Frank wrote:My brad points are probably a cheaper brand - Harbor Freight(?). They have a slight taper from the outer edge to the brad point. Sort of like a 3-point crown when viewed in profile.
Thanks for the info, Frank. It's good to know that not all brad points will net the same results. I've been meaning to switch to forstners to drill my mortises. Does anyone have a recommendation for forstners that fit the 5/16" Delrin? I've been using Freud precision forstners for facing and like them but haven't used the smaller diameter ones for drilling.
Couldn't find one at Home D or Lowe's so I bought one at Woodcraft for 6-7 bucks. . Can't tell you the brand, I'm not home to see if it is stamped but they only sell one brand. It's slightly larger than the brad p I had been using. With the bp it took some force to insert the 5/16 delrin, with the F it inserts easily. With a bp I always had to use a center drill to center then chuck up the pb, without the center drill the bp would wander. Using the F I can eliminate the center drill, the F doesn't wander.
Great. Thanks, Bob. That's the main reason I want to switch. Brad points seem to get off track pretty easily and drill pretty rough if you're not careful.
Brad point bits are about the worst kind for maintaining a straight wander-free hole in my experience. I have no idea what they ARE useful for, but I hate them. I like plain, uncoated, HSS twist bits for 99% of the holes I make in stuff.
I've tried an end mill, brad point, and regular twist drill for a mortise. I have found that the end mill and brad point make over-sized holes whereas a twist drill makes the perfect size mortise for the standard delrin tenon.
Wayne, perhaps I did not understand your first question? I thought the question was a bit to place delrin in the stem. The bit I pointed you toward is not for drilling the mortice, it is too large to make a perfect fit for a 5/16 delrin tenon/mortice, at least the delrin sold by online metals. I use the bit to fit a 5/16 tenon in the stem blank. It works perfect for doing so. It leaves a hole which is a loose fit for the delrin, which in my opinion allows more epoxy to surround the delrin tenon. After glueing the delrin tenon in the stem blank I insert the same 5/32 taper drill, which I used to drill the draft hole in the stem blank, through the tenon and as far as it will go into the stem to make sure the tenon is at a perfect angle to dry. Without doing this, I fear the hole has just enough slop to dry perhaps some small part of a degree off center. Hope this clears the air and you have not already purchased the bit from Woodcraft with the intention of drilling mortices.
