Petergun
Aluminum
- Joined
- Mar 27, 2007
- Location
- Belgrade, MT USA
we are trying to turn 1.25 dia. barrels with out chatter . can anyone offer some ideas ?
Thanks for the help.
Thanks for the help.
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How do you turn a barrel with out chatter?
- Thread starter Petergun
- Start date
- Replies 42
- Views 4,398
john.k
Diamond
- Joined
- Dec 21, 2012
- Location
- Brisbane Qld Australia
You build yourself a hydraulic follower,is how you stop chatter......if you look at old pictures,the makers use to solder on steel rings for fixed steadies ,and profile the barrel around them ,reposition to finish the barrel.
michiganbuck
Diamond
- Joined
- Jun 28, 2012
- Location
- Mt Clemens, Michigan 48035
Very sharp cutting edge and rake angles proper for the material.
A poor edge can resit cutting until enough pressure is obtained, then a sudden material break-away occurs so causing a part jump/Chatter, too big a radius can make chatter in a lighter machine. the intersection of two clearance angles can cause too much clearance so the point or radius can be bumped back to proper clearance, perhaps 8 to 10 * ballpark.
For mild steel, file medium a positive 10,10,10 back rake / side rake / back rake is a ballpark amount.
The wrong rake angle can cause to part to push away from the cutter so again causing more and more pressure until the material can be penetrated by the edge.
Sometimes the wrong rake angle can pull the material into the cutting action.
Some materials fracture away, like cast Iron so this material can prefer zero or negative rake angles and a more stout machine.
*And with all metals/materials too high of a stock removal and feed rate can be a bugger for chatter...along with unsupported long parts (barrels).
A poor edge can resit cutting until enough pressure is obtained, then a sudden material break-away occurs so causing a part jump/Chatter, too big a radius can make chatter in a lighter machine. the intersection of two clearance angles can cause too much clearance so the point or radius can be bumped back to proper clearance, perhaps 8 to 10 * ballpark.
For mild steel, file medium a positive 10,10,10 back rake / side rake / back rake is a ballpark amount.
The wrong rake angle can cause to part to push away from the cutter so again causing more and more pressure until the material can be penetrated by the edge.
Sometimes the wrong rake angle can pull the material into the cutting action.
Some materials fracture away, like cast Iron so this material can prefer zero or negative rake angles and a more stout machine.
*And with all metals/materials too high of a stock removal and feed rate can be a bugger for chatter...along with unsupported long parts (barrels).
Last edited:
ErnieD
Cast Iron
- Joined
- Jan 15, 2006
- Location
- Toledo, Ohio
Maybe grind up a skiving tool . You would not even have to worry about the tool being on center .
I recently had to turn a section of an AK barrel and had chatter problems. I use a shear tool to do my final cuts which worked perfectly. I think it is the same as what ErnieD is calling a skiving tool. I found videos on youtube that showed the grinding and setup of the tool which is basically is a lathe tool that cuts very small amounts using the side of the cutter.
michiganbuck
Diamond
- Joined
- Jun 28, 2012
- Location
- Mt Clemens, Michigan 48035
Proper tool geometry and sharpness..along with the position of your compound being well centered on the saddle.
I see a lot of videos with the compound slide extended way out so downward cutting forces would tend to try to tip/rock the saddle.
1.125" barrels should be solid as a rock.
Poor part centers, not round/not honed could also be a factor.
Too much rpm and balance can cause chatter. or with a wobble live tail center.
Fingernail sharp for fileable steel.
I used to turn 98 barrels on a small Sheldon, and they came out near perfect using hand-sharpened HSS bits. Some inserts are not fingered nail shaving sharp.
I see a lot of videos with the compound slide extended way out so downward cutting forces would tend to try to tip/rock the saddle.
1.125" barrels should be solid as a rock.
Poor part centers, not round/not honed could also be a factor.
Too much rpm and balance can cause chatter. or with a wobble live tail center.
Fingernail sharp for fileable steel.
I used to turn 98 barrels on a small Sheldon, and they came out near perfect using hand-sharpened HSS bits. Some inserts are not fingered nail shaving sharp.
Last edited:
MCritchley
Hot Rolled
- Joined
- Mar 22, 2007
- Location
- Milwaukee
In a pinch I’ll hold a stick behind a cutting tool on a long turned part. Push harder in the middle to get the belly out of the part. It’s surprising how little force it takes to keep chatter at bay. Once the chatter begins it’s too late. Start the turn with the stick engaged. I’ve also hooked up a stick on a pivot mounted to the cross slide and wrapped a rubber band from the tool post to the top of the stick for a bit of consistency.
Sounds weird but sometimes you need to get a part done quickly.
This of course is an option if you have one or two to turn. John K’ suggestion of a hydraulic follower is correct if your going to make a bunch of barreled.
Sounds weird but sometimes you need to get a part done quickly.
This of course is an option if you have one or two to turn. John K’ suggestion of a hydraulic follower is correct if your going to make a bunch of barreled.
triumph406
Titanium
- Joined
- Sep 14, 2008
- Location
- ca
TPGT inserts work well for me
deltaenterprizes
Stainless
- Joined
- May 9, 2006
- Location
- Longview,TX
An adjustable follow rest that I copied from YouTube videos worked for me!
mhajicek
Titanium
- Joined
- May 11, 2017
- Location
- Minneapolis, MN, USA
Want to turn a barrel without chatter? Tell everyone to shut up while you're working!
john.k
Diamond
- Joined
- Dec 21, 2012
- Location
- Brisbane Qld Australia
Various combinations of lead sheet, lead wire and lead dust shot are also effective against chatter in some setups.
MilGunsmith
Stainless
- Joined
- Mar 6, 2006
- Location
- Sandyston, NJ
What is your current setup? Are you turning a straight or tapered profile? Type and condition of the equipment that you are currently using? Using HSS or carbide? Lots of variables, before we can give you a correct answer.
michiganbuck
Diamond
- Joined
- Jun 28, 2012
- Location
- Mt Clemens, Michigan 48035
Along with a photo of the set-up, with material and hardness.
Some chatter is the result of building forces until the material can be penetrated and then a sudden temporary release causes a change in forces. The same thing can happen when grinding.
Last edited:
trevj
Titanium
- Joined
- May 17, 2005
- Location
- Interior British Columbia
Pretty much this above.
You solve problems by asking intelligent questions, and help folks that want to help you, by providing decent amounts of information in order that they are not having to guess wildly at what you are already doing, and how, because you provided absolute crap for information.
michiganbuck
Diamond
- Joined
- Jun 28, 2012
- Location
- Mt Clemens, Michigan 48035
Compound cranked back so not way out extended, perhaps C clamp it tight down and use the cross only for in feeding, , or with having gibbs set tighter. and centered pretty much centered over the protractor.
The tool bit/insert and too bit/insert holder as short as possible. the toool bit /insert with proper geometry (shape), and sharpness. A radius point nose suitable for the size of the machine. Headstock beatings being good/OK. No wobble from a poor live tail center.
Use some lard, grease, or cutting oil .with taking reasonable speeds and feeds appropriate to the machine.
Perhaps make a crackerjack abrasive paper holder so to take .002 or so if that might clean up the chatter.
The tool bit/insert and too bit/insert holder as short as possible. the toool bit /insert with proper geometry (shape), and sharpness. A radius point nose suitable for the size of the machine. Headstock beatings being good/OK. No wobble from a poor live tail center.
Use some lard, grease, or cutting oil .with taking reasonable speeds and feeds appropriate to the machine.
Perhaps make a crackerjack abrasive paper holder so to take .002 or so if that might clean up the chatter.
Last edited:
john.k
Diamond
- Joined
- Dec 21, 2012
- Location
- Brisbane Qld Australia
Oddly enough , taking light cuts can be the cause of chatter......a final heavy cut is often the cure....Howe recommends profiling barrels with only four cuts.
EmanuelGoldstein
Diamond
- Joined
- Apr 14, 2018
If you want something easier to try than a follow rest, fill the barrel with cerrometal. Then the positive inserts, a bit more feed, and bigger depth of cut.
'Course by the time you try all this you won't have much barrel left, so I hope you have more than one
'Course by the time you try all this you won't have much barrel left, so I hope you have more than one
trevj
Titanium
- Joined
- May 17, 2005
- Location
- Interior British Columbia
Has the OP ever been back?
Jes' wonderin'...
While all and sundry guess at what and how he is doing that isn't working, so far, the only data point we have is the diameter of the barrels at 1.25 inch. No length, material, speeds and feeds, tooling, machine, setups, or what systems he may have in hand to utilize.
Gonna throw this out there, but guessing at what the guy is doing, doesn't get him anywhere. Or us.
Jes' wonderin'...
While all and sundry guess at what and how he is doing that isn't working, so far, the only data point we have is the diameter of the barrels at 1.25 inch. No length, material, speeds and feeds, tooling, machine, setups, or what systems he may have in hand to utilize.
Gonna throw this out there, but guessing at what the guy is doing, doesn't get him anywhere. Or us.
michiganbuck
Diamond
- Joined
- Jun 28, 2012
- Location
- Mt Clemens, Michigan 48035
Still, a lot of chatter solutions may be handy for another lathe enthusiast
And lathe chatter is a better subject than Hen's Chatter.
And lathe chatter is a better subject than Hen's Chatter.
