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...Why Marlin has to Practice such Precision, as he was Trained too.
The 4 Bearings in the first Photo, were 'cut' from a Phosphor Bronze Bar, 5 Feet Long and 10.125" in Diameter, weighing in at over 1000Lbs. Each Bar costs $12,000.00
The Blanks are sawed on a Massive Horizontal Bandsaw, and it Takes 2-3 Hours to finish cutting through, One. Being the Bronze is of a Bearing Material.
The Four Bearings were for a High Speed Gearbox we custom Built for Honda Automotive, to 'Run-In' their Racing Engines. The Shaft in the pic was for a Different Gearbox. The Gearbox for Honda, ran so Smooth, Vibrationless, that one had to Touch their Hand on it, to it, to tell it was Running. The Huge Gears, once the Teeth were 'Cut', were sent up to a Specialty Shop in Seatle WA, to be Balanced. Honda ordered a 2nd Gearbox.
What You see in the Photo is the Result of Three Days of Marlins' Machining.
The 10.125" Diameters were Machined down to 8.5030" the Bores were to 4.0030" All Measurements are Plus or Minus 0.0005".
The Only Tools used Were a Bore Gauge, Boring Bar, Length Gages, Dial Indicator, Dial Caliper and a 6" and 8" Micrometer.
All 4 Bearings are Exact 'Mirror' Images of the Other 3, to with-in 0.0005", Period.
If Marlin were to 'Cut' 'Smaller' on any of the Measurements, by as Little as 0.0010" The Bearing becomes 'Unacceptable', and is Useless! The Part would be Scrapped and Marlin would Lose His Job...On The Spot!! There were No Errors. Just One of the many 'Projects' in the 9 Years Marlin worked for LFW Machining.
The Following Photos are 2 of the 3 Bearings ordered by Tammy, in Florida.
It is impossible for Marlin to 'Drop' the Level of Discipline, learned in 40 some years, in Practice.
...6 More. And I DO use a Micrometer (Should be Known as a 'MICRO-Inch). And I use a Dial Caliper...to check Both. Calibrated to a 1.0000" Gauge Block, the Micrometer reads 0.0010" OVER the 1.3800" O.D.
I No Longer use a 17mm Reamer to obtain 0.67150" (After Sanding and Polishing with Emery Cloth). The reamer will only cut to 0.6700" NOT Large enough for the Shaft that is AT 0.6700", since Two Objects cannot Occupy the Same Space at the same time.
I used a 'Single-Point' Boring Bar to cut the I.D. to fit the Gage (see Pic). This is The MOST Accurate operation to Bore, as the Tip Is NOT Influenced by Multiple Cutting Edges! The Gage is a 0.67001" to Match the ZF Shaft. The Tool is fed (out) to Cut to the Desired 0.67150" On the Dial Every .001" OUT, is Doubled as is the Design of the Lathe, and Cuts .002", Theoretically! There are always, many Surprises! The Bronze Wears the Tool Cutting Edge, Fast! And Then...'Tool Push". The Work and Tooling, gets Hot and Cools, in Cycles.
Enjoy the Photos Tammy and All.
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...The 'Cross-Slide' Or 'Top Slide', is set at 30 Degrees, to Cut the Chamfer that Matches Up with the 30 Degrees, on the Tip of the ZF Shaft SNOUT. In the Pictures you can see the thin Yellow Oil coming out of the Sintered Bronze Pores, once they are cut open.
Why don't you do a video so your customers can watch you make their bearing?
Very good idea, the comparator on the turret to measure the progress of the tool very exactly, I had never thought of it.
I only knew the method which consists of orienting the Cross-Slide by 5.7° (tangent = 0.1) and advancing it 10 times the desired depth.
This is the difference between a professional machinist and an amateur.
The Top Slide has a Engraved Protractor!
...For Years on the Job, I have often said "The DIAL Indicator Does NOT Lie!!"
On any Machine that is used and 'Warn-In', The Micrometer Dials on the 'Handles' are Useless, for Back-Lash, Only ONE Direction must Be 'Loaded', and used.* This is where I discovered...there are 3 'Zeros', Zero from the Minus, Zero from the Plus, then In-Be-Tween those Two Points, we have the 'Dead-Nuts' ZERO!
The Indicator Dial WILL Be inaccurate, Itself, When the 'Work' Gets HOT and is Machined, then cools down Later! And, Also, Not accounting for 'Tool Push', and tool wear! Very Small Measurements MUST be 'Snuck-Up' Upon! Most of the Time, I come to within 0.001", and Then Polish to Exact Size, where ANY 'Going-Over' (Undersized) Will Ruin the Part.
We must always Know that Every Amount of Movement on that Dial, is Doubled as the Lathe Machines it Off.
* When I first Started for the Company...I worked to 0.001", on a Lathe with a Backlash of 0.019" "The Dial Doesn't LIE!!", to Those Who are Experienced and Know How to Use It!
Re-Posting This:
PANTERA - GT40. Oilite Bronze Pilot Bearing Installation Instructions. 351C to ZF-2
First: Clean the Snout of the Transaxle Input Shaft, and Test-Fit this Bearing onto the Transaxle Shaft. If the shaft is Free of Damage, burrs, dirt...the bearing will slide-on, Smoothly and with Precision. If the Finish on the Steel Shaft is Not 'Smooth to the touch', Polish It with 'Crocus Cloth' ONLY! Polishing Cloth, The Finest Grit You can obtain.
Next: Clean the Crankshaft Bearing POCKET, of all dirt rust Debris, OIL, BUT Do NOT make it Larger!
The Bearing must be Hammered Straight in Square, and DRY. Use NO Lubrication! Using a hand held 'Sledge' hammer, Heavy!, NOT a Carpenters Hammer (too light). AND Using a block/piece of hardwood, IN BETWEEN the bearing and hammering...start the Bearing in Straight and True, There is a 6 degree Chamfer to help in Alignment. If it starts Crooked, STOP!! and pull it out and start again. Using the Wood on the Face of the Bearing...Hammer the Bearing Straight-In UNTIL Fully Seated, You'll feel IT and STOP! The Bearing will Protrude Aprox.1/4", It will NOT be Flush with the Crankshaft Flange.
Do NOT Hammer directly on the Face of this bearing. (You May see a 'Sliver' of bronze peel-off, this is to be Expected, as there is a .0050" 'Interference Fit'. .0025" Per side, This is Necessary to keep the Bearing In Place during Hard Shifting. Bronze is Very 'Slick'!) If You Hammer Directly Onto the Face, You will Destroy any Chance of the Transaxle Shaft Sliding-In!!!. That's a Warning!! Here's Another and Be advised, if the Crankshaft IS Installed in the Engine...You are Also Hammering on the 3RD Main Thrust Bearing!!! GO EASY. It will Not Take a Lot of Force. Just before Bolting up the Trans, Smear 3 Drops of light oil onto the 'Transaxle Input Shaft Snout', At the bearing contact area. This is so the bearing does not start 'Dry'. Although...as Oilite wears/gets warm, a Thin Oil Oozes-Out of the Pores. DO NOT Carry it in your pants pocket, it will leave a Stain. Congratulations!! You have just 'Custom' Fitted a Bronze Bearing to Your 351 Cleveland Crankshaft!
There is a Specially Machined 'Inside-Chamfer' at the Lip of the Bearing. This Specific Angle Mates-Up with the Angle On the Snout of the Input Shaft. What It Does, It Kicks the Shaft Up Into Perfect Alignment. Just Slide the Transaxle Into Position, NO Surprises!!
MJ 2019
...There are 2 Different, Very Simple Tricks, to Adjusting the Top Slide to Accurate Angles, to Duplicate, or make up, Tapers. They are Fast and don't involve Trigonometry or the use of a 'Taper Attachment'. I don't have a Problem with Trig.
What I find Exciting is Dividing 360 Degrees of a 4 Foot Rotary Tabel, of a Vertical 'Slotter', to Cut 26 Internal Splines in a 5" or 6"?? Diameter*. Comes down to Multiple Movements in Degrees, Minutes and Seconds. An Even Number makes it easier than if it were Odd. Because we can start with 2 at 180 Degrees to 'Set' the Depth of Cut, Before Proceeding with the remaining 24. I think I have it...360 Degrees Divided by 26, comes out to Each Movement, (13 Degrees, 50 Minutes and 45.6 Seconds!)
26 Rotary Adjustments in One Direction Only, CW. Set up with Dial Indicators, to keep the Table Centered X and y, and feed the Depth of Cut on the +X, Directly to the Front of the Slot-Cutter. The Degrees were read around the circumference of the 4 Foot Rotary Table, with the Minutes and Seconds read on the Tables' Rotating Crank, Micrometer Dial. Then, every completed movement is Locked before cutting.
I came up with the Divisions in 13.0 Degrees, 50.0 Minutes, and 45.6 Seconds, in 26 Splines. I do remember, I had to draw a spreadsheet 'MAP', to Check-Off Each point I was Leaving, to move to the next point to cut. Or I would be Lost!! To fix it, I would have to Crank ALL the way around CW find ZERO, and count Off, Again. NO REVERSING!!
A Lot of room for Messing up...I Nailed It!
* This Splined Sleeve was for a Rack Storage Mount, for the Propeller to a P-51 Mustang. Leo, My boss, would help His friends who Raced a P-51 at the Reno Air Races.
I cut the Blanks for 2 Mating Gears, Gil cut the Teeth. Leo, a 'Gear Engineering' Genius, designed the Modification of the Gear-Drive for the Super-Charger of a Racing P-51 Mustang...To Run at a 1.1% Overdrive.
It was a Great Success, The Custom Set-Up Worked!! I don't remember what Year, the Race in Reno, was. But the Mustang Crossed the Finish Line and WON First Place!!...As the Engine BLEW-UP!! All true, Believe It!
MJ
...For My first customer in a Few Years. Here's Your Bearings Tammy, Hot off the Lathe, finished them, and shipped out today!!
Thank You!
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...Next Up, FROGMIKE gets his Bearing 'Cut' Tomorrow, Friday.
Received your payment, Thank You.
@marlinjack posted:The Top Slide has a Engraved Protractor!
...For Years on the Job, I have often said "The DIAL Does NOT Lie!!"
On any Machine that is used and 'Warn-In', The Micrometer Dials on the 'Handles' are Useless, for Back-Lash, Only ONE Direction must Be 'Loaded', and used.* This is where I discovered...there are 3 'Zeros', Zero from the Minus, Zero from the Plus, then In-Be-Tween those Two Points, we have the 'Dead-Nuts' ZERO!
The Indicator Dial WILL Be inaccurate, Itself, When the 'Work' Gets HOT and is Machined, then cools down Later! And, Also, Not accounting for 'Tool Push', and tool wear! Very Small Measurements MUST be 'Snuck-Up' Upon! Most of the Time, I come to within 0.001", and Then Polish to Exact Size, where ANY 'Going-Over' (Undersized) Will Ruin the Part.
We must always Know that Every Amount of Movement on that Dial, is Doubled as the Lathe Machines it Off.
* When I first Started for the Company...I worked to 0.001", on a Lathe with a Backlash of 0.019" "The Dial Doesn't LIE!!", to Those Who Know How to Use It!
MJ 2019
“Catch up on the clearance” is the first thing our first machining teacher taught us, that and safety! WOE to the one who left the key lying on his chuck, he thought that lightning was falling on him because the teacher was shouting so loudly.
I have to say that it was 1967 and the lathes we were learning on dated well before the Second World War, with still flat leather belts and stepped cones...... but we still managed to make adjustments H7g6.
...Yes, I started learning on South Bend Lathes, back in 1963 when I was 12 Years Old. 'Turning a Shaft True Between Centers' using a 'lathe Dog'. Can be flipped end for end and remain true.
The teacher, R. Coleman, was adamant about the Belts being Loosened at the end of every class. If you didn't have safety googles on, don't come in the shop.
Never ask 'WHY', if so, he would hit the top of your head with his fist.
He was a Instructor for Navy Machinists during world war II...would tell me, at the end of classes he would have to go down a row of 150 Lathes and 'Lever Up' Each one to Loosen the Belts.
In most recent years...a Navy Machinist, who I worked with, told Me, "If You ever Left the Chuck Key in the Lathe Chuck, You would be Punished, By having to Wear it Around Your NECK for a Week!!"
Upon graduation in 1966, I was Awarded the Trophy for Best Student in 'Metal Shop'. We Learned most all phases.
Yes, it was a different time, teachers had the right to yell at and punish students. When 30 years later one of my sons did the same studies as me, the teachers no longer had much right to punish the students and the students almost no longer had the right to touch the machines, it was the teachers who fixed the parts, adjusted the tools, selected the speeds, etc... and the students had the right to press the "on" button, all in the name of safety..... I gave him a little learned on my lathe but nothing to do with what I had learned in high school and then later in my engineering school.
Sad.. so sad….
and all the rules are done to protect the Weakest link…. Even Darwin had to retire…