Brakes for Computer Controlled Winder

[ken]

Hello...

I got my CNC winder to work, but I need a method to stop the wind when I get to the end of the coil. Does anyone know where I can get a small electric clutch/braking system to automatically stop my machine with, or am I stuck with a DC motor and 'dynamic braking' with big resistors like a big CNC machine tool uses?

Thank you,
Ken

[R.G.]

I got my CNC winder to work, but I need a method to stop the wind when I get to the end of the coil. Does anyone know where I can get a small electric clutch/braking system to automatically stop my machine with, or am I stuck with a DC motor and 'dynamic braking' with big resistors like a big CNC machine tool uses?

I went through a lot of electronic braking setup research when I was looking for automatic tensioners. For a winder to stop at the end of the wind, you need a much simpler system, just a calibrated "stop now" that gives a non-jerky stop.

About the simplest is a solenoid pulling one end of a leather band around a pulley or shaft. Set the full tension on the band so it isn't a hard stop.

Another that's simple is an electro magnet "caliper" turned on around an aluminum disk, for an eddy current brake.

If you have access to some machining capability, you can do an electro magnet that pulls a steel disk in contact with a leather disk. Some of the commercial stuff works essentially this way.

The commercial stuff is great, but starts at about $300.

[Joe Gwinn]

I got my CNC winder to work, but I need a method to stop the wind when I get to the end of the coil. Does anyone know where I can get a small electric clutch/braking system to automatically stop my machine with, or am I stuck with a DC motor and 'dynamic braking' with big resistors like a big CNC machine tool uses?What's wrong with a permanent magnet DC motor and a switched resistor? This does not have to be complex.

[ken]

I think Joe is right about the DC motor, the Moriseiki CNC lathe I used to run used the 'big resistor' dynamic braking system. I found some 12v DC motors from the seat lifter part of a Rascal scooter at a industrial junkyard, so I'm going to try them for a main motor instead of the AC motor I was using. It would sure make direction reversing easier too.

Ken

[David King]

Seems like a perfect excuse to use a 3 phase motor, to stop on a dime just throw it into reverse for a second. A stepper motor would stop within an arc-minute or less. Granted i have 3 phase in my shop and variable frequency drive for the mill.

[Joe Gwinn]

Seems like a perfect excuse to use a 3 phase motor, to stop on a dime just throw it into reverse for a second. A stepper motor would stop within an arc-minute or less. Granted i have 3 phase in my shop and variable frequency drive for the mill.But if you stop too quickly, the coil will unwind itself. As the bobbin flys off the holder.

[Ampclutz]

If you have a CNC winder can't you program it to ramp up and down?

AC

[David Schwab]

Speaking of CNC winders... someone gave me a Lego MindStorms System 2.0... they say you can program it to work as a flatbed image scanner...

Wonder if I can get that same stepper to work as a traverse?

Anyone ever mess with one of these things?

[ken]

I'm going to do both... start ramping down the speed near the end of the coil, and try a dynamic brake for the final stop. Geez, I shoulda thought of that one before. :D

My kid is a Legomaniac, I used to buy him all those toys every Christmas and never thought of them as actually 'useful'. Maybe I'll build my next winder strictly from Legos... just for laughs.

Ken

[David Schwab]

I actually saw a winder made from legos somewhere on the 'net.

I just want to try the stepper motors and see what can be done with them.

I'm not sure how fast they move. If you can use them for a scanner, they must be somewhat precise.

Then of course I'd have to figure out how to program the thing.

[kevinT]

I actually saw a winder made from legos somewhere on the 'net.

i did too. i think it's on YouTube.

[murof]

I'm not sure how fast they move.

about 600 rpm max.... for a stepper with 1ohm 2A/phase with 24volt supply
acceleration and deceleration is programmable

i'm building a cnc winder.... :D





excuse my english... :confused:

[fuzzman93]

Hi Ken,
Try to find an broken tape recorder.The brake system is fine for stopping and there's all the pieces you need for .I'm just doing my first rewinder with a broken 4tracks Tascam.The motor is running at 1600 rpm with 24V DC .The motor is very quiet and very strong!It tooks me only two day for doing a nice rewinder with junk parts .The only missing part is the pedal for changing speed.I put the tape counter with his pulley for the moment maybe i'm going to improve it with an electronic and a stop.
I will just have to adapt the breake inside the box if i can.
I'll put photo this weekend here like that everybody here may find some ideas.
@Bruno

[Peter Naglitsch]

Project guitar had a thread about building winders with Lego:
http://projectguitar.ibforums.com/index.php?showtopic=16999&hl=Lego
Unfortunately most of the pics are gone. It was hilariously funny. And it worked!

[fuzzman93]

Hi there,
Nice toy,but if i'm remenber the only negative thing about lego's is you've got to glue the parts themselves if you want your project win at the first baby attack or a fall from the table!!Haha!But very clever i like it ,in france we had got another toy for building some nice projects,it was called Meccano.You can always find some parts on E-bay.Motor,pulleys,everything to mount a nice winder!I will put some photo's next week.

Here's some shoots about my project.It is not finished(guide ,paint ,varispeed and maybe an optional electronic automatic turn/stop controler with breakers.),but i want to show it's possible to DIY for FREE!!I'll put news shoots once it will be finished.Today,i'm going to put a voltage speed controller(with hand or by a pedal ,depend if i could put the pot in a enclosure.



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