That article was great! Thank you

I may have spoken too soon when I claimed success. I'm beginning to think learning to make flutes is similar to what historian Will Durant was talking about when he call knowledge a "receding mirage in an expanding desert of ignorance"!

Puzzled by why one of my reamers cut very well and another very poorly, I discovered under magnification that (1) the good reamer has a tiny ragged burr remaining from machining which cuts quickly, roughly, but slightly larger than the reamer diameter and that (2) the bad reamer has no burr, just a nice sharp polished edge, and doesn't cut well at all.

So a dilemma:

A reamer with a machining burr remaining cuts well but slightly over sized, and a reamer with the burr removed cuts poorly (sometimes just rubs and can even split the wood) but keeps dimensions true if it can be coaxed to work at all.

I'm not sure where to go next with this.

Also, a related issue for those of you using your lathe to do your reaming. Holding on to a piece of wood while pushing/pulling it up the spinning reamer poses a serious injury risk if a hand slips off the wood onto the reamer. Is this a necessary risk of flute making, or do some of you put a handle on your reamers and hold your wood in a vise? I'm 63, don't have a very firm grip anymore (I have a slight tremor in fact), and lost part of a finger to a machine years ago so don't find this question purely theoretical.

My own experience with that reamer design was also disappointing. I made two such reamers, with that same style of blade, and I can't get them to work at all. They barely feed into the work and it takes tremendous effort. I'm still puzzled by that. I based mine on a drawing done by Rod Cameron, who presumably used this same design, and who presumably got a better result!

I've made two and four blade versions as well, but to date my favorite for cutting efficiency is a modified D-profile. With these, you do risk warping, and because of that I switched from 41L40 (which is cold roll) to 01 tool steel for this reamer that I just finished last week. It was a very slow process, the tool steel being way harder than the leaded stuff I'd been using. So my results were definitely not as pretty (in terms of the finish) but in terms of function I've never made a better one.

This is a short reamer with a very long shaft that use for my Essential Flutes, which have a Boehm taper in the head of a single piece body. This requires the reamer to reach well up the bore to do it's cutting, so the reamer and shaft is 3' long. You'll see that I did a D-profile cut, then I turned it face up and used a 1/4" ball endmill to create that scoop right at the cutting edge. This was very tricky. I had to put bluing on the surface so that could see better, and then slowly cut along the very edge of the reamer. Took a couple of hours maybe to do this without ruining the edge, because the idea is to get so close that the blade of the scoop is just a few thousandths of an inch thick. The result is a crazy sharp cutting edge.

These photos look a bit disreputable because I took the finished reamer shots right after cutting some ebonite with it. You'll also see the result of the ebonite cut! When ebonite shaves like that, you are dealing with a very sharp blade, because otherwise it turns to powder.

The other advantage of this style is that you minimize torque. Four blade reamers create a lot of torque, so you have a harder time controlling the piece of stock you are holding. I don't use my lathe for reaming, having instead a dedicated work station with a gear motor set up that holds my reamers. Then I hold my work by clamping it into a v-block. If it is round stock, then I wrap it in hose clamps to stabilize it and allow it to be grabbed by the v-block. I clamp the block with simple large c-clamps, which hold the block together and give me handles with a lot of leverage. This is still a very physical approach, and I'm looking to improve on it. It has an element of danger if one is careless, because that gear motor is so powerful that if you get tangled up with the handles of the clamps, things can go wrong very quickly. Happened to me yesterday and nearly broke my arm, motivating me to make some changes to the procedure. You can see this in action if you are willing to sit through a short micro-documentary about me . https://vimeo.com/321618537

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Geoffrey Ellis Flutes

Great video! Thanks! I showed it to my marketing entrepreneur daughter-in-law and she thought it was brilliant.

Earlier in this thread when I posted a back-of-an-envelope sketch for a two bladed reamer I hoped would eliminate warping you wrote that it looked like a good approach or something to that effect. But now you write you've had poor results making one like that yourself. I must be confused somehow about what you're saying. Could you clarify? Thanks!

Hi, wondering if you guys have read any of the posts in the old Flutemakers and Woodenflute email lists regarding reamers. I was doing some searches, and found a lot of references to rough reaming first with a flat reamer. Then makers having the most success with D reamers with a raised burr as the actual cutting edge (and I guess some relief on the rest of the surface to minimize rubbing against the intended bore). Hammy Hamilton seemed to do this, at least back in 2005. I believe he suggested something like tallow as a lubricant.

Also, I have this vague recollection from old reading that the reamer is held stationary & the wood blank is slowly fed (spinning, maybe 300rpm?) onto the reamer, vs. the other way around.

Any of this make any sense to you guys?

_________________
International Traditional Music Society, Inc.
A non-profit 501c3 charity/educational public benefit corporation
Wooden Flute Obsession CDs (3 volumes, 6 discs, 7 hours, 120 players/tracks)
http://www.worldtrad.org

I'm new to all of this and hadn't heard of those email lists. Link? Thanks!

Logic would suggest that a reamer will just rub instead of cut unless it presents either a burr or an extremely sharp edge to the wood. That the wood that needs chiseling is concave presents special challenges given that the outer "bevel" of the "chisel" can't be honed or it will lose contact with the wood.

From my limited research and and even more limited experience, I'd say 300 rpm is a bit fast. I'd also say that spinning the blank and holding the reamer in a tailstock is not an option if your (my) lathe's spindle bore is too small and/or your (my) lathe ways are too short. Otherwise it sound workable, and it would certainly minimize risk of injury as contrasted with hand-held wood fed into a spinning reamer.

The following photos illustrate as best I can the problem I see with taking a reamer design and making it work in the real world.

In this first picture (highly exaggerated to make the idea clear) we see what a dull, rounded edge looks like--the reamer just rubs without any cutting action.



In this second picture we see a small burr--it cuts because it stands higher than the reamer body itself, cuts well, but cuts a larger diameter than desired and cuts rough because the shape of the burr can't be controlled.



In this third picture we see a perfect, honed edge at the right diameter where it meets the wood--in theory it should work, but on the reamer where I produced something like this I get very poor results.

I know nothing of reamers and have no experience but I kind of think you'd want a leading edge to get the cut started, somewhat like the point of a knife. When I use a scraper of a chisel I'm almost always adjusting the angle, to control the depth of cut but also to get the cut started, if the makes sense.

Again I have ZERO experience but looking at your reamer I want there to be a leading edge slightly wider than the non-cutting part of the reamer?

I think I'm the confused one Your reamer in the photos does not look like a two-bladed reamer, so I thought you had chosen to make a single blade version after all. I had bad luck with the single blade version, but my two blade version works just fine. So now I'm as puzzled as you are! Can you post a photo that shows both sides of your reamer (sort of shot from the business end?). Not easy, I know, but I'm curious to see how it looks. But the D-profile one I posted works better than everything I've made previously.

But I do think that if I were using this approach on a longer, thinner reamer it would be more complicated and might actually warp a bit.

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Geoffrey Ellis Flutes

Thanks for the clarifications. Makes sense.

Here are four photos at 0°, 90°, 180°, and 270°.

The Flutemakers list was moved from Yahoo and is archived in the link below. See the Readme.txt first to see if you'll be able to access it usefully.
https://app.box.com/s/y9n6vsahct4v0cvgv8xtk2qtoxl5z4b7

I don't believe the Woodenflute list is archived on the net.

If you have the Mozilla Thunderbird email program, than I can put together an archive of both lists, which is then indexed, and searchable using Thunderbird. That's how I use it as a reference. I was going to extract relevant reamer portions & put into a text file, but there's too much work in editing and assembling multiple conversations about the issue. Unfortunately, my archive is text only, and does not have any of the photos or files that may have accompanied some of the posts.

My understanding about the burr, is that it is raised from the internal cut of the reamer, to make a cutting edge (not necessairly even along the whole length), and is usually good for boring quite a lot of wood before needing to pull up a new burr. Again, not uncommon for pilot holes to be drilled first, & rough reamed with a simple flat reamer undersized to your final profile.

I personally think any hand feeding is a bad & dangerous idea. Hopefully you can arrive at some other solution. Shorter reamers for each section? The Box archive of the Flutemaker's list may have some photos of tools & rests. Maybe if the spindle bore is too small you can attach something to the wood stock to aid in holding it (probably easiest if wood blank is rectangular rather than already turned round). Just throwing out ideas - I have no concept of how to work a lathe, or understanding of its components.

Let me know if I need to put my Thunderbird archive together. You then just copy the files to your Thunderbird message directory, and use Thunderbird's menu to index the new folder(s). Thunderbird has a Search Messages panel to match relevant criteria, and you can use the Search in Message function to find the specific word or phrase. All text can be copied & pasted into other documents to collect the materials you're interested in.

Kevin Krell

_________________
International Traditional Music Society, Inc.
A non-profit 501c3 charity/educational public benefit corporation
Wooden Flute Obsession CDs (3 volumes, 6 discs, 7 hours, 120 players/tracks)
http://www.worldtrad.org

I also know very little about reamers, but it seems to me that a leading edge slightly wider than the non cutting part of the reamer renders the reamer's dimensions meaningless. I'm new though and all ears. Anyone with expertise here is most welcome to mentor me.

Thanks for your thoughts here, and for the Flutemakers archive link. Looking through those files today.

Bill

I put the reamer back on the mill and cut the slots .050" deeper. This gave each edge a new, ragged burr and made the cutting wedge angles more acute.

In these pictures you can't see the more acute angle but you can see a burr that will cut like a mother bear. At least I think it will.

My fear, though, is that the aggressive cutting will be at the expense of accuracy and yield a bore that's as rough as a pine cone and also too large. My instinct as a machinist is to remove the burr and hone the flat side till a keen edge develops. Unfortunately that's exactly what I did before and what produced a poor reamer.

I think I'll take the beast off the mill and try cutting with it a little just to confirm that a reamer with a burr at least cuts--even if not cleanly or accurately. Then I'll take it from there.

Yeah, I don't think you want to rely on a ragged burr to do your cutting! I clean those off thoroughly before I deploy my reamer.

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Geoffrey Ellis Flutes