Robert Hermann Pfauter (RHP) invented the method of hobbing helical gears by adding a differential mechanism to the drivetrain of his machine. "The Secret" is the slight retarding and advancement of the workpiece by the differential
Pfauter made the hob head rotate on the vertical column of his machine for the helix angle – in concert with the differential – the hobber produces helical gears. With the formulas and setup schematics in the owners/operators manual the machine can cut right-hand and left-hand helical gears.
These advancements added to his hobbing machine's capabilities to make spur gears, sprockets, spline shafts, ratchets and worm gears making a differential equipped Pfauter a very Universal Machine Tool.
Timestamps:
0:00 Types of Gears
1:24 Gears and History
2:45 Pfauter
3:52 Modern Pfauter
5:57 Machine Setup
9:05 Pfauter Logo
10:36 Differential
12:09 Scallop Surface Finish
13:14 Wrap-up
Helical Gear Manufacturing Characteristics:
RHP's first German patent was in 1897, and his US patent in 1900. Advancements in CNC hobbing equipment came late compared to mills and lathes. In the early 1970's some of the drivetrain components were simplified with electric motors and rotary encoders. So any machine you buy prior to this date will be all mechanical.
There were many hobbing machine manufacturers making machines prior to 1970 and surprisingly there is a very active market for these machines. Some brands of interest: Pfauter (obviously), Mikron (for instrument gears), Barber-Coleman (American company, still being serviced by Bourn & Koch), Gleason (for bevel gearing), LIEBHERR, Gould & Eberhardt, and Fellows (for gear shaping)
If you have a mill, get a lathe. If you have a lathe, get a mill. If you have both, get a hobber!
The Pfauter (code name Jersey) used in this video is a RS00 Model, made in about 1950. Refurbished with all new bearings & seals. Nothing special, easy to source and commonly available. We spec'd bearings by Timken. Gear Oil Pump-resurfaced, bench checked and reinstalled. New stud post (scissor) for the differential gear cluster, new quadrant studs and hardware. Rebuilt operator panel to allow for more & modern pushbuttons. All new PLC and VFD's drive the machine, just a few dozen lines of ladder logic make it function safely
References:
Gears From The Greeks - Derek de Solla Price
Interesting Gear schematics can be found in Tony Freeth's 2012 research paper
Pfauter - Hobbing, The engineer’s pocket book for Hobbing with Pfauter's Hob Cutter Catalog Julius Springer Approximately 1930 (In German If anyone knows the exact date please let me know) Pfauter - Hobbing, Volume 1, Springer-Verlag, 1976 (In German)
Jesse Ramsden (1735-1800) Science, Technology and Culture, 1700-1945
Sir Joseph Whitworth, "A Pioneer of Mechanical Engineering"
Woodbury, Robert S, "History of the Gear-Cutting Machine"
Video Credits:
The CT and PTM data that the AMRP have made publicly available can be found here
Gleason Corp - Pfauter Training Video - Encyclopedia/GE-EN Dictionary
Chris Maj - Helical Gearbox clip
Pfauter US Patent (1900)
NASA Reference Guide on Gearing
The history of gears is surprisingly interesting - the process of milling and hobbing gears plus the transmission of torque and movement all find a place here. We will open the "Secret Gear Case" to YT as well through this channel - a personal mission
]]>
Removing oil from your machine is easier than ever with correct methods and tools. Our Tsugami hydraulic oil sump has an unknown size and the drain plug is very low on the machine. So we remove it safely with a vacuum pump and take it to RECYCLE
Timestamps:
0:00 Tools
2:36 Starting to drain
4:11 Inspecting the oil
5:32 Finding a leak
7:55 Breaking the vaccuum
8:53 Finishing draining
Notes: 6.5L = 1.71 Gallons
We removed 9 gallons from the machine which is much more than we expected.
Tools used in this video:
We restore this beautiful Tsugami cylindrical grinder from 1952 back into working order. There can be many hurdles in a project like this and we will show you the tools, techniques to keep the project moving so you do not get stuck. Machines have been around a long time.
The Tsugami "Design Philosophy" will make you want one of your own. Rigidity was key and built into every component on the machine, mostly through the massive cast iron casting. The machine weighs over 6000 pounds and we hope to make it function, and not just as a boat anchor.
Usually older machines have some weakness or problem requiring attention. Tools, information, materials, and tech are easier and more available than ever to put a good old machine back in service. Breaking the machine systems down into parts helps.
Mechanical
It is a machine so this is important to get right so it will perform as you expect and deliver the result you require. Because of the design philosophy of Tsugami and our assessment of the machine, we think this machine can deliver tolerance and reliability. It also looks like it can be used for more than my lifetime making it a "Generational Machine". The basic building blocks of machinery can be found in this awesome book.
Electrical
Often the electrical systems in machines fails far in advance of the mechanical system. This has sent us to the drawing board(Other YouTube Vids) and calling electricians frequently. But there are better and safer systems than ever if the original system is not functional.
Hydraulic
The Tsugami has a hydraulic system to actuate the table for the primary grinding operation. Sometimes sampling and analysis can help assess the equipment condition to set interval oil changes or understand problems. Hydraulic oils should be selected in the correct viscosity range for your machine. This site has some good information to help you make informed decisions about your oil along with some general pricing. Tech article on Hydraulic oils.
Pneumatic
Or also more practically "air" systems exist to clean chips or spray coolant, but they are an aftermarket add-on. For our Tsugami, there is a Pneumatic ID grinder that will take some care and work to perform properly. We may also add a Kool-Mist system that requires air.
Lubrication System
Hydraulic oil, Way oil, Spindle Oil, and Grease all play a key roll in making the machine operate properly and last a very long time. This one is especially important to modernize for older machinery where Zerks have failed, passageways are plugged etc. Also get those sight glasses cleared up, replace your gaskets and fix you piping so the machine will not leak. RECYCYLE when you change the fluids.
Coolant System
When you modernize this is one of the first trick upgrades to improve cutting, no matter the type of machine. Sump pumps, circulating systems, chip control, filtration, managing tramp oil etch.
Metrology
Those knobs may have marks every 0.001 or 0.005 inches or mm. But what about adding a digital readout with some common memory storage and machine location information. Take your shop from being able to create parts within 0.010 inches to 0.001 inches or maybe even 0.0001 inches with this fairly easy add-on.
Lighting
The better you can see the part and machine the better you can perform your duties. If the machine did not come with lighting, there are a multitude of options here.
Tech Articles http://bit.ly/2LjzCCB http://bit.ly/3onfQon
]]>Today we're rebuilding an "old-style" size 14N Jacobs Super Chuck, our favorite for its balance between overall size and capacity. All the Super Chucks end in "N" and range in size from 8-1/2N to 20N, and have a similar rebuild procedure.
As we break it down to individual parts, clean, and reassemble it, we share a special appreciation for Arthur Jacobs' timeless classic. Super Chucks feature a clever internal mechanism (almost unchanged from its original 1902 patent) that will keep them running for years. But when the time comes they're also easy to repair and rebuild — making them a workhorse in many machine shops and woodworking shops.
Whether you put it on your mill, lathe, drill press, or any other tool, you're bound to find a Jacobs Chuck wherever high-quality and durable tools are required!
Keep your chuck working after the rebuild, use the right Service Ring
]]>We used our Ellis Dividing Head to make a new clock for the shop! There are easier ways to do this project, but given a simple dividing instrument, a drill press and some manual tools, you can achieve the same results. Check out our article with free charts
Astronomy, Math, Science and Engineering are all related and have been carried through history by watch and clockmakers. Gears and mechanisms have been here and astonishingly long time. The Antikythera Mechanism is a great testament to this.
More Tech, History and Mechanical Articles
Some of the tools we used, where to find them so you can build your own:
]]>A prime example of toolholding from the early 1900s, the Jacobs Super Chuck is a staple in machine shops around the world. Used in machines from drill presses to lathes, the Super Chuck features robust tool-holding and durability in an easily accessible package. Our collection features six chucks, an original repair kit, and an antique shipping crate.
While the same design is still made and sold today, with some care an original will last for generations. Watch future vids to see how to rebuild them. Get that feel of a new chuck that Arthur designed over 100 years ago.
To purchase Jacobs Super Chuck Press Rings: http://bit.ly/35fiXHl
Kit Contents
The Kit has a mixture of parts for super chucks and parts for other popular chucks. Sticking with the super chucks here is table regarding the reamers
The rings are not complete for the Superchucks, only the 20N, 18N, 16N, 8-1/2N. rings were in the original kit. We are still decoding the others and checking other common chucks to see what fits. So there will probably be another set of rings for the "Non-Super Chucks" in the future.
From our basic research here are the Ball Bearings for each chuck. The race needs to be as full as possible to evenly distribute the load. The quantities for each chuck vary from 29 for the 8-1/2 to 36 for the 20N.
Tight Tolerance ($$$) | Probably These ($) | ||
Chuck | Ball Bearing Diameter | McMaster Number | McMaster Number |
8 1/2N | 1/8" | 9528K45 | 9528K11 |
11N | 5/32" | 9528K47 | 9528K12 |
14N | 3/16" | 9528K48 | 9528K13 |
16N | 3/16" | 9528K48 | 9528K13 |
18N | 7/32" | 9528K49 | 9528K14 |
20N | 1/4" | 9528K53 | 9528K15 |
Chuck | Key Number | JT Arbor # | JT Arbor Dia (in) | Force (using 7000# grease) |
8 1/2N | 30 | 2 | 0.559 | 1300 (no room for zerk) |
11N | 32 | 2 | 0.559 | 1300 |
14N | 3 | 3 | 0.811 | 3000 |
16N | 4 | 3 | 0.811 | 3000 |
18N | 4 | 4 | 1.124 | 5900 |
20N | 5 | 5 | 1.413 | 9500 |
]]>
Precisely dividing a circle into multiple segments can be a challenge for the manual machine shop. The Ellis Dividing Head makes quick work of it. All dividing heads with a 40:1 ratio use the same chart found here
Practical
The dividing head adds many new capabilities to a machine tool like a Bridgeport Mill, or even a drill press if it has a sufficiently large table. With some math and creative setups, the complexity of parts you can make with your conventional mill is significantly expanded.
History
Jesse Ramsden built one of the first high quality dividing engines in the 1700s to accurately divide circles for marking instruments. We walk through the Ellis Dividing Head, how to use it, and as we cut an external spur gear.
See our blogposts on the Ellis Dividing head and many other Mechanical, Historical and How-To topics here. BTW Free downloadable charts are included
USED on eBay or at your local used machine tool dealer, search phrases for eBay
USED There are many manufacturers for these devices, expect high quality from some of the finest American Machine Tool Makers:
The world of gears is a very special place that I am learning about. The history, the process of hobbing and the transmission of torque and movement all find a place here. I started from scratch with a non-functional hobbing machine, no instructions and a lot to learn. With the help of others I can now hob gears. We will open this door to YT as well through this channel - a personal mission. https://www.instagram.com/villagehobber/
]]>