Speed Reducer And Servo Motor?

[Dignitas1980]

I have taking the idea of user northmound and i want to make myself a speed reducer. I found a pulley, it weight 675 grams, i will need a 13 mm belt, its an aluminium pulley and the owner has measured the outsite not the inside, but you`ll see what i`m talking about. I will need this one, a steel shaft and 2 ball bearings. I have skill so this will not be a problem. What do you think?

[Northmount]

Pulleys are typically measured at the outside diameter since the belt surface should ride even with the rim of the pulley, not on the bottom of the groove. You don't want a belt to ride on the bottom of the groove as you lose the surface area contact on the side of the belt and pulley. Then you have to tighten the belt too much to stop it from slipping. Overly tight belts may damage the supporting bearings.

Pulleys and belts should be bought as matching widths.

Tom

[Dignitas1980]

Absolutely you are right! My "question" was about these 2 diameters.. It will make the machine more powerfull with a speed reducer 37mm - 120mm? Its enough this raport 37-120 mm or i need a bigger raport between diameters, something like 37-160 mm?

[Constabulary]

the smaller the small pulley and the bigger the large pulley the more reduction you have. You can run your servo at higher speed and you have more torque and lower sewing speed.

37mm -160 is about 1:3 reduction and 37mm to 160mm is about 1:4 reduction

[Dignitas1980]

the smaller the small pulley and the bigger the large pulley the more reduction you have. You can run your servo at higher speed and you have more torque and lower sewing speed.

37mm -160 is about 1:3 reduction and 37mm to 160mm is about 1:4 reduction

37mm-160 is 1:3 reduction and 37mm-160mm is different, you mean 1:4? How come? The values are equals, no?

[Constabulary]

mistyped - I think you know what I mean, don´t you?

37mm - 120mm is approx 1:3 and 37mm - 160mm is about approx 1:4 reduction

Edited February 4, 2015 by Constabulary

[SARK9]

The pulleys I make myself are usually 50mm-->215mm or so, for a bit over 4:1. You will want to use a 10mm (9.7mm?) wide belt with very small pulleys, since they flex much more easily. Stay with very good quality belts, since the uneven splices on the cheap ones can cause a horrible *thump thump* that I promise you will hate.

-DC

[Dignitas1980]

Thank you, guys! Its easy for me to make the speed reducer, i think there is no problem if i use aluminum, right?

Yes, i have to use its a 10 mm belt and i will buy some good quality belts, don`t worry!

[Wellington]

On 1/22/2013 at 7:39 PM, Northmount said:

Here are a couple pictures.

The slot in the table had to be lengthened to use the same belt as had been used for the motor. The pillowblock bearings are for a furnace fan that typically runs 900 RPM so I'm not worried about them lasting. Had to shift the motor over a bit, and play with the tensioning adjustments, finally decided to keep it real simple and use a bungee cord for the motor belt tension. For the belt to the head, just slide the jackshaft bracket down to adjust, then tighten the clamp to the leg. Since the leg material is on the light side, there is a block inside to keep the leg from being squashed.

Tom

Tom (or anyone else who might know):

Where did you find the sheaves for this? I might want to do a jackshaft speed reducer for my Adler 67 / Consew 550, but I'm not sure where to find sheaves at a decent price. Surplus Center, maybe? Ebay? I'd try Grainger or MSC but suspect they're $$$$$$$$ there (like most things)...

Also, what kind of reduction are we generally looking for here? Something like 3-to-1 I'm guessing (3-1/2" to 10-1/2" for examaple)?

Thanks in advance for any help.

W.

Edited November 3, 2019 by Wellington

[Northmount]

1 hour ago, Wellington said:

Tom (or anyone else who might know):

Where did you find the sheaves for this? I might want to do a jackshaft speed reducer for my Adler 67 / Consew 550, but I'm not sure where to find sheaves at a decent price. Surplus Center, maybe? Ebay? I'd try Grainger or MSC but suspect they're $$$$$$$$ there (like most things)...

Also, what kind of reduction are we generally looking for here? Something like 3-to-1 I'm guessing (3-1/2" to 10-1/2" for example)?

Thanks in advance for any help.

W.

My junk box has a number of sheaves and other odds and ends in it from other projects, or stuff I have salvaged.  Only thing I had to purchase was the bearings.

Chances are, you should be able to get sheaves and pillow block bearings from Harbor Freight, or from some of the local hardware or big box stores.

Tom