|
|
|
Spring
1998 |
|
Volume 2
Number 5 |
Precision Billet Cranks Up
Productivity with
Haas Brushless Axis Motor Machining Centers
| story and photos by
Preston Gratiot |
|
 ou’re flying
down a rocky ski run and the trees are just a greenish blur framing the
perilous path ahead. This is not the time to worry about your components,
and the fact that there is no snow on the ground is of little consolation.
If you miss the next apex, you’re likely in for the biggest
“face-plant” of your life, and insurance doesn’t cover this kind of
downhill dementia. This is no time for cheap bicycle parts!
Precision Billet designs,
manufactures and markets a proprietary line of mountain
bike components. |
Precision Billet is a
high-end job shop and manufacturer of the specialized, high-
performance cycling components that you can depend on in this
fast-paced world of gonzo biking.
Precision Billet, true
to the sport, recently shifted gears, took a calculated chance and
replaced several of its older machining centers with three new Haas
Automation VF-0 brushless servo motor machining centers. This single
production change sent productivity rates climbing by more than 25
percent. |
|
Bolstered by this
success, the shop soon replaced another aging piece of equipment
with a new Haas HL-2 CNC lathe. Payback was reached in just nine
months, again with an impressive gain in production efficiency. And
so, as the company continues to grow, so grows the number of Haas
machines on the shop floor. Precision Billet has just added an
additional HL-1 lathe to its mechanical workforce.
Precision Billet, situated in Santee,
California, fabricates a wide array of high-tech components for the
highly competitive mountain bike business. The company designs,
manufactures and markets a proprietary line of mountain bike and
bicycle motocross (BMX) components under the brand names ProShift
and Atomic Industries.
The machined-billet product line
includes operator-serviceable front and rear derailleurs, handle bar
shifters, brake levers, brakes, hubs and adapter clamps. In
addition, as a job shop, Precision Billet also makes parts,
including pulleys and frame and suspension components, for
other bicycle manufacturers. |
ProShift’s
derailleur systems are completely user serviceable, with replacement
parts available – very important features for rough & tumble
mountain bike enthusiasts. |
Proof in
Production
“Where most job shops specialize in quantities of
less than 100 parts or so, we make lots of up to 10,000 pieces, so every
second of cycle time is critical,” said Gary Hickman, president of
Precision Billet. “We know there’s a big difference with Haas
brushless servo motors because we still have one machining center with
brush servo motors and set the same job up on both types of machining
centers to make a comparison.”
|
The comparison of brushless versus brush
servo motors was made with a component called an aluminum backstop
(cable hanger). Typically, Precision Billet machines 1,000 backstops
in a normal production run. Five tool changes are required to
machine the backstop, including a 1/2" endmill, #2 center
drill, 1/8" drill, keyway saw and a 45° endmill. |
Three of Precision Billet’s
Haas VF-0s with
brushless motors. |
“We set both machines up to run the backstop,”
said Hickman. “The Haas machining center with brushless servo motors
finished 1,000 parts in 16 hours. The machining center with DC servo
motors required 20 hours. The high-speed rapids and cutting feed rates of
the brushless servo motors proved their worth by saving one-half day of
production time.”
Group Ganging
Because many of the parts machined by Precision
Billet are small extrusions or other odd shapes, Chick vices are employed
to increase throughput by grouping multiple parts in a single cut program.
According to Hickman, the multiple-piece vices do a much better holding
job while reducing manual operator time in running large part orders.
Controls and
Cycle Time
Another feature of the Haas machining centers that
Hickman appreciates is the control. Precision Billet utilizes several CAM
programs for offline programming, such as EZ Mill for 2D parts and Geopath
for advanced 3D parts, such as brake handles.
product photos courtesy
of Precision Billet
|
“The Haas control is very powerful with a lot
of features, such as 100 tool offsets and 26 work coordinates, a
floppy drive, text editor and graphics. It’s faster and makes it
easier to get parts into production,” said Hickman. “For
example, the Haas control allows the operator to view the cycle
times for each tool by selecting the tool life display screen. The
display shows the total cycle time, feed time and number of uses. By
subtracting feed time from total cycle time, we can determine the
time spent cutting air. We use these figures to reduce excess moves
and are able to cut cycle times by as much as 30 percent. Plus, tool
life calculations can easily be made by estimating the number of
uses for each tool and inputting an alarm number for each tool.”
With the Haas control, work offsets can be set
in the CNC part program and the offsets can be verified on the
control. To do this, the operator runs the program from the
control’s graphics page. If a wrong number has been keyed in or a
decimal put in the wrong place, it will be immediately visible.
“By verifying part programs on the control
before proving them on the machine, we avoid scrap parts and tool
breakage,” said Hickman. “And the Haas control is fast. We can
load ten tool offsets in the same time it took our previous machines
to load two tool offsets.” |
Latest in
Lathes
Precision Billet previously owned a 1983 vintage CNC
lathe. When repeatability problems became apparent, a Haas HL-2 CNC lathe
was purchased. Continued productivity and growth in the marketplace soon
had Hickman on the phone ordering another HL-1 lathe.
“We found that lathe controls had not progressed as
much as machining center controls,” said Hickman. “But the Haas lathe
was surprisingly easy to operate. Setting tool offsets is easy and turret
indexing is quick and precise. We saw a demonstration of the lathe cutting
steel and were convinced to buy it.
“Mostly, we turn brass or aluminum,” said
Hickman. “With the Haas lathe, we can hold 0.0002 inch, even when we
start it stone cold in the morning. We can put in a fresh bar and the
diameter will be within a tolerance of plus or minus 0.0002 inch.”
| Precision Billet has reduced lathe programming time
substantially with several control features unique to the Haas
lathe. For example, G81, G83 and G84 canned drilling cycles are
identical to those found on mill controls. And the Haas lathe
control can be programmed in either Fanuc™ or Yasnac™ mode, the
latter most commonly used at Precision Billet. |
 |
Gary Hickman at the
control of the Haas lathe. Precision
Billet has reduced programming time substantially with several
control features unique to
the Haas lathe, such
as G81, G83 and G84 canned drilling cycles identical to those found
on mill controls. |
Cycle times have decreased even more because the new
HL-1 has AC drives with 710-ipm rapids.
“Typical lathe cycle times are 50 percent faster
because of faster rapids and turret indexing, as well as higher feeds and
speeds. Setup times have also decreased by 50 percent due to ease of tool
offsetting and Haas’ unique turret tool holders. We have tool holders
set up for specific jobs. All we have to do is install a new holder in the
turret. Repeatability is high enough that offsets can be preset for that
specific job,” said Hickman.
Production +
Payback = Success
|
“During the past 12 months we have
quadrupled our growth rate. We can make 500 rear derailleurs a week,
instead of 500 a month. Payback on the VF-0s has been less than a
year,” said Hickman. “Plus, we have more time to design,
prototype and make new products. Haas’ speed, accuracy and ease of
setup have allowed us to increase our throughput. And the faster we
make parts, the faster we get paid.” |
The Precision Billet crew can load
ten tool offsets on the Haas VF-0s in the same time it took to load
two tool offsets on the previous machines.
|
Precision
Billet
9437 Wheatlands Court, Suite A
Santee, CA 92071
619-448-4508
[ Home ] [ Sizeable Cuts ] [ Industry News ] [ Race Report ] [ PrecisionBikes ] [ Speedway Eng ] [ Swift Racers ] [ Aircraft Engg ] [ CAD/CAM ] [ Cutting Fluids ] [ New Products ] [ Back Page ] [ Spring98.pdf ]
Search Online!
|
