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Latest from NHI...
Monday, 21 March 2016 11:15

In our final installment we have some fun photos from our own employees and their favorite pulley applications. As we’ve seen in past installments, there is quite the range of grownup “toys” that use pulleys. We all have our own personal favorites, what’s yours?

 

Ruth - Accounting (with NHI since early 2015)

Pictured with her father in the early 70’s, he’s showing her his John Deere bulldozer. Ruth says that her father had several of the same kind over the next 30 years.

 

Ross - Engineering (with NHI since mid 2015)

Pictured with his brand new John Deere D140 lawn tractor. Ross says this is the first ride-on he’s ever owned.

 

Crystal - Planning (with NHI since early 2013)

Pictured with her parents’ Toro 50” TimeCutter zero-turn lawn mower. They’re ready for spring and another mowing season.

 

Terri – Production (with NHI since early 2013)

Pictured with a John Deere 5065E tractor. Terri is “window shopping” at her local tractor dealership.

 

Erik – Marketing (with NHI since late 2010)

Pictured with his Ariens Compact22 snowblower. He’s enjoying this past winter’s unseasonal warmth. Perhaps he’s enjoying the warmth a bit too much…

 

It’s quite remarkable all the places pulleys are found!

 

If you have any questions or just want to chat please don’t hesitate to send an email to This email address is being protected from spambots. You need JavaScript enabled to view it. or leave a comment here.

 

New Hampshire Industries (NHI)

 

68 Etna Rd, Lebanon, NH 03766

Monday, 07 March 2016 11:15

In this installment we’re going to take you through some maintenance tips for the most common pulley applications; lawn mowers and snow blowers. With a few simple tasks your machine can purr for years to come. For the most up to date information on your specific machine please refer to the manual that came with it. If you don’t have the manual please contact the manufacturer of your machine for a copy.

 

 

 

 

Lawn Mowers

How to Maintain a Lawn Mower - This Old House

Simple Lawn Mower Tune-Up and Maintenance

Push Mower Maintenance – Lowe’s Home Improvement

How Does A Lawn Mower Work? — Repair & Troubleshooting Tips

NOTE: Before any maintenance, disengage the spark plug so the mower will not start.

 

Beginning of Season (Spring) Tips:

-          Change oil

-          Check air filter for dirt/debris, change as necessary

-          Change spark plug

-          Lubricate wheels and all moving cables

-          Check tire pressure

-          Check all nuts and bolts and tighten as necessary

-          Check blade for sharpness, sharpen/replace as necessary

-          Clean the undercarriage of the mower deck of debris and buildup

-          Gas should be stored in a proper container and out of direct sunlight

End of Season (Fall) Tips:

-          Run mower out of gas (for the health of the engine and carburetor)

-          Clean the undercarriage of the mower deck of debris and buildup

-          Spray lubricant on any bare metal structural parts to prevent rusting

 

 

 

Snow Blowers

How to Maintain Your Snow Blower - This Old House

How Does a Snowblower Work? — Repair & Troubleshooting Tips

NOTE: Before any maintenance, disengage the spark plug so the blower will not start.

 

Beginning of Season (Fall) Tips:

-          Change oil

-          Check spark plug, change as necessary

-          Check belts, change as necessary

-          Lubricate wheels and all moving parts

-          Check all nuts and bolts and tighten as necessary

-          Have spare shear pins on hand

-          Gas should be stored in a proper container and out of direct sunlight

End of Season (Spring) Tips:

-          Run blower out of gas (for the health of the engine and carburetor)

-          Clean the auger housing and impeller of debris and buildup

-          Spray lubricant on any bare metal structural parts to prevent rusting

 

 

Look Before you Pump

Ethanol Education for Equipment Users

Ethanol Education - Look Before You Pump!

Almost all unleaded fuel found at your average gas station today contains at least 10% ethanol (e.g. E10, E15, E85). Current outdoor power equipment is designed to handle up to 10% ethanol (E10) though the less ethanol in your gas the better. Special fuel containing no ethanol can also be purchased for your outdoor power equipment. There is much debate over ethanol’s corrosive properties and the effect it can have on engines and system parts not designed to handle it. As technologies update and adapt to be compatible with higher percentage ethanol fuels it will become safer and common place to use such fuels. As it stands currently though, current fuel systems are designed to run best and last the longest with E10 or less.

 

Additional Sources

Maintenance Tips for your Lawn Mower

http://www.repairclinic.com/Lawn-Mower-Maintenance-Tips

http://www.repairclinic.com/Snowblower-Maintenance-Tips

https://www.nmma.org/assets/cabinets/Cabinet528/CONSUMER-FACT-SHEET_BOAT.pdf

 

In the next installment we’ll show our employees’ favorite pulley applications and top picks from across the country.

 

If you have any questions or just want to chat please don’t hesitate to send an email to This email address is being protected from spambots. You need JavaScript enabled to view it. or leave a comment here.

 

New Hampshire Industries (NHI)

68 Etna Rd, Lebanon, NH 03766

Monday, 25 January 2016 11:15

In this fourth and final installment we’ll be discussing the processes used to create pulleys. Spinning, splitting, stamping, molding, machining, casting and powder metallurgy each have their own strengths & weakness. We’ll also discuss best uses as some processes suit certain industries or applications better.

 

Spinning involves taking a stamped blank, typically having a domed or cup shape, and forming it between an upper & lower mold and form tooling. The part is held tightly between the molds (e.g. 25,000psi) and spun at high rates of speed (e.g. 900rpm). As the part spins, form tooling comes in and presses against it, forcing the material to change according to the shape of the form and mold which matches the desired groove profile. A typical pulley can use anywhere from two to four form tools, each attached to its own machine arm/holder which forms the part in consecutive stages.

Strengths: Pulley is a single piece which helps maintain consistent material thickness throughout the pulley

Weaknesses: Tolerances cannot generally be held as tight compared to processes like machining

Best Uses: Both drive and idler pulleys, standard single groove and poly-V pulleys, moderate to large sizes, all applications, steel

 


 …held tightly between the molds

 (e.g. 25,000psi)…


  

Splitting takes a flat stamped blank (think dinner plate) and forms it between a set of upper & lower molds and split/form tooling. The part is held tightly between the molds (e.g. 25,000psi) and spun at high rates of speed (e.g. 900rpm). As the part spins, the split tooling (think knife) comes in and presses against the edge of the blank. This causes the material to start to split in half. The form tool then comes in forcing the material to change according to the shape of the mold and desired groove profile. The material is pressed firmly against the molds, forcing it into its final shape. A typical pulley uses two individual form tools (one splitter/knife and one form), each attached to its own machine arm/holder which forms the part in consecutive stages.

Strengths: Pulley is a single piece which reduces thin points that can be created by assembling separate pieces.

Weaknesses: Tolerances cannot generally be held as closely as they otherwise can be in processes like machining.

Best Uses: Both drive and idler pulleys, standard single groove and poly-V pulleys, moderate to large sizes, all applications, steel

 

Stamping uses compound or progressive dies in a press to convert coils or sheets of metal into the desired shape/component. Depending on the size of the pulley a press uses anywhere from 30 to 800 tons of force.  The press may use what’s called a progressive die or a single stage (compound) die. A single stage die is just that, a die with a single stage where the pulley is stamped in one stroke/revolution of the press. A progressive die has several stages where the metal is moved from stage to stage and stamped into shape over the course of several strokes of the press. Generally, stamping in itself cannot create a whole pulley. It can only create one half at a time so two halves must be assembled using rivets and/or welding as a secondary process.

Strengths: Highly efficient and thus low cost

Weaknesses: Because of the size of presses and tooling needed to stamp metal, thinner materials are used which reduces overall strength compared to other processes like spinning and splitting.

Best Uses: Idler pulleys, standard single groove pulleys, small to moderate sizes, moderate applications, steel

 


 …press uses anywhere from

 30 to 800 tons of force.


 

Molding melts plastic pellets/beads by use of a reciprocating screw & heaters, forcing the now molten material through a small nozzle and into a mold. The material cools inside the mold, the mold separates in half and the molded part is removed. Molded parts from a cold runner system require finishing processes to remove excess plastic. This can be done by robotics. Hot runner systems do not necessary require extra processing. 

Strengths: Highly efficient process and thus low cost

Weaknesses: Material can melt or break/shatter under high load or high heat applications. Due to shrinkage during cooling, tolerances cannot be held as closely as with other processes. Inside and outside corners/edges must be rounded in order for the finished part to be properly removed from the mold.

Best Uses: Idler pulleys, standard single groove pulleys, moderate sizes, low load & low heat applications, nylon

 

Machining can take several forms including hobbing. In each instance a computer numerical control (CNC) or similar machine is used with precision tooling to remove material from a bar or slug. This process is controlled by a computer program entered into the machines terminal. Because each movement and process is controlled so finely, finished product can adhere to minute tolerances.

Strengths: The smallest of tolerances can be held.

Weaknesses: This is the slowest process by far and may require additional finishing processes depending on the part.

Best Uses: Both drive and idler pulleys, standard single groove and poly-V pulleys, timing pulleys, gears, small to large sizes, all applications, steel, aluminum, brass

 

Casting involves melting material and pouring that material into a mold. This can be done under pressure or not. Once the material cools the mold can be separated and the cast part (also called a casting) can be removed. The casting typically requires secondary operations including removing excess material and machining specified surfaces in order to hold tighter tolerances.

Strengths: Very strong and durable finished product.

Weaknesses: Castings are very heavy compared to pulleys made in other processes.

Best Uses: Both drive and idler pulleys, standard single groove pulleys, gears, small to large sizes, heavy load applications, aluminum, brass, iron (ductile & gray)

 

Powder Metallurgy is similar to both molding and casting in that a material is put into a mold to form the desired product. The difference is that a powder is used and, under pressure, forced into the mold. The subsequent part is fairly brittle and must be sintered in order for the powdered material to fully bond.

Strengths: More cost effective than many processes

Weaknesses: Tends to be more brittle than steel and other processes which reduces applicable uses

Best Uses: Bore adapters/plugs, hubs, small to moderate sizes, moderate applications

 


 Who knew there was

 so much to pulleys?


  

Throughout the course of these four installments we’ve covered quite a lot of information, from pulley basics & types to materials & processes used. Who knew there was so much to pulleys?

 

If you have any questions or just want to chat please don’t hesitate to send an email to This email address is being protected from spambots. You need JavaScript enabled to view it. or leave a comment here. We’ve been doing this since 1960. We know a thing or three.

 

New Hampshire Industries (NHI) 

68 Etna Rd, Lebanon, NH 03766

Monday, 18 January 2016 11:15

In this third of four installments we will be detailing what makes a drive pulley different from an idler pulley and what each typically look like.

 

To begin, what is a drive pulley? According to thefreedictionary.com a drive pulley is one “that drives a conveyor belt”. Could it be that simple? Not entirely. A drive pulley is a pulley that applies force to the belt, cable, chain, etc. to drive the system it’s attached to. A shaft connects the pulley to an engine or motor. A drive pulley drives the system it’s attached to.

 


 A drive pulley spins

 with its shaft


 

What is an idler pulley? Merriam Webster simply calls an idler pulley “a guide or tightening pulley for a belt or chain”. A more complex definition, describing more of the function of an idler comes from audioenglish.org. It’s “a simple machine consisting of a wheel with a groove in which a rope can run to change the direction or point of application of a force applied to the rope”. An interesting point is that an idler can provide tension to either side of the belt depending on the assembly and application. Typical applications have the drive pulley on the front side of the belt and the idler on the flat backside of the belt.

 


 An idler pulley does not

 spin with its shaft


 

Put simply, a drive pulley spins with its shaft and an idler does not.

 

There are instances where a drive (below right) and idler (below left) look very much the same.

 

Typically they look very different. From the definitions above do you know which of the below pictures are drives and which are idlers?

Key differences include the presence of a static shaft at the center of a drive pulley (upper set of pulleys above) and a bearing or special bushing at the center of an idler (lower set of pulleys above). The idler must spin freely so it can be driven where the drive pulley must be able to transfer and apply force generated by the engine or motor it’s attached to.

 

Another large difference you may have already noticed is the space allowed for a belt. Typical drive pulleys have a narrow groove, also known as a V groove, which the belt sits in. Tension applied to the belt snugs it into the V groove, allowing the groove to pinch and grip it. Idler pulleys have a larger flat groove that allows a belt to freely move along its surface.

 

What if a pulley is a drive pulley but isn’t attached to the main source of force, the engine or motor? The pulley is being driven by another source (typically a drive pulley on the engine or motor) but is also driving more pulleys or components of an assembly. It’s both driven and driving. That would simply be a driven pulley.

 


 A driven pulley both

 drives and is driven


 

To recap; a drive pulley spins with its shaft. An idler pulley does not spin with its shaft. A driven pulley spins with its shaft but is being driven by a source other than the engine or motor, typically a drive pulley.

 

If you have any questions or just want to chat please don’t hesitate to send an email to This email address is being protected from spambots. You need JavaScript enabled to view it. or leave a comment here.

 

New Hampshire Industries (NHI)

68 Etna Rd, Lebanon, NH 03766

 

Monday, 04 January 2016 11:15

When was the last time we had a winter start like this? What are you looking forward to do in the snow this weekend?

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