The term “wear items” refers to parts of a machine that are likely to fail and need to be replaced at some point.
For example, two common wear items most people are already aware of on most machines are bearings and motors. Just like the bearings and motor in your vehicle, you need to pay attention to these parts and keep them properly maintained. But, eventually, they will likely fail from just normal use–and even faster if you’re pushing them to their limits or beyond on a regular basis.
While you won’t be able keep most wear items from eventually failing, but you can mitigate and plan for their failure through preventative maintenance and regular inspections. Read on to learn about the most common pre-press wear items (with the exceptions of the previously mentioned bearings and motors) and how to recognize when they’re going.
Please note that this is not a comprehensive list. Use it as a reference, but always refer to your machine’s manual and OEM for complete details.
Pallet Uncoilers
If your organization uses materials that come on a coil, you likely use some sort of uncoiler, such as a pallet uncoiler. These machines are generally built to be simple and robust, but there are still some pieces your team need to inspect for wear on a regular basis.
- Drum – Many pallet uncoilers feature a drum that helps guide the material from the coil to the feed. Often, this drum is made of aluminum, so any harder material will wear it down. You can combat this by upgrading the drum to a harder material, such as chrome steel or stainless steel. The drum upgrade will cost more, but you’ll make up for it when you don’t have to replace the drum as often.
- Cables – Pallet uncoilers have a set of cables that help keep tension on the control head. Over time, the cables will wear out, which will be obvious with a simple inspection. Once your team sees any stretched or torn wires, go ahead and replace it.
- Gears – Cables turn a pulley that is tied to a set of gears that then turn the potentiometer. Again, because they’re moving parts, the gears can be considered a wear item. You can see the gears are worn and in need of replacement with a simple visual inspection.
- Potentiometer – A potentiometer is an electronic part that provides a 0-10 frequency, allowing the drive to speed up or slow down. Because of its moving parts, it will eventually wear and fail. When it begins to fail, you’ll notice that speeds start varying a bit between runs.
- Gear reducer – Gear reducers allow you to modify torque to accommodate different materials. Unlike the previous wear items, gear reducers are a longer-lasting wear item–the typical life expectancy of a gear reducer is 3-5 years. This is another item that you can see wear through inconsistencies in how the machine runs.
Payout Reels
Like pallet uncoilers, payout reels feature a simple design and robust craftsmanship, so there’s not too much to worry about. But, there are a couple key wear items to watch.
- Adjustment shaft – The adjustment shaft allows you to expand and/or contract the arbor to accommodate the changing ID size of your coil. Over time, this will wear out and you will no longer be able to adjust the arbor size. It is never a good idea to continue using the machine after this goes out–your coil won’t sit tight on the arbor, so the coil can bounce and potentially break shoes or wear out pins prematurely.
- Gear reducer – This part offers the same functionality as its pallet uncoiler counterpart. And just like that part, you’ll know it’s wearing out when you have a lot of slop with the coil. In that case, replace the reducer before you snap a shaft or break a gear.
Feeds
Feeds help ensure your materials run through the subsequent machines, whether that’s a press, shear or whatnot, at a consistent speed and timing. Therefore, it’s imperative to your line that your feeds are running smoothly all the time. And of course, one way to do that is keep an eye on your wear items and replace them before they fail.
- Rolls (servo feed) – Like straighteners, servo feeds feature rolls that move material along. Those rolls often have a surface coating on them to help grip the material, and that coating can wear down. When it wears down enough, you’ll run into accuracy issues, so make sure you’re doing visual inspections regularly on the rolls. The amount of time it takes to wear down a roll depends on your materials.
- Belts (servo feed) – Servo feeds have belts that help keep parts moving. Eventually, those belts will wear out, even though they take a long time and don’t require much, if any, maintenance.
- Gears (servo feed) – Just like gears in every other machine, these will wear out after a while. They last a long time, but if you start seeing accuracy issues, this is another place to check.
- Seals & O-rings (air feed) – Any time you work with air, you’re going to have seals and O-rings that can eventually fail. Unfortunately, there’s not much you can do to prevent them from failing except your standard maintenance. When these parts start going on, you’ll hear leaking air and the feed’s accuracy will start to go off.
- Springs (air feed) – Air feeds depend on springs. Just like all springs, after they are collapsed and stretched enough times, they will wear out and not be as springy. Once again, you’ll see accuracy issues when these start failing.
- Cable cylinder (air feed) – Depending on the OEM and design, your feed might have a cable cylinder. As with other machines, the cables will eventually stretch and break, depending on your usage. Instead of just changing one cable at a time, though, you can purchase a cable cylinder kit to replace the entire thing at once to reduce the number of times you need to shut the feed down and take it apart to fix this part.
- Shock pistons (air feed) – Feeds spend their entire life moving back and forth, so it’s no wonder that shock pistons will eventually go out as well. Just like the shocks on your vehicle, these are filled with fluid that helps them run smoothly. When the seals start to fail, you’ll be able to see fluid leaking and they will hit harder.
Straightener
Straighteners ensure your material reaches your press ready to go, helping ensure you end up with quality parts down the line. Obviously, then, it’s imperative that you and your team ensure all the parts are in tip-top shape.
- Roll bearings – Straightening rolls ride inside a series of bearings that can wear down. Make sure you keep your bearings greased properly and regularly to extend their life. It’s extremely important to ensure your bearings are in good condition because failing bearings can cause grooves to be worn into the drums of the rollers. Rollers are much more expensive to replace than bearings. You could expect 5-8 years out of your bearings. In addition to visual inspections, you’ll be able to tell when bearings are going out by the rise in noise levels or by the smell.
- Rolls – Straightening rolls are hardened and therefore will last quite a long time. If you’re running hard materials, though, you may see grooving in the rolls after a bunch of uses. Eventually, you’ll start to notice slippage with your materials. A great thing about the rolls is that you can often send them back to the OEM to have them recoated, rather than having to purchase new rolls altogether.
- Adjustment gears – Adjustment gears allow you to move the rolls up or down to accommodate your materials. As you use those gears over time, they will wear down and need to be replaced to ensure you can continue adjusting your rolls as the need arises.
Cut-to-Length Machine
Cut-to-length machines use a feed and shear system. So, you’ll run into the same wear items as other air or servo feeds. But then, you’ll also have the following wear item associated with the shear section.
- Blades – Blades go dull and wear out. Depending on what materials you run, your blades might go out faster or slower. When you notice the cuts aren’t as smooth, it’s time to look at your blades. Sometimes, it’s as simple as rotating them (some blades are four-sided). Other times, you can have them sharpened. But if those two options have already been exhausted-or just aren’t applicable to your organization-it’s time to replace them altogether.
The best way to ensure all the parts of your machines last as long as possible is to keep them properly maintained and greased. In addition, your team should be performing scheduled inspections on the machine. While there is little danger to your employees from a failing wear item, unexpected parts failures can lead to extended downtime and high costs as you frantically try to get replacement parts.
To learn more about replacement parts for your pre-press machines, as well as for insight into keeping your line running as smooth as possible, we invite you to contact your EnSight industrial processing sales specialist now.
