half way. What about using a reamer as a final operation that may be stiffer than the standard #44 drill. My basic worry is walking off of location.
Another option may be to use a purchased drill guide. If you do not have access to a mill or drill press a drill guide may be your best option if you are questing for the best construction technique.
Another idea I have heard is to cross drill your cars block using a ¼ inch drill along the centerline of your axle holes. Open the hole up and then tightly back fill the drilled hole with something like Aluminum filled epoxy. Now you have a homogenous material to drill into with your #44 drill. Wood having grain may have some hard spots and it might deflect your drill causing problems with alignment.
I am student of Stan Pope’s alignment ideas, and one component to creating a great car is to get some really straight axle holes, however now that you have an Aluminum Epoxy axle hole will the wax paper shim for final tuning still work? Maybe this is illegal in some races, but would it work?
Is the first step in making a great car, very straight axle holes in the body of the car? If true the car body needs to be stable and robust so that axle hole alignment will not vary over the life of the car. Maybe a strong car body needs to be a design consideration as well. How much wood does that take? Would a symmetrical amount of wood around the axle hole help?
These may be somewhat advanced questions, is there a separation between cub and adult pinewood techniques?
- referencing the right side holes to the left side of the block, and
- referencing the left side holes to the right side of the block.
This only works if the sides of the block are perfectly parallel. Most of the time they are not.
So, the solution is to reference all holes to the bottom of the block. The Pro-Body tool does this.
It can also be done on a drill press/mill if the bottom of the block is clamped to the drill press fence for all drilling operations.
Regarding the bit, I use cobalt stubby bits (this may not be the correct machinist's term). I only extend the bit out far enough for the desired depth. I also drill the hole slowly. All of these factors (stiff bit, short bit, slow drilling) minimizing drill bit deflection.
Carbide drills are really stiff and they cut aluminum easily. I might think that if there is a tendency to walk off of center while using the pro body tool at the bottom of the hole the carbide would slice through aluminum and make the guide hole egg shaped. I would also think that if there is a tendency for carbide to bend it might bend at the end of its shaft away from the tooling guide.
I would prefer to able to drill both rear wheel holes at the same time by going all the way through the block. The steps in drilling might be as follows.
1. Use a center to mark the spot where the drill is going to go.
2. Use an undersize carbide drill to go all of the way through the car. Does Carbide cut wood very well? Maybe a fresh spade drill that is very sharp would be better?
3. Use a finish reamer to ream the hole all the way through the body. The reamer should be pretty stiff and not going through much material so it should not walk off.
4. Drill both the rear wheel holes and the dominant drive hole in one holding of block.
5. Flip the block over and raise the hole about .100 for the non-drive wheel.
6. Check your work. Use a gage pin on a surface plate to see if both sides of the axle hole are at the same height relative to the bottom of block.
How do you check if the front drive wheel hole is parallel to the rear wheel holes?
With having non-homogenous material i.e. wood is the epoxy solution really that much more attractive to improve your axle straightness? Another idea for making the wood more consistent that I have heard is too soak the axle holes in super glue and then ream the final holes. The goal is to make the wood less likely to deform and give you a good finish final cut and robust long lasting straightness as you work through the LBW Alignment operation as shown by Stan Pope.
That is why I recommend drilling holes only half way through - much less flexing of the bit, and use the stiffest bit possible (cobalt).
If all drilling is referenced from the bottom of the block, then the left/right holes will be parallel.
Regarding front to back parallel, that will occur with a drill press or body tool as long as the wood block is not twisted.
or similar at
This should fix it for me. A smaller drill press is not an option.
- Master Pine Head
- Posts: 447
- Joined: Sun Feb 08, 2004 6:10 pm
- Location: Connecticut
I don't doubt this is true....I'm just wondering why. Stephen gets nervous drilling axles (with the Pro Body tool) & so he creeps the bit into the body. So far, the holes have always met in the middle. The result always appears nice & straight. But is it? Without some very small diameter & very long gage pins, I would know how to ever be entirely certain.Also with a small bit you should be drilling at a faster rate of speed about 3,000 RPM
- Pinewood Daddy
- Pine Head Legend
- Posts: 1498
- Joined: Mon Feb 28, 2005 7:04 pm
- Location: Wallingford, Connecticut
DerbyWorx has said, in this forum, to not use the Pro-Body tool in a drill press. Any misalignment will wear out the tool quickly. I did that last year. We use a reamer in a pin vise and twist by hand. I had a new and improved Pro-Body tool made at work (made from steel!). You're only removing .009 per side (.067 slot to .086 hole).pinecarpro wrote:I don’t think you would want to drill that fast with a Pro Body Tool. Does the Pro body tool have drilling sleeves to prevent the drill from wearing out the tools holes? I would drill slow with tool and fast with a drill press.
I'd use a jointer if available. A good tablesaw will do as well.