speed reducer

[gigi]

Currently I have this setup: the original old 0,24 kW clutch motor at 1400 RPM, a small motor pulley (40 mm from https://www.college-sewing.co.uk). Motor is controlled by a 0,75 kW Yaskawa V1000 frequency inverter drive bought in used condition from eBay (about 50 bucks). Speed is preset with a potentiometer knob, clutch is engaged and disengaged by original machine pedal. Advantage: you have good torque from 0 to 1400 RPM.  Also not a lot of changes to original setup. Works even for veg-tan leather, at least 6-7 mm. I have 2 machines with the same type of setup: a Pfaff 335 and a Durkopp 239-525.   I am working to develop a potentiometer pedal and replace the clutch motor with regular motor to vary the speed easier, without having to stop (even though I can manage to turn the potentiometer knob while sewing).  Just a different setup...

Edited November 7, 2016 by gigi

[TinkerTailor]

3 hours ago, gigi said:

Currently I have this setup: the original old 0,24 kW clutch motor at 1400 RPM, a small motor pulley (40 mm from https://www.college-sewing.co.uk). Motor is controlled by a 0,75 kW Yaskawa V1000 frequency inverter drive bought in used condition from eBay (about 50 bucks). Speed is preset with a potentiometer knob, clutch is engaged and disengaged by original machine pedal. Advantage: you have good torque from 0 to 1400 RPM.  Also not a lot of changes to original setup. Works even for veg-tan leather, at least 6-7 mm. I have 2 machines with the same type of setup: a Pfaff 335 and a Durkopp 239-525.   I am working to develop a potentiometer pedal and replace the clutch motor with regular motor to vary the speed easier, without having to stop (even though I can manage to turn the potentiometer knob while sewing).  Just a different setup...

Bass drum pedals from drum kits may be a good source for a pedal to mount a potentiometer too.

[TinkerTailor]

VFD's generally cost the same if not more than a servo new. If you find one used, go for it. If you are ordering new, go with the servo. It is less work and cheaper. And yes, the motor needs to be wired into the vfd and the vfd plugged into the wall. Some rewiring is likely to be necessary.

[gigi]

1 hour ago, TinkerTailor said:

Bass drum pedals from drum kits may be a good source for a pedal to mount a potentiometer too.

Thank you for the idea! We need to find a potentiometer with low amplitude movement to work with the pedal or a magnetic sensor.

1 hour ago, Sticks said:

Any photos.?

My husband did the rewiring. First he read the manual to see how the connections should be made (they may differ from other inverters). 

Edited November 7, 2016 by gigi

[TinkerTailor]

Machinists use vfds all the time to use  3 phase 220 volt machine  motors with single phase 220 power at home. It is important to get the right type with the right input and output.  Look on sites like practical machinist for info and used vfds for sale.

 

[TinkerTailor]

20 minutes ago, gigi said:

Thank you for the idea! We need to find a potentiometer with low amplitude movement to work with the pedal or a magnetic sensor.

If you use a sliding pot, the length of the lever arm actuating the pot will effect the slope of the ramp up from min to max speed. The longer the lever arm, the slower it changes from slow to fast. You could make an arm with a couple holes allowing you to tune the pedal ramp up once you figure out a pot with close to the same values as the internal one.  Places like digikey have lots of sliding pototentiometers. They make some really smooth ones for not too much money because they are used in audio applications. They need to work good because when the beats cut out,  the dj gets beer thrown at him...As a matter of fact they make midi bass drum pedals that have the pot built in.....as to building your own,  Tons of choices for a pot under 20 bux, most under 5. .....

And now that i thought about this, here is your solution, sustain pedals for guitar/keyboard, why reinvent the wheel? You could probably use a rockband controller from a garage sale.....

http://www.sweetwater.com/c520--Keyboard_Pedals

Edited November 7, 2016 by TinkerTailor

[TinkerTailor]

10 minutes ago, Sticks said:

Im loving this thread.

How can this be set up to control the pedal lever.?

I kinda have two ideas going there, one is to add a sliding pot to some kind of pedal allowing you to adjust the attacment point. The other is to use/modify an existing electronic pedal from a guitar or keyboard. Or even a domestic sewing machine.

For the first idea, to connect the sliding pot to the pedal, I would use a linkage rod to the pot slider from the pedal or a chain and return spring.

The keyboard pedal option may just be plug and play, as in cut leads to pot on vfd and patch in the pedal. Have to look up a few values to be sure.

[gigi]

So far didn't find a pedal with the exact parameters we need (2200 Ohm). So it might require modifying one.  

[TinkerTailor]

30 minutes ago, Sticks said:

Im loving this thread.

I am as well. I don't go by Tinker for nothing. I am always thinking of things like this. Problem on here is if you make these kinds of suggestions to someone who is too much of a novice, and they are in way over their head, They could very well let the smoke out and electrocute themselves. Never a good thing.... When i find someone of like mind with an obvious foundation of knowledge and access to help if needed, it is fun and refreshing to discuss some kind of weird design......that may be dangerous to man and machine.

[gigi]

Sticks's fault: he asked for photos  ***kidding***.

I will edit the post and remove the photos. You have them on email. 

[Wizcrafts]

For those of you who are thinking about instituting a pot pedal, are you aware of the floor pedal used by pedal steel guitarists?  They are made of aluminum and are fully enclosed. Some, like my Goodrich pedal, have a power jack on the back that uses a standard wall wart converter. Others, like the Hilton, use a different jack for a plus/minus supply. These pedals come up for sale on the Steel Guitar Forum on a regular basis.

 

Here is an ad for a used Goodrich pot pedal for sale.

[gigi]

Thank you for the suggestions! We thought about the floor pedal too (adding this after replacing the clutch motor with a regular one):  just need to find a pedal with the proper resistance. Also would like to keep this solution under a certain cost, otherwise would be more economical to buy a servo.  

[Wizcrafts]

7 hours ago, Sticks said:

How would this be implemented in this case.? 

I don't know how the foot pedal's pot would be connected to the servo motor. That's for the electronics gurus to figure out. My pedal uses a 500k audio log taper long life pot with a sealed carbon element. But, once they come up with a way to have an external pot, as long as the cable can be up to 3 feet long, a steel guitarist's volume pedal makes an excellent enclosure. They pivot very smoothly from the rear and have tension adjustments that can be set to your foot action. I set mine so it stays put wherever I have it when I take my foot off the pedal.

There are 4 screw-on rubber feet to keep the pedal in place.

Anybody pondering this idea needs only to go to your nearest bar that has live Country Music bands that have a steel player. I'm sure he will let you look over his floor volume pedal. If you are in mid-Michigan, look me up for where I'm playing on any given weekend.

[dikman]

TT has a good point about proffering information that could cause problems for someone who doesn't really understand the subject. If you already have a 3-phase motor on your sewing machine then a suitable VFD (particularly if the price is right) could be a viable solution to speed control. However, as Gigi has pointed out, there are problems making speed adjustments on-the-fly unless you have three hands! It will need work to enable speed control via a foot pedal.

If you have a conventional (single-phase) clutch motor then a servo is the only way to go. Fitting a VFD/3-phase setup will be costlier and require additional work, whereas swapping to a servo is a straightforward changeover process.

Gigi also mentioned changing her clutch motor to a "normal" motor, but again unless you can pick up a suitable 3-phase motor cheap (unless you have one lying around) then it would be much simpler to just fit a servo.

[dikman]

Could be a bit tricky to implement, Sticks, but worth trying as basically all it will cost you is time. If it works then fine, if not you (we) will have learned a bit more.

[Constabulary]

what do you think how much torque you need? Better buy an electrical safe and out of the box servo motor. College Sewing sells 550W Servos for 99GBP + tax. At the end it´s cheaper than any tinkering + no electrical experiments and you have warranty. An additional speed reducer for sure is a good idea but depends on your purposes.

My 2 cents.

[Constabulary]

All servos work will with speed reducers. I have 2 JACK servos both bought from College Sewing and both run with a speed reducer. BUT Jack servo motors with needle positioning system do not work with speed reducers. At least the NPS does not work with a speed reducer but you can tun off the NPS. CS probably does not know speed reducers because they don´t have em for sale or have not setup a machine with a speed reducer ever. It does not matter if clutch or servo motors - they all can work with speed reducers. Check this forum you will find dozens of different SR setups.

https://www.google.de/search?q=speed+reducer+site:+leatehrworker.nert#q=speed+reducer+site:leatherworker.net

Edited November 9, 2016 by Constabulary

[TinkerTailor]

2 hours ago, Constabulary said:

what do you think how much torque you need?

My 2 cents.

I was looking for motors for a bench buffer/sander project and I found a westinghouse, is that good? Here it is:  http://vancouver.craigslist.ca/rch/hvo/5842965788.html

The advertisement said it was 3 phase and I was wondering if it will work? It may be a little overpowered (600hp) but hey, better safe than sorry. Now I have to find some kind of converter to get a motor rated for 4000 volts and 76 amps down to 120volt. And some helper springs so my volvo can carry it home. Its only 6900 lbs. Ill just keep it to second gear.

Do you think i will need a speed reducer to get more punch?

[billybopp]

That'll work just fine, Tinker.  At 1190 RPM you will need a reducer, but this motor has the huge advantage of not needing a table at all.  You just mount the head on the motor itself.

Bill

[gigi]

5 hours ago, TinkerTailor said:

Do you think i will need a speed reducer to get more punch?

Good luck finding a speed reducer for this motor!  

Now seriously: I want to make a DIY finishing/buffing/polishing/burnishing/sanding machine too using probably also a VFD since some wheels or brushes require a different speed than the others. 

[dikman]

TT, you'd probably blow every breaker in the neighbourhood when that monster was turned on!

Gigi, that sounds simple enough.

[Constabulary]

depends on the actual specs and "how similar" your motor is. Motors like this sometimes find use on patcher machines (at least on my side of the pond) but they just have 90Watts. You still need an accelerator pedal that is matching the specs of the actual motor. But I´m not an electric expert so someone else has to jump in here.

http://naehmaschinentechnik-forum.de/viewtopic.php?f=14&t=1183

See pictures

http://altenaehmaschine.de/Adler-30-1-9

Edited November 10, 2016 by Constabulary

[billybopp]

It would work if you can work out how to control it.

[dikman]

Any of them could work, I guess, but some would require considerable modification/fabrication to do the job. Forget 24v motors as sourcing a suitable power supply would be an issue.

At the end of the day a servo that's designed for the job and simply bolts in place is hard to beat.

[Constabulary]

A treadmill? Whats next - an electric lawnmower or an E-Bike? I absolutely agree with dikman. Tinkering is nice as long as it is much (much) cheaper and / or you get much more performance out of it but in general I´d (again) say an out the box servo + speed reducer is the best you can do. But thats entirely up to you. If you like tinkering start with making a speed reducer.

Edited November 11, 2016 by Constabulary