A More Affordable Approach to 5-Axis Large Part Machining

Meeting your budget is now more important than ever. Consider this more affordable approach to 5-axis large part machining.

According to Modern Machine Shop:

“There are some amazing large format 5-axis machining centers on the market these days. They can machine titanium all day long and hold incredible tolerances. The problem is that you may have to spend north of $2 million to buy one. And good luck getting shipment anytime soon.

“But what if you don’t need all that? What if you’re cutting aluminum or other free machining materials that just happen to be large?

“American machine tool manufacturer C.R. Onsrud has an answer for that with its line of large 3- and 5-axis machining centers designed specifically for machining of aluminum and other materials. Will you want to try to cut Inconel or titanium with these machines? Not yet. But if you’re primarily machining large aluminum parts — with prices ranging from under $300,000 to $1.5 million for five-axis machining centers ranging from 144 in. x 60 in. x 41 in. to 100 ft. x 20 ft. x 10 ft. — this is an option you can’t afford to ignore.

Machining Centers for Large Aircraft Parts and More

“While the name C.R. Onsrud may be new to you, the company has been around a long time. The Onsrud family has been manufacturing machinery for the aerospace, woodworking, plastics, and composites industries for five generations. While the company still serves these applications, more recent product development has concentrated on building machining centers aimed at underserved portions of the metalworking market, and large aluminum part machining is a big one. All C.R. Onsrud machines are entirely built in the company’s factory in Troutman, North Carolina.

“C.R Onsrud machining centers share three things in common: They are big. They are fast. And they are comparatively inexpensive relative to most other like-size machining centers in the market. These machines have 20,000 or 24,000 rpm spindles that can machine at feed rates up 3000 ipm. Rapid traverse rates of 4000 ipm are standard on many models and with high acceleration and deceleration rates, which is particularly important when traversing large distances from one workpiece feature to another or to the tool changer and back.

“Standard machines hold ±0.005” or better across the full axis travel range. Optional linear scales and volumetric laser compensation allow tolerances below 0.001”. While that might not sound super precise to some, it is difficult to do much better with very large parts on virtually any machine outside of a closely controlled thermal environment. Remember that these machines are quite large and the coefficient for expansion of steel works out to almost 0.001” per degree change in temperature over a 12 ft. machining bed. Across shorter machining travel distances the standard machining centers routinely hold tolerances to 0.001” or less. All are equipped with Fanuc CNC control systems.

“A large variety of options are available for C.R. Onsrud machining centers. All the machines can be equipped with an integrated vacuum work-holding system for fixtureless work holding. Not having to machine around clamps is particularly useful for things like large plate work. They also offer traditional T-slot tables and other fixturing options. Spindle head C-axis capability is available which can be used to articulate auxiliary milling heads or apply multi-spindle options. Large vertical or horizontal rotary tables can be integrated with the machines. In addition, a range of work handling automation can be integrated as well.

“C.R. Onsrud machines are routinely used in aircraft applications where up to 90% of the workpiece material is being removed. Standard spindles typically are 15 hp but spindle models up to 75 hp are available. Other common applications include the large battery plates that comprise the bottom of electric vehicles, nested-base machining where multiple parts are cut from a single plate, monolithic structures for buses, RVs and other large vehicles, large aluminum molds, and a variety of defense applications.

“C.R. Onsrud offers four main types of machines: enclosed machining centers, linear extrusion processing machines, high rail portal mills for extra-large parts, and traditional open format CNC routers. It will help to get a better sense of C.R. Onsrud’s capabilities for machine shops by taking a closer look at three machining centers designed for cutting large metal parts.

Affordable Large-Format 5-Axis Machining

“The five-axis machining line starts with the QUBE Series. This fully enclosed vertical CNC machining center has a moving gantry design and provides a large work volume for machining aluminum molds and prototypes, and complex composite or thermoformed plastic parts. A 12 hp, 24,000 rpm spindle is standard, and a 15 hp version is available. The standard model has a 144” x 60” table with 41” of Z travel. The side panels are removable so even larger parts can pass through to be accommodated. It comes equipped with a Fanuc 31i-B5 control.

“QUBE Series machines can be equipped with automatic tool measurement and on-machine probing capability which can be particularly useful with large parts for on-machine quality validation as well as establishing workpiece offsets to speed setups. It can also be fitted with an MQL (minimum quantity lubrication) delivery system. MQL is important for high speed machining of aluminum to enhance tool life and resist built-up edge on an insert or solid tool. It also creates far less cleanup of the part after machining and dealing with changing over of coolant tanks.

“QUBE Series 5-axis machining centers start at about $260,000.

Advanced Large-Format  5-Axis Machining

“The Hybrid Mill (HM) Series offers a more robust five-axis machining platform with a standard 15 hp, 24,000 rpm spindle and optional spindles that range up to 75 hp with high-torque versions available. Standard Hybrid Mill models (F98HM and F148HM) have X-Y-Z travel ranges of 122” x 196” x 41” or 146” x 244” x 41”. The Hybrid Mill can machine at up to 3000 ipm and rapid traverse at 4200 ipm. For the higher horsepower machines, the spindle is fit for HSK A63 tool holders. This machining center is suitable for a wide range of large or smaller parts made of aluminum or other nonferrous materials, and is the best choice in high metal removal applications.

“The Hybrid Mill features twin 72” x 72” tables that can be operated independently or synchronized as one big table. This enhances efficiency through easier setup and the ability to process two parts in a single machining cycle. It gives you the flexibility of a shuttle table (like a pallet changer) where you can change over one table while machining on the other table, or lock the tables together for the occasional larger part. With the optional Dual Process system, a second Z-ram and head can be added to the gantry so that two different machining programs can be run simultaneously. It comes standard with a Fanuc 31iB5 Control.

“A wide variety of options are available to tailor Hybrid Mill machining centers to specific machining environments. It can be equipped with flood coolant, MQL, or through-the-tool coolant. Standard tool capacity is 24 and large capacity ATCs of 120+ tools are available. An array of workpiece handling automation is also available.

“Hybrid Mill 5-axis machining centers start at about $400,000.

Heavy-Duty Large-Format 5-Axis Machining

“Compact High Rail (CH) 5-axis machining centers are designed for very large and heavy workpieces. In addition to typical aerospace parts this machine is a good choice for large aluminum dies and molds, composite structures and large patterns. Key to this bed and moving bridge design is a stationary one-piece, steel base with internal steel reinforcements that provide a machine bed engineered to handle the extreme weights of large blocks of material. The work envelope is 144” x 84” x 53”. Available spindles range from 15 – 75 hp and up to 24,000 rpm. The CH can machine at up to 3000 ipm and rapid traverse at 3600 ipm. Large horsepower machines are fit for an HSK 63 A or F tool holders. A Fanuc 31iB5 control is standard.

“The large, heavy bridge of the Compact High Rail allows use of a taller, stiffer Z-axis ram which is more accurate at taller workpiece heights. The addition of internal perimeter walkways in the Compact High Rail’s newest version and optional retractable roof bellows allow for easier material loading and part unloading. Large vertical rotary tables up to 40” in diameter can be added to further enable 5-sided machining workpiece access.

“Like the HM, a Compact High Rail machining center can be fit for wet or dry machining, large capacity tool changers and workpiece handling automation.

“Compact High Rail Series 5-axis machining centers start at $475,000.

Still More Machines from C.R. Onsrud

“There are still more large CNC milling and routing machines available from C.R. Onsrud for special purpose applications. They include:

“X-Series — For heavy and complex linear profile extrusions in aluminum, plastic and other advanced materials, the X-Series delivers five-sided machining capability and a fully programmable, servo adjustable clamping system. The modular design allows for extended platform lengths to be configured according to a shop’s needs. View video on X Series machining centers.

“High-Rail – The High Rail Gantry CNC machining center has the very large working envelope needed by manufacturers producing high-precision, large and/or awkwardly shaped components in non-ferrous, light ferrous, or advanced composite materials. It offers C.R. Onsrud’s largest variety of options, sizes, upgrades, and machining possibilities. The flexible High Rail Gantry series is engineered and built to order. View video on High Rail Series machining centers.

“E-Series – Based on a twin-table, fixed bridge design, E Series machines are fast (4000 ipm rapid) and flexible. The design starts with a rigid steel frame and then is customized to a shop’s specific needs. Models are available with a single or twin Z-ram with 3- or 5-axis machining heads. The wide range of customizable options allows these machines to be configured for many different manufacturing or prototyping applications in plastics, composites, aluminum and other non-ferrous metals. View video on E Series machining centers.

American Made and Available
“While the point that C.R. Onsrud machining centers are built in the USA may strike some mainly as a feel-good thing, there are real advantages to sourcing close to home with these kinds of large machines. For one thing, parts and skilled service people are generally more readily accessible. As an added plus, you can get a machine in a much more reasonable timeframe. Aside from stock machines, C.R. Onsrud typically ships in three to four months. Onsrud also offers the ability to fully tailor your machine to your application, so if you have something a little out of the box, they may be able to tweak a standard model to fit your exact needs.

“Moreover, these machining centers are simple to install. Most models ship as one piece that is fully assembled and can run with minimal setup time. All they really need is to be leveled, powered and they are ready to go.

“The reason C.R. Onsrud can build machines so quickly is that they apply modular design principles that allow them to use common components across multiple machine models. Not only does this speed the assembly process, but it also enables a high degree of flexibility to customize machines to customer specifications without significant delays in build time or exorbitant additional cost. For example, while the machines mentioned above have published standard dimensions, variations in size and features are easily achievable. The same is true of automation solutions that can be built quickly and cost-effectively.

“To be clear, as customized machines get larger, and as more high-end options are added, the cost of these machines will go up, sometimes significantly relative to the starting prices. But compare those machines to other alternatives in the market today and they’ll still be a bargain for the right kinds of applications. If you machine large aluminum or other non-ferrous parts, this is an option you can’t afford to ignore…”

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