Calling all ferrule makers - puzzling problem

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (Hollowbuilt) — Mon, 30 Mar 2009 00:24:50 GMT

Blake,
You are describing a classic "bellmouth" in the female. The opening is larger than the midpoint. This is caused by misalignment of the reamer. Does not matter whether it is cocked in, out, up or down. It will do this. The cutter (reamer) is stationary, and the part is turning. The misalignment causes side pressure on the part, which causes bell mouthing. As a possible fix, you may try boring the hole with a Micro 100 boring bar after drilling. They make them...

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (Blue Quill) — Mon, 23 Mar 2009 21:53:04 GMT

Hi Brooke,

I agree with AJ; .005-.006 tops for reaming, and make sure you are going slow enough.

If you look at the end of a reamer you can see the rake of each cutter is significant. If you cut too much, they will actually spring-out while cutting and make the reamed hole oversize.

Old-timers would often measure a reamed hole, and if they had the part in the set-up, and needed to ream the hole a thousanth ot two over, they would simply re-ream the same hole...

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (Grayson Davis) — Mon, 23 Mar 2009 14:12:58 GMT

Check the inside diameter of the female with a ball gage. I got mine from SHARS. They are not US made, but they are fairly good (OK, I polished them a little) and really cheap.

When I first made females from bar stock, I drilled 1/64" under then followed with a chucking reamer. Where I screwed up was in forcing the reamer at the bottom of the hole. This does very little to flatten the bottom, but is very good at making the reamer flex. The reamer is held straight at the...

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (Eebarral) — Thu, 05 Mar 2009 10:08:00 GMT

I agree with jgestar make sure everything is concentric. Check you tail stock and make sure it is dead nuts centered with the head stock. If it is not and you can't get it trued in, especially if it is off up to down, you may need to go to a floating reamer holder. The reamer will follow the hole of the drill, but if out of alignment, the sides of the reamer can make contact and taper the hole, especially when you are as small as 0.177" Speaking of the reamer, we never ream more than...

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (AJ Bamboo) — Thu, 05 Mar 2009 03:32:51 GMT

B177
from real world experience on my 10" lathe that is used only by myself and is dead on. use a reamer that is just under the finished size. the hole will be slightly tapered this way and more tapered with each and every pass of the reamer. you want only a bit of 'dust' in the reamer flutes. there is one maker of these bar stock ferrules who does not seem to have this problem, but only one in my experience. .036" is asking way too much. maybe .005 or .006" tops....

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (jgestar) — Thu, 05 Mar 2009 00:06:17 GMT

Try mounting an indicator on a bar held in your collet. Then indicate the shank of the reamer. If the collet and reamer are not bang on concentric, it is unlikely you will get an accurate cut.

Tom

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (brooke777) — Thu, 05 Mar 2009 00:00:36 GMT

AJ Bamboo wrote:
i am guessing the female is from bar stock and drilled/reamed? if that is true then even many (but not all) of the commercial examples i have worked on exhibit this 'flared' female profile to some degree or another. without knowing the exact process you use to remove material from the interior of the female i can only offer a few educated guesses. the finish ream should be no more than .001 to .002 and...

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (brooke777) — Wed, 04 Mar 2009 23:58:13 GMT

Lee Koch wrote:
Since you mentioned a reamer, can we assume you are making your ferrules out of bar stock? I don't have an answer, but here is a thought: for the female, did you turn the outside of the barrel before reaming, so as to be sure that the bar being held by the 3-jaw chuck is round straight and centered? If not, if the outside of the bar stock were not exactly round, your bar may turn slightly out of round, i.e....

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (JimmyB11) — Wed, 04 Mar 2009 22:25:09 GMT

Traditional reaming techniques call for a much heavier final cut with the reamer. For the sizes we are dealing with (13/64) you would normally have closer 15 thou cut with the reamer. What is the reasoning for such a light cut?

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (AJ Bamboo) — Wed, 04 Mar 2009 21:06:04 GMT

i am guessing the female is from bar stock and drilled/reamed? if that is true then even many (but not all) of the commercial examples i have worked on exhibit this 'flared' female profile to some degree or another. without knowing the exact process you use to remove material from the interior of the female i can only offer a few educated guesses. the finish ream should be no more than .001 to .002 and be well lubricated with liquid tapping fluid. any more and you have to withdraw and...

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (Lee Koch) — Wed, 04 Mar 2009 20:56:29 GMT

Since you mentioned a reamer, can we assume you are making your ferrules out of bar stock? I don't have an answer, but here is a thought: for the female, did you turn the outside of the barrel before reaming, so as to be sure that the bar being held by the 3-jaw chuck is round straight and centered? If not, if the outside of the bar stock were not exactly round, your bar may turn slightly out of round, i.e. with some runout, which I think could make your reamer eat away a little bit more...

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (brooke777) — Wed, 04 Mar 2009 19:55:55 GMT

I put sharpie marks on the end of the male, put it in the female, and spun it. The sharpie marks came off, and I could see them in the female tube.

Re: Calling all ferrule makers - puzzling problem

feeds@yuku.com (drbaits) — Wed, 04 Mar 2009 19:48:35 GMT

Might you be dealing with an air seal? maybe you're too good and fit is too good...something about objects not being able to occupy the same space at the same time :-]...not sure of the solution short of poorer fit or vent hole.

Calling all ferrule makers - puzzling problem

feeds@yuku.com (brooke777) — Wed, 04 Mar 2009 19:03:54 GMT

I was fitting the male ferrule by hand after making both the male and female, and was struggling with the last 1/2 of the male. It seems to stop inside the female ferrule, as if the bottom part of the female was a smaller diameter than that of the top half (closest to the opening). I measured many times, and had the male slide down to the same dimensions the entire length, but it still stuck. I made the male twice, and it happened both times. I measured the reamer as well, and it is...