Tolerances And Surface Finish

When we here at Redwood Plastics and Rubber get our estimators to work on a project we are required to fill out an internal form that, among other properties, specifies surface finish of the part and tolerances. Assumptions in these matters can occasionally result in customer disappointment but equally important the customer may be paying for tight tolerances or a surface finish that isn’t required for proper performance of the part. To reiterate: requiring tighter tolerances and a smoother surface finish than is required for a part means you are wasting money!

One of the biggest barriers to figuring out what tolerances and surface finish are required is that technical drawings rarely provide accurate information. Most commonly, drawings are supplied with metal tolerances – these are tolerances that are difficult or impossible to hold with plastics. Certain plastics such as acetal can be held to fairly tight tolerances but other commonly specified plastics such as UHMW-PE cannot. Questioning about how critical tolerances are at the very least can delay a quotation until we figure out what is required and doable.

A similar issue is that drawings often come with parts that have 90 degree square corners. This is also very difficult to supply and definitely adds cost. Our standard edge radius would be .125″ and knowing how critical the edge is or not will potentially save you, the customer, money and time.

Surface finish is a little bit of a tougher issue to tackle. Many customers do not know that a variety of surface finishes are available. Our standard is a “125 end mill” but do you know what that actually looks like? The tough part here is the customer may be expecting a “smooth” (very smooth!) part but if that isn’t specified we’d default to the end mill, which has small, but noticeable, grooving. Likewise, a rougher surface finish like a “500 shape turn” will potentially save the customer money.

At the end of the day we rely on you, the customer, to give us as precise information as is possible. It helps us not only supply a quicker quote but also a more competitive quote and that helps you as much as it helps us!

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4 Tips For Your Fabricated Plastic Application

Have an idea for an application requiring machined, molded, or fabricated plastic and now you’re ready for some pricing? Having your requirements organized and prepared will not only lead to a quicker quotation but could also lead to a more successful application and quite possibly – save some money. If you’re ready for that quote these tips will help make it the smoothest possible process:

1.) Have some sort of drawing or sketch to send

We don’t expect everyone to have a technical drawing but we at least need a sketch to get started. Sometimes applications that seem simple (a bearing or a pulley) are more involved than you would think. Take a bearing for example, if you just give us the outer diameter/inner diameter/length that doesn’t answer all we need to know. We’d want to know what the tolerances are, specifically in relation to a press fit or running clearance. Does it have a grease groove? Any flanges? A simple sketch can answer many of those questions.

2.) Have quantity and budget in mind

Truth is there isn’t always just one plastic that works in an application. Often there are multiple options that are “good, better, best” and your budget determines where the ideal material lies. Quantity is important too, as quantity can (but not always) lead to price breaks. However, narrow it down to 2-3 quantities at most for quotation. There are not price breaks at all quantities and putting too many tiers will delay your quote.

3.) Know the operational environment and inform us proactively

Often our reps will ask you questions about your application. Basic, yet important parts of the operational environment often get overlooked when choosing a plastic, so think of this in advance and, better yet, inform us at the outset. For example: is the application outside and therefore needs UV-protection? Is it exposed to any chemicals, acids, or bases? Does it take impact or is immersed in water? All of those are critical to the success of an application.

4.) Ask questions

We can’t answer absolutely everything, but we do know our plastics. So if you’re unsure if a plastic is best for your application then ask. Even if we’re not familiar with the application itself, we can at least discuss how other plastics compare to the one you’re considering and that may lead to more success and satisfaction with the end result.

For help with your plastic applications please contact us.

Budgetary Expectations And Lifecycle Cost

One of the most important topics that comes up in a plastic application are issues of cost, budget, and expectations. Most commonly the request we get is to provide a better better performing plastic at less cost. In the vast majority of situations, frankly, this is unreasonable. Plastics, like any quality product, generally follow the old cliche “you get what you pay for” and a better performing, longer-lasting, plastic will almost always cost more money. There are rare exceptions, for example everything being equal, reprocessed (“repro”) UHMW will actually outperform the slightly more expensive natural grade in wear applications specifically. However, these are very rare exceptions to the rule.

It is important to know your budget up front. If there is no ability to fund a higher priced solution you may simply need to make due. However, if you have room in your budget then we have some room to work. Most commonly, a premium grade of the same material would be suggested. For example, switching from reprocessed UHMW to Redco Titanium or Tivar 88. This is generally the first step to take as the premium product provides all of the properties of the lower grade, just much improved. For example, slicker, better wear properties, and UV resistance or weathering.

At times, the application may require a jump to a new plastic. For example, if a nylon part is failing due to being brittle in cold temperatures or moisture swell, then a switch to Redco Tuffkast may be in order. Similarly, most plastics cannot hold tight tolerances; however, acetal is perhaps the best at doing so and bears a similar load to nylon. Were a nylon part to fall out or be unable to retain tolerances, acetal would be an excellent substitute in most applications.

However, the most important point of all is this: selection of the optimal material for an application will almost always result in a lower lifecycle cost and therefore cost-savings. Reduced maintenance costs, replacement, and downtime, will all save the customer money in the long run. It is this critical factor which is often overlooked in the decision to switch to a premium grade of plastic or a more expensive, but ideal, plastic for an application!

For assistance in choosing the best grade or plastic for your application please contact us.

Redco Outrigger Pads: 10 FAQs

Redco Outrigger Pads are perhaps our most popular product we manufacture ourselves and they have a proven track record of success for customers in various industries all over North America. From construction, to power utilities, tree service firms, green energy installers, and others. Frequently asked questions often come up regarding this product and today we’ll answer some of them.

1.) Are custom sizes available?

Yes! Our literature only provides sizes and loading for the most popular sizes. But we can fabricate them in any size from 12″ x 12″ to 48″ x 60″.

2.) Is an anti-slip option available?

Yes! But actually two options of anti-slip are offered. There is the ‘scuffed’ version, which is done in our shops at each branch and uses sanding equipment to rough up the smooth surface. There is also a premium-grade of anti-slip pad using an embedded clean coal slag surface. However, minimum orders and longer lead times do apply to the clean slag surface variant so please inquire.

3.) Can I customize the pads to have extra handles or corners left on?

Yes again, as we make them this can all be customized. Extra handles (beyond two) will add a nominal cost of $5.00/pad. Corners are regularly removed as standard for square pads, but leaving them on if you prefer, obviously has no cost.

4.) Is there a price difference between square and round pads?

Yes, round pads are substantially more difficult to manufacture and require much more labor.

5.) Do you carry stock?

No, due to the wide range of profiles and thickness for the outrigger pads that are requested from us, we do not carry any stock. All pads are made to-order.

7.) What is your lead time to ship an order?

That depends on both stock levels of the base plastic at our branch and the current branch’s overall lead time to ship an order. In general it’s about 3 weeks.

8.) Are your outrigger pads guaranteed?

No, they are not. We understand that a guarantee puts some customer’s minds at ease but this is a high-load product that will take abuse in operational environments we have no control over. It’s unfair to offer a standing guarantee as the customer may incorrectly use the pads (such as not using them on a level surface) or may wear them out by using them on abrasive substrates for a few years and then asking for a replacement. In addition, issues with too much flex are often due to a customer purchasing pads that are not thick enough as a cost-saving measure and we cannot be liable for that. There is not a single case we’ve ever had where a pad has broken, however.

9.) Can you quote with a shipping cost?

Of course, but to do so we require your full address (if in Canada) or zip code (if in the U.S.). Often customers will simply give a city name and state (or province) and unfortunately that is not enough for the freight companies we work with to provide an accurate quotation. We also need a firm quantity of pads to quote, as the shipping cost is based on weight.

10.) Can I get our name or logo engraved on the pad?

Not for a nominal fee. Most of our branches do not have the capability to provide engraved outrigger pads. This engraving can be done by our Canadian and U.S.-based central machine shops, but the costs of transporting the pads to and from those facilities, the cost of the engraving itself, and the additional delivery adds so much expense that it’s not worth it to the customer who isn’t absolutely insistent of this requirement.

For a quote on your outrigger pad needs contact Redwood Plastics.

New Product: Woodgrain HDPE

Redwood Plastics is happy to announce a new product offering* under our HDPE line: Redco Woodgrain HDPE. This attractive product is durable, UV-stable, tough, and easy to work with saws, drills, lathes, and other tools that would regularly be used for wood products. This product is optimized for outdoor use and will never require repainting. Highly weather-resistant, with fade resistant colorant (impregnated throughout the entire sheet), this product can take the impact of everyday life and will outlast wood.

Redco Woodgrain is currently available in a single sheet size and a single thickness: 4′ x 8′ x 3/4″ thick. Available colors are espresso brown, tan, and black. Custom thicknesses are available but only with a 5,000 lbs or greater minimum order. The attractive faux wood surface makes the product excellent for applications such as outdoor kitchens, tables, marine furniture, playground equipment, decking, or anything else you feel would be suited to a strong, weather-resistant, attractive replacement to wood.

This is a premium product and it will not be competitive on price alone when compared to the cost of wood. However, for the individual or organization that is looking for a product with a low life-cycle cost requiring very little maintenance, repainting, cleaning, or other labor, and wants a premium product then Redco Woodgrain HDPE offers an excellent solution.

To inquire about pricing or if you have questions on this product please contact us. 

*Please note the product is not currently stocked at our locations and will need to be brought in as required for orders. Typical lead time to land the product is 2 weeks. The minimum order is a single full sheet, it is not sold in smaller sizes or partials.

Plastic Spotlight: Redcomp 300A

One plastic we offer though not on our website’s list currently is the remarkable Redcomp 300A. This is a super strong (14,000 PSI bearing) composite material with incredible strength, self-lubrication, and an ace up its sleeve. This product was invented for use in marine applications, particularly those involving salt water. Anyone who’s worked with equipment in marine applications knows that salt water brings with it corrosion and rust issues. But Redcomp 300A is immune from the effects of salt water.

In addition, PTFE is layered in the resin. PTFE is an exceptionally slick and chemical resistant dry lubricant and is embedded throughout the entire product. This can be confusing as customers will sometimes request the addition of a bearing into their Redcomp 300A part…But the Redcomp material itself is a bearing! And a much better one than any you could press in. To put things in perspective, the Redcomp 300A has a 0.08 coefficient of friction. Redcomp 300A material should run by itself on the shaft. Other benefits include continuing operating temperatures from 266 degrees Fahrenheit to “cryogenic” low temperatures. The product is also impact-resistant, light-weight, and easily machined.

For a quotation on Redcomp 300A material or help with your bearing application please contact us today.

3 Critical Issues You Need To Know About These Popular Plastics

Many industrial plastics can “overlap” in applications where sometimes the optimal choice is only marginally better than several others. Many plastics may work in an application, such as nylon and acetal for sheaves, but certain issues in the operational environment may mean you need to stay away from a certain plastic! Three of the most popular plastics we carry are UHMW polyethylene, cast nylon, and PTFE. But each of the following has a critical issue you need to know about that often discredits the material in certain applications.

UHMW – Impingement

UHMW is a great wear material at an affordable cost…Usually. The one place where it isn’t good at all is with impinging wear, that is wear from a mating partner (could be anything from grains, to rocks, to another sliding component). Impingement is when something hits that UHMW on an angle. With UHMW anything that is remotely abrasive needs to hit it on a 90 degree angle. If the angle is any sharper you risk very quick deterioration of the UHMW plastic. It simply does not hold up to impingement. Often polyurethane, which has excellent impingement resistance, is a substitute and one can be creative, for example only using polyurethane in the impact zone and use UHMW for the rest of the application.

Nylon – Cold Temperatures

Many people know that nylon is affected by moisture swell, what fewer people know is that it gets brittle in cold temperatures, about 10 Fahrenheit or -12 Celsius. This can come as a shock, as nylon is known as a high-load plastic able to handle 4,000 PSI in bearing applications. It is not intuitive to think that cold temperatures would greatly affect the nylon but it is true. Fortunately, replacements are available, specifically Redco Tuffkast is often best to replace nylon. Tuffkast solves not only cold weather issues with nylon but also absorbs much less moisture, so Tuffkast’s properties help in that case as well.

PTFE – Wear

It is often that customers request PTFE for a wear or lining application, even including heavy applications such as dump truck liners! We do try to warn them that PTFE has very poor wearing ability. It is a soft, almost waxy material, that while it is available in sheet form (and seems solid enough) it really cannot hold up to aggressive wear. Bronze filled PTFE is available which increases the wear capabilities; however, by that point there is often a less expensive, more available plastic, that can be suggested as a replacement. PTFE should be avoided in high wear applications wherever possible.

Hopefully you are surprised by at least one of those points, in the hopes that it will assist your material choice in your next application.

To discuss the optimal plastic for your application, get in touch with us today.