Converting Singer Sewing Machines from Electric to Treadle or Hand Crank

© 1998 Richard P. Wightman

(All rights reserved unless otherwise specified… may be downloaded for personal use, but may not be reproduced for distribution, sale or inclusion in any other published work without the express written consent of the author)


Sewing machine collectors, and especially those with an interest in actually using the older machines, often find themselves in possession of machines that have been converted from treadle to electric, or they may have a nice treadle that has had it's machine removed. Possibly they have a treadle that's nice, but the machine in it is badly worn or damaged. Any of these situations can indicate the desirability of finding a better head and/or converting some Singer head back to treadle, or possibly to hand crank. These pages should enable you to carry out this conversion in most instances.

First, machines older than the Model 66 are rarely found in original electric installations. The vast majority of Model VS #2, 27, and 127 machines were treadles or hand cranks to start with, and if found with motors, were almost always something that was converted after original sale. These models do not have the cast on motor boss at the right side of the pillar, which later became standard on all Singers until the modern castings for internal motors were introduced in the late 1950's. Conversion of these machines back to treadle status is usually extremely simple. The original conversion to electricity generally involved the drilling and tapping of screw holes on the machine to attach a motor and or light. Remove the motor and/or light and put the head in a treadle cabinet. That's it. Conversion to hand crank is more difficult, as the hand crank used on these older machines was one that mounted on the wood base of the portable case. Usually, this is long gone. The modern hand crank available today is designed to attach to the standard motor boss, and cannot readily be attached to these older models that don't have that boss.

A word about hand wheels… there are two varieties of standard Singer hand wheel. These are the spoked wheel, common to the older heads that were designed for treadles, and the solid wheel, used for the somewhat later machines when an electric motor was the original installation. There are two differences in these wheels. The spoked wheel is 4 ounces, or 20%, heavier. This gives it a little better momentum for smoother, easier treadling. It is also somewhat larger in diameter, and the outside edge is thicker. This makes hand contact, which is a standard element of treadling, easier. However, in converting an electric to treadle, it is not an absolute necessity that the hand wheel be changed. The electric style, solid hand wheel will work quite well in a treadle if you don't happen to have access to a spoked wheel. Bear this in mind when using the following instructions.

Following will be first a brief narrative outline of the conversion procedure, then a step by step description, with pictures, of the conversion process. Two machines are shown… a Model 66-19 and a Model 99. The conversion process is essentially the same for both, except that the 99 requires some additional work to accommodate the bobbin winder to the smaller inside diameter of the spoked wheel used. Again, remember, you don't have to change to the spoked wheel. If you retain the solid wheel, no adjustment to the bobbin winder is necessary.

Two other models should be mentioned… the 15-88/89/90 and the 201K. The 15-88/89/90 are all the same machine. The only difference is the motive power. The 88 was the designation for treadles, 89 was for hand cranks, and 90 was for electrics. The 88 and 89 had the spoked wheel. These are frequently encountered converted to electric, but with the spoked wheel still in place. The 90 had the solid wheel. This machine is more common than the other two. Until I discovered the 201K, this model series was my favorite treadle machine. It is a real workhorse, and offers both reverse and lowering feed dogs. If you find one of these heads, don't pass it up.

Singer's Model 201 is often credited as the best sewing machine ever built, certainly it is the best Singer ever built. However, the most common U.S. version is an internal motor machine and is not readily convertible to treadle. However, due to late rural electrification in Europe, the British Model 201, the 201K, was made without the internal motor, and was offered in treadle, hand crank, and electric with external motor and belt drive. Many of these were imported into the US after production of the U.S. version stopped. Many others came in by way of Canada. There are also a few U.S. produced external motor machines, though these appear to be much less common. In any event, all of these machines will fit in a standard Singer treadle and if you can find one you will have the best treadle machine available, in my opinion.

Note: conversion of either the Model 15 or the Model 201 will involve bobbin winder adjustment as described for the Model 99 below.


Steps in Converting from Electric to Treadle or Crank:

  1. Remove motor and light... belt will stay on machine.
  2. Back set screw out of clutch release wheel and remove clutch release wheel.
  3. Remove clutch control washer (three eared washer behind clutch release wheel).
  4. Remove hand wheel.
  5. Remove belt and if bobbin winder tire is worn, replace it with a new one.
  6. Replace solid style hand wheel with spoked hand wheel if available, if not, replace original hand wheel.
  7. Replace clutch control washer and clutch release wheel
  8. Screw in set screw in clutch release wheel and check adjustment of clutch. If it does not release fully in the release position or engage fully in the engaged position, remove the clutch release wheel and rotate the control washer. Reassemble and check again.
  9. Check function of bobbin winder. If spoked wheel was used to replace solid wheel, on some models the bobbin winder tire will not have sufficient adjustment to contact the hand wheel for bobbin winding.
  10. If the above situation exists, remove bobbin winder adjustment screw. Bobbins can be wound by using finger pressure to press bobbin winder against wheel. This is the standard system on some Singer models in any event. If desired, the adjustment slot in the bobbin winder assembly can be opened up (see pictures below) to allow a greater range of adjustment.


At this point, you are ready to place the head in a treadle. If hand crank operation is desired, either an original or reproduction crank can be used. The crank is attached to the motor mount boss with one screw, just as the motor mount was. CAUTION: The screw used to mount the motor and the screw used to mount the crank are not the same length. The motor mount screw is too short to firmly attach the crank. The new cranks come with a new screw. DO NOT attempt to use this screw if re-attaching the motor. It is too long, will bottom out in the threads and can break off, leaving you unable to mount either the motor or the crank. If you have an old crank and no screw, you will have to find a correct screw at a hardware or sewing machine repair outlet.


Pictorial Review of Conversion of Model 66-19


Here is the back of a 66-19, showing the light, attached to a metal bracket that is in turn attached to the machine behind the silver access plate.


The access plate was swung aside, the metal bracket and light removed, and the screw that held the bracket replace in it's hole so it won't be lost.

Here you see the right end of a Model 66-19, where our work will be done. Note the motor mount below the hand wheel, one screw holding it on. If you look closely, you can also see the set screw at 9:00 o'clock in the silver clutch release wheel.

Here the set screw in the clutch release wheel has been backed out enough to unscrew the wheel.

Clutch wheel has been removed, revealing the clutch release wheel control washer. This washer has three ears, which are not evenly spaced… these provide the adjustment for the clutch wheel, which will come into play later. Note how this washer is mounted so you can get it back in properly.


Handwheel has been removed, revealing the shaft and also allowing clear access to the bobbin winder tire. The motor belt should have come off with the hand wheel. Note that we have been dealing with the solid, or electric machine, style hand wheel.

Bobbin winder tire has been removed (just pressure it off sideways). New bobbin tire can be seen to lower left.

New bobbin winder tire in place.


Spoked hand wheel has been placed on shaft. Put a drop of oil on the inside of the wheel before putting it on. Control washer is also back in place, ready to screw clutch wheel back in..

 No picture here… just discussion of clutch wheel adjustment. The little set screw in the clutch wheel, when screwed in, sticks out in back and bumps against the ears on the control washer. This controls the clutch adjustment. When you have the clutch wheel installed and the set screw in, test the adjustment range. Tighten the clutch wheel… does it tighten down so that the needle bar moves when the hand wheel is moved. When the clutch wheel is loosened, does the hand wheel spin freely without moving the needle bar? If so, then the adjustment is correct. If not, remove the clutch wheel and rotate the control washer, then re-install the clutch wheel and try again until you have found the position that is correct. It is often easiest to install and uninstall the clutch wheel if you stand the machine on end, as the washer tends to fall out of place as you try to put the wheel back in.

To the right, you see the bobbin winder on 66-19. No problems here. This model has a bobbin winder that is very simple. The bobbin is slipped on pin opposite tire and the whole assembly simply pivots on the silver screw to the left. It is designed so that you just hold it so that the tire rubs against the hand wheel until the bobbin is full. You are the control mechanism. This bobbin winder has sufficient adjustment that it works with either style of hand wheel.


At this point, you have completed conversion of the Model 66 to treadle. If you are converting to hand crank, you will find the next pictures helpful:

Machine is stood on end and hand crank has been mounted on the motor boss. Note that a new screw, silver as opposed to the old one which was black, is used. As noted above, you cannot use the motor mounting screw for the hand crank or vice versa.

If you look very closely at the picture to the right, you can see, at about 8 o'clock on the wheel, the rubber finger of the crank engaged in the wheel spokes. This finger has a pivot, and can be flipped up to disengage the wheel. This means that you can mount the crank on a machine in a treadle cabinet, release the treadle belt and use the hand crank, or disengage the hand crank, replace the belt and treadle. You need not remove the hand crank.



Here is a final picture that throws one more caution at you… the hand crank, when installed, will prevent the machine from fitting into a modern portable case. While the handle will flip up, reducing the length, it is not sufficient gain to enable you to put the lid on the base.



Additional Information for Conversion of Models 99, 15 and 201K. (Model 99 Shown)

On the Model 99, the light is screwed directly into the casting of the machine. The mounting screw cannot be reached directly with a screwdriver, the light is in the way. Here, the machine has been stood on end, showing the bottom of the light. Remove the screw from the light itself. This will permit access to the screw fastening the bracket to the machine

Bobbin assembly on 99 is much more complex. It has the automatic release when full mechanism. If you changed to the spoked wheel, this will no longer work. (Note that you don't HAVE to change hand wheels.) If you are changing wheels, which I personally do prefer, then follow the steps in the next pictures.

The simplest way to handle the bobbin winder problem is just to remove the screw that controls the adjustment. Here you see that that screw has been removed. You can now press the bobbin winder down far enough to hold the tire against the spoked wheel… releasing the pressure when the bobbin is full. Essentially the same system as on the Model 66 above.

Discussion time again.. In many past cases, I have handled the bobbin winder adjustment problem and retained the automatic release feature by sawing or filing out the end of the adjustment slot to permit a greater range of movement. If you wish to do this, keep on going…

The easiest way t get at the bobbin assembly is to remove the whole belt guard piece it is mounted on. Here you see screwdriver removing the single screw that holds the guard on. Be careful with the actual bobbin assembly when you remove it from the guard. The central pin screw is spring mounted… don't let the whole works come undone!

Bobbin winder assembly clamped in portable vise (a must have tool!), ready to have end of slot hack sawed and filed out.


Slot with end cut out. Note that the curve of the bottom edge has been carried out. This is necessary to get the needed adjustment.


Assembly put back on the belt guard plate. Obviously, the final step is to replace this assembly and adjust the bobbin winder. In this particular case, there almost wasn't enough room to get the needed adjustment. I ended up with very little screw surface bearing on the slot piece… but it worked.


That's all folks… put the 99 in a treadle or attach a hand crank as above, and have fun.


Hope you have been able to follow all of this, and that it helps you to save a machine or two for treadling.


Dick Wightman