Reconditioning Cutters

Hi BZimm84,

What is the wire material exactly? Was there dialogue with Lindstrom to decide what cutters best for your application?

From the Lindstrom site:

What types and diameters of material are to be cut?
We rate our cutters for copper and some for tougher material such as spring wire. However cutting something as tough as spring wire is unusual in hand assembly. So a bit of common sense must be used.
--Is the material a little tougher than copper or a lot? Depending on the answer, the field can be narrowed by eliminating the cutters not likely suitable for the application.

I would also contact the wire manufacturers and see what they recommend for types of cutters.

Mike

We have tried a couple style cutters from Lindstrom and other companies that are made for harder materiels (even tungsten carbide ones). The problem with the harder ones is everyone squeezes cutters with different pressures. They would end up squeezing so hard that the tips would break or once they were dull then how do we sharpen them without destroying the cutter head material properties. We have also tried relief angles on the head of the cutter and offset cutters. We always keep comming back to the hardened carbon steel cutters, because even if they wear out we could for the most part grind them by hand to work (The heat to the head of the cutter then again becomes a problem).

The materials that we are cutting are Stainless Steel, Tantalum, Titanium, Platinum, and a couple other randoms in between. Another problem in the loop is that they are wound next to each other so we may have 1-5 wires next to each other to cut at the same time to length.

I also found a pair that are tungsten cobalt (Tronex Class W). They claim to be hard but not as brittle as the carbide ones. If we could get those to work and then a way to sharpen them while grinding or honing under a coolant flood then that would be great.

Sharpening the cutters can be done with friable aluminum-oxide wheels. Just use a light touch and practice with some junk cutters. 

Here is a good overview of grinding wheel types: All About Abrasives

I would directly contact Norton (or your preferred manufacturer) for specific recommendations.

There are miniature belt sanders, with belts about 1/2 inch (13 mm) wide, used for finishing close-contour work. They may be able to reach nicely into the jaws of your nippers. See a W.W. Grainger catalog, for instance. You can get various abrasives and grit sizes; with a little experimentation you might find just what you need.

That might be better than the hand-held version I was thinking of. If the belt on this unit is too wide, it could be slit in half circumferentially. By adjusting the table on this, you could get a consistent angle on the nipper blades.

Delta manufactures a belt sander very similar to this, but it also has a vertically mounted sanding pad and bench to boot. You can purchase them directly from Lowe's or Sears for a good price, especially when they go on sale from time-to-time, sometimes for less then $100 USD! I swear that I'll never go without one of these ever again in my garage-based 'Lil Metal shop!!!!

Sanding belts and pads are fairly easy to find at Lowe's, Sears, Grainger's, and of course in Ebay. I usually purchase belts made by Norton for my Delta machine and they last a good long time if you don't abuse them.

Good luck finding a solution, and please have a great sunny day!

Check out Starrett Ratcheting End Nippers. I've seen them in the Starrett catalog

and they look very nice. The jaws are removeable and they are flush cutting.

I will have to look for those, but if they are what I think they are the tip wont fit inside the ID winding of the coil that we are cutting.

Not interested in stealing offering a re-conditioner a job?

carbide insert wire cutter ... http://www.excelta.com/product_categories/hard-wire-cutters/products/small-semi-flush-hard-wire-cutter-2

We actually tried those cutters once and since they are carbide they are a little brittle and some operators squeeze to hard and chip the insert.

A one size fits all doesn't work for everyone all the time. There are several grades of carbide some softer possibly C2 would be suitable, slightly different cutting angle or the insert maybe available in a high-speed steel grade too.

Also high-speed steel cutters with T15 high-speed tool steel may with stand greater abuse.

I remember using dual action wire cutters where the jaw first clamped the wires then a second jaw cut the wire, those were excellent but I don't recall the manu...

I do have a bench top tool and cutter sharpening machine suitable for your purposes as I recall, I'll check on it and PM...

Your first task is to determine why the cutters require sharpening. You can do this with a stereo microscope. If the edges are becoming rounded, you need harder blades. If the edges are chipping, you need tougher blades. High speed steel might be a good choice for your application (better than carbon steel), although tungsten carbide is just about as hard as you can get. I find that diamond hones are a very good way to sharpen the edges. A fixture will help maintain the proper honing angle. It should only take a few swipes with a hone to restore the cutting edge.

I agree with you on the diamond hone. Thats kinda the direction I was going in, but trying to see if there was maybe a way I could automate the process.

I was also going to try a Tungsten Cobalt pair that claims to be not as hard as Carbide so it shouldn't be as brittle.

The other problem once we start sharpening we get into since the edges come together by a pivot in the pliers every time we sharpen them we need to find out how much more we need to take off the tips so that once both sides are sharpened the edges sit flush again.

I suggest you look at a system like the KME knife sharpening system. www.kmesharp.com. It is inexpensive and will help maintain the best honing angle. Although optimized for knives, the principle can be adapted to most cutting tools.

I like the answer from cwarner 7 11 concerning using a Drimel or something similiar to do the cutting. If your people are squeezing hard enough to break cutter heads then they are doing enough repetitive motion to come up with some physical problems that will impact your bottom line a lot more than the price of cutter heads.

That I absoulutly agree with. The problem is back a couple years ago when the parts were done on a "Qualified Process" the customer is not very receptive about changing the process. This includes how the wire is cut and how the burr ends up looking like in the end.

We are implimenting pneumatic punch cutters for new qualified parts, but the old parts still need to be run the old fashioned way. In my research I am hopeing to find an ergonomic solution while keeping really sharp cutters so we do not have to worry about people pressing to hard and putting there hands in danger for problems in the future.