If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
Reaming
Charles Vincent wrote in
t: "In drilling the experimental holes to establish drilling technique, the 120° (probably actually 118 0 ) twist drill appeared to produce the smoothest hole. The 60° twist drill was about equally effective, but offered no apparent advantages over the more common 120° drill. A hole drilled with a machine bit with a slow spiral did not appear to differ materially from one drilled with a machine bit with a fast spiral, or from one drilled with a Foerstner bit." and "The machine bit and the Forstner bit had a tendency to produce large chips which sometimes wedged underneath the horizontal cutting edge. Some of the chips were complete washers in form, the full diameter of the drill in size, up to 1/32 inch thick, and strong enough to remain intact when the bit was withdrawn. In a few cases a chip became wedged between the side of the bit and the wall of the hole and scored the wall." Thanks, this is exactly what I discovered. It's good to know I'm going down the correct path. Couple of things I'm still uncertain of, though. The steel parts have quite a tight fit on the bolts. Obviously any paint on the inside of these holes is simply going to be forced out when I push a bolt through. this is normal? Also, there's a small ridge formed on the edge of each hole. I figure it's OK to leave the excess material there for a couple of reasons, one, it provides more material for the bolt to rest against, and two it won'ts interfere with tightening the bolts down since there will only be a washer up against the hole anyway. If it is poor practice to leave the ridge on the edge, what's the best method for getting rid of it? Aside from a special machien, I thought of carefully cutting it down with a large dril bit, but I'd be afraid of doing some damage to the part. Any suggestions? |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Reaming needed on aft wing attach point. | Boelkowj | Home Built | 0 | November 7th 03 01:30 AM |