Cut off tooling??
- Thread starter skeetlee
- Start date
lathe tie down
Ian:
How are things in New Zeland?
Reading your post about the concrete. I have a concrete floor. I made a base for my lathe with 6" X 2" square 1/4" wall tubing frame 36" X 96". I then welded a a piece of 1" steel plate to it. Underneath I put 4 steel caster wheels and 4 leveling feet that can screw up and down. The aformentioned steel weighs several hundred pounds and gives me a good leveling surface to bolt to. The casters allow me the option to roll my lathe around in my shop. The levelers/feet give me the ability to level the whole thing, where I want it. Using the 6" X 2" square wall tubing raised my lathe up so it is eye level and I don't have to bend over to work at the lathe. I have a rubber mat in front of my lathe to keep me off the concrete. I have made simular dollys for my other heavy machinery.
Nat Lambeth
Ian:
How are things in New Zeland?
Reading your post about the concrete. I have a concrete floor. I made a base for my lathe with 6" X 2" square 1/4" wall tubing frame 36" X 96". I then welded a a piece of 1" steel plate to it. Underneath I put 4 steel caster wheels and 4 leveling feet that can screw up and down. The aformentioned steel weighs several hundred pounds and gives me a good leveling surface to bolt to. The casters allow me the option to roll my lathe around in my shop. The levelers/feet give me the ability to level the whole thing, where I want it. Using the 6" X 2" square wall tubing raised my lathe up so it is eye level and I don't have to bend over to work at the lathe. I have a rubber mat in front of my lathe to keep me off the concrete. I have made simular dollys for my other heavy machinery.
Nat Lambeth
C
Chip Soles
Guest
I was told by a machinery dealer that a an Austrian builder of small CNC turning centers, who's name has been lost in my old brain, built their machines on a frame of welded rectangular steel tubing. After the weldment was complete, and any machining and assy. done, the frame was filled with sand to give it a mass close to an iron casting, and less vibration. True???
As Jackie has stated, I don't know why it does it, but I know it does it. It seems to be more a matter of the tool being inverted, as I have used both the normal and inverted tool on both the front and rear of the spindle. With a roller bearing spindle, it is probably not spindle movement. Is it tool flex, chip jamming? The chip forming carbide inserts do not seem to have an issue, which then leaves another area of thought. Can the hss with it's rather neutral back rake, take the higher surface speeds and feed rates that these tools seem to like so well.
Regards,
Bob
As Jackie has stated, I don't know why it does it, but I know it does it. It seems to be more a matter of the tool being inverted, as I have used both the normal and inverted tool on both the front and rear of the spindle. With a roller bearing spindle, it is probably not spindle movement. Is it tool flex, chip jamming? The chip forming carbide inserts do not seem to have an issue, which then leaves another area of thought. Can the hss with it's rather neutral back rake, take the higher surface speeds and feed rates that these tools seem to like so well.
Regards,
Bob
J
Jdh
Guest
This comes from the PM fourm on lathe mounting for war production of small parts.
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Hi, Paula,
Well, I'm very impressed with your exquisite restoration work on the little South Bend...... : )
If I may, I'd like to offer a suggestion about setting it up on a bench, one which may seem a ludicrous amount of work at first hearing, but really is worth the amount of work it takes to do.
First, tho, the background.....in early 1942, our government, and the 'War Production Board' in particular, was in quite a panic, to get volume production of many different sorts of war materiel items on line.
One of the many 'bottlenecks' was the capability for manufacture of small, but very close-tolerance, turned parts. The optical equipment manufacturers, particularly, were over-whelmed with demand for parts which had, historically, been made on Hardinge and Rivett bench lathes, with tight turn dia. tolerances, and fine threads which had to be single-pointed to gage.
One answer to this demand was to 'enlist' the many older small lathes held by thousands of small automotive shops and in private shops, by setting them up for tight-tolerance, high-finish work.
The War Production Board issued a pamphlet describing this procedure, of which I had a copy, years ago (yes, I know, I should have had copies made, foolish me)
Given an unworn small lathe, like the South Bend, the 'secret' to getting it to produce high-quality work lay in providing a suitable 'foundation' for the machine.
The WPB pamphlet had drawings of the base design with they found to be the best system, a 'monolithic' casting of poured concrete.
This involved first making up a plate of suitable size, with drilled or drilled/tapped holes for the lathe's mounting bolts. This plate was, preferably, 1/2" or thicker steel, but could be a suitable piece of hard maple plank, well sealed against moisture with spar varnish.
The concrete base would be cast upside-down, with the lathe base forming the bottom of the pour.
A simple plywood form would be built, with radiused internal corners of sheet metal tacked in, a near-vertical front edge with a bit of a recess for toe-clearance in the centre, and a suitable angle to the back to allow for a wide stance on the floor.
The form would be provided with a suitable pattern of 're-bar' to strengthen or stabilise the base.
Care would be taken to have the board or plate for the lathe level, before the pour, and then the top of the pour, which would be the bottom of the finished base, would be finished level and smooth, creating parallelism with the top.
After the concrete cured, which would take two weeks to a month, owing to the thickness of the concrete, the forms would be stripped, the base turned upright, moved to its intended position, and provided with a three-point mounting of three thick, dense industrial rubber 'biscuits' suitably arranged, the same idea as the three-point mounting of a granite surface plate.
With the lathe firmly bolted down to this very heavy base (with shims as needed to take any twist out of the lathe bed), the great damping mass of the heavy base greatly strengthened the lathe itself, in terms of removing vibration and resonances.
The next step was to re-position the motor and countershaft to isolate it from the lathe. The motor and c'shaft might be mounted on the wall or on a bench or pedestal behind the machine, or mounted on the ceiling, if the ceiling height was low enough, as in a basement.
(back during the war, many basement and garage shops ran three shifts making small parts....often, the housework would be neglected, and meals done 'from a tin', as home-makers spent their days, and evenings was well, making parts for the war effort.......an older gentleman I knew, years ago, had a job for awhile as a driver for a manufacturing firm, in which he 'made the rounds' of quite a number of basement/garage shops, picking up parts, and leaving dwgs/material for more parts)
Anyway....if you can see your way clearly to investing the time and work involved in setting your South Bend up per the 1942 WPB specs, you will be well and truly impressed with the way in which it will do close-tolerance, high-finish work, much more easily than if it were set up on the common sort of bench which won't inhibit resonances in the same way that heavy base will do.
I've been shown a few of these machines which were set up with heavy bases this way, and have operated a couple of them myself, one, in particular, which impressed me, was an early '30's 13" South Bend, probably one of the last of the 13" South Bends to be built as a 'bench lathe'.
That one had been re-fitted and scraped-in during the war sometime, and was competitive with an EE Monarch or HLVH Hardinge for quality of work.....with certain limitations, such as lead-screw lead accuracy, to be sure.
The plain-bearing spindle of a South Bend, set up correctly, is every bit as good for roundness and workpiece finish as is the EE or a Hardinge.
(the lead accuracy of an unworn South Bend leadscrew is plenty good enough for the generality of the short thread lengths common in optical work)
In practise, its owner made good money on it, making up lots of small parts which would have otherwise been run on a far more costly machine....it was a truly excellent example of practical cost-effectiveness.
cheers
Carla
--------------------------------------------------------------------------------
Hi, Paula,
Well, I'm very impressed with your exquisite restoration work on the little South Bend...... : )
If I may, I'd like to offer a suggestion about setting it up on a bench, one which may seem a ludicrous amount of work at first hearing, but really is worth the amount of work it takes to do.
First, tho, the background.....in early 1942, our government, and the 'War Production Board' in particular, was in quite a panic, to get volume production of many different sorts of war materiel items on line.
One of the many 'bottlenecks' was the capability for manufacture of small, but very close-tolerance, turned parts. The optical equipment manufacturers, particularly, were over-whelmed with demand for parts which had, historically, been made on Hardinge and Rivett bench lathes, with tight turn dia. tolerances, and fine threads which had to be single-pointed to gage.
One answer to this demand was to 'enlist' the many older small lathes held by thousands of small automotive shops and in private shops, by setting them up for tight-tolerance, high-finish work.
The War Production Board issued a pamphlet describing this procedure, of which I had a copy, years ago (yes, I know, I should have had copies made, foolish me)
Given an unworn small lathe, like the South Bend, the 'secret' to getting it to produce high-quality work lay in providing a suitable 'foundation' for the machine.
The WPB pamphlet had drawings of the base design with they found to be the best system, a 'monolithic' casting of poured concrete.
This involved first making up a plate of suitable size, with drilled or drilled/tapped holes for the lathe's mounting bolts. This plate was, preferably, 1/2" or thicker steel, but could be a suitable piece of hard maple plank, well sealed against moisture with spar varnish.
The concrete base would be cast upside-down, with the lathe base forming the bottom of the pour.
A simple plywood form would be built, with radiused internal corners of sheet metal tacked in, a near-vertical front edge with a bit of a recess for toe-clearance in the centre, and a suitable angle to the back to allow for a wide stance on the floor.
The form would be provided with a suitable pattern of 're-bar' to strengthen or stabilise the base.
Care would be taken to have the board or plate for the lathe level, before the pour, and then the top of the pour, which would be the bottom of the finished base, would be finished level and smooth, creating parallelism with the top.
After the concrete cured, which would take two weeks to a month, owing to the thickness of the concrete, the forms would be stripped, the base turned upright, moved to its intended position, and provided with a three-point mounting of three thick, dense industrial rubber 'biscuits' suitably arranged, the same idea as the three-point mounting of a granite surface plate.
With the lathe firmly bolted down to this very heavy base (with shims as needed to take any twist out of the lathe bed), the great damping mass of the heavy base greatly strengthened the lathe itself, in terms of removing vibration and resonances.
The next step was to re-position the motor and countershaft to isolate it from the lathe. The motor and c'shaft might be mounted on the wall or on a bench or pedestal behind the machine, or mounted on the ceiling, if the ceiling height was low enough, as in a basement.
(back during the war, many basement and garage shops ran three shifts making small parts....often, the housework would be neglected, and meals done 'from a tin', as home-makers spent their days, and evenings was well, making parts for the war effort.......an older gentleman I knew, years ago, had a job for awhile as a driver for a manufacturing firm, in which he 'made the rounds' of quite a number of basement/garage shops, picking up parts, and leaving dwgs/material for more parts)
Anyway....if you can see your way clearly to investing the time and work involved in setting your South Bend up per the 1942 WPB specs, you will be well and truly impressed with the way in which it will do close-tolerance, high-finish work, much more easily than if it were set up on the common sort of bench which won't inhibit resonances in the same way that heavy base will do.
I've been shown a few of these machines which were set up with heavy bases this way, and have operated a couple of them myself, one, in particular, which impressed me, was an early '30's 13" South Bend, probably one of the last of the 13" South Bends to be built as a 'bench lathe'.
That one had been re-fitted and scraped-in during the war sometime, and was competitive with an EE Monarch or HLVH Hardinge for quality of work.....with certain limitations, such as lead-screw lead accuracy, to be sure.
The plain-bearing spindle of a South Bend, set up correctly, is every bit as good for roundness and workpiece finish as is the EE or a Hardinge.
(the lead accuracy of an unworn South Bend leadscrew is plenty good enough for the generality of the short thread lengths common in optical work)
In practise, its owner made good money on it, making up lots of small parts which would have otherwise been run on a far more costly machine....it was a truly excellent example of practical cost-effectiveness.
cheers
Carla
Hi Nat,
Things are good, just came back from Aussie after going over for the Australia day shoot last weekend.......had fun.
Cheers
Ian
N
ncnbrsa
Guest
When ever I'm doing any work on my lathe I lock all parts of the carriage that I won't be using. This may also help.
Ron
Ron
M.D.Spencer
New member
My Southbend 16" I use Carbide inserts(2000 lbs machine is the big bother to the Heavy 10"). I can part almost anything off. What I learned with my Rockwell 10"(825lbs machine) is turning the HSS parting tool up side down and running in reverse. Made all the difference. Feed everything by hand. No power feeding. Speeds all depend on material. Experience is everything.
W
Woodhunter
Guest
As it has been said in the previous posts, I just use properly ground tooling, a stout setup, decent spindle speed and a quality cutting oil. Piece of cake, easy as pie.
However, most of the time I just fire up the big Wells, set auto downfeed, hit the go button and walk away:
However, most of the time I just fire up the big Wells, set auto downfeed, hit the go button and walk away:
Last edited by a moderator:
"Experience is everything."
That really does sum it up! This machining business is just like anything else. They guys that a really really good at it have been doing it for a while and they absorb all the little details they learned along the way. Nothing compares to experience and hands on working. I finished my first rifle barrel chamber job this morning. The hole project took me about 5hr. This time next year and a few barrel lather i might be able to do it in 4hr. LOL!! No everything went really smooth. i took my time and thought about every move i made. heck the barrel even shoots well!
Dad repaired one of the Kennametal parting tools i broke. Im not real sure how he did it, but he did and it works great. He asked me not ti use it until we could get together and he can show me a couple little tricks to setting it up. Our work schedules are very different so i dont know when that will happen. In the mean time i ground a HSS blade type parting tool and it seems to do the trick. Lee
That really does sum it up! This machining business is just like anything else. They guys that a really really good at it have been doing it for a while and they absorb all the little details they learned along the way. Nothing compares to experience and hands on working. I finished my first rifle barrel chamber job this morning. The hole project took me about 5hr. This time next year and a few barrel lather i might be able to do it in 4hr. LOL!! No everything went really smooth. i took my time and thought about every move i made. heck the barrel even shoots well!
Dad repaired one of the Kennametal parting tools i broke. Im not real sure how he did it, but he did and it works great. He asked me not ti use it until we could get together and he can show me a couple little tricks to setting it up. Our work schedules are very different so i dont know when that will happen. In the mean time i ground a HSS blade type parting tool and it seems to do the trick. Lee