monophoto
Member
I've been intrigued with the idea of making pens that use Sharpie refills, and I've read most of the posts here. I've also watched a few videos on the process. But I've encountered a significant issue - - -
The dimensions reported in many of the posts and videos cite dimensions that don't seem to correspond to the refills that I bought at Staples a few weeks ago. Is it possible that the dimensions of the Sharpie refills have changed in the last year or so?
The material I have read suggested drilling the body using a 7/16" bit. But when I measure the actual refill, I find that the diameter is almost exactly 3/8". I can understand drilling the blank for the body using a slightly larger bit so that the blank isn't in solid contact with the refill - perhaps 25/64".
But that then begs the next question - the dimensions of the threading. I know that several years ago someone special ordered taps to match the measured thread, but there was also some discussion of metric taps (eg, M12x1) instead of the 0.450x25tpi threads. But on the refills I purchased, the major diameter of the threads was only perceptibly larger than the measured 3/8" diameter of the body - I measured 25/64" - which doesn't leave much material for threading if the hole is 3/8". And the pitch is much coarser - more like 12 tpi.
The third critical dimension in the material I've found on the web is to drill a 1/2" hole about 0.05" deep to accommodate the rim around the end of the refill body. But a 1/2" hole is way too big - and in fact, the rim will actually fit into the 7/16" hole suggested for the body.
Am I missing something, or are the dimensions of the refills I purchased different from the dimensions that people were working with when this was under discussion a few years ago?
The dimensions reported in many of the posts and videos cite dimensions that don't seem to correspond to the refills that I bought at Staples a few weeks ago. Is it possible that the dimensions of the Sharpie refills have changed in the last year or so?
The material I have read suggested drilling the body using a 7/16" bit. But when I measure the actual refill, I find that the diameter is almost exactly 3/8". I can understand drilling the blank for the body using a slightly larger bit so that the blank isn't in solid contact with the refill - perhaps 25/64".
But that then begs the next question - the dimensions of the threading. I know that several years ago someone special ordered taps to match the measured thread, but there was also some discussion of metric taps (eg, M12x1) instead of the 0.450x25tpi threads. But on the refills I purchased, the major diameter of the threads was only perceptibly larger than the measured 3/8" diameter of the body - I measured 25/64" - which doesn't leave much material for threading if the hole is 3/8". And the pitch is much coarser - more like 12 tpi.
The third critical dimension in the material I've found on the web is to drill a 1/2" hole about 0.05" deep to accommodate the rim around the end of the refill body. But a 1/2" hole is way too big - and in fact, the rim will actually fit into the 7/16" hole suggested for the body.
Am I missing something, or are the dimensions of the refills I purchased different from the dimensions that people were working with when this was under discussion a few years ago?