Reamer cutting inconsistent on body.

[msalm]

You stated you were supporting the reamer with a center in the tailstock. I would try a floating reamer holder. You could have the barrel dialed in to a 'zero' runout condition, but if your tailstock isn't dead 'zero' in line with the spindle axis you will have troubles. Oversize chambers for one, and the reamer cutting on one or two flutes on the side the tailstock is off.

I think this could be the issue, as with 'chatter' you'll see all flutes collecting those long chips, not just one flute as in your picture.

Either dial in your tailstock dead nuts, or try a floating holder or pusher for the reamer.

 

[INTJ]

Since theres so many doing the same thing im still betting its your setup. Using a cathead does that on some barrels because of the limited contact points.

So a cathead or spider is more prone to chatter than a four jaw?

 

[Dusty Stevens]

So a cathead or spider is more prone to chatter than a four jaw?

Seems to be for me

 

[MDSpencer]

I wouldn’t mind looking at that reamer. If you would like to send it to me. I can check for runout. Will call you with the results

 

[Ggmac]

Can anybody help explain why a reamer might cut like this on the body? The neck and shoulder seem to cut fine, but as I progress into the chamber, it will start to drag or "tighten up", until I feel a jerk on the handle, followed by what I can only describe as a "scraping noise" and then chips like the ones pointed to in the pic are flushed out. They are long, and coiled inwards like a spiral pin. After that happens, it turns freely in the chamber for another .100" until it starts over again. This is the 4th reamer I've recently gotten that cut like this. 3 from the same manufacturer, and the 4th from another one. Neither manufacturer is who you are probably thinking. I'm driving the reamers off a center in the tailstock and flushing with a high sulphur threading oil. I've tried rotating the reamers 180* in my holder thinking I had an alignment problem, but the chips seem to appear on random flutes. I've chambered multiple barrels in between these 4 with other reamers I own and had no issue with them.
I'm obviously going to send them back for inspection, but having 4 of them with nearly the same problem makes me wonder if it's not something unique to my setup.
Has anybody else seen a reamer do this?

Only when i push it too fast /hard .

 

[Bugholes]

Id bet the reamer is dull on the body, or too much margin was stoned on the cutting face. Reamer loads up with tool pressure, the flutes flex, then they take a bite all at once

 

[skeetlee]

Is your Barrel a 5R when the trouble happens? Most wont admit or they don't measure closely enough to see it but 5R barrel will chatter unless you control the situation. 5R Barrels can be a real choir if your not careful . Most wont talk about it but I can assure you this is a real issue. good luck I hope you find your solution

 

[Ksracer]

Id bet the reamer is dull on the body, or too much margin was stoned on the cutting face. Reamer loads up with tool pressure, the flutes flex, then they take a bite all at once

You described what was happening perfectly. After speaking to Will Henry I'm confident it was an issue with the margins.
I can 100% guarantee that it's not "Chatter". The only times I've had a reamer chatter was when I was forced to start one without the pilot engaged. What I described happening this time is nothing even remotely close to a chatter issue.

 

[Canadian bushman]

The very first thing i would do once you experience this problem is pull the reamer out and look at the cutting edges with a loupe or magnifying glass.

This will tell you where the wear is happening and can sometimes highlight a bad flute, poor geometry or uneven grind.

Its important to do this during the process because it may also highlight set up issues. If your tailstock was not aligned, the wear would be heavier on on side of the reamer than the other. Typically toward the rear ( action side ) of the reamer.

It really sounds like poor cutting geometry, overly worn cutting edge(s), or possibly work hardened material.

 

[Shooter71]

Feed might be too slow, or edges built up.

 

[boltfluter]

In my experience your reamer needs to float in some manner. Or it becomes a boring bar. I have yet to see a perfectly aligned tail stock. More than one brand of reamer doing the same thing seems to point to some kind of problem with the set up. Just my 2 cents.

Paul

 

[Mark Buettgen]

Is your Barrel a 5R when the trouble happens? Most wont admit or they don't measure closely enough to see it but 5R barrel will chatter unless you control the situation. 5R Barrels can be a real choir if your not careful . Most wont talk about it but I can assure you this is a real issue. good luck I hope you find your solution

Hey Skeet,
No disrespect intended, but that's just not true. there are thousands and thousdands of 5R barrels chambered all year long with out any problems.
Where some folks get into trouble, is running way too slow RPM's.
A chambering reamer is not like a chucking reamer, it's a form tool, and a HSS chambering reamer should be run at somewhere between 180 and 220 RPM's, not 40 to 60.

For chatter, too loose a bushing, dull reamer, brand new reamer on initial cut sometimes, too loose a set up, tailstock misalignment when not using a floating reamer holder----
Later, Mark Buettgen
Bartlein Barrels Inc

 

[dnellans]

Any chance these barrels are chromoly when you're used to stainless, or bartlein's new steel? Just a shot in the dark about something changing you've overlooked.

 

[JPB3]

I agree, it's chatter..

You said you were pushing the reamer with a center in the TS.. Is it a live center or a dead center?

 

[geo.ulrich]

Here is a pic of a reamer from the second manufacturer that bit hard enough to pull the handle from my grasp. It was turning smoothly, just very tight before it happened. I can't visually see a third angle on this one. If I put these between centers and roll them under a tenth DTI as Tucker65 suggested, will I be able to measure a drop in the relief areas?
View attachment 1174751

rolling between centers isn't going to get relief numbers , setup between center and find high point with edge on center. then move cross slide in and record drop off. going by memory .060 in travel with .001 drop should come to around 55 mins. of angle. you can figure from there . first pic. relief looks a little wide second pictures not wide enough. I haven't had to calculate this in yrs. sold cutter business more than 25 yrs. ago...