yeoman's lathe -...

Yeoman's Lathe

Imagine a lathe that can be constructed out of scrap materials for a few hundred dollars or less and used to fix things like truck rotors, water pumps, windmill parts, or even a better version of itself. A self-replicating homemade machine tool that improves every iteration.

This document is being released for public review and comment. This design is a work in progress. We are seeking feedback on the feasibility, constructability, and advisability of this design.

Please submit all comments, ideas, suggestions, and criticisms in whatever form you choose, to Pat Delaney and Tyler Disney.

For more information and documentation, go to the project's wiki:

concretelathe.wikispaces.com

radically cheap diy machine tools for informal economies

Models, Drawings, and Renders:

Tyler [email protected]

Concept and Design:

Pat [email protected]

Concrete Lathe Concept

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CONSTRUCTION 1002011.08.21

Tyler Disney

Design By: Pat Delany

CARRIAGE ASSEMBLY

DUAL HUMP YEOMAN STYLE HEADSTOCK

CONCRETE TAILSTOCK

ANGLE IRON WAY SUPPORTS

TOOL POST

MORSE TAPER SOCKET

1" DIA GROUT HOLE (TYP.)

CHUCK

CROSS SLIDE

WAY CLAMP

WAY ALIGNMENT JIG

8" SHEAVE


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Tyler Disney


42"

4" 4"3 1/8"

10"

8 1/8" 29 7/8"

12"

6 3/8"

8"

4"

8"

6 15

/16"

2"1"

1 9/

16"

TOP VIEW

6" = 1' 0"

1103

FRONT VIEW

6" = 1' 0"

2101

RIGHT VIEW

6" = 1' 0"

3101

ISOMETRIC VIEW

NTS

4103

15"

8 1/8"

16 1/4"

2 3/

4"

8"


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CONSTRUCTION 102.12011.08.21

Tyler Disney


LONGITUDINAL SECTION

9" = 1' 0"

1102.1

LEADSCREW

MORSE TAPER

SPINDLE

1" DIA HOLE FOR GROUT

1 5/

8" CROSS SLIDE

SLIDE BASE

CARRIAGE SPACER

CROSS-SLIDE LEADSCREW

BOLT EMBEDDED IN CONCRETE

SPINDLE ASSEMBLY

9" = 1' 0"

2102.1

SPINDLE - EXPLODED

SPINDLE - ASSEMBLEDSPINDLE BORE

CAST ZINC-BRONZE BUSHING

STEEL PIPE

6"

TAILSTOCK CLAMP THREADED ROD


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CONSTRUCTION 102.22011.08.21

Tyler Disney


SECTION VIEW

6" = 1' 0"

2102.2

RIGHT VIEW

6" = 1' 0"

3102

18 9

/16"

3/4"


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CAST CONCRETE BED WITH EMBEDDED BOLTS

WAYS, WAY SUPPORTS, AND SPINDLE INSTALLED

CARRIAGE ASSEMBLY ADDED

TAILSTOCK ADDED


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CARRIAGE

ASSEMBLY

CARRIAGE FRAME

6" = 1' 0"

1104

CONCRETE BASE AND LEADSCREW ASSEMBLY

6" = 1' 0"

2104

BASE PLATE

6" = 1' 0"

3104

TOP SLIDE BASE

6" = 1' 0"

4104

COMPLETE CARRIAGE ASSEMBLY

6" = 1' 0"

5104

TOOL POST

CROSS SLIDEBASE PLATE

WELD JOINT

ANGLE IRONWAY SHOES

STEEL CROSS BAR

CAST IN PLACE CONCRETE CARRIAGE BASE

EMBEDDED BOLTS

WAY FOLLOWER PLATE

NUT AND HANDWHEEL ASSEMBLY

CARRIAGE SPACERPLATE

ANGLE IRON CROSS-SLIDEFEEDSCREW

CROSS SLIDE


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WAY ALIGNMENT JIG

NTS

1105

Straight, accurate ways are central to machine accuracy and finding proper round bar or pipe may be difficult. For a 8" lathe, ways 32 to 38mm diameter should be fine.

Used hydraulic piston rods should be the first thing to look for because they are more likely to be straight than the other kinds of steel bar or pipe available.

The straightness of the ways can be checked by holding them side by side, first rotating one then the other and using a light from below or a feeler gauge to check for gaps.

A method exists to correct small errors in the way stock. It is called the "3 rounds" method and foudn in an old Scientific American article found in an appendix somewhere.

Wrapping the ends of the ways with greased sheet metal will allow the ways to be rotated when they wear. All lathe ways wear eventually and round ways that wear against a flat surface will definitely wear more quickly than others. The advantage of our design is that wear is easily repaired; rotating the ways with a pipe wrench that has padded jaws and replacing the wear strips will bring the machine back to new condition, something impossible with regular lathes.

Wrap the ways tightly, carefully hammer the sheet metal over the ends and hold everything together with hose clamps. you can then replace the hose clamps with tightly wrapped tie wire if you need to save them. To make absolutely certain that no corossive concrete touches the ways, a thin layer of cut up plastic bottle coudl be added to the sheet metal sandwich.

Accurate alighnment is vital! A metal plate attached to a straight edge can be used as a guage for way separation as long as it is kept at right angles to the ways. Putting the ways in the same plane is more difficult.A Starett ways quality level is $700, a grizley machine level is $61.25. I am certain there is a difference in quality but the cheaper one is adjustable and accuracy is claimed to be 0.0005" over a 10" span. If you have found or made really accurate round ways you should seriously consider buying one of these to take advantage of the accuracy you have achieved so far. Besides ensuring that the ways are in the same plane you will also be able to level the spindle and the cross slide and make certain that the cross slide pieces are flat and have parallel edges.

An economical if less accuratye method is to use a piece of plate glass and a ball bearing, light taps will increase sensitivity.

[sketch & description of way indicator level idea]

Way Alignment

yeoman's lathe -...

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