Wire Manufacturer

Modern Grinding is a contract wire manufacturer. When it comes to the processes used in wire manufacturing, it seems like a fairly straightforward trade to us. Manufacturing wire hasn’t really evolved too much since the days of blacksmiths. It’s just become a lot more automated and precise. This blog post is a quick cheat sheet to help get you up to speed on some of the tools used by  modern day wire manufacturers. The writer of this article (Dan Voell) is a lay person, not an engineer. This post is to give non-technical designers a little background in wire manufacturing.

Raw Wire Manufacturer

Modern Grinding is not a raw wire manufacturer. We purchase raw wire materials and then fabricate it based on our customer’s needs. Raw wire can be purchased by the piece or by the spool depending on wire size. Most wire manufacturers and medical device companies do not make their own wire, they purchase wire raw materials.

Raw Wire Ready for Manufacturing
Raw Wire Ready for Manufacturing

Wire Grinding

Grinding involves using a fast moving wheel (2,000 RPM) and touching it to a wire which is not moving as fast. The grinding wheel is abrasive, like sandpaper. Grinding can be used to create a variety of profiles and finishes to the wire. Grinding can be used to smooth a product or cut it down to length. It can be used to cut sharp tips such as those on k-wires or Steinmann Pins.  It can also be used to flatten or round an object.

Wire Metal Stamping

Stamping involves creating a fixture with a product profile designed into it and then stamping wire into the profile to create the shape. This is used to create many different types of tools for the medical industry. The stamping machine is a form of press.

Lathe Machining

A lathe involves spinning a part on its axis and touching it against a work tool. Some common applications of lathe machining are threading, cutting or sanding a piece of wire.

Wire Forging

Wire forging is the process of shaping wire using localized compressive forces. Most frequently it is done while the wire is heated but it can be done at a variety of temperatures. Originally it was done by blacksmiths with a hammer and anvil. Today it is done with presses.

Heat Treating Wire

The process of applying heat to a wire can change its properties. For instance, many medical products are heat treated to give them a certain level of flexibility or firmness.

Wire EDM

Wire EDM is similar to a band saw process. It stands for electrical discharge machining. You have a metal piece which is submerged in fluid and you have a vertical piece of wire with a charge. When the wire touches the metal piece, it cuts it. Many tool and die shops will have wire edm capabilities.

Wire Welding

The most common welding that we do is laser welding. YAG laser welding involves placing two pieces of metal up against one another and focusing a laser on one of the pieces of metal. One the laser hits the metal, it expands and forms against the second piece of metal which closes the gap between the two pieces of metal. Examples of this type of welding are needles in which we weld the ground tip and a hypotube together.

Laser Cutting

Laser Cutting is a technology that uses a laser to cut materials and is typically used for industrial manufacturing applications but can also be used by hobbyists. In the medical field laser cutting can be used to cut stents and very intricate shapes into the outside walls of  tubes.

Wire Forming

Modern Grinding has automated machinery to take wire off of a spook and bend, form, shape, sharpen and cut to length. Here is a video of the custom wire bending process process

Wire Cutting

For most wire cutting, we use good old fashion Knipex cutters. For more advanced cutting we use automated shears to cut wire lengths to size.

Wire Cutting
Wire Cutting

Beginner Wire Manufacturer

This post was meant to scratch the surface of wire manufacturing possibilities and give an overview to those just starting the trade or trying to figure out how to make a device. You can now consider yourself a beginner wire manufacturer. If you have questions don’t hesitate to reach out to us.

Length Markers on a Medical Device

medical device marking
medical device marking

For Medical Device designers there are multiple ways to add length markers to your device so surgeons are able to see them. These markings can be viewed visually, or they can viewed with another device such as an X-Ray machine. I wanted to mention three marking techniques: laser marking, medical ink and material cuts.

Laser Marking A Medical Device

This is probably the most common way to mark a device. It’s basically burned into the material which means it is difficult to rub off,

Medical Class Ink

There are a variety of inks that meet the FDA requirements for Class VI certification, and can be used with confidence on any of your medical device components. Modern Grinding has a variety of fixtures set up to help with your next device.

Grinding Groove Markers Into the Device

This is a method that we have found ourselves performing more of recently. Basically we plunge grind the wire to make grooves along the length of it. These grooves can remain as is for scanning or they can be filled with a marker type of material such as radiopaque material. This can be the easiest to manufacture since you are able to save additional steps in device machining.

Depending on the complexity of your device and the marking, any of the options can be the most affordable. Reach out today and find out about our advanced capabilities.

 

 

Reverse Engineering A Guidewire Assembly

At Modern Grinding we often get inquiries to help medical device designers reverse engineer a guidewire assembly so that we can manufacture something similar for their device or for their distribution business. It seems like a simple enough request. Modern Grinding is in the guidewire assembly business, how difficult can it be to slap a coil, safety ribbon and core wire together? It actually isn’t too difficult (for us), but we need to know the exact design. Here are some of the hiccups that occur when reverse engineering a guidewire assembly.

Guidewire Assembly Formed Core Wires
Guidewire Assembly Formed Core Wires

Guidewire Use Case

The most important part of a guidewire is how it is used. At Modern Grinding, we are contract manufacturers, we aren’t doctors. When someone comes to us and asks us to “copy” a guidewire, we don’t always know that exact guidewires use case. If we were to get something wrong, that can affect how the guidewire performs in surgery. Often foreign distributors will try to gloss over that fact, and say just give us something close (to another product in the market). At Modern Grinding, we take a deep concern for how our guidewires perform and we won’t accept “close”.

Guidewire Concerns

There are many small pieces of the puzzle which affect how a guidewire performs. How is the core wire connected to the coil? Is it welded or glued or fused? What tensile strength is the core wire? This can affect it’s flexibility and propensity to return to its original shape. Was the core wire heat treated? This again can affect the shape of the core wire and how it returns to its original form. What dimensions does the core wire have and what dimensions do the coils have? How much of the coil is coated? What is the tip coated with? How is the handle connected? Are all forms of PTFE the same? Are all hydrophilic  and hydrophobic coatings the same? While these all seem like little details, when you combine them all, you can lead to vastly different guidewires that appear the same.

New Guidewire Designs from Doctors

When doctors reach out for help, I feel bad if we can’t help. Often doctors come to us with a problem that they recognize with a pre-existing device. They are in the perfect position to come up with a new guidewire design that could better serve patients and help other doctors as well. The problem is that doctors don’t realize how difficult it can be to reverse engineer a product and then make a fairly similar guidewire assembly. We can do it, but we need to be able to nail down all of the key characteristics (see concerns section above) before we can start to make alterations on the wire. It takes a lot of engineering time to reverse engineer a complex product which is used in surgical applications.

This post wasn’t meant to scare anyone, just to let you know what goes into reverse engineering a guidewire assembly. We can do it, but it typically takes a couple days in engineering time, we aren’t able to just “copy” an existing wire without going through a very refined process.

Ground Hypotube

Modern Grinding can help with your next ground hyptotube project. We have found more and more medical device companies needing help with profile grounding on the outside diameter of hypotubes. We don’t have our own laser marking equipment, the majority of ground hypotube work comes from laser cutting companies who typically apply some of sort of cut to open up the tube after we work on it. This cut can be something like a stent design or just a hole for a cannula or needle type of product.

Some of the reasons for hypotube grinding are for flexibility or for connecting the hypotube to the rest of the product.

Hypotube Flexibility

Modern Grinding can provide more flexibility to your hypotube by grinding a taper into the outside of the tube. Our capabilities allow us to grind precise dimensions down to a little over .001″ hypotube wall thickness. This allows for a firm tube which leads down to a more flexible or floppy hyptube.

Hypotube Connection

Medical Device Designers, may create a ground slot on the end of a hypotube to allow for connecting to another object. This other object may be on the proximal or distal end of the product for connecting to something on the patient or handling end. Our most recent product had a step on the outside profile of the hypotube. This step allowed for welding to a luer lock.

Don’t hesitate to contact us for help with your next ground hypotube project.

 

 

Stainless Steel Medical Device (Taper vs. Step vs. Radius)

I will start out this post by saying we are always game for trying out new projects.  Over time we have learned what is possible, what is difficult but possible, and what is not possible when making stainless steel medical device components. We have also learned why device designers want to take certain approaches.

One consideration when deciding between taper vs. flat step vs. radius is whether or not the wire will be formed after the machining process. From our experience, if the form uses both sides of the step or radius, there can be many difficulties. For one, if you are planning to clip the wire to a form (cylindrical) and then heat set, the different sized radius wire will form differently. A second difficulty can be trying to put through a machine such as a coiler. Many times the radius or step may kink when going through the process. If the wire is going to be formed, we tend to suggest that the wire is tapered, to avoid the miscues.

Why use a flat step or radius vs. a long taper on a stainless steel medical device? We find that most steps and radii are used as a “catch” for some component that goes over it. For instance, you would slide on a coil until it catches on the stainless steel lip. You would then weld the two together at the step or radius.

I hope this helps dispel some myths and helps provide some guidance for stainless steel medical device designers who are working on their next great invention.

 

Medical Device Assembly Process

As Modern Grinding grows and starts to develop manufacturing processes for a variety of products, we are getting into more and more multi-step medical device assembly processes. Our capabilities now include wire forming, wire grinding, coiling, microcoiling, welding, electropolishing and metal stamping.

Multi-Filar machine part of medical device assembly
Multi-Filar machine part of medical device assembly

One major product that we manufacture and assemble is guidewires. Many guidewires include a ground core wire (also referred to as mandrel), a coil (or microcoil) and a safety ribbon. These multiple parts typically are formed and welded together. While it would seem like this is a simple medical device assembly process, during the prototype phase it can be very time consuming to nail down the correct process. For one, your machines open up at different times. If you are trying figure out the correct process to form your ground core wires, you might need to try several different core wire designs. Once you have manufactured your core wires, you might realize that you need a different design once you get to the forming stage. This is fine if your grinding machine is always, open but ours rarely is, so you need to wait until machines open up to start over.

We recently started to pick and choose components of the six sigma process program to create a more robust project management process for medical device assembly. In the past, we did this type of project management in our heads, but as our production capabilities became more complex we realized the need for this type of system. Along with the principles of six sigma, we relied on the lean software principles of starting with a minimal design for project management and working with the main customers to create a product that everyone could use.

The main goals for me were to make sure that when we get a medical device assembly job, we get buy in from all of the departments we will be working with and we get confirmation from each department that they can accomplish the job within a given time frame. In the past, managers would take responsibility for department that they didn’t run and when a project started to get hard, the buck would get passed.

Here are a few tips from our medical device assembly project management experience:

  • Have a manager responsible for each step in the process
  • Think about alternative process routes while developing your process
  • Put your process on paper, from step 1 to shipment

Does anyone use simple project management tools for medical device assembly? We would love to hear about your trials and successes.

 

Medical Component Grinding

We are going to be mentioned in an upcoming article of Micro Manufacturing magazine so we had a photo shoot with our in process medical component grinding machine. Are there any good in process machine photo enthusiasts out there? How does this look? Any suggestions for future photos?

Diamond Grinding Wheel
Diamond Grinding Wheel

 

Coil Automation

Modern Grinding is proud to announce we have added coil manufacturing to our list of capabilities. We can achieve coil automation manufacturing for repeatability and lower costs than our competitors. We added a page to our website and a quick video of the machine in process. We are looking for new projects to help show off our capabilities don’t hesitate to reach out with your project.

Watch it in action: