Chamber problems

[rem40xb1]

The reamer I am using is a Manson 22 creedmore--I received an email from one of the members and they asked if the reamer I was using was a Manson and went on to say they had the same problem with a new Manson reamer and that they never could correct it. I ran a 22-250 reamer about 100 thou in the chamber and it did not chatter

 

[DaveTooley]

Besides being a personality trait of some reamers, sharp shoulders and straight bodies also contribute.
One thing I do with 40 degree shoulder angle reamers is run the finish reamer in about .100" of the body, then rough out the rest of the chamber.

 

[Alex Wheeler]

Most chatter issues are caused from reamer misalignment. Floating reamer holders dont really float under a load so everything should be aligned first. Which negates the need for the floating holder.

 

[LVLAaron]

^ They certainly have to be used "correctly" or they make life miserable. They aren't a get out of jail free card.

 

[DaveTooley]

I'll add reamer core diameter and flute width can and do play a role in this. I worked on this issue when Dave Mason was running Cylmer many years ago. You could watch the reamer twist as the shoulder started cutting.

 

[LVLAaron]

Ooh! Free spiral cutter!

 

[cricket2386]

Floating tool holders have been around for years as we all know, chatter is always an issue we have delt with
I design with the company that first developed them called jc glenzer/and the second wmziegler tool
they were made at first for the automotive industry to due away with multi head issues out of alignment with the spindle then develop for lathes like you are using i own both now and make special floating holders for large auto companies
That said the miss conception on the floating holder is angular misalignment a real true floating holder can only stop chatter by floating radially not angular
if you have a holder that does both it is not a tru floating tool holder
we lap all our holders in to be parallel to the shank to the bore to the spindle
i do not make the morse taper shank ones as standard anymore but can if any one wants to try one email me and we can work something out we have supplied floating tool holders to ruger, smith and many other gun mfg in the past . all i have done all my life is floating tool holders (45 years )
i am 70 now retired now and have a lot of left over stock on the parts to assemble a tru holder
with that said i am not a gun smith but do know a lot about floating tool holder's design
when we got chatter several things were be an issue the first if it is a new reamer we would dust with a stone to take the edge off that is why one said it would get settle down by use
using a floating holder does two things if it a true floating holder it will follow the hole drilled before holed size and make up for the misalignment of the part to the spindle or tail stock .
if you reach the float limit of cause an angular misalignment you will force the holder to one side to cut oversize
This is called bell mouthing the front is larger and the back .Pushing the reamer in not floating!
We also have to remember the floating tool holder needs to engage and settle down to follow the hole so a good lead is needed with that the adjusted spring pressure talked about below also comes into effect in this holder
Floating tool holders had a coupler inside that allows them to float and how this is designed makes all the difference in chatter and what it is culpable of doing.
That is why we lap the assemble parts at the time of assembly to make sure it can only float radially side to side and the backlash is also lapped in set to a minimum. No angular float! this causes over size and chatter
Also there is a spring load on them to be adjusted on the size of the reamer and for horizontal or vertical use also rpms and weight of the reamer ie carbide or steel through the back of the holder.
And then there is the collet used regofix is the best but you can get a UP or standard and the kind of oil or coolant you use ? ALSO IF YOU USE A STANDARD COLLET AND Collapse TO SIZE YOU LOOSE ACRACY!
ALSO THE COLLET NUT MAKES A DIFFERENCE bearing nuts give you more accuracy
With that said using the right floating holder design and collet set up can solve many problems with sizing your bore issue, but speeds feeds type of reamer lead coatings and several other things also come into effect on this set up

sorry for the long typing but over the years so many have asked me about reaming
if anyone needs a reamer holder let me know
this shows the internals on a standard used for years in automotive, but the back shank was developed in many shank styles morse taper straight and the front also was developed for er style collets to, but this was the style collet the tc type collets were used in many gun mfg in the us
It is not a complicated as it sounds but all of you know much more about gunsmithing then i will ever know so i hope this helps in some way
thanks

 

[LVLAaron]

That looks similar to the way the PTG is built. Yours is more advanced. I'd like to play with one.

 

[Will Henry]

Of course, If you just set the thing up straight, you don't need a floating holder. However, if your reamer is ground incorrectly, it can still chatter. WH

 

[LVLAaron]

Setting it up straight is no small task.

 

[ricco1949]

I've never experienced any chatter in 50+ chamberings....50 is not many by some of the standards on here I fully recognize.

However, I've often wondered if I've just been lucky or if it's because I use a Gre Tan reamer holder mounted on tool post that I center before each use?

Hope I ain't awoken the sleepin' dog.....

 

[GenePoole]

I've never experienced any chatter in 50+ chamberings....50 is not many by some of the standards on here I fully recognize.

However, I've often wondered if I've just been lucky or if it's because I use a Gre Tan reamer holder mounted on tool post that I center before each use?

Hope I ain't awoken the sleepin' dog.....

I've only gotten chatter once, and that was not a barrel, but a seating die blank (no rifling). I wrote it off as the reamer being unsupported at the tip; the die was bored large for a seating stem so no pilot. A wrap or two of sack paper cleaned it up.

 

[ricco1949]

Gene, I doubt my no chatter success is due to a reamer pilot because I often use a solid pilot, I've even used no pilot when I don't have the correct bushing..

However you made me think of another reason for my no chatter history. I taper bore to within a few thousands of chamber dimension so the reamer is well supported and has very little work to do.

Maybe that's my lucky star.

 

[rwj]

Put some wax paper on the flutes to clean it up.

I wrap the body of the reamer with one full turn of wax paper. In extreme cases it may take more than one application but it has never failed to eventually stop the chatter. I have a couple of problem reamers that I know will cause a problem. I keep cut to size paper with other odds and ends handy.

I have no machining experience, but do have a curiosity to understand why this works to eliminate chatter. Does the wax simply provide a lubricant or is there more to the story?

 

[LVLAaron]

Wax paper / patch / chalk / grease / whatever - All kinda the same. It makes the reamer tight in the chamber... The cutter will cut through the wax/patch on a high spot in your chatter and eventually smooth it out.

 

[Sniperhandle]

Wax paper / patch / chalk / grease / whatever - All kinda the same. It makes the reamer tight in the chamber... The cutter will cut through the wax/patch on a high spot in your chatter and eventually smooth it out.

I figured it was more like a harmonic damper, Like packing the reamer full of heavy grease works too, I think it dampens the vibrations, Because that's all chatter really is, Is vibrations that are out of control.

 

[LVLAaron]

I wont dismiss that. Never tried grease/chalk. With a floating holder I don't think it'd make much difference to correct any caused chatter. Stranger things have happened though

 

[DaveTooley]

Just my simple mind but I think the wax paper fills in behind the primary cutting edge. Thus making a wider supporting surface so to speak, that moves less from flute to flute in the chamber, then gradually cleans up the high spots.

 

[Sniperhandle]

I know old machinists would tie a bicycle inner tube around a shaft to dampen vibration to stop chatter when turning something.

 

[Sniperhandle]

Just my simple mind but I think the wax paper fills in behind the primary cutting edge. Thus making a wider supporting surface so to speak, that moves less from flute to flute in the chamber, then gradually cleans up the high spots.

Whoever figured out the wax paper was pretty handy.