Torsion spring winder.

Guys, I have a manual spring bender that I made from a small 7/12 lathe spindle and chuck.
There are no motors on it and I would like some help designing some controls for simple motors. The springs I make are both left and right hand twist torsion springs with 4 coils made from .31 SS spring wire.
They turn out fine by hand, but tedious to make. I might use a couple hundred a month of each side. A motorized machine will most certainly be of value.
I can show a picture or two of the spindle and the fitting I made for the chuck.
I will need some help with the controls I think.
It needs to turn clockwise for one side spring and counterclockwise for the other. Each gets 4 turns. Not sure what kind of control and motor might be best for this.
Any thoughts or ideas?

Thanks in advance for any light you can shine.

Yup! I will love to see what is it that your are manufacturing and if possible I would love to help!

Thanks, Mark.
Here are a couple images of the assembly. This is part of a tablesaw blade guard system that we make. The springs just keep pressure on the front toothed parts called anti-kickback pawls. The spring keeps thos parts in contact with the material being cut.
In the second image, you can see that what we make are torsion springs. 3 3/4 coil. One end has a 90 degree bend that goes into a hole in the red part. The other has a hook that catches the backside of the pawl. The pawls ride on the brass bushings. Pretty simple spring really. The wire size is actually .031" diameter. Not .31".

I will show my little manual spring maker soon as well. I have asked several spring companies if they could make these and the ones that replied said they could not. It may have been the 1000 to 5000 count for each side that kept them from wanting to take the job. Apparently that is small numbers for spring makers. :(

Attachment 243644

Attachment 243646

Yup! I understand, and you literally took the words out of my mouth. Most companies wouldn't do the tooling for any less than some what around $1500 contract! and if they only do the tooling for only the money it cost to make the tooling! then there is not profit! Will be waiting to see your video thanks for the images!

Here is a short video showing my manual machine and how it works.
It has a steel roll pin installed beside a 3/8" brass rod. Both installed into a steel collet and that is captured in the chuck.
I currently turn it by hand. I have to turn 4 rotations to get 3 3/4 coils needed. There is a bit of spring back when released.
I stick the wire into the roll pin. Then bend 90 degrees in this direction. I rotate clockwise for right handed springs and CC for left.

I know typical spring machines work differently. The material is usually sent through the spindle and has pinchers or pinch rollers that advance the material. Then they have numerous tools on the face plate that activate to form the springs precisely. Then cut and start all over.

Not sure that I could even use something like that to make a torsion spring. This works pretty well, but since it is manual, it lacks a certain repeatability. Not to mention it is hard on the fingers. ;)
Rotating the spindle with a motor will be the easy part. I actually have a spare G540 here, so could use that. Mach 3 even, so may not need an Arduino.

I am thinking that I could use a swivel type attachment to take the place on my hand. Goes from parallel with the roll pin to 90 degrees on it to create the initial bend.
The pinch roller or roller feed (like on a wire feed welder) would be mounted on it.

So far, that is three motors. Spindle drive, worm gear on a 1/4 radius rack to swivel the feed roller and then feed roller operation. I am comfortable doing the Gcode by hand on this.
Anyway, I will start designing some more parts on it and see where we would be headed. Any other input would be appreciated. :)

https://www.youtube.com/watch?v=NMh3V4u_NJM

Well I can see your point! but unless you make a decision to feed the wire through the spindle and make a few robot arms that work either by timing or by program! then, the only thing that you need to do is just to put a planetary. gear down, on the shaft of the machine that you are using! and if you manage to get to know the amount of steps per final revolution... I can share with you the G code that I'm using for my tool changer, so you can tell the machine how many turns you need the stepper motor to give you and in that way. "AT LEAST THE TURNING OF THE SPRING" will be done automatically!

Good luck man!

Thanks, Mark.
Since I have to use this manual winder every week, I will use it and just start motorizing parts of it. That will solve a few minor issues. As I mentioned, this setup isn't like a normal spring machine. I think they are not only heavy duty, but most likely have a very short spindle. Maybe a single large bearing. The wire feed is probably right behind the face plate and heavy duty itself.
I would like to design a proper one that is on a small scale though. A purpose built one like that should not break the bank and would not have too many tools on it. I imagine most of the tools would be air operated. That would be a fun part to tackle.
I'll start getting some parts together to motorize this one and go from there.
Thanks.

Here is a really nice video of making a torsion spring. :)
I imagine that machine cost a few bucks, but would certainly make what I need.

https://www.youtube.com/watch?v=SfnIoH_0N_k

Excellent! may I ask you do you have any cnc machine at this time! of any kind? Just for your records.. I have not yet expend not even 1000 dollars on my project! Given. I know that as an engineer, I can overcome a truck load of obstacles simply by making my own parts! I have lathe's a milling machine, and almost any kind of hand tool and welding machine under the sun.. and have been making my own tools since I have recollection of memory! my dad was a industrial mechanic! I think that here in the US are called a Shop Wright. and are the people that make the initial set up of large factories, and manufacturing facilities. so I grow up with the I don't care how much it cost! I only care to know how it works so I can fabricate mine....
Let me know when ever you are ready for my macro! I will gladly post it so you can use it according to your needs! perhaps the only other advice that I may give you. Is to look on the pawn shops for the oldest possible cordless drill that you can put your hands around! The quality of the planetary gears on those oldies, is way better than what you can get of the shelf.. and way the hell cheaper than any thing else!

Good luck man.

Mark.

Yeah.
I have built my own cnc router, mill, lathe and plasma cutter. Also have a Novakon Torus mill. No stranger to that. I also used to set up furniture plants that would produce wooden dinette sets and bunk beds. I built all the jigs and setup all the machinery. I even designed a built a dust collection system for the smaller plant.
Just watching some of the videos, especially the ones that have close up and slow motion makes it pretty easy to understand. It has me thinking about making one with a short spindle and face plate, but also make the coils on a secondary spindle.
I have some more thinking to do on this matter. :)

Found another nice link.
Spring Manufacturers Institute

Good info there. In fact, after reading that, it is probably entirely possible to make my springs with tools all mounted on a simple flat plate. Wire feed accuracy would be a key element.
I know the one on my small wire feed welder would probably do the job and it is compact as well. It would need a small stepper motor and gear. The wire would then feed through a collet. A punch would then engage to make the first 1/4" bend on the first leg.
Then the left or right hand coiling tool would engage. Then coil in the correct rotation. Then disengage.
Feed a bit more wire and a pincher or needle nose would make the last hook twist. Then the shear.
It does sound pretty simple. It would be a design I could easily modify on the prototype. Initially I could mount elements to plywood to work out the kinks.
A simple machine like this could even hang on the wall and not take much space.
I think I will proceed with a design along these lines.
I don't want to get into the spring making business. ;)

Here is a fairly simple one.
http://www.springmachine.net/upload/month_1105/26a.jpg

I can see that you are digging really hard! and don't think that you will have any kind of problem! I was kind of surprised to find that you are so experienced! I'm here because it was my first CNC machine! and was hoping for some feedback!
I don't think that there is to much help that you can receive from the people in this forum!
YOU MAY BE ABLE TO HELP AND SUPPORT! but I don't really see it happening in the opposite direction.

Mark

Lee,

Have you seen this? https://www.kickstarter.com/projects...op-wire-bender

You might be able to find some inspiration there.

bob

Thanks Guys. That is a pretty cool bender for sure. Looks like it could bend some substantial wire. I am thinking that this machine I am contemplating can most likely use all nema 17 motors. A geared Nema 17 would be pretty strong. The main job or hardest part would be driving the wire itself. When coiling, it would be assisted with another motor in rotary motion. Then I could actually use a drive board from one of the 3D printers. It would be a pretty small footprint machine, but it is only working .031" wire. I may have to move up to .035" wire if I cannibalize my little old wire feed welder. That is the size it uses and the feeder was designed for. Should not make any difference in the operation on the product.
A little stronger is fine.

Now, the other day I did another round of submitting my needs for quotes from a few new spring makers.
I did get one returned so far and they are only wanting .24 cents each for 1000. That is a little more than a years supply, so I think I am going that route to start with. That would give me plenty of time to develop a good machine to take over when the first order runs out.
I will still keep updating on the design. I need to do it while the research is fresh on my mind. ;)

Well guys, I am picking this back up.
I did get a geared head 12 VDC 13 amp motor that will do some turning. Have a Power supply and a few switches and leds in hand. I will use 35 chain to drive it with.
It is 20 RPM. That will get the chuck turning okay. I will mock it up to start with in plywood. Then I can decide where things can go like the wire reel holder and feed mechanism. I'll work out the details later. I may be able to put an encoder on this for positioning.
More will come sooner than the last time. :)

I did finally get the machine mocked up on a plastic base plate. 1" starboard.
I will get some pictures up at some point.
Now that the machine is motorized, it makes more consistent coils in the springs. I have been using a smooth brass rod as an arbor or mandrel to turn the springs around.
I ordered some threaded rod and coupling nuts in both left and right hand thread. I will use those instead of the smooth rod. The spring coils will lay in the threads and give an even more consistent coil. Just swap out the mandrel for RH and LH threads. The gearing in the motor is a beast. No way to turn it by hand. The #35 roller chain is a good drive choice as well. Nice, cheap and strong.
It rotates pretty slowly, which is perfect for semi automated. Semi manual if you like. :)

I will cannibalize my little welder for the wire feed mechanism and the coil caddy. Probably install it at 12 o'clock over the spindle. That way both CW and CCW springs will have the exact same amount of coils. Easier to see what is going on that way too.
More will follow when I receive the coupling nuts and get the new mandrels built.

A little update.
I did tear into my little welder. I do believe the motor is a little DC motor, but not sure of the voltage. I will check it out on 12 VDC. I am not sure that I even need to power up the motor. I have to pull tension on the spring wire when I am forming them on the mandrel. I may only need the back pressure from the feeder through the gearing and the little motor. It will need to be connected though to get a new roll started when that needs done. My wire does not come on a spool. Just a coil. It can get away from you quickly. For that reason, I will need to make a canister with a screw on lid and a hole with a grommet to feed the wire off the coil. The typical wire on the welder comes on a reel, but it is not spring loaded. ;)
This layout is just temporary. The finished machine will be quite a bit different. It will be more vertical rather than horizontal like this one.
I also intend to eliminate the chuck. Just use the spindle face with a draw bar setup for each mandrel. Anyway, pictures as promised.

The wire feed mechanism is DC. 12 VDC runs it fine.
The main issue with it is that it will not hold tension when turned off. The gearing (nylon) just isn't strong enough. It starts to hold tension, but when the gear does move, it surges forward. This got me thinking about backlash in a fishing reel. I found a nice big old reel on Ebay that should kill two birds with one stone. It will secure the spring wire and due to the drag, will let me tension it's release. That mounted right on top of the spindle casting should do great.
I did remove the chuck and have both left and right threaded mandrel drawbars. It is already a lot better than it was originally. When I get the reel, that should make it easier on the hands too.


I will keep using this like this for production, however, now I am curious if I can build a small standard spring bender that can be run on Mach 3. Since I will not be able to use the wire feed for this coiler, I can certainly use it for one that will do all the bends like the big boys.
Have it mounted on a rotary behind the face plate. Then on the face plate, use gear rack and pinions to actuate the tools. The actual tools need to be adjustable and could be mounted like lathe tools. I may work up a design at some point. I might just make it a personal challenge. :)
Should be kinda fun to toy with it. Nema 17 motors are cheap as are Arduino drivers thanks to 3D printer communities.