cnc winder controller board

[David Schwab]

What was ever decided on for a tensioner?

[mikejn70]

Hello all I'm new to the forum and would like to show my interest in a group-buy. I,ve been sitting on the fence watching this project develop for while. Although I play guitar I admit I,ve no interest in winding my own pickups but do have interest in winding flyback transformers.

keep up the great work.

Mike

[David King]

David,
The tensioner is a solenoid that presses the wire between two pieces of felt. Up the voltage supply to the solenoid and the tension should go up. I don't know linear it will be but that's something to find out later.

[Arndawg56]

Nice drawings, but I noticed they don't look much like your mockup in the uTube video. Have you tried them or is it just computer renderings?

[Joe Gwinn]

IWe could simply publish a PDF docs with all the holes that can be printed and stuck onto the MDF, wood, plastic, aluminum etc the person prefers to use. ....

If I were to use ball bearing I'd use the type that are already mounted on a plate (Flange bearing) for vertical mounting surface or in a pillow block for horizontal surface that will compensate for less than perfect alignment.
Like these...
POBCO TriMount® 2-Bolt Side Flange Metal Mounted Bearings

If one will build the frame of wood, one must design to accommodate the the changes in frame dimensions and alignment when the humidity changes, or the winder will be useless in seasons other than the season in which it was built.

Spherical bearings (like those mentioned above) and flat or toothed belts are a good approach, as they can be made quite insensitive to such changes. And to minor errors of construction.

But tolerance of humidity and temperature changes and construction inaccuracy must be built in from the start.

[David King]

Baltic birch plywood would be my first choice because I have tons of scraps laying around.
The 1/2" acrylic scraps from Tap plastics at $1/lb are another good option.
MDF, HDF are good because they are dirt cheap or free scrap at most cabinet shops and do a decent job dampening the stepper motor singing.

Top of the line would be 3/8" 6061 plate or 3/8" "L" section angle if you can afford it.
Thin aluminum will sing like a freight train unless you build it rigid with dampening or use rubber "O" rings on all the motor mounts.
I wouldn't be averse to cutting up birch ply and drilling all the holes on the milling machine. That goes very quickly once it's set up so cost is minimal and shipping weight isn't too bad.

The leadscrew, rubber hose connectors, leadscrew nut, end bearings and spacers would be part of the metal kit along with screws, washers nuts etc.
I'm happy to turn birch plywood faceplates with collars to fit the main motor. What diameter? 4"?

If someone wants to do a belt drive to get a higher speed then they can figure out their own transmission systems. The steppers max out at around 1000 RPM i.e. ten minutes per coil or less. That's just enough time to solder your leads and tape things up for the hot wax while the next PU is in the winder.

I want to test out some traverse ideas before committing.
What's the maximum coil height people need? Is 2" of traverse travel enough? Does anyone intend to wind 2 or more coils at a time?

I really like having a live tailstock that holds the bobbin on and slides out of the way in a hurry.

Oh and what's a fly-back transformer?


Found these http://cgi.ebay.com/Delrin-Flange-Nu...mZ330365030143

http://cgi.ebay.com/18-inch-3-8-10-R...mZ330365021048

[-Elepro-]

about 9$each (for 20 pieces production) for the big brackets
and about 7$each (for 20 pieces production) for the small brackets...

each of ou would pay 32$ for 4 metal (3mmtickness) brackets..... (if you are 10)

Get a Real-Time quote for your bracket needs.

[David Schwab]

David,
The tensioner is a solenoid that presses the wire between two pieces of felt. Up the voltage supply to the solenoid and the tension should go up. I don't know linear it will be but that's something to find out later.

OK, cool. I had been skimming through a lot of the posts back then.

[Joe Gwinn]

The tensioner is a solenoid that presses the wire between two pieces of felt. Up the voltage supply to the solenoid and the tension should go up. I don't know linear it will be but that's something to find out later.

Also worry about how quickly the tension can be changed, as big solenoids have a lot of inductance, making it hard to change the current (and thus clamping force) quickly.

Speed matters because a servo tensioner must be a factor quicker than the wire speed and tension pulsations from winding on an oblong bobbin.

The alternative is to use a very light and elastic dancer to handle the pulsations, so the felt tensioner need not be nearly so quick.

[RedHouse]

...The steppers max out at around 1000 RPM i.e. ten minutes per coil or less....

Not the motors Elepro suggested in this post which I bought. A tach on my test build shows it does 593-RPM max w/o the pulley transmission using the Dragon driver boards in 1/2 step mode and Elepro's controller.

Did you measure 1000-RPM or are you still using the flapping-tape guess method for RPM measurement?

[-Elepro-]

Not the motors Elepro suggested....

excuse me.... i'm ingenuous..... i choose it reading datasheet and i have not considered very cheap price.... but i did it Hoping you would save money... of course i could suggest a 100$ sanyo denky motor.... as you can see dragon driver datasheet suggest same motor specifications.....

A tach on my test build shows it does 593-RPM max....

about difference from speed setted on controller (600 rpm i hope) and speed measured, it depend on PIC internal oscillator tollerance.... (it has not an external xtal).... but i think it's not important if you set 600 and have 590 or 610 rpm...

[David King]

Brad,
I'll stand by my flapping tape method. When you misspend a few years of your life operating lathes you get tuned into things like spindle speeds. I can send you a motor or you can send me a tachometer if you're still in doubt.
I should point out that the larger motors can handle the full 2.4A and the motor resolution is much better at the higher current levels.
The motors that Tim W is selling were chosen by someone long ago to work with those drivers. They were all pulled out of some medical or scientific equipment that was scrapped when it became obsolete. Probably some engineer actually got paid to match everything up.

Benefit of the brackets is that they will help keep the motors cooler.

Elepro,
Are the brackets cnc drilled for that price?
I can buy a 12' length of 1/4" alu "L" bracket and saw it up for about 1/2 that price.

[-Elepro-]

Elepro,
Are the brackets cnc drilled for that price?

i think yes

I can buy a 12' length of 1/4" alu "L" bracket and saw it up for about 1/2 that price.

good, i think metal brackets is best solution... your price is with holes too??

after my final test we will open a new thread..

[David King]

No holes on the thicker brackets, I don't have CNC or a cold saw for accurate cut length so jigging for holes would require facing the ends on the mill and jigging up for the holes, =more time and $.

The brackets will probably be happier with some wood pieces between them to build box shapes. What dimensions did you enter? Will there be enough room for motors, controller, drivers and X-former inside? We may need a little fan too if folks decide to enclose everything.

I'd like to think that people who makes pickups will own a drill press at least. The guys I know who want an automated pickup winder are all guitar makers and will have jointers, tablesaws, planers and routers too (but no money).

[David King]

Also worry about how quickly the tension can be changed, as big solenoids have a lot of inductance, making it hard to change the current (and thus clamping force) quickly.

Speed matters because a servo tensioner must be a factor quicker than the wire speed and tension pulsations from winding on an oblong bobbin.

The alternative is to use a very light and elastic dancer to handle the pulsations, so the felt tensioner need not be nearly so quick.

Joe we are no longer considering a servo tensioner with feedback loop or trying to alter tension mid turn. Instead the solenoid will just apply a constant pressure that's regulated in 100 steps by the controller.

Dancers are fine but they always have a resonant frequency where they end up doing more harm than good. Dan (Immoderator) has suggested keeping 1-2 feet of wire between the tensioner and the coil to minimize localized stretching and breaking.

This tensioner is separate from the traverse. No one needs to use the tensioner if they have a different preference...