Photo Index - Oliver Machinery Co. - Model 51-A-42"

Machinery Photo Index

Manufactured/Badged by:
Oliver Machinery Co.
Grand Rapids, MI

Machine Specifications
Machine Class:	Wood Working Machinery
Machine Type:	Lathe, Wood
Machine Size:	12" swing, 42" bed
Submitted By:	Ray Muno

Machine Specifications
Description/Model:	Model 51-A-42"
Date of Manufacturer:	1923
Serial Number:	27047 (View SN Registry Entry)
Last Updated	12/7/2006 9:33:56 PM

Comments:

Oliver Model 51-A-42". Serial Number 27047.

This is a "little" Oliver lathe I obtained from fellow OWWM'er Eric Tuck. Eric had this one plus a 48" version and decided he only needed the larger one.

It is an early version of the second type of Model 51 lathes that came equipped with a variable speed Kimble motor. The Model 51 was also available with a 4-speed 3-phase motor/headstock. This machine is designated 51-A. The later machines with VS Kimble motors were designated as 51-K.

An overview of the various style of Kimble variable speed motor headstocks can be found on the Kimble page.

http://www.owwm.com/MfgIndex/detail.asp?ID=1752

The motor is quite unique. It is a dual voltage, single phase Repulsion motor (not RI). It is variable speed, 600-3600RPM, controlled by a fly-ball governor. The governor is driven by a jackshaft that is perpindicular to the armature/spindle shaft. The jackshaft is driven by a spring loaded leather cone clutch directly from the armature shaft. The governor assembly is shown in the second picture. The governor operation is simple. It regulates the flow of current in the armature, opening the connections to the brushes when it is at speed. The governor is adjustable. I tweaked the setting to get the dial speed to correspond to the spindle speed, checked with a hand held dial tachometer. Once set, it seems to hit the selected speed quite well. The literature indicates that they do a good job of maintaining the selected speed under load. We shall see if that hold true.

The motor is rated at 1/2 HP and 5A/220V. The motor must weigh close to 200 pounds and has very large bearings. I think 1/2HP is an awful conservative rating.

The bed is only 42". This is a size I do not see mentioned in any Oliver literature. The smallest version shown is the 51-A sized at 48". The bed casting is marked with a 19-1-42" casting number so it shows its ancestory to be common with the flat belt drive Model 19. I think this is the case with the entire line of 12" "Speed" lathes that Oliver produced over the course of many decades. This was probably a special version aimed at schools and other vocational training programs. It has a brass tag labeled with "Board of Education" and the 43 stenciled on it probably meant it was one of many machines populating a student workshop. With the short bed, it has the spindle capacity of one of todays mini lathes. I guess I will just have to think of it as a 750 pound "Mini".

The machine is missing a few parts, namely the tailstock and toolrest banjo. It came with a tailstock that will work with a simple riser block. I guess my quest begins for a few parts. Also missing was the outboard bearing retainer.

The third photo shows the motor in an exploded view. Parts are, left to right, top to bottom:

Field coil assembly
Outboard end bell
Governor housing cover
Governor housing
Governor contact assembly
Governor
Upper brush holder
Governor speed adjusting fork
Outboard bearing frame
Armature (with threaded bearing retainer for inner race)
Inboard end bell with governor jackshaft and driven cone
Lower brush holder
Outboard bearing retainers, outer race
Governor drive cone with spring and locking collar
Inboard bearing retainer, outer race

The main bearings are 1207 double row, self aligning ball bearings. The jackshaft bearings are 1204's.

The switch is arranged so that it can only be turned on at low speed. It is a push button switch, exactly the same type you would find in Grandma's house, complete with mother of pearl inlay. The only problem for replacement is that it is a double pole switch. Reproduction single pole switches of this type are readily available but I have not seen a double pole.

UPDATE
------

The machine is coming along. The first picture shows the machine in its "as obtained" condition as well as after clean up and partial assembly. It is waiting for bearings and a couple parts. The tailstock is from a No. 159 lathe. The banjo is an older Delta.

I was the lucky winner of the Eagle Machinery monthly contest for a "birth certificate". A PDF copy of the invoice is available here: http://www.aem.umn.edu/~muno/Oliver/Model_90/Invoice_51.pdf
This machine was one machine of eight that were special ordered with a 42" bed. The eight machines were Serial numbers 27045-27052. Ordered December 7. 1922. Shipped January, 1923. Ordered by the Minneapolis Board of Education for Lincoln Middle School. $298 each.

Photo 1:

Comments: Lathe, before and almost complete
Source: Ray Muno, digital camera

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Photo 2:

Comments: Motor/Headstock showing fly-ball governor
Source: Ray Muno, digital camera

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Photo 3:

Comments: Exploded view
Source: Ray Muno, digital camera

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