Simple cheap speed reducer

[327fed]

I have a Consew 225 on a Pfaff table. I thought I could make a speed reducer that clamped to the square tubing table leg (many sewing tables have these). To adjust I could slide the reducer up and down. Doing this, the clutch motor does not have to be moved, the belt slot in the table does not have to be widened. I did have to move the bobbin winder back, move the motor pulley all the way right, and remove the belt shield on the motor. I had a 3/4 bore by 7 inch and 2.25 inch pulley, some 3/4 shaft, and some 6 inch channel. I would have preferred flat bar but had none. I oredered 2 $12.50 pillow blocks from Surplus Center, got 4.  3.5 x 3/8 bolts and nurs, and 2 pieces of 2  x 1/4 flat bar to clamp the reducer. Would have preferred square u bolts but could locate none. My cost with belts around $50 plus shipping. Can quickly change back to full speed if needed. 

[DonInReno]

Good job - looks great!   

[dikman]

That's a nice approach, fairly simple and makes for easy adjustment.

[327fed]

Thanks. Sure changed the personality of the machine. 

[Scoutmom103]

Nice.   Are the 2 small pieces of metal laying on the larger pully both attached to the back side of the leg?  I can tell the top on is in the picture?

 

[327fed]

Yes. The bolts go on each side of the table leg and through the holes in the flat plates behind the post. Creates 2 clamps similar to a u bolt. No  holes or attachment to post except the bolts pull tight. The extra hole was in the plate from its last life. Loosen bolts to slide reducer up and down. I will get a picture tonite maybe.

[327fed]

If one were starting from scratch, 1/2 inch bearings, shaft and pulleys would be plenty heavy. 1/4 x 6 flat bar on front and back, maybe 5 inch wide, would be cleaner. 4 inch bolts would leave room for lock nuts. Grey primer would match better than red oxide. And a sheet metal belt guard to save the knees would be a good idea. I just had all this Saturday and did not want to drive to town.I measured belts and used 2 online belt length estimators and still made 3 trips to Autozone to get a fit. 

[Scoutmom103]

Thanks for the pics and info

[AlizabethThomas]

Glad to see this idea, it sure beats being upside down fiddling with very limited, almost nonexistent real estate between my knee lift and wire routing .I've already been getting familiar with pillow block bearings and shafts because of my ongoing home built shoe sanding machine project. 

[327fed]

https://www.amazon.com/Dipped-Galvanized-Square-U-Bolt-Trailer/dp/B06Y3XS19S/ref=sr_1_7?dchild=1&gclid=EAIaIQobChMI2cGQ-tnH7wIVZ_HjBx127wGoEAAYAiAAEgJ9VvD_BwE&hvadid=409940667309&hvdev=t&hvlocphy=9013241&hvnetw=g&hvqmt=e&hvrand=12634043513001628544&hvtargid=kwd-3097009597&hydadcr=24661_11410854&keywords=square+u-bolts&qid=1616546908&sr=8-7

These u bolts might make this simpler. 

Could use a wood 2x6 on each side and longer bolts I guess if you lack a drill press or steel. I guess I’m a metal guy. 

Edited March 24, 2021 by 327fed
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[327fed]

A question on pulleys. The sewing machine belts seem to be 3/8 inch. Some companies call them L or M series. Auto zone has a 15 series. All the pulleys I have found for sale are A series (1/2) or A and  B series ( 5/8 inch). I just had the narrow pulleys on hand, one came off my clutch motor. What pulley series matches 3/8 inch sewing machine belts? 

[DonInReno]

1 hour ago, 327fed said:

A question on pulleys. The sewing machine belts seem to be 3/8 inch. Some companies call them L or M series. Auto zone has a 15 series. All the pulleys I have found for sale are A series (1/2) or A and  B series ( 5/8 inch). I just had the narrow pulleys on hand, one came off my clutch motor. What pulley series matches 3/8 inch sewing machine belts? 

3L and 3v pulleys are for 3/8” belts,  but I don’t know how much of a difference there is between them.

[327fed]

https://postimg.cc/cK5THjZF

This machine for sale on leatherworker.net has a simple reducer but I am unsure what type of bearing is used.