Acetal Ball Maze

Posted: December 15, 2014 in Acetal, Cool Projects
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You know what they say about simple ideas – sometimes they’re the best!

We found a video of a DIY project where a CNC machine is used to etch a ball maze into a piece of acetal plastic (of which the name of the homopolymer variety is ‘Delrin’). Apparently the project was for students who designed the game from an initial paper sketch all the way through the CAD program. This project is simple enough for students yet creates a functional and fun piece of work. In short, it seems like genius. Acetal is a great plastic for machining, probably the best thermoplastic in holding tight tolerances.

Acetal has numerous other “Do-It-Yourselfer” applications. Most common is probably aftermarket paintball equipment, which we have blogged about previously here. Acetal replaces small, precise metal parts and often replaces polyamide (nylon) in applications where moisture is a concern.

The video is a little blurry but you will still get the gist of the project and the final design:


UHMW Toboggan Super Sled

Posted: December 2, 2014 in UHMW
Tags: , , ,

It’s winter and it’s cold through much of North America. But if you can’t beat the deep freeze you might as well have fun with it, right?

One of the most fun – and easiest – industrial plastic projects you can work on for winter is a UHMW toboggan. Snowmobiles and dog sledders know well the benefits of UHMW polyethylene for sled tracks. UHMW is economical compared to other industrial plastics and has a very low coefficient of friction combined with no water absorption. In short, it will make your sled glide smoothly over the snow and ice. In fact, UHMW is a cryogenic plastic meaning that its properties actually improve in cold temperatures. But while sledders bolt UHMW rails to the bottom of their metal rails an entire toboggan can actually be made out of UHMW.

It’s simple too, information is widely available on the internet. Essentially you need a sheet of UHMW (natural-white seems to be used the most) about 12″ x 120″ long and 1/4″ thick. This will set you back about $90.00. Next, you need some rope and some 1-2″ wide x 12″ long wood (to be orientated as spars across the UHMW strip) and finally, some flat ended bolts. You tap the wood for the bolts, affixing theme to that the head of the bolts touches the snow (there will be less friction that way). The rope is particularly important to bend the front of the toboggan to produce that signature curl…And that’s pretty much it. You just need some snow and you’re on your way!

Information, tips and instructions are widely available on the internet but here are a few pictures of how a successful design should look:

















One everyday application that uses performance industrial plastic is guitar picks. The rigors of many thousands of abrasive strokes against guitar strings means quality plastic is ideally suited to this application. ULTEM (semi-transparent amber or black color) is sometimes used but acetal (opaque white or black) is more common. Black nylon is also a good plastic for this application but is less well known. We recently found a website all about a do-it-yourself product called the “Pick Punch” this lets you take acetal and punch your own picks at home – you might never run out again! This is much more economical (and fun) than simply buying picks, wouldn’t you say?

The website gives lots of tips on how to finish your picks as well as which types of plastic or items to NOT punch with the machine. You can check it out here:



Involved in North American mining?

You know the hassle it can be to get MSHA approved materials at times. Polyurethane and UHMW are workhorses in the mining industry and MSHA need not be a barrier any longer…

VYPUR™ FRAS is a high-performance elastomer grade of polyurethane designed for applications where exceptional wear and abrasion resistance is required due to shock, vibration and impact. These properties are coupled with MSHA certified Fire Retardant and Anti-Static properties in accordance with MSHA IC-297.

Cast polyurethanes are tough, rubbery materials that can be depended upon to retain their original shape and properties for a long service life. They are cost effective and dependable elastomers that combine some of the performance advantages of engineering plastics, metals and ceramics along with the resiliency and flexibility of rubber.
VYPUR™ Urethanes are renowned for their high load bearing capacity, high impact strength, high abrasion resistance, high resilience and excellent resistance to oil and grease. Often chosen where resistance to the actions of sliding, stretching, load-bearing, impacting, cutting and tearing, compression, torsional forces, aging and oil-resistance are involved.

VYPUR™ FRAS is a specially formulated range of grades available from 85 Shore “A” through 75 Shore “D” hardness and can be molded or machined into parts of virtually unlimited configuration. Most common urethane parts can also become MSHA compliant by molding them using VYPUR™ FRAS.

– MSHA Regulated Mining Operations
-Above & below ground operations
– Port and Marine
– Rail & Transportation
– Any application where fire and flame propagation is restricted.

Typical Parts:
– Conveyor Headrig, Take-up and Idler pulleys
– Belt Cleaners, Scrapers and Wipers
– Skirtboard
– Transfer Chute Liners
– Pivot & Hanger Bearings
– Bumpers
– Conveyor load-out bars
– Cable Protectors & crossover mats
– Chain Flights
– Sprockets, Bearings & Bushings

Also of note is MSHA approved Tivar Burnguard™. This UHMW-PE grade has many applications in mining involving coal bins, bunkers, chutes, hoppers, feeders, slider beds and skirtboards. The material is UL 94V-0 registered. Burnguard also meets ASTM E-662 and Bombardier 800 standards.

If you have interest in how MSHA compliant plastics can  reduce your downtime and maintenance needs, contact Redwood Plastics today.


Many polyurethane parts can now be supplied in MSHA compliant VYPUR

So…You have a project. You’ve decided that you’re going to use “plastic” for it. Ok, which kind?

Sometimes it’s obvious. Plastic “do-it-yourselfer” applications that involve piping probably involve PVC since it’s so readily available and inexpensive compared to the alternatives. Same goes for acrylic or polycarbonate – the two primary clear (glazing) plastics. But sometimes there are more choices especially as the application becomes more vague. Common plastic applications taken on by amateurs include wear strips, bumpers, sheaves, pulleys, wheels, shock absorbers, ramps, bushings and everything else you can think of. With the array of industrial plastics available these days – how do you select the right plastic?

Well, the easiest way is just to ask. A reputable distributor will be able to take your information and make a recommendation; however, the more information you bring to the representative – the more he or she can help you. Many of the questions you ask should be the same as any of our industrial customers would ask. And we can help you out right here!

Questions you should know the answer to before approaching the plastic distributor:

What is the project?

What is the operating environment? (temperature, any chemical or weather exposure – exposure to UV light is of special concern)

What load or pressure does it bear?

What properties are important in your application? (stiffness, ease of machining, low friction, high friction, etc)

What is your budget?

Based on that information we can help you select a material that will suit your project’s needs.

For more information contact Redwood Plastics.





“I told you to plow the driveway not destroy it!”

Not something you want to hear. In many parts of North America the brutal winters means a brisk business for snow plow and snow blowers both equipment and entrepreneurs looking to cash in clearing some of the fluffy white stuff. Often the equipment comes with a metal plow blade on the front. This can damage or mark the pavement you’re clearing and eventually the metal will wear. An increasingly popular solution is taking a UHMW polyethylene strip and attaching it to the metal plow. The UHMW is very strong and wear-resistant but will not damage the pavement. Snow slides off it easily and the material has a low coefficient of friction. Known as a “cryogenic plastic” UHMW’s properties actually increase in the cold, meaning the colder it is outside, the better the UHMW will perform. Reprocessed-black UHMW is most commonly used but virgin-white will do fine.

What you do is measure a the length and width you need, a long thin rectangular block will work just fine. You don’t want to go too thin with the material or else it will wear quickly and not do well on pullbacks. 1.5″ thick seems to be an accepted standard with 72″ length being the most common we could find. Seeing as UHMW comes in 10′ long sheets, any size up to 120″ is possible. One important note is to do the drilling and installing on site. UHMW will expand and contract due to temperature and while it might be easier to get your distributor to drills the holes you risk the very real possibility that the holes won’t match up to your metal part when you do the install – you have been warned!

In summary, UHMW plow and blower blades are an excellent do-it-yourself application if you have a snow plow or blower. So take a bite out of the snow this winter – but not your pavement!





When it comes to multi-wall polycarbonate, demand outstrips supply. Meaning demand for sheet sizes and profiles outside of the 4′ x 10′ x 6mm (1/4″ nominal) standard. Multi-wall polycarbonate is an excellent plastic for several home projects. The standard sheets are relatively cheap in comparison to other industrial plastics. Unlike standard polycarbonate, multi-wall comes UV-stabilized for outdoor use and can be easily fabricated using household tools. It does not require special hardware – any screw with a washer affixes it just fine.

The problem we see as a plastic distributor is demand for non-standard thicknesses and sizes, most commonly 16mm or 8mm thick material. What you need to realize is those profiles are much rarer and the increase in cost will not be proportional to the increase in sheet thickness. What you also might not realize is the tradeoff you make in properties, not simply in cost.

For example, while there is slight variance among manufacturers, for the most part the properties are very similar. Take these two as an example:

6mm thick twin-wall polycarbonate:

R-value 1.6
Light transmission: 85%

10mm thick twin-wall polycarbonate:

R-value 1.9
Light transmission: 75%*

*In the often requested 16mm multi-wall, light transmission drops to around 64%

Note that by adding 40% to the thickness of the material you gain only 15% R-value (thermal insulation) yet you lose 10% light transmission. In the case of a greenhouse application that 10% can have an effect on plant growth.

The point of all this is to have a clear picture of the cost and consequences of going with thicker multi-wall polycarbonate. It is still an excellent product, but it comes down to a tradeoff you need to be aware of – increased thermal insulation in exchange for increased price and less light transmission.

Any questions? Contact us.