Replacing a servo motor

[LumpenDoodle2]

I have a Juki ls-341, and I think the servo motor may be losing its "ooomph", so I was having a think.   I have a laser engraver, and a 3D printer, if a motor were to die, I would just plug in a new motor.   I don't buy a whole new system with control box, etc.

Question, can you do the same with a sewing machine servo motor.   Could you not just buy a 1.5hp motor, and plug it in to an existing system, to replace a 1hp motor.

Just curious.

[bikermutt07]

The guys on here sell just the servos. I think they are around 150.

[mikesc]

In theory, yes, but to be certain you'd have to open up the control box of each to check that the circuitry was the same ( all components had the same values, and the "chipset" was the same etc ) ..Yes I know that you wouldn't have the second control box, but the only way to be certain would be to have two "sets" to compare from the same manufacturer..The thing is, the servo motors and control boxes are always sold as sets, ( ex factory in the same box with the polystyrene packaging pre moulded fro a "set", even down to the EPS ( if you don't order EPS, the factory just does not put it in, but the dedicated space is there in the box for it ) I'd be very surprised if you can get any distributors to sell you just a motor, because they'd have to open a box with a set in it and take just the motor out..Leaving them with a spare control box.

Of the hundred pounds or so ( retail price for a kit in the UK ), I'd be surprised if the control box cost more than £30.oo of that.

But nothing ventured etc..so You could ask College or another UK supplier about it.

biker mutt..when the guys on here talk of selling servos at $150.oo they mean the complete kit, servo motor and controller ( some are mounted directly onto the motor, some are "remote" ) but that is the price for the kit..and LumpenDoodle2 is in the UK ..220-240 V..the guys selling on here are USA..110V..

Edited October 21, 2016 by mikesc

[LumpenDoodle2]

Thanks, I was going to give College a call, but I like to sound as if I vaguely know what I'm talking about when I do.

[mikesc]

When you call, ask to be put through to "Dave" ..their machine mechanic..really nice guy ..

[CowboyBob]

It will help them if you know the brand & model# of your current motor.Should have a tag on it with all the info.

[TinkerTailor]

Since you are from the UK, I should also note that I think there is an issue with some of the cheaper motors and using british power, not because of the 110/220 volts but because the frequency of the power is at 50hz and not 60hz like in the North America.  I think this is why the motor Harry Rogers on youtube  has squeels/beeps constantly. It is a circuit running on a frequency it was not designed for and is causing audible interference.

[brmax]

no you cannot use a standard motor, Sorry.

Some of the new hype with the servo motor is its easily made to start and stop at will "with" your control of choice (foot) in our case.

Them other motors have to have an additional setup for "starting" for other machinery. On our sew machines there is a bit older design ya heard of as clutch style, and just as a car, the motors running all the time you just have to use the clutch for starting and or gear engagement.

A part of your question is yes motors can be wired to plug in some where, but are required to have a means of power switching to off.

So on your present setup, most motors have the wires going to the switch box area at a certain reachable position, in this box there is generally international wire color codes used for power and ground.

Floyd

[dikman]

Good question. The only way I can think of to really find out is to spend time searching alibaba and aliexpress, the two main Chinese online selling sites. If you can find the same motor that you have, sold separately, then the answer should be yes. I know they sell many different types of servo motors but I've never seen any listed as a spare for sewing machines. As Mike said they're generally sold as complete "kits", with the wiring and connections specific to the particular control box. Even if you did find one on those sites, whether anyone outside of China would bother stocking just the motor is another matter - and it would probably cost you nearly as much as a complete replacement anyway.

[hackish]

Sadly, most of the Chinese motors are absolute garbage. The common EPS systems are generally the same inside and would never pass the electrical and safety requirements of most countries. Live 120v power inside the EPS box? Yikes! I may have said a bad word or two when I first took mine apart and learned this. I'm just waiting for a shipment of Panasonic servo motors and controllers to arrive. If your motor is losing umph, try pulling the belt and making sure the shaft turns properly and that the machine itself is not in need of lubrication. Sometimes threads caught on the motor shaft can cause your power reduction. Since they're brushless, the motors don't electrically "wear out" unless you started overheating the heck out of them, but in that case, usually the driver will give up the ghost in a smelly cloud  of smoke.

[LumpenDoodle2]

6 minutes ago, hackish said:

Sometimes threads caught on the motor shaft can cause your power reduction. Since they're brushless, the motors don't electrically "wear out" unless you started overheating the heck out of them, but in that case, usually the driver will give up the ghost in a smelly cloud  of smoke.

Many thanks for replies folks.  Hakish, this motor cane from a well used and abused machine, and whenever I try to sew something thicker than a couple of millimetres, the motor makes slipping sounds, stops working, and I get an error message which apparently means low voltage.

 

[hackish]

The two I have are the sewquiet 5000 and consew premiere csm 1001. You get what you pay for. If I thought there was any money in it I'd design a proper controller for these things. If you're getting a low voltage error then maybe the wiring to the motor has become worn or the plugs are dirty. You should be able to test the resistance of the motor coils to narrow it down as well.

[TinkerTailor]

How overloaded is the circuit the machine is on? An overloaded circuit will brown out and drop voltage. Have you tried the motor on a dedicated plug to be sure you don't actually have low voltage coming from the wall?

It could also be that the motor is not powerful enough for how it is geared. If it has pulleys designed for fast speeds and you are running it slow into thick stuff, it may be running out of jam. A speed reducer will fix this, as will a more powerful servo motor. How many watts is the current one?

[LumpenDoodle2]

It's an Aerostar JM-811, 4,000rm, 750w, max torque 7.8n.m., and It was bahaving like this with the standard 50(+?) pulley.