CNC Brand Profile

Thermwood: The Plastics Molder That Built Its Own Control

Thermwood did not set out to build CNC routers. It set out to mold plastic that looked like wood, and it needed a better way to trim the parts. Routers cost too much, so the company built its own control. That decision, made in Dale, Indiana, in the 1970s, still shapes every Thermwood on a shop floor today.

Here is how a plastics molder became one of the oldest CNC router companies, what it builds now and what to know before you buy a used Thermwood.

Thermwood at a Glance

1969: Plastic That Looked Like Wood

Ken Susnjara started Thermwood while he was a college student at a small engineering school in central Indiana, now Rose-Hulman Institute of Technology. In an interview with CNC King, he said his first product was thermoformed wheel pants for small fixed-gear airplanes, sold as $22 kits.

The business that named the company came next: thermoformed plastic parts with a wood grain, sold to furniture makers. Thermwood's own history describes it as "a plastic molder of wood grained parts for the furniture industry," using a molding process it developed and molding and trimming machinery it built in-house.

The Router Was Too Expensive, So Thermwood Built a Control

Then the oil embargo raised plastic prices and hurt the furniture business. Thermwood needed to cut the cost of trimming its parts. Susnjara told CNC King that the NC routers of the day ran on punched tape and cost about a quarter of a million dollars each. That was too much.

His first attempt used the memory positions of a calculator to drive a sequence of up to nine moves. The next step was a microprocessor-based control, built with an outside developer. The estimate was $6,000 to $8,000 and six weeks. It took eighteen months and about $1.5 million. Early programs were entered in hex on a small keypad.

Here's the part most buyers never think about: the control came first, and the router came second. Thermwood says it developed the first commercial CNC machine tool control in the mid-1970s, then sold trim equipment for plastics, composites and woodworking. In its words, "the CNC router was born." The company sold its plastics business in the early 1980s and kept the machinery.

Why Thermwood Still Builds Its Own Control

Thermwood calls itself the only major CNC router company that designs and builds its own high-end control. Every current 3-axis Thermwood router runs the Thermwood SuperControl, according to the company's product pages.

It also patents what it builds. Thermwood says it holds more CNC router patents than all other CNC router manufacturers combined. Dennis Palmer, Thermwood's vice president of sales, summed up the attitude to Business View Magazine: "If it doesn't move, we paint it. If it moves, we patent it."

For a used buyer, the in-house control cuts both ways. The machine and control come from one company, and that company still supports them. But a Thermwood control is not a FANUC or a Siemens, so plan on Thermwood for control service and training. For another builder that makes its own control, see Okuma: The Only Builder That Makes Its Own Machine and Its Own Control.

The Lineup in Shop Language

3-axis CNC routers

Thermwood's 3-axis line covers sheet work from cabinet nesting to large composite parts:

The current Model 45 ships with a 12 hp HSD spindle running 3,000 to 24,000 rpm, with 18 hp optional, on a stress-relieved steel frame with a fixed steel table and moving gantry.

5-axis CNC routers

The 5-axis line runs from the Model 67, with single or dual moving aluminum tables for trimming formed parts, patterns and molds, up through the Model 90 for heavy-duty trimming and pattern work, the Models 70 and 77 for aerospace and composites, and the MAX 5, a high-clearance machine for very large 3D parts.

LSAM

LSAM stands for Large Scale Additive Systems. One moving gantry carries a print head and a trim head, so the same machine prints a large part from reinforced thermoplastic and then trims it. It does one or the other at a time, not both at once. According to Business View Magazine, the idea started when Purdue University and an aerospace company asked Thermwood to add an extruder to its 5-axis router.

Thermwood's 2020 review lists real jobs: a CNC trim tool for General Atomics with reported savings of about $50,000 and lead time cut from 6 to 8 weeks to under 2, a multi-piece foundry pattern printed in 6 hours and 40 minutes, and sections of a 51-foot yacht hull mold.

The Cabinet Shop Connection

Much of the used Thermwood market comes from cabinet shops. Thermwood built the CabinetShop series for cabinet boxes and furniture cases and paired it with eCabinet Systems, design software it gave away free. Its 2009 history described eCabinet Systems as a cooperative of more than 25,000 custom cabinet shops.

Today that idea lives on as Cut Ready, Thermwood software that lets a shop design and cut cabinet jobs without CNC programming. It is built into the Cut Center and can be added to most other Thermwood 3-axis models.

How to Read a Used Thermwood Model Name

Used listings mix older series names with newer model numbers. A few patterns help:

• CS means CabinetShop. The CabinetShop 45 was sold as the CS45-510, CS45-612 and CS45-712.
• The suffix tracks table size. Our 2006 CS45-510 has a 5 by 10 foot table. Confirm the size on the machine, not just the suffix.
• Current machines use model numbers, such as the Model 43, Model 45 and Model 67.
• C-series machines, such as the C40, are older 3-axis routers. Check the control and spindle carefully on these.

The CabinetShop 45 catalog lists a 10 hp, 3,000 to 24,000 rpm spindle as standard, with 18 hp available on the larger tables, and the Gen2 SuperControl, which accepts a whole job as one file, including DXF files from major CAD programs.

Where Thermwood Machines Have Worked

Thermwood says its machines have processed the interiors of most commercial jet airliners, and that its control is a worldwide standard in certain aerospace and defense applications. The company also says NASA used Thermwood machines on the Mars Flyer and Mars Lander, and that its machines helped rebuild Windsor Castle and the Opera House in London. These are Thermwood's own claims, but they show how far the routers reach past cabinet shops.

What to Check When Buying a Used Thermwood

• Identify the control: SuperControl, Gen2 SuperControl or QCore, and the computer and operating system it runs on.
• Check the spindle: make, horsepower, taper and hours. Current Thermwood routers use HSD spindles, and our CS45-510 has one.
• Check the tool changer type and number of positions.
• Inspect the vacuum table, plenum and pump. Vacuum hold-down makes or breaks nesting work.
• Ask what software comes with it, and ask Thermwood whether licenses such as Cut Ready transfer to a new owner.
• Run every axis through full travel and check ball screws, linear bearings and lubrication.

For another American router builder, see C.R. Onsrud and the Family That Has Been Cutting Since 1915.

Resell CNC Take

Thermwood is one of the few router builders where the machine, the control and the cabinet software all come from the same company in Indiana. That gives a used Thermwood one source for machine, control and software support, as long as you know which control and software you are getting. Confirm both before you buy, and a used Thermwood can keep cutting sheet goods for years.

Built Around the Control

Thermwood started with plastic that looked like wood and a router it could not afford. It built the control instead, and it never stopped. More than fifty years later, that is still what sets a Thermwood apart.

Frequently Asked Questions