A question about servo motors

[Jeff51]

I’ve been looking at servo motors on Amazon. I see conflicting statements in the reviews.

Some seem to indicate that the servo speed jumps from 0rpm up to the setting on the servo control.

Or, the speed jumps from 0 to 400rpm (for example) then is variable up to the set point on the controller.

Meaning there is no option to run the servo at slow speeds – IE just a few RPMs.

 

Others seem to indicate that the serve will run from 0rpm variable up to the speed set on the controller.

I realize that most Amazon reviews are to be taken with a huge lump of salt…

Which is correct?

 

The Mophorn brand seems to offer quite a few options at very reasonable prices. For example:

Amazon Morphon Servo

Any of you have any experience with this brand?

Thanks for the help,

All the Best,

Jeff

 

 

[Wizcrafts]

Jeff;

I went through the same thing with digital servo motors. Now I only buy analog control servo motors, such as those sold here. These motors can be setup with a tiny 45mm motor pulley, or a larger 70mm. The smaller one makes it easier to feather the machine for very slow sewing. The larger one gives more top speed. I find the larger one unnecessary in leather sewing where you probably won't want to exceed 10 to 15 stitches per second flat out.

[Jeff51]

Thanks Wiz for the quick response.  With the digital servos are they basically all the same?  The needle positioning ability seems like a handy feature.

I'm at the tire kicking phase of looking for a machine.  Not much available locally.  And unfortunately most dealers are 300 miles away or so.  Did find a good deal on a Techsew 1660, but decided to pass on it because a cylinder arm will be more versatile.  I'd just end up replacing it eventually.  

Thanks again, All the Best, Jeff 

[chrisash]

No motor will start at 1 rpm they all have a minimum low speed start up, some will say 100 others about 400 rpm,, the ones wiz likes have little slow speed torque whilst the other servo have good start up torque the choice is yours. I would suggest searching YouTube for the various models and see what you fancy. don't forget most come with 75mm pulley so a 40-45mm is nearly a half reduction and then reduced again with your machine pully so one that states it starts at 400 rpm may be more like 100-200 at the machine with a 40-45 puller, which will be more than suitable for most and far down on clutch motors by a mile

[kgg]

43 minutes ago, Jeff51 said:

The needle positioning ability seems like a handy feature.

A lot of people find the needle positioner good but.... but not all are equal or work properly with all combinations of digital servo motors. If you are considering a needle positioner buy the complete setup (motor / speed reducer / needle positioner) all at one time from a company that have a proven combination setup.

As far as servo motors you basically got two options i) a good old fashion proven brush servo motor with a small knob speed dial or ii) a digital controlled brush-less servo motor. One of the problems with the digital servo motors is the number of internal coils that the motor is constructed with. The more coils the better the control and torque for the motor. I suspect the cheaper ones have 6 or maybe 9 coils. A good 12 coil digital servo motor would be similar to the Reliable Sewquiet (www.reliablecorporation.com/products/sewquiet-6000sm-servomotor ) or the Sailrite clone. My thought is for most use, a brush servo motor if it is properly broken in under no load, should provide a lot of decent reliable service. I have this type on three of my machines Juki 1181n, Juki 1541 S and Kobe LS -1341 (Juki 341 clone).

kgg

 

 

 

[Pintodeluxe]

I've had digital servos that were super slow-sewing, and other digital servos that were jumpy.  I agree with Wiz that the analog are more predictable, and easier to sew slowly with.

The analog servos do truly seem to be all the same.  Rex, Family, Hi-Tech and other brands all seem to re-badge the same motor as their own.

Try one.  Worst case scenario... it's still not slow enough for you and you can add a speed reducer at a later date.  I added a box style speed reducer with an analog servo and it is perfect for me.

I could have gotten away with the servo only, but the reducer adds power and further reduces speed.  

[kgg]

6 hours ago, Jeff51 said:

The needle positioning ability seems like a handy feature.

Also you may want to view the topic and discussion around a new Consew servo motor ------  "Need Help with new Servo Motor install and Needle Positioner "

kgg

[dikman]

If you want slow speed control in my opinion a speed reducer is a necessity with a servo. If used with the digital servos it tends to compensate for the low-speed jerkiness they sometimes display and provides more torque at low speeds. The "downside" is that your top speed will be a lot lower and you will have to change the servo settings to increase it (this isn't a problem for me because I like slow speeds for leather, but if you do production work it could be an issue). Also be aware that some servo needle positioners don't work if a speed reducer is used.

I tried a needle positioner but didn't like it much, fortunately because I like slow speed sewing I find I don't need it.

[Jeff51]

Thank you for the replys.  I had planned on getting the smaller pulley to slow things down further.  The info about the number of poles was informative.  Never considered that aspect of it.  The ones I had been looking at had 9 poles.

Other than the Family Sew FS-550s, Sailright, and the Reliable Sewquiet are there any other brands that are known to be good performers?

Thanks again,   All the Best, Jeff

[bj139]

Here is one of those brushless servo motors.  I have no experience with the brushed type.

 

Edited July 22, 2021 by bj139

[kgg]

1 hour ago, bj139 said:

Here is one of those brushless servo motors. 

Interesting the speed difference between the two machines using the same motor and same size handwheel.

kgg

[bj139]

3 minutes ago, kgg said:

Interesting the speed difference between the two machines using the same motor and same size handwheel.

kgg

I'm pretty sure both were run at minimum speed for that motor.  Both are slow enough for me I think.  I have to get some leather to try.

Are they really different?  I don't see it.

Edited July 22, 2021 by bj139

[kgg]

5 hours ago, bj139 said:

Are they really different?

I thought the video with the Singer was slower then the other one. Maybe just me. Either will give you the control for those places where you need really slow precise thread placement control. Nice simple speed reducer setup.

kgg

[dikman]

I've used the same method, bj139, and it's a very effective way of getting slow speeds on a machine. I also added a speed reducer to one and it made yours look like an express train!

[bj139]

On 7/22/2021 at 7:06 PM, dikman said:

I've used the same method, bj139, and it's a very effective way of getting slow speeds on a machine. I also added a speed reducer to one and it made yours look like an express train!

$18 for the pulley is a cost effective way of getting slower speeds.  My reaction time is quick enough for this lightning speed setup.