- Joined
- Feb 21, 2022
- Messages
- 771
Is a c drill a reference to a centre drill?using reamers isn't a trivial undertaking. Seems like it should be, but it's hard to get right than would appear. First up I would drill with a good sharp C drill with plenty of WD40 or kerosene. Then countersink hole, which will be handy for getting the pins started anyway. Then ream with your undersize reamer and plenty of cutting fluid at 1/4-1/3 of the speed you used to drill the hole. Try and do it in one go if you can but keep an ear out for the motor slowing, as that will indicate that the flutes are packing with chips. Having a set of homemade go-no go gauges, or a set of small hole gauges, would be handy here for checking size.
There are reams of information everywhere confirming the advantages of a correct angle spot drill to a centre drill. In fact; there is a global industry making spot drills precisely for this purpose.
Centre drills are for centres!!
For standard sizes - use a spot drill of the finished diameter to produce a precisely positioned counterbore as a spot for the drill and a precise guide for the reamer.