Been wanting to Post this for a while.
I have had calls on guys have trouble with bad finishes in babbitt, and or all kinds metal.
The fastest way for me is to deaden the boring bar, and or tool post.
This is one way, but you still have to have a tool bit sharpened correctly.
Thanks - good idea. No expensive seldom used equipment needed, thatīs an extra plus for us cheap tinkerers
HSS boring bars are notorious for transmitting harmonics to the work piece. We use only 100% carbide bars or heavy metal bars when we have issues. We'll run .005R or less for tool nose radius. RPM and feed also come into play.
Welcome to the world of machining.
Also, use only enough bar to get through the piece. Cross slide and compound locks on each pass help too. I noticed your lathe has neither. Easy enough to make with a lathe. The compound lock in the picture below was later shortened to the same length as the cross slide lock.
The only place I can ever feel anything is in the boring bar, or a little in the holder.
Same as the other lathes the 16", and the 18", just bar and holder.
Nothing in the other two slides, well in any case no Harmonics
What if you wrapped rubber bands around the shaft?
When we bored brake drums we wrapped a cow strap (that's a leather strap you drape over a cow and cinch it with a connector.......there's a loop at the bottom for hanging a milking machine) around the drum to reduce or eliminate harmonic vibrations.......
To stop boring bar chatter I put a piece of heavy rubber belting between the cross slide and boring bar, and "drive" a steel wood splitting wedge between the rubber and cross slide.
Worked (WORKS) like a champ.
I love SIMPLE ways to deal with difficult problems.
You can stop "Boring Chatter" by feeding her some chocolates
Well I'll be Ken, with all them years under my belt
I never gave that a thought.
A heavy enough lathe for the job at hand does wonders. Here is a 1918 Lodge & Shipley with a little 40,000 lb piece in it.
Pour a block of lead and hold it against the back side of the bar.Approx 1-2 pound block. Steve
I'm not sure what is meant by "harmonics". Is that vibrations from the motor, gears/belts or tool chatter? If it's tool chatter, sharpen the tool bit, decrease DoC or replace the operator.
Brass and cast iron breaks rather than shears. That's why you don't see long "curlies". The cutting edge of the tool bites in then the material breaks and tool bounces if there's any tool flex.
I'm not sure what is meant by "harmonics". Is that vibrations from the motor, gears/belts or tool chatter? If it's tool chatter, sharpen the tool bit, decrease DoC or replace the operator."END QUOTE"
In your wildest Dreams!
Billet Brass (not cast) will make curly Qs all day long. Bronze runs like cast iron. Snug the gibs on the carriage and cross slide. Fe makes little (like really small) 2-3 turn curlies but they break readily. Notice that's with a good grade of cast iron. Not todays' pacific rim trash.
-Use the correct length & dia boring bar for the job.
-Lock the cross & compound slide.
-Oiling the ways right before boring may help if your machine is a little loose.
-cut & rpm do make a difference.
I would say use the largest diameter boring bar possible and the shortest length would be obvious. Also using a bar holder that provides full support closest to the work would be much better then the one pictured in the first of this thread.
Driving 100 year old cars is great fun. 100 year old tooling should be sent to the scrappers and some real tooling should be used. KDK and insert tool holders will solve most problems. Machining with flimsy tooling is a joke. We now have great oil, grease and good tool holders. Time to step up. The old stuff did its job but the new tooling is light years ahead of the old American tool post holders and cresents. Scott
So Scott, do you have a definite opinion, or what are you really trying to say?
Sounds like somebody needs to find somebody for a huge today!
Scott. My mentor and teacher told me to learn to machine on worn out equipment. He said if I did I would become a machinist. If I needed new equipment I would be an operator.... Part of the fun of our hobby is also using all the old tools the original builders of our cars used. My lathe is pre 1936, my milling machine is a 1886 model, my planer (if your very young you may not even know what that is) is 1917 model, ect... All have some wear. In about 30 years of machining I have never been unable to make something I needed with a tolerance of less than .001. It may take me longer than a modern cnc machine, but I bet I had more fun (and cost a lot less)
Hi Herm, I know that you know your stuff and this is not a dig at you. I have used the American tool post stuff years ago. It will work on light jobs but I have fought tough materials, long shafting and chatter for years. The KDK tooling works quite well but it will sing with the best of them if you let it. And a Hug any and everyday is very nice. Scott
Here is the old stuff on hardly light stuff back in the brass era. Check out the border around the photo. ATW was pushing the envelope with the fairly new High Speed Steel cutting tools.
Well, I sure would like to have all new lathes, but since my Gold mine petered out, I am going to have to use what I have.
I guess if I had a contract to make 10,000 parts all the same, I might need a new Lathe to make some money.
But all my work is a different piece at a time, and I can get it to the 1/10 of a thousandths, with out compromise.
I do know that KDK style of Tooling will not work for me with the odd stuff I work on.
My 95 year old Dad would drape a bag/sock containing Lead Shot over the tool holder/boring bar to reduce tool chatter when all else failed.
That is a good idea Les, and it would fit a lot of different shape's also!
OK to add to the confusion. I was once told that lathes running on single phase would be more likely to have chatter compared to ones running on three phase current since single phase motors are shutting off and on 60 cycles a second and that can set up a harmonic in the cut. Having run both phases I have seen this. If you notice most lathes sold today and sold with over 2 horse power motors are sold powered with 3 phase motors. Bob
Just a little curl off some Silicon Bronze I was turning down to make a new adjustment rod for a Holley S two screw. This is off a .255 nominal being turned down to .245 before threading.
HSS bit, spindle speed 1500, turning on my 8 x 16 LittleMachineShop bench lathe. My Logan will also do this, my Jet isn't quite as tight as the Logan anymore and tends to break the curl.
And the beat goes on! My view? It all comes down
to whats in your back pocket. Lanterns v/s pistons,
and pistons v/s wedge's. Kind of like putin Lincoln
hub caps on a Falcon aint going to make a Falcon
better and in no way I'm makin fun out of people
with an Atlas but does a high buck wedge qctp really make it better? As to put power steering on a "T"??
My lifetime advancement was 3 axis $30 mill dro's. I just bought--
Ya I know, But for my mill, a real setup is way over
a grand. all cause I can't see dials no more. But as Khonke said ya gotta make do. And then the customer has no clue as what, or how old the machine is that made the part. 90% of our machines
are 1940's and before only 9% are in the 1950's
and 1% in the late 2000's being migs and tigs and
plasma's. One of our big lathe's is older than the
model T. And yes its still got a kerosene lantern
tool post no way to afford a quick change for that one!!
That is just funny, if one can't laugh at this, well something is wrong. Great post.