Colchester Chipmaster Bed Grind

After devising a design on how a portable bed grinder should work, and coming up with the theoretical tolerances a home build solution would yield, it became apparent, this is a perhaps a bit ambitious. And if I want to restore the lathe to better than "factory" specification, this might be the risky route.

The Machine tool re-seller, from whom I bought my Eagle Surface grinder, named a very reputable company they use for rebuilding. I contacted the owner and after some negotiating, he agreed to regrind the bed only, although they specialize in complete rebuilds. Henning a very knowledgeable gentleman with a wealth of experience in machine tool rebuilding from Atlantic Enterprises situated in Johannesburg, assisted me in regrinding the bed on their Churchill lathe bed grinders.

When inspecting, it immersed that the two v-ways where aligned, but the flat ways were not in alignment, most likely a factory defect, which probably is not a big issue if the tail stock and head stock are custom fit to the machine. 

This misalignment gives me indication, the head stock is custom fit. So now my next problem how to measure the error of the head stock on the surface plate. Here I will have to come up with an accurate technique to establish the spindle center height front and back. the problem is the spindle surface is not freshly ground.

HP65 Vintage Calculator - First programmable in space

Recently I found this gem on local classifieds, it was advertised as dead, but in excellent condition :)
After I got it i recharged the batteries and she still worked!

Next I need to make a power supply for it and some PAC programmable magnetic cards.

Great site with emulator and some technical details. http://www.teenix.org/

 

Deckel FP2 Horizontal Spindle 1967

Three manuals three stories. I am writing this post to help me make sense of the the information I have at hand, and after reading up on practical machinist forums. There are various tidbits floating around but nothing concise. 

The German manual I have, resembling an old book depicts a spindle very similar in design and layout as seen in the English manual version from 1974. The 1974 manual describes a machine with single wheel speed and feed dials, and external motor. Where the other two manuals describe the two wheel machines with internal motors. However the older English Manual title page has the distinct 70's look seen on other NC Machines, and the font used looks modern compared to the German version. This makes me believe the German version describes the 60's models, the English version describes the early 70's models and the second English version describes later 70's models?

The main differences I can spot are what looks like a second set of needle roller bearings closer behind the first set on the older versions. The English 2 Wheel Manual with 70's font, actually describes these as "loosen 6 tighten 7 to adjust the front roller bearing" further the roller bearing clearance should be a maximum of  .0004"/.01mm. The clearance of the rear roller bearing, is determined by the dimensions of ring 9..." So in this version the needle bearings can be adjusted, implying them to run on tapered sections, which correlates with some information on practical machinist forums. The older German manual does not make reference to this, but the features exist on the drawing. What makes it more confusing is that 6,7 are referring to adjustment rings in the other two manuals, used for adjusting axial clearance on the spindle.

Now the question, what spindle does my FP2 have? The spindle, quill and head bear the engraving 137/137 A with -1.0, which was later 'erased'. This makes me think the parts where custom fit for each machine. With initial test results engraved on the parts, for easier fitting to final machines.

Are some spindles adjustable radially? or is this an error in the manual, introduced by translation/ draftsman in the middle?

Bearing grease to use original KLUBER ISOFLEX SUPER TEL or Franz Singer recommends LDS18

 

If you have more information on the spindle serial numbers, or spindle versions, please leave a comment.

Fig 1. German Manual ( 2Wheel Speed Feed/Internal motor)

Fig 2.  English Manual ( 2Wheel Speed Feed/Internal motor)

 Fig 3. English Manual ( 1 Wheel Speed Feed, External motor)

The entire machine is marked with what looks like a smiley with long eyes  =) anybody know what this symbol represents?

-1.0 Engraved on side of slot, not sure what this means since it was erased afterwards

137 on Spindle shaft, etch process

 A 137 and the erase -1.0 on the spindle quill

Deckel FP2 Serial Numbers

My Serial number and machine marking research summary.

6252 FP2 (2200 type)
2382 FP2E (2205 type)
4491 FP2 (2202 type)
1768 FP2 (probably the 2 motor type)
14893 TOTAL FP2 variants built from 1953 to 1982

FP2 Mill Model Designation:
1953, serial number 45000 (first machine)
1953, serial number 45012
1954, serial number 45141
1955, serial number 45340
1956, serial number 45598
1957, serial number 45958
1958, serial number 45660
1959, serial number 46639
1960, serial number 46640
In January 1960, a new numbering scheme started with 2200/1644
1960, serial number 2200/1892
1961, serial number 2200/2183
1962, serial number 2200/2534
1963, serial number 2200/2995
1964, serial number 2200/3581
1965, serial number 2200/4299
1966, serial number 2200/5149
1967, serial number 2200/5256
last machine produced in the series

FP2E Mill Model Designation:
1958, serial number 46326 (first machine)
1959, serial number 46418 (nur dleso Masch.)
1960, serial numbers 48500 to 48542
In 1960, a new numbering system started with 2205/0046 (ohne Spindelboch)
1960, serial number 2205/0111
1961, serial number 2205/0172
1962, serial number 2205/0196
1963, serial number 2205/0212
Fertigung im April ausgelaufen


FP2-2202 Mill Model Designation:
1967, serial numbers 5301 to 5580
1968, serial number 5925
1969, serial number 6338
1970, serial number 6800
1971, serial number 7399
1972, serial number 7955
1973, serial number 8527
1974, serial number 8993
1975, serial number 9235
1976, serial number 9542
last machine, S/N 9792

1977, serial number 10001
Einhatssupport ab 1954
9196 - 9200
9142 - 9161

Stufe I ab 10001

Ausfrus??? fur X-Mo?stab ab 9150 - 9792
v. Shulf I - 10001 ... 2202

1980, serial number 11009
1981, serial numbers 11010 to 11434
1982, serial number 11769

Die Masch. -Serien-Nr. ist auf dem Firmenschild - am StänderfuB in
Hohe der oelablassschraube vom Vorschubgetribe u. am Staender oben -
sichtbar wenn der Spindelbock in ruckwartiger Stellung - eingeschlagen.

Lever operated collet chuck for Schaublin B32 collets on the Chipmaster Lathe

Usually when starting with a project I realise what I need in order to complete the project, and often get stuck on some prerequisite to get to the actual project. a tool to make a tool, to make a tool..

This project is no different, I will need an ID and OD grinder, should I want to preserve some of the Schublin collets accuracy. Here I can convert my Eagle Surface Grinder to hold ID and OD spindles perpendicular to the existing spindle axis. Well I need to rebuild it first. Or build a tool post grinder for the Chinese lathe.

Scouring the internet in search of ideas of how to construct such a beast, I came across some similar but different ways to implement the lever closer.

Originally I wanted to base my design on this drawing out of  the book "Taschenbuch für den Maschinenbau" by Dubbel. A plate clutch mechanism similar to the one used in the Matrix clutch on the Chipmaster lathe. 

Below two designs from South Bend Lathe co. The first drawing uses balls for the wedging action. The later heavy 10 model uses a more "common" lever arm action.

 

 

http://cdn0.grizzly.com/manuals/g4026_m.pdf

http://sherline.com/Wordpress/wp-content/uploads/2015/09/1150inst.pdf 

Design elements to consider

• physical dimension (constrained by lathe spindle bore and collets) 
• materials
• clamping force
• balance
• safety
• easy to maintain, quick to install, usability, ease of use, attention to detail

The spindle bore on the Chipmaster is 35mm, the minimum OD for the pull bar is specified at 33.5mm, this gives the the draw bar its dimension of OD 34,5 x ID 27.7 

sources on popular forums suggest the pulling distance to be no more than 1/8 inch

The collect requires a clamping force of 11500N. My interpretation of this is 112,8 Kg. How to derive the distance the draw bar needs to be pulled back? The lever pull on the ramp, which engages the lever action to pull the draw bar in. Lever action on lever action with force on incline.

https://www.engineeringtoolbox.com/inclined-planes-forces-d_1305.html

Collet pull force	11500	Newton	1173,469
lever ratio prawl	2,75
cam force	4181,818	Newton	426,7161
Cam Angle	37	deg
C3*SIN(RADIANS(C6))+0,2*C3*COS(RADIANS(C6))	3184,631	Newton
	324,9623	Kg
Lever closer ratio	10
Force required	32,49623	Kg

Schaublin Collets B32 72 65

With the Deckel FP2, I got a box of what looked like big Deckel collets, as used on my Cutter Grinder, but the threads where finer.

A bit of googling revealed the Deckel cutter grinder collets are part of the standard  DIN 6341 - 300 Series, more precise 355. So I assumed it might be the same series just bigger, but could not find any match on size and threads. 29.7x1.693mm ; 15TPI ; 45°/5° buttress

(http://www.schaublin.ch/app/webroot/pdf/cat/5.pdf, threads page 57)

So I cleaned one up to measure and found the VS engraving on the face, never seen it before and postponed my investigation. Then an australian youtube contributer posted a video on restoring an old schaublin lathe, which he had found under a tree. Wow and I recognized the logo :) Back to my google search now I knew they where most likely schaublin collets, so I started searching for old catalogues, and eventually found the spec in the modern catalogue. So I decided to make use of these on my Chipmaster, but could not find any collet chuck for these online. So I have to build my own. And so the journey of learning about collet closers and collet chucks started.

Steel Grades Selection and Equivalents

When selecting the material for a project, I find myself spending considerable time to research materials. The local steel supplier makes this easier since he only stocks commonly used materials. But I still like to understand which material is best for which application.

Carbon Steel

    EN3A – 070M20 /C22/ 1018 -  Mild Steel - Red
    EN8 – 080M40/  C45/ 1038 - Medium Carbon - Yellow
    EN9 – 070M55 / C55 /1060 - High Carbon - Green

Alloy Steel

    EN19 – 709M40/ 42CrMo4/4240 - Black
    EN24 – 817M40/ 40CrMo8/ 4340 -
    EN26 – 826M40/ 40NiMoCr10-5/ 1.6745 -
    EN30B – 835M30/ 36NiCrMo16/ 1.6773 -
    EN36B – 655M13/ 15NiCr13/ 3316/ 1.5752 -

Specification: EN8 – 080M40

Colour Code: Yellow

Availability: Bright Cold Drawn Round Bar: 6mm diameter to 75mm diameter Bright Peeled Round Bar: 16mm diameter to 160mm diameter Bright Cold Drawn Hexagon Bar: 8mm A/F to 55mm A/F Black Round Bar: 16mm diameter  to 400mm diameter (as rolled and as forged) Black Square Bar: 25mm A/F to 105mm A/F

Characteristics: Commonly known in South Africa as “Axle Steel” or “40 Ton Steel” Known as “40 Carbon” in steelmakers parlance Good enough welding properties as the carbon content is relatively low. When welding, pre heating the steel to approximately 100⁰Celcius is recommended as well as the use of low hydrogen electrodes. Tig or Mig welding is recommended Machinability is good but allow 6% on outside diameter for removal of surface defects EN8 is preferred to EN3A to machine as the material “chips” and makes machining easier and a better machined finish can be achieved Not recommended for high tensile applications for example. 50-60 ton tensile Heat treatment only to limited ruling sections (see schedule below)

Applications: All uses where a higher tensile in Carbon Steel is required including the more popular uses for spindles, shafts, axles, cylinders, bolts and nuts Armature, dynamo and motor shafts Heat treated bolts Connecting  rods Driving rings Flanges Railway Couplings Brackets, bushes and studs Pulleys (both light and heavy duty) Housing and parts not subject to high stresses or severe wear Uses where the tensile rating of 510MPa minimum is a requirement Bolt Specification: 8.8 (in condition “Q”) Bolt Specification: 9.8 (in condition “Q”) Bolt Specification: 10.9 (in condition “R”)

Comparable Specifications: Din C45 SAE 1038/44 Deutsche W/No 1.1186/1.0511 Euro Norm EN10083-1 (1991) 970 Part1; C40E BS970 Part 1 1983, 080M40 BS970 of 1955 EN8 American AISI 1042

Chemical Composition (%): Carbon (C) 0.36 (Min) – 0.44 (Max) Silicon (Si) 0.10 (Min) – 0.40 (Max) Manganese (Mn) 0.60 (Min) – 1.00 Max) Sulphur (S) Nil (Min) – 0.050 (Max) Phosphorus (P) Nil (Min) – 0.050 Max)

Mechanical Properties: Normalised Condition “Q” Condition “R” Ruling Section 254mm 65mm 20mm Tensile Strength 510/540 MPa 620/770 MPa 690/850 MPa Yield Stress (Min) 245 MPa 385 MPa 465 MPa Elongation 17% 16% 16% ISO V Impact 20 Joule 33 Joule 33 Joule Hardness 152/207 Brinell 179/229 Brinell 201/255 Brinell

Heat Treatment: Normalise at a temperature of 830⁰/860⁰Celsius Harden in oil from a temperature between 830⁰/860⁰ Celsius Temper at a suitable temperature, 550⁰Celsius for condition “R” and 660 – Celsius for condition “Q”

Specification: EN9 – 070M55

Colour Code: Green
Availability: Black Round Bar: 20mm diameter to 400mm diameter
Characteristics: This material is the highest carbon steel available from special steel merchants in South Africa for general use Heat treatment only to limited ruling sections It lends itself to induction hardening and shorterising (flame hardening) Care should be taken that hardened  components are properly tempered after quenching in water as the material can become “glass hard” and brittle Should small components require a “glass hard” surface, temper by boiling in brine for 30 minutes minimum. Brine of 9% salt in water is required Machinability is good  but allow 6% on outside diameter  for removal of surface defects Material can be welded on but is not recommended Ideal for 45 ton tensile applications Not recommended for carburising
Typical Applications: This steel is also used to make machine collets. After quenching, ensure that the components are tempered three times (spring tempering) All applications where wear resistance is required Can be used in the “as forged” condition for bending brake tools Commonly used for press eccentric shafts and bending brake tools Also used for shafts, spindles and general machine components including sprockets, cylinders, cams, crankshafts, small gears, machine tools, keys, grinding balls for ball mills, pulleys, ball race rings, bolts and nuts No bolt specifications are applied to this specification
Comparable Specifications: Din C55 SAE 1060 Deutsche W/No  1.0535 Euro Norm EN 10083-1 (1991) 970 Part 1; C55E. BS970 Part 1 1983, 070M55 BS970 of 1955 EN9
Chemical Composition (%): Carbon (C) 0.50 (Min)- 0.60 (Max) Silicon (Si)                         0.10 (Min) – 0.40 (Max) Manganese (Mn) 0.50 (Min) – 0.90 (Max) Sulphur (S)                      Nil (Min) – 0.05 (Max) Phosphorus (P)              Nil (Min) – 0.05 (Max)
Mechanical Properties: Normalised Condition “R” Condition “S” Condition “T” Ruling Section 254mm 100mm 65mm 20mm Tensile Strength 600/700 MPa 690/850 MPa 770/930 MPa 850/1000 MPa Yield Stress (Min) 310 MPa 415 MPa 480 MPa 570 MPa Elongation 13% 14% 14% 12% ISO V Impact Void Void Void Void Hardness 201/255 Brinell 201/255 Brinell 223/277 Brinell 248/302 Brinell
Heat Treatment: Normalise at a temperature of  810C/840CCelsius Harden in oil from a temperature between  810C/840CCelsius Temper at a suitable temperature, 550CCelsius for condition “T”, 610CCelsius for condition “S” and 660C Celsius for condition “R”  Specification: EN19 – 709M40 Colour Code: Black Availability: Black Round Bar in “as rolled “ and hardened and tempered to condition “T” Black rolled and forged surface: 16mm diameter to 350mm diameter Bright Peeled Round Bar, “as rolled” and condition “T”: 16mm diameter to 160mm diameter Characteristics: This material distorts when machining shafts or long spindles, especially once hardened and tempered In practice, the work pieces should be rough machined to plus tolerance and left in the open on the floor for 36 hours after which the material would have “aged” and stress relieved itself and thereby minimising distortion on the finishing of the product Machinability is good but allow 6% on outside diameter for removal of surface defects This material can be welded but welding should only be attempted by using the appropriate methods and materials as advised by welding expertise Ideal for 60 ton tensile applications up to 100mm max Sizes above limited ruling section will be heat treated to hardness only, with no guarantee on mechanical properties Applications: Utilised when higher than carbon steel mechanical properties are required Commonly used for axles, drive shafts, crankshaft connecting rods, high tensile bolts, studs, propeller shaft joints, rifle barrels, and induction hardened pins Bolt specification: 9.8 (in condition “T”) Bolt specification: 10.9 (in condition “U”) Comparable Specifications: Din 42CrMo4 SAE 4240 Deutsche W/No  1.7225 Euro Norm EN 10083-1 (1991) 970 Part 1; 42CrMo4 BS970 Part 1 1983, 709M40 BS970 of 1955 EN19 Chemical Composition (%): Carbon (C) 0.36 (Min) – 0.44 (Max) Silicon (Si) 0.10 (Min)- 0.40 (Max) Manganese (Mn) 0.70 (Min) -  1.00 (Max) Chromium (Cr) 0.90 (Min) – 1.20 (Max) Sulphur (S) nil (Min) – 0.04 (Max) Phosphorus (P) nil (Min)- 0.035 (Max) Molybdenum (Mo) 0.25 (Min) – 0.35 (Max) Working and Heat Treatment: Forging: Forge within the temperature range of 1250C/900C Celsius Anneal: Anneal at a temperature of 850C Celsius and cool steadily Normalising: not applicable Hardening: oil quench from a temperature of  850C/880C Celsius Mechanical Properties: Annealed R S T U V W Y Ruling Section (mm) 150 150 100 65 65 30 30 25 Tensile Strength (MPa) 680/720 690/850 770/930 850/1000 930/1080 1000/1160 1080/1240 1280 Yield Stress (MPa) 440/480 480 570 665 740 835 895 1050 Elongation (% Min) 22 15 15 13 12 12 10 10 ISO V Impact (Joule) 30 30 30 30 25 25 22 7 Hardness (Brinell) 190/210 201/255 223/277 248/302 269/321 293/341 311/375 363/415 Proof Stress (0.2%) if required (MPa, Min) 495 550 630 710 770 850 985 Specification: EN24 – 817M40 Colour Code: Blue and Black Availability: Black Round Bar in “as rolled” or hardened and tempered to condition “T” Black Round Bar: 20mm diameter to 350mm diameter (as rolled / as forged) Characteristics: This is more versatile specification than 709M40 as the limiting ruling sections for heat treatment are amplified because of the addition of Nickel Welding should only be attempted by using the appropriate methods and materials as advised by welding expertise Machinability is good and has little distortion in machining  Allow 6% on the outside diameter for removal of surface defects during machining Ideal for 60 ton tensile applications up to 250mm diameter max This material is often used in the annealed, as rolled or as forged condition for machining.  Subsequent heat treatment is used to achieve a higher tensile i.e. condition “T”, “U”,” V”,     ”W”, “X”, “Y” and “Z” This material can be certified as a safety specification in lifting equipment when such equipment is subject to impacts and requires a high tensile property, such as shaft sinking equipment in the mining industry Applications: This material is used where high tensile strengths and good impact values are required Some of the more popular uses include differential shafts, pinion sleeves, eccentric crusher shafts, eccentric high pressure shafts, high duty connection rods, power transmission slide gears and slide cams, mandrels for tube mills, heavy axles and high tensile gears, bolts and nuts Bolt Specification: 10.9 (in condition “U”) Bolt Specification: 12.9 (in condition “V”) Comparable Specifications: Din 40CrM0 8 – 4 SAE 4340 Deutsche W/No 1.6562 Euro Norm EN10083-1 (1991) 970 Part 1; 34CrN1Mo6 BS970 Part 1 1983, 817M40 BS970 of 1955 EN24 American AISI 4340 Chemical Composition (%): Carbon (C) 0.36 (Min) – 0.44 (Max)                                  Silicon (Si) 0.10 (Min) – 0.35 (Max) Manganese (Mn) 0.45 (Min) – 0.70 (Max) Sulphur (S) Nil (Min) – 0.04 (Max) Phosphorus (P) Nil (Min) – 0.040(Max) Nickel (Ni) 1.30 (Min) – 1.70 (Max) Chromium (Cr) 1.00 (Min) – 1.40 (Max) Molybdenum (Mo) 0.20 (Min) – 0.35 (Max) Working and Heat Treatment: Forging within the temperature range 1100⁰/850⁰ Celsius Anneal at a temperature of 760⁰ Celsius, soaking for four hours after reaching temperature Normalising is not applicable Hardening by oil quench at a temperature of 820⁰/850 Celsius after soaking through Mechanical Properties: Annealed S T U V W X Y Z Ruling Section (mm) 250 250 250 100 65 30 30 30 30 Tensile Strength (MPa) 620 680/770 850/1000 930/1080 1000/1160 1080/1240 1235 (Min) 1540 (Min) 1540 (Min) Yield Stress (MPa) 410 480 635 740 835 925 1005 1130 1130 Elongation (% Min) 16 16 12 12 12 11 10 5 5 ISO V Impact (Joule) 30 32 40.7 47.5 47.5 40.7 34 30 10 Hardness (Brinell) 180/220 223/277 248/302 269/321 293/341 311/375 341/388 363/415 444 (Min) Proof Stress (0.2%) if required (MPa, Min) 550 630 710 770 850 910 990 1235 Note: Interestingly, the impact values do not alter between condition “U” and condition “V”. Specification: EN26 – 826M40 Colour Code:  Black/Orange Availability: Availability is extremely limited in the South African market Prospective users of this specification are advised to check availability before any commitments Characteristics: A 6% allowance should always be made for removal of surface defects during machining Welding is not recommended on this specification Machinability good Ideal for heat treated condition (U/60/70 ton tensile) or V (65/75 ton tensile) As with EN24, this material is ordered in the annealed, as rolled or as forged condition for machining.  Subsequent heat treatment is used to achieve higher tensile strength                                        i.e. Condition T, U, V, W, X, Y and Z Some applications require this material to be heat treated to BS2772 Part 2 Grade 826M31 to qualify as a safety standard Applications: Similar applications and uses as EN24 817M40 but for higher tensile requirements This specification is prescribed by the mining industry in South Africa for lifting equipment e.g. stress parts in winches and cranes and general lifting tackle such as eyebolts, shackles and hooks. However, the material has to be manufactured to 826M31 procedures to qualify as a safety standard When this material is specified for safety reasons it is used in spline shafts, gear shafts, winder equipment parts, heavy duty mining head gears and in other safety critical mining applications It is further used as high impact eccentric shafts, crusher shafts, turnbuckles, brake pins, tie rods and main line railway armature shafts Comparable Specifications: Din 40NiMoCr 10-5 Deutsche W/No 1.6745 BS970 Part 1 1983, 826M40 BS970 of 1955 EN26 Chemical Composition (%): Carbon (C) 0.36 (Min)- 0.44 (Max)                                   Silicon (Si)                               0.10 (Min) – 0.35 (Max) Manganese (Mn) 0.45 (Min) – 0.70 (Max) Sulphur (S) Nil (Min) – 0.040 (Max) Phosphorus (P)                     Nil (Min) – 0.040 (Max) Nickel (Ni)                              2.30 (Min) – 2.80 (Max) Chromium (Cr)                      0.50 (Min) – 0.80 (Max) Molybdenum (Mo) 0.45 (Min) – 0.65 (Max) Working and Heat Treatment: Forging is done within the temperature range 1100⁰ / 850⁰ Celsius Annealing at a temperature of 670⁰ Celsius, soaking for 4 hours after reaching temperature Normalising, not applicable Hardening, oil quench at a temperature of 820⁰/850⁰ Celsius, after soaking through Mechanical Properties: U V W X Y Z Ruling Section (mm) 150 150 150 100 100 100 Tensile Strength (MPa) 930/1080 1000/1160 1080/1240 1235 (Min) 1540 (Min) 1540 (Min) Yield Stress (MPa) 740 835 925 1005 1130 1130 Elongation (% Min) 17 14 13 14 14 10 ISO V Impact (Joule) 47.5 47.5 40.7 34 34 14 Hardness (Brinell) 269/321 293/341 311/375 341/388 363/415 444 (Min) Proof Stress (0.2%) if required (Mpa, Min) 710 770 850 910 990 1235 Specification: EN30B – 835M30 (Annealed) Colour Code: Orange Availability: Black Round Bars supplied only in the annealed condition Availability is extremely restricted and prospective users of this specification are advised to check availability before committing to using it Characteristics: This is a very expensive steel specification not just because of the high alloying elements but also the refining methods utilised to keep the hydrogen (H) content of the steel to less than two parts per million, (H = ≤ 2PPM). It is more costly than other B.S. 970 specifications This is 1500 MPa minimum tensile steel , air hardening in sections up to 65mm diameter Specially recommended for intricately shaped parts where an air hardening steel is preferred This material can be case hardened , can be carburised and induction hardened or shorterised (flame hardened) Applications: 835M30 is a versatile specification. The applications of this material are numerous and includes the following In Engineering: ultra high tensile applications, shafts, gears, bolts, spline shafts, crusher shafts, eccentric shafts, hard wearing bushes and high impact pistons In mining: rock drill, knock off bits, mill hammers, cyclone plates, high tensile mechanical and thermal shock applications In Tooling: plastic extrusion dies, die bolster rings and punches Comparable Specifications: Din 36NiCrMo16 Deutsche W/No 1.6773 Euro Norm EN 10220-3 (1999) 36NiCrMo16 Chemical Composition (%): Carbon (C) 0.26% (Min) 0.34% (Max) Silicon (Si) 0.10% (Min) 0.35% (Max) Manganese (Mn) 0.40% (Min) 0.60% (Max) Sulphur (S) Nil 0.25% (Max) Phosphorus (P) Nil 0.25% (Max) Nickel (Ni) 3.90% (Min) 4.30% (Max) Chronium (Cr) 1.10% (Min) 1.40% (Max) Molybdenum (Mo) 0.20% (Min) 0.40% (Max) Mechanical Properties: Tensile Strength 1500 MPa (Min) Yield Stress 1300 MPa (Min) Elongation 10% (Min) ISO V Impact 20 Joule (Min) Hardness 444 Brinell (Min) Working and Heat Treatment: Forging: Do not charge into a hot or preheated furnace. Heat from cold to forging temperature 950⁰/1000⁰Celsius. Do not exceed 1100⁰ Celsius. Forge carefully and do not work on the steel  below 850⁰/900⁰ Celsius as the material is then hardening and this condition excessive stresses will build up in the workpiece. Cool the forging slowly and out of draughts or bury in lime or ashes. Annealing: Heat carefully to 810⁰ Celsius and allow to cool in the furnace or still air. Re-heat the steel slowly in the furnace to 630⁰/640⁰ Celsius and soak for about four hours after wich it may be cooled in still air (sub critically annealed). All parts for machining should be annealed. Normalising: Not applicable Hardening:  To harden in air or oil, heat the parts gradually and uniformly to a temperature of 810⁰/830⁰ Celsius. When air hardening, place the parts out of draughts to avoid unequal hardening and consequent stresses. For up to 65mm diameter the properties are obtainable through air hardening. For larger sections, oil hardening should be performed. Tempering: Where extreme toughness is desired, the pieces, whether air or oil hardened should be subsequently tempered at a maximum temperature of 250⁰ Celsius allowing time for tempering through. Test results obtained on a 30mm diameter test piece after hardening at 820⁰ Celsius and tempering at 250⁰ Celsius   Specification: EN36B – 655M13 Colour Code:  White Availability: Black Round Bars: 20mm diameter to 350mm diameter (as rolled and as forged) Characteristics: This material is also known as 3% Nickel-Chromium Case-Hardening Steel This specification is good for welding, prior to Carburising and Case Hardening Machinability is good but allow 6% on the outside diameter  for removal of surface defects Required hardness can be achieved by case hardening the outer surface by means of one of the following, Carburising, Carbonitriding, Nitriding, Nitrocarbursing, Tufftriding Applications: This material is often used in the manufacturing of gears, worm shafts, pinion shafts and spline shafts This specification is largely utilised when wear resistant hard surface is required along with high core strength Other common uses include Auto and heavy vehicle transmission components, engineering machinery gear box parts, aircraft gears mining steering worms, chuck jaws, track pins, gudgeon pins,mining gearbox gears, pinions and cogs Comparable Specifications: Din 15NiCr13 SAE 3316 Deutsche W NO 1.5752 Euro Norm EN 10084 (1998) 15NiCr13 BS970 Part 1 1983, 655M13 BS970 of 1955 EN36B Chemical Composition  (%): % Min % Max Carbon (C) 0.10 0.16 Silicon (Si) 0.10 0.035 Manganese (Mn) 0.35 0.60 Phosphorus (P) Nil 0.04 Sulphur (S) Nil 0.04 Chromium (Cr) 0.70 1.00 Nickel (Ni) 3.0 3.75 Mechanical Properties: Mechanical Properties of the core of a case hardened test bar of 28mm diameter Hardness of the test bar surface, Rc65 Tensile Strength (Min) 1000 MPa Elongation (Min) 9% ISO V Impact 40 Joule Working and Heat Treatment: Carburise at a temperature of 900⁰/930⁰ Celsius Refine at a temperature of 860⁰/880⁰ Celsius (see Note) Harden at a temperature of 760⁰/780⁰ Celsius in oil Note:  A “Single Quench” treatment may suffice to obtain the specified results. Intricate parts, or  parts of large sectional differences may distort in the refining treatment, thus the tendency to avoid refining after carburising. However, should the hardness not be uniform, cryogenic (sub zero) treatment is recommended. Through the analysis (chemical composition), the refining treatment after carburising may be omitted  an a “Single Quench” treatment may be employed

Metrology - the science of measurement

Some notes of interesting techniques, sites and people concerning this topic.

On YouTube there are some very interesting video clips on prototyping and machine metrology which are a must see by Dan Gelbart. He shares a measurement technique, which he refers to as reversal technique. In essence two unknown surfaces can be mapped, and compared if a common reference surface also of unknown dimension is used.
https://makezine.com/2015/03/20/18-lessons-smart-prototyping-self-made-billionaire/

Airy and Bessel Points effects explained.
https://www.mitutoyo.co.jp/eng/pdf/E4329_QuickGuide.pdf

31/03/2018 - Recently I browsed  through Stefan Gotteswinter web site, wealth of knowledge! Here he shared a link to 50 tidbits for precision work, #47 references Donaldson Reversal, still need to read up more on this, but I believe this is what Dan Gelbart refers to.

Colchester Chipmaster Spindle and Bearings

The site at precision rpm has a list of bearing designations used in Cochester Lathes.

http://www.precisionrpm.com/pub/gamets/lathes_1

The Chipmaster uses these bearings


Spindle Nose Bearing: 113060X/113101XH 

Dimensions (mm)
d	D	T	C	E	F
60.325	101.6	58	46.88	18.94	5.56

Spindle tail bearing: 111050/111090

111050-111090-gamet-single-row-plain-cup-50x90x26-75mm

Dimensions (mm)
d	D	T	C	B	F
50	90	26.75	20.4	29	6.35

Static Stiffness		Basic Rating		Speed	Weight	Brand
Radial	Axial	Radial	Axial
60	11	1435	830	7400	1.38

LATHE	GAMET FRONT BEARING	600 LATHES FRONT BEARING REFERENCE	GAMET REAR BEARING	600 LATHES REAR BEARING REFERENCE
Colchester Bantam	111050/111090C	BA-0070	112045/112085C	BA-0060
Colchester Chipmaster 6-inch Colchester Student 1200	113060X/113101XHE+10	-	111050/111090	-
Colchester Master 2500 Colchester Student 1800	130070/130120C	B336-1219 BA-0090	113060X/113101XP	B336-1218
Colchester Triumph	131093X/131152XC	B336-1228	133075/133130P ( 20 Springs )	B336-1322
Colchester Triumph ( SPECIAL ) APPROX 100 M/C's	160098X/160152XC	-	133075/133130P ( 20 Springs )	B336-1322
Colchester Mascot 1600	181118/181190X C	-	131097/131152XP ( 8 Springs )	B336-1331 BA-0010
Colchester Mascot 8 1/2-inch	181118/181190XHE+20	-	131095/131152X	-
Colchester Mascot / Mastiff	164133X/164196XHSE+60 ( X1124A ) 24 Rollers in A track 12 Rollers in B track	B336-1787	105115/105165P ( 8 Springs ) ( X1125A ) 15 Rollers	B336-1353
Colchester Mascot - Dalian	164133XD/164196XHS ( X1291A ) 24 Rollers in A track 12 Rollers in B track	B336-1805	105115/105165P ( 8 Springs ) ( X1125A ) 15 Rollers	B336-1353
Colchester Mastiff - Dalian	163150D/163210HR ( X1292A ) 26 Rollers in A track 13 Rollers in B track	B336-1806	109127X/109175P ( 8 Springs ) ( X1216A ) 15 Rollers	B336-1354
Colchester Mastiff (104 Bore )	163150/163210HRE+60 ( X1262A ) 26 Rollers in A track 13 Rollers in B track	B336-1789	109127X/109175P ( 8 Springs ) ( X1216A ) 15 Rollers	B336-1354
Colchester Magnum (120 Bore )	203156/203235HRE+10 ( X950A )	B336-1785	203145/203235P ( 8 Springs ) ( X951A )	B336-1348
CNC 650	164133X/164196XHSE+10	-	184120/184190P	-
Colchester Magnum ( 170 Bore )	206210/206290C	B336-1349	206190X/206290C	B336-1351
Harrison M250 Harrison V280 Harrison M280 Harrison VS280	111050/111090 C	BA-0070	112045/112085C	BA-0060
Harrison M300 Harrison VS330 Harrison V330	124070/124112XC	BA-0040	110055/110100C	BA-0050
Harrison M350	140085/140140C	BA-0080	130070/130120C	BA-0090
Harrison M400 Harrison M450 Harrison M500 Harrison V450 Harrison V530	141107X/141165XHSRE-10	BA-0020	140085/140140 P	BA-0030
Harrison Alpha 330	G124070/124112XC	BA-0250	G113060/113100P	BA-0260
Harrison Alpha 800 (120 BORE)	203156/203235HE+40	B336-1794	203145/203235P ( 12 Springs )	B336-1795
Harrison Alpha 800 (170 BORE)	206210/206290C	B336-1349	206190X/206290C	B336-1351
Colchester Combi K2 Harrison Alpha 400 U	131093X/131155C ( X1268A )	B336-1792	131092X/131152XD ( X1269A )	B336-1793
Harrison Alpha 400 T	131093X/131152XC	B336-1228	133075/133130P ( 20 SPRINGS )	B336-1322
Colchester Combi K3 Harrison Alpha 460 U	164130/164202C ( X1270A )	B336-1796	164127X/164200XD ( X1271A )	B336-1797
Harrison Alpha 460 T	164133X/164196XHSE+60 ( X1124A ) 24 Rollers in A track 12 Rollers in B track	B336-1787	105115/105165P ( 8 Springs ) ( X1125A ) 15 Rollers	B336-1353
Colchester Combi K4 Harrison Alpha 550 U	163145/163215XC ( X1272A )	B336-1798	163144/163213D ( X1273A )	B336-1799
Harrison Alpha 550 T	163150/163210HRE+60 ( X1262A ) 26 Rollers in A track 13 Rollers in B track	B336-1789	109127X/109175P ( 8 Springs ) ( X1216A ) 15 Rollers	B336-1354
Colchester Tornado 80 Colchester Tornado A50	B7016FA7ETBL	B313-6115	B7014FA7CDBL	B336-6116
Colchester Tornado 100 Colchester Tornado 110 Colchester Tornado A90	B7018FA7ETBL	B313-6105	B7017FA7CDBL	B313-6106
Colchester Tornado 200 Colchester Tornado 210	B7022FA7ETBL	BA-0140	B7021FA7CDBL	BA-0220
Colchester Tornado 220	B7022FA7ETBL	BA-0140	B7020FA7CDB 80 daN	B313-6122
Colchester Tornado 300 Colchester Tornado 310	B7026FA7ETBM	BA-0230	B7024FA7CDBL	BA-0240