floating tool holder - can we actually talk about metal working


while the 99% scream about politics, can the three remaining people who
remember anything about metal and working chime in here?
I use a chucking reamer to make accurate holes after drilling them on my
lathe (these are adapters of various kinds) - I center drill, then drill,
then put the reamer into the drill chuck to ream. But there is a problem -
drill chucks, even on the best of days are not high precision - the spec is
.015 runout measured 2 inches from the chuck at 1/2 max diameter (from the
Jacob's site) - so with a chucking reamer that is 6 to 8 inches long, that
.015 becomes a much more significant number. The answer is, of course some
kind of floating holder - and I can get ones in various configurations - so
the question is, what makes sense? Glenco makes nice units with a MT3
(male and female) so one can put them in series with the chuck, there is
quite a range of other units
thoughts, about this subject please (no politics - let's see if it's
possible)
Reply to
Bill Noble
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I use kennametal floating collet chucks, they work well in both the lathe and drill press. They show up on ebay on a regular basis.
Best Regards Tom.
Reply to
azotic
1. When folks post metalworking stuff..they get metalworking answers. When other stuff is posted..they get other answers related to that stuff.
2. Deal with it
Now as to your question...have you considered MT split collets?
I have a rather complete set of them that fit in my Hardinges tailstock and can hold a range of sizes down to 1/6"..plus quite a number of taps.
I also have a full set of splt collets for #3 MT.
Here are some examples if you have never seen them before...
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And so forth.
I also have MT adapters to run the above holders all the way up to #5 MT so I can hold them in the tailstock of my Clausing 1501
Gunner
Reply to
Gunner Asch
Hi Bill, I was taught on old worn out equipment. We used to load the reamer in the tailstock and push the whole tailstock in by hand - that is usually enough float to avoid bellmouthing. After all, your feed rate is at least triple the drill feed. I've seen very few reamers with dead nuts shanks. Hope that helps.
ww
Reply to
wws
I guide reamers with the dead center and hold or turn them with a tap wrench.
jsw
Reply to
Jim Wilkins
There are floating reamer holders, gunsmiths use them all the time with chambering reamers. I assume they're a standard item in the supplier catalogs. Here are a couple, don't look too complicated to make:
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Stan
Reply to
stans4
If you read this group through Google Groups, there is a flag on each posting "report spam".
I would assume that if enough people read the group through google and report blatently off topic posts as spam...
Try it on this post if you like.
DOC
Reply to
doc
I use ER40 collets with in a ER40 collet holder adapted to a #3 morse taper with shank. Which is also real nice to hold assorted mills to cutting un-tapered holes.
cheers T.Alan
Reply to
T.Alan Kraus
Hmm ... you need the floating holder to be able to self center as the reamer contacts the workpiece. For this, you would want the mass which has to move to be minimal -- thus no chuck involved.
The ones which I have are made with 1" cylindrical shanks, to be used in the bed turret for my lathe. Six stations, each with its own simple tool, complex tool, or combination tool.
If I were drilling and reaming lots of parts, I would set the a depth stop in the first station, a center drill in the second station, the pre-ream drill bit in the third station, and the forth station would have the reamer in a floating holder, and on the first workpiece I would tease it into the hole while the lock-downs were loose, tap it a bit as I worked my may about half-way down the reamer or so, then lock down the floating holder so it would start and remain on center every time that station came up.
Of course, my floating reamer holders are not the same as others. They will move a bit sideways in all directions until I lock up the clamping bolts.
Here is one on eBay which looks interesting, and which might do what you need:
200466895813
It is rather different from the ones which I have (which came with my lathe and bed turret -- two of those, three Jacobs drill chucks, and no other tools. I spent a while picking up turret tooling from eBay and learning what each did for me.
It is for me.
Enjoy, DoN.
Reply to
DoN. Nichols
There are floating reamer holders, gunsmiths use them all the time with chambering reamers. I assume they're a standard item in the supplier catalogs. Here are a couple, don't look too complicated to make:
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Stan
Rank amateur machinist that I am, I have to ask this dumb question. The reamer used in this gunsmith floating holder would have to be prevented from turning once engaged in the hole, right? With a tap wrench, etc.?
Garrett Fulton
Reply to
Garrett Fulton
Then I take you are using hand reamers. Chucking reamers do not have a square on them.
Morse taper to collet adaptor might be the answer.
Thank You, Randy
Remove 333 from email address to reply.
Reply to
Randy
Chamber reamers have a square on the end, so fall into the hand or manual category. If you look at the Bald Eagle brand reamer holder in the link, you'll see a bar clearly screwed into the shank holder portion. So, the answer to your question is that, yes, there has to be a way to keep the reamer from rotating. Sans specialty reamer holder, guys have used a center in the tailstock and a clamp-on tap wrench, AKA "dogbone". If everything isn't lined up right, you end up with an off-center chamber or at least an over-sized one.
Stan
Reply to
stans4
Chamber reamers have a square on the end, so fall into the hand or manual category. If you look at the Bald Eagle brand reamer holder in the link, you'll see a bar clearly screwed into the shank holder portion. So, the answer to your question is that, yes, there has to be a way to keep the reamer from rotating. Sans specialty reamer holder, guys have used a center in the tailstock and a clamp-on tap wrench, AKA "dogbone". If everything isn't lined up right, you end up with an off-center chamber or at least an over-sized one.
Stan
Thanks, Stan. That clears it up.
Garrett
Reply to
Garrett Fulton
Not initially.
jsw
Reply to
Jim Wilkins
That 0.015", is that TIR?
I tried Albrechs site and didn't find any usable info on accuracy.
ER series collets? They don't look symetrical as far as tapers on each end.
Jacobs made Rubberflex collets that had a large range.
Wes
Reply to
Wes
You could easily indicate it and mark the chuck This Side Up.
Cut a short piece of 0.500 drill rod to center in the spindle chuck and a longer one to put in the tailstock chuck. Move them together and see how closely they align. A milling edge finder works, but doesn't show runout away from the drill chuck.
jsw
Reply to
Jim Wilkins
A chucking reamer does not have the flats needed for a tap wrench to be of use. That only works with a hand reamer (which also has a much longer lead-in taper).
The floating reamer holder allows the reamer to self center, but prevents it from freely rotating.
Enjoy, DoN.
Reply to
DoN. Nichols
1. thanks for all the hints - some useful to me, some seem to be helpful to others
2. per comment above - a chuck on an MT3 taper has a tang so there are two and only two orientations - but it doesn't matter if you think about it - in whatever orientation it is used, the angular error will put the reamer (or drill, for that matter) off center.
3. runout specs for Jacob's chucks are here
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(ENG)-1.pdf - the typical value is .004 at 1.5 inches. So, if my chuck were in spec, and a 5/8 reamer was 9 inches long, protruding say 6 inches, I'd expect to have .016 misalignment - I get more than that, so the chuck probably has some wear (or older chucks weren't as accurate - I remember a much larger number the last time I looked at the spec).
4. I looked at the holders with collets - that's great, but I have these reamers that go from really small to 1/2 inch by 64ths - the reason for using the chuck was just to not deal with a zillion collets - but maybe I should reconsider???
It seems to me that "chucking reamers" are designed to be held in a chuck, so why can't I do that? Don N makes the moving mass point - that makes sense - of course I have a regular Logan/Powermatic 12 inch lathe, not a turret lathe so I can't do his trickery with the turret. I'd like to be able to hold this range - from 1/8 to 1/2 (at least) in a floating holder - of course I could get reamers with an MT-3 end, but like many with a home shop, I have a space problem and even with unlimited funds I couldn't store all the 'perfect' tools - the chucking reamers and some kind of floating holder seems like the perfect solution.
so ?????
there is a range of items on e-bay, and other places - I find many with an "automotive shank" - I can borrow a friend's lathe and turn the automotive shank to a MT-3 and then I have what I want - maybe this is the way to go????
(and miracle of miracles - two days and no politics intruding - excellent)
Reply to
Bill Noble
That is a run out figure at a distance. What we don't know is what kinds of errors caused that amount of run out. Are the jaws and jaw body made at the correct angles to hold a drill parallel to the centerline of the chuck or maybe the drill is pointing straight but not centered perfectly? It would make a difference on how you extrapolate the numbers. I assume it is a mix of both but what is the bias?
You drilled the hole with the lathe. Drilling a hole by turning the work vs turning the drill tends to make the straightest hole. It also tends to drive the drill to the center of rotation of the work piece. Why wouldn't running a reamer have the same benefit from the unique properties of drilling on a lathe?
Wes
Reply to
Wes
[EDIT]
errors caused
would make a difference on how you extrapolate the numbers. I
-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller
Reply to
Wes

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