I’m up to about six flutes made (five completed). Everything is going really well except for reaming the left-hand piece. The reamer vibrates, and this causes things to loosen. If I crank down hard enough on the wood in the lathe chuck, it’s fine. I’ve put some flats on the reamer in the drill chuck. So the drill chuck comes loose in the taper of the tailstock ram and the reamer seizes in the wood. Both the male and female tapers (on the drill chuck and tailstock ram) are now scored, so new ones of those will be ordered soon.
I’m reaming at 130 rpm. I’ve had three different types of reamers, one homemade and two commercially made. The 3/4 round one I made didn’t chatter the way the commercial ones do, but it sure seized a lot.
This only happens with the left-hand piece, which is the biggest both in length and diameter. I step-drill it, and the seizing only happens once the piece is almost finished. The inside is burnished and just about glassy, and almost no sawdust is being created at this point.
Any suggestions? Hand reaming isn’t an option with my arthritic hands.
Thanks in advance for any advice. Once I’ve gotten the flutes made, I’ve been really pleased with them.
Hi Charlie, did you see my description in a recent thread of the process we used? Might be something useful there for you.
130 rpm sounds kinda fast. I don’t remember the exact speed I reamed at, but I’m fairly certain it was about half the rpm you’re using, maybe even less.
Can you tell us about your reamers? Am I right in thinking that the “three-quarters round” one is a cone with a 90 degree segment cut out? And are the others straight D-bits (ie half round), or something else?
I’m guessing from “and the reamer seizes in the wood” that your reamers are not sharp enough. But it’s easy to say that from the safety of a small coastal village at the bottom of the world…
Coincidentally, I’m engaged in a project to try to map out the early days of Irish flute making. My co-conspirator brought this video to my attention. About 4 mins in you’ll see Hammy Hamilton, way back around 1980, with reamer in hand. Note the cross sectional shape. Such reamers - sometimes made by grinding flat files - removed a lot of wood pretty quickly, but didn’t leave a fine finish. Never tried one myself, but could be of interest. You can always clean up the bore later…
Re-reading your post and thinking about it some more:
Surely check the sharpness of your reamers as Terry suggests, but assuming that’s not the issue, it sounds to me like you may have too many twisting and flexing forces acting on a relatively unstable reamer end of the system. If I’m understanding correctly, you’ve got the reamer chucked in an MT drill chuck, going into your lathe’s tail stock MT. Is that correct? Is it a #2 MT? That set-up seems problematic to me, if I’m envisioning it properly. Far too much opportunity for movement/flex between the far end of the reamer and where the tailstock and ways meet, and it sounds like you’re putting more rotational forces on the MT connection than it can handle, and possibly you’ve got some flex or other movement happening along that chain. Things you can do to help:
Cut the RPM’s way back to somewhere in the range of 30 to 70 RPM. Experiment within that range.
Use less forward pressure on the reamer - advance more slowly.
(Note: Heat build-up could also be a contributing factor so lowering speed and feed rates would also help in that regard.)
Lubricate the ways well prior to reaming so that you can make the tailstock as tight to the ways as possible while still being able to smoothly advance the reamer.
If the reamers are sharp, and rigid enough to avoid flexing, and the above suggestions don’t solve your problems, then you should consider chucking the reamers in the HS and feeding the pieces over the reamer, using the chain whip method to deal with the rotational forces.
I’m sure there must be other other options, but I do know that solution works extremely well, having reamed thousands of sections that way.
Certainly there could be other things contributing to the problems you’re having, a bit difficult to know without actually seeing your lathe, reamers, technique, what coffee you drink….. could be anything
Honestly, Mad Props to the guys who had to work this stuff out mostly on their own through trial and error. It’s become much easier to get some helpful advice in the last 20+ years or so.
Will be interested to hear how it all works out Charlie, hope you’re having fun with it, despite the challenges!
P.S. Serious answer to Kevin’s question: It would seem counter productive to the process of scraping off wood from the bore, but hey, it might be worth a try. I imagine the trick would be finding a lubricant that could be applied to the non-cutting surface of the reamer, one that would dry prior to reaming and stay put.
I suppose if you reamed slowly enough, then a light rubbing of the right sort of hard wax on the back of the reamer might work without melting into the wood……possibly? Once hot wax melts into wood it’s a problem.
Am I right in assuming that you are holding the wood in the lathe chuck and have the reamer held firm in a drill chuck mounted in the tailstock?
In other words, the wood is rotating and the reamer is stationary?
If so, then you have the problem that the reamer will be acting more like a boring bar than a reamer, and will generally not cut a bore the same
shape as the reamer itself. The issue is that neither the wood nor the reamer can move to ensure that the reamer is in the center of the bore,
so the hole cut by the reamer can be arbitrarily larger than the diameter of the reamer, just as the hole cut by a boring bar does not end up the
same size as the boring bar. The size depends on the degree to which the cutting edge is off-center.
I think the chatter you experience may stem from this problem. Basically, the cutting edge cuts for a while, then the reamer, drill chuck and
tail-stock flex enough to allow the reamer to move slightly away from the cutting edge. This movement would not be possible if the reamer
was self-centering, because the back of the reamer would be pressed against the opposite side of the bore.
A better approach is to mount the reamer in the headstock (so the reamer is rotating) and to hold the wood in such a way that it can be freely
fed onto the rotating reamer and retain the ability to move and self-center. Most people do this “by hand” but rather than directly holding the
wooden piece in their hand they use some kind of handle that improves leverage and saves straining the hands. I use a strap wrench. Loren’s
post in another thread described using a chain whip. In both cases the handle rests against the lathe ways to prevent it from rotating.
Geoffrey Ellis clamps a device (T-bar?) onto the wood so he can hold it by hand.
Charlie,
Recent learning for me: The initial bore can be off center. For best results, I must do the initial drilling (and drying), then hold the workpiece between centers. Skim a little off the OD so it’s concentric with the ID*. Making the workpiece co-axial with the tool reduces chatter and the bell-ends described by Loren. Maybe this step would have to be done a 2nd time if the reaming removes a lot of material (and introduces irregularities).
Are you using a machine lathe? Get a quick-change tool post (Phase ii) for the carriage. Get the wedge-block to hold your 2MT. Does your drill-chuck have a shank with a flat tang? This arrangement will prevent slippage.
*or skim a little off one end, where the chuck will get a new grip.
Yes Walt, good points. FWIW our process also involved turning sections round (again) just prior to reaming. I’d certainly reface at least the headstock end of the piece as well if I were chucking the wood, rather than the reamer. In our case we had specialized final reamers that had either a either a length stop which also faced the end, or a built in socket cutter which faced as it finished the socket.
Are you using a machine lathe? Get a quick-change tool post (Phase ii) for the carriage. Get the wedge-block to hold your 2MT. Does your drill-chuck have a shank with a flat tang? This arrangement will prevent slippage.
*or skim a little off one end, where the chuck will get a new grip.
Interesting idea Walt, if I were a real machinist I might have actually thought of that! Maybe.
I always enjoy seeing/hearing other maker’s solutions to these problems, and I envy those with more extensive manual machine tool skills and experience.
Looking forward to hearing what ends up solving Charlie’s current problems.
And yeah, if you don’t have one already Charlie, get a QC tool post. Better yet, get a dozen. Well, maybe get a dozen after you sell a few flutes, those things are pricey.
Paddler, looks like maybe we were both composing our replies at the same time.
What comes to mind is that the cutting edge is not sharp enough and is distorting the whole work. If you imagine a 20cm wide plane (or scraper) for example and expecting it to cut smoothly/evenly without great outward (downward) pressure, it would have to be very sharp. So the moment part of the reamer blade stops cutting but pushes outwards, or the combined pressure along the whole blade ends up doing the same, then the work will get distorted around the length of the edge, and that change of shape will eventually jam the reamer. I don’t know if the number of edges would help or not, it would be balancing of the work having more support to stay round (say with four edges) vs the effect of all the cutting pressure being given to just one edge if it were a single cutting edge (which therefore might manage to cut better) ? So from that perspective keeping the blades very sharp and introducing the reamer more slowly would be my answer… after listening to what all the other commentators have to say first because I am sure they are vastly more experienced at lathe work and power reaming than myself.
Well, folks, this is why I so often turn to the Chiffboard with important (and not-so-important, and even trivial) questions.
I’ll address questions and comments in the order they were posted.
First, Loren, thanks for pointing to your post. It hadn’t occurred to me that the Delrin Pratten thread would drift into reaming. Silly me. It never would have occurred to me either to use a chain whip for reaming a flute. But the idea is brilliant. It’s something that would grip REALLY well as long as the wood has a large enough diameter (as you alluded).
Terry, the reamer set I’m using now has multiple spiral flutes. The two smaller ones work great, it’s just the biggest one that seizes. These were from a company that, I think Walt had mentioned awhile back. It took me two solid weeks of turning and milling a few hours a day to make my own reamers; that’s not gonna happen again till I’m retired, and I haven’t found vendors who make D-type reamers. This one shouldn’t be dull, since I’m only on about my fourth or fifth pass with it, and the first four were with castello, which isn’t hard nor abrasive.
I think everybody has identified the problem(s), and thank you all. I am putting the wood in the headstock and fixing the reamer in the tailstock. I have a 9x20 lathe, so not much room at all, and I’ll have to think carefully about fixturing the wood so that it’s stationary. I will think about the chain whip. I do see the reamer precess. I have trued up the wood to the holes in both ends, but the reamer doesn’t stick out the pilot at the beginning of reaming, so no way to true that up. I hadn’t appreciated that fixing the work piece and fixing the reamer were not equivalent. Too much physics, just thought it was changing the reference frame. (My undergraduate thesis was literally about rotating reference frames) I agree that is the origin of the chattering. At this point, if I just turn the reamer in the work by hand, it screams, and while I can’t see where the flutes have grabbed, I can feel it.
Walt, can I ask you what sort of design reamers you’ve gotten from the Connecticut company? The guy I talked to was very helpful, said he’s supplied wind makers, they could sharpen them for wood, and suggested the spiral flutes.
Again, thanks everybody, and if anything else occurs to y’all, keep the suggestions coming. I love this community of knowledgable and helpful folks.
Hmmm, spiral fluted reamers you say? Interesting, I thought that type design was primarily intended for enlarging holes, not long bores, but again, unfortunately not my area of expertise. That said, all our custom made multi flute reamers had straight, relatively wide flutes. IIRC, it was 2-3 flutes together, spaced over 1/3-1/2 of the reamer, while the rest of the reamer body was solid and smooth. So essentially a scraping side and a burnishing/stabilizing side. Not that a conical fluted piece of steel has sides, but you see what I mean. Hopefully.
I’m trying to imagine how longish multi-fluted spiral reamer would work compared with a straight fluted reamer. Am I wrong in thinking that anything spiral fluted is going to have a cutting action in this sort of application, rather than the scraping accomplished by a straight fluted reamer? I miss Glenn Schultz right about now…
As far as I know, the main purpose of spiral fluted reamers is to help with chip clearing.
Depending on the relative direction of the spiral vs the rotation they either push the chips
forward (through the pilot hole) or evacuate them back up the reamer. Straight fluted
reamers don’t encourage the chips to move along the reamer in either direction. But
no matter what configuration you have, the flutes are going to clog with chips quite frequently
when reaming flute sections … especially long sections.
In my experience, chip clearance is one of the key challenges when reaming flute bores.
The more cutting edges you have, the smaller the flutes tend to be, and they tend to clog
more easily. In part this is also because more cutting edges remove material faster.
I have found that the reamer needs to be removed from the billet and the chips hand-cleared
from the flutes many times during the reaming of a single flute section. If you don’t do this the
reamer quickly clogs, screams at you, and ultimately binds in the hole. The high frequency
of reamer removal and chip clearance is one reason why I don’t like to clamp the reamer
in the tailstock. That really complicates the process of removing the reamer from the hole
entirely. If either reamer or wood billet is held by hand it is easy to quickly
extract the reamer from the hole (or take the hole off the reamer), clear chips, reinsert
and continue reaming.
The other reason I like one or other to be free floating is for accuracy. If both reamer and
wood are clamped in place, then you require perfect concentricity and alignment of both to get
a bore that accurately replicates the dimensions of the reamer. The OP mentioned filing
flats on the reamer so that it can be held in the drill chuck. This raises the question of how
accurate those flats are relative to the axis of the reamer. Even if the axis of the M2 taper
in the tail stock is perfectly centered and aligned with the axis of rotation of the lathe head,
even a slight variation in distance between the filed flat surfaces and the axis of the reamer will
lead to the reamer being positioned off-center, and likely also pointing in a direction that
is misaligned with the axis of rotation. This will produce a bore that is larger, and a different
shape than that of the reamer.
The main point of a reamer is that the non-cutting parts of the reamer hold it centered and aligned
with the axis of the hole being cut, simply by resting against the wall. A reamer only really needs
external stabilization to prevent it from rotating with the material being cut.
It does not need external stabilization for centering or alignment. In fact, trying to achieve
this externally tends to introduce inaccuracies that kind of defeat the purpose of reaming
in the first place, assuming you are reaming primarily for accuracy in the final bore dimensions.
To those above thanking me for putting up the link to the Hammy video, the thanks should go to my co-conspirator, who presumably will out himself when the climate is right. I imagine like me, few were aware of this video. I suspect from the fact that the earliest comments were from only 5 months ago that it has only recently been made public, despite being shot 42 years ago! The contributor’s title - CR’s Video Vaults - probably confirms that it’s been in solitary confinement for most of those 42 years…
Heh heh, just for fun I looked up my CV to see what I was doing in 1980. “Exhibition of musical instruments, Berrima Gallery” was the big ticket item. This was from before the Internet. Making flutes wasn’t the big challenge then - I’d been doing it for 4 or 5 years. The big challenge was finding anyone who wanted to buy one. How times have changed!
There’s another PhD topic - “How the Internet has impacted on Irish Music, and relevant musical instrument making”.
Oh and yes, the musical input from the presenter on the spanners (US: wrenches). And from the bodhran coming in before it, which seemed to have quite a different rhythm in mind to the polka Hammy had introduced. I thought Hammy and the young whistle player did well to battle on, in the teeth of the percussive gale.
I do understand the purpose and intended function of the flutes ( Manual Machine Tooling 101 at a technical college did teach me that much ) , however my thoughts and comments, questions on the subject are more about how spiral vs straight flutes may react differently in wood with regards to stability (and therefore accuracy), and the final finishing action by means of cutting vs. scraping.
I suspect that when most machine shops make a spiral multi-flute reamer for a woodwind maker, they are simply making a metal working reamer to the conical profile specs one supplies, unless very specific technical specs are given for all aspects of the reamer. I mean, how will a machine shop know what works best when reaming a conical wood bore? How many new flute makers will, for that matter to even be able to give specs other than bore profile?
IME, when machine tooling wood, one can often get better results and significantly better efficiency with cutting and scraping tools designed specifically for wood, and the specific task. For example, one can certainly use a stock cutting bit for multiple lathe tasks, but custom shape (hand ground) cutting bits for different actions can work better and faster - boat shaped bit for rough and final turning allows you to use higher speed and feed rates while also leaving a smoother finish at a given speeds/feeds. Having separate left and right hand flat sided long bits for cutting tenons and some facing operations can save time and make the tasks a little easier.
Getting back to stability during reaming, I do wonder if the design of the reamer - number of flutes, type of flutes, size of flutes affects the stability of a reamer, and in what ways. I suspect a spiral fluted reamer in wood might have more of a tendency to wander and vibrate/chatter, but I simply don’t know.
Then there’s the issue of cutting vs scraping, or perhaps planing vs. scraping would be more accurate. Obviously one doesn’t want to try to hog out a ton of wood during rough reaming by scraping. But scraping wood to final finish has advantages over cutting/planing to a final finish. I learned this from the legendary master woodworker Philip Lowe, who tragically passed away last April, RIP. Spiral flutes, as I think about it would have more of a cutting/planing action and that’s what I was asking about specifically in my previous post. Of course I realize the height and angle of the cutting edges play a role as well.
But no matter what configuration you have, the flutes are going to clog with chips quite frequently when reaming flute sections … especially long sections.
Sounds like a statement of fact my friend so maybe you can guess what comes next
Nope, not my experience, didn’t have those problems.
In my experience, chip clearance is one of the key challenges when reaming flute bores.
It needn’t be. I’d have probably quit after my first day faced with the usual 60+ pieces to ream in a single sitting if it was that much hassle. OK, I wouldn’t have quit, but I sure would have liked my job a whole lot less.
The more cutting edges you have, the smaller the flutes tend to be, and they tend to clog more easily. In part this is also because more cutting edges remove material faster.
“One giant scoop shaped flute for rough reaming GOOOD, many small flutes BAAAAD! Say Grok”
Likewise, 2-3 deep wide grooves are plenty for final reaming. At least when they are straight flutes, don’t know about spirals because we didn’t use any that I recall.
I have found that the reamer needs to be removed from the billet and the chips hand-cleared from the flutes many times during the reaming of a single flute section. If you don’t do this the reamer quickly clogs, screams at you, and ultimately binds in the hole.
Again, not my experience, so I’d suggest better tools and processes could save you a lot of time and aggravation. I typically would have to sometimes clear chips once, occasionally twice. Often, no chip clearing needed at all.
Now I will grant you this: I was primarily reaming recorder sections (but there were some flutes) so the dimensions of bore length and diameter were not identical to what you are working with, but close enough that I can’t imagine there being a significant difference. Won’t state it as fact though, since I haven’t run the experiment
The high frequency of reamer removal and chip clearance is one reason why I don’t like to clamp the reamer
in the tailstock. That really complicates the process of removing the reamer from the hole
entirely. If either reamer or wood billet is held by hand it is easy to quickly
extract the reamer from the hole (or take the hole off the reamer), clear chips, reinsert
and continue reaming.
Agree 1000% on this: The tailstock feed method is a PITA when you need to back out and then re engage, particularly if that needs to be done repeatedly. This can also markedly speed up the wear on your tailstock parts and lathe ways, especially if they are not of the hardened variety. And if you are using an older lathe that already has wear and runout from end to end, you really shouldn’t be aggravating the problem if you care about accuracy for operations like making precision jigs/tooling, or reamers of any length. That runout is going to affect your reaming as well, I suspect, if you’re feeding the reamer from the back side. Which is causing more wear and greater runout, which is negatively impacting your reaming, which is putting more force on those already worn parts, which is…….
Not really something to worry about when you’re making your first few flutes, but if you get set in your processes early on, next thing you know you’ve reamed hundreds or thousands of pieces and you lathe parts are starting to wear and you’ve got little motivation to change your process because orders need to be filled, the waitlist is growing, and it’s easier to say well, I’ll just have the ways ground or buy a new lathe when the time comes. Of course if you a just using the lathe for rough turning, it doesn’t matter, but these ideas were drilled into my head by the few more experienced machinists I’ve been exposed to, take it FWIW Charlie.
Paddler’s additional comments on accuracy sort of overlap my own, so need to comment on any of that, plus I think that’s about enough out of me for one morning.
Loren: Were you working primarily boxwood or pear or something other than blackwood for the recorders? And if Paddler is referring to blackwood, would that make a difference in the approaches/results? Asking out of ignorance having never turned anything on a lathe (or ever intending to).
Yes, the majority of our instruments were made from Boxwood, however since we had so many different instrument models we made, we typically did most of the early and middle stages of production, including all reaming procedures, in large batches to save time with regards to machine set-up/reconfiguration. That being the case, it was not uncommon for me to be turning, reaming, etc. some blackwood or various other woods right along with the Box, no change in tooling for the different woods.
Do the different woods ream differently? Yes, a bit. Let’s be honest, Boxwood is a dream to work. Blackwood and the other rosewoods I worked with did mostly require more forward pressure during the reaming process.
Some woods can be more grabby in the rotational direction, depending on the hardness and grain of the wood, but thankfully my reaming co-worker Mr. Chainwhip didn’t seem to notice or care.
Chatter/vibration can be more of an issue with certain woods but I do think the specific reamer design can alleviate problems to a large degree and then it’s up to the tool operator to pay attention to what they are seeing, hearing, and feeling ……then adjust your technique accordingly. I mean don’t try to ram a piece of Blackwood onto the reamer at the same speed and force you’d comfortably use with a section of Box, right? All that chatter is speaking to you, trying to inform you. How’s that walking on rice paper coming along Grasshopper? Sorry, for some that classic TV show just popped in my head
Regarding chips and clogging, I really don’t recall any significant differences, and I usually remember things that make my life more difficult
I feel like I’m maybe forgetting to mention something here, but I’ve been typing between weight lifting sets, so shifting focus back and forth, maybe isn’t helping, but hey, I gotta keep the biological machine well maintained too! Probably fair to say my ways are a bit worn at this point, but what are ya gonna do? Time and wear catches up with us all. Anyway, let me know if there is something I haven’t answered Steve.
I suspect that the different experiences Loren and I have, regarding reamers clogging with chips, is due to the
amount of material being removed. I don’t do much in the way of step drilling prior to reaming. Instead, I have
a roughing reamer and a finish reamer. The roughing reamer turns a non-stepped, cylindrical, pilot hole into a
conical hole slightly smaller than the finish bore. The finish reamer produces the final shape. Given the small
scale of my operation it is just more efficient for me to do it this way. There is a lot of set-up work (and risk)
involved in step drilling billets in my workshop, so I use reamers, fed by hand, to make my life easier. It is quite
quick and easy the way I do it, but I would probably change my process a bit if I were part of a large scale
operation like Loren was.
I totally agree that cutting edge geometry should be material specific. That makes a big difference in my experience.
I didn’t answer Loren’s specific question about cutting vs scraping with spiral reamers because I have not done
that experiment myself. I would guess that the cutting edge on a spiral reamer would work more like a planing
action and produce a smoother surface, but I haven’t done a side-by-side test of this.
I have reamed a few different wood types, including blackwood, fruitwoods, boxwood, and some delrin. I just have
one set of reamers, so I use the same reamers for all of them.
(My undergraduate thesis was literally about rotating reference frames) I agree that is the origin of the chattering. At this point, if I just turn the reamer in the work by hand, it screams, and while I can’t see where the flutes have grabbed, I can feel it.
) , however my thoughts and comments, questions on the subject are more about how spiral vs straight flutes may react differently in wood with regards to stability (and therefore accuracy), and the final finishing action by means of cutting vs. scraping.
so maybe you can guess what comes next 
