CVC Cuts Customer's Welding & Assembly Time
CVC is a job shop in Florence, Kentucky,
fabricating component parts, assemblies and complete products.
In 2001, the company installed a 2000w, 5' x 10', 3D rotary
laser (Mazak's SpaceGear) to do pipe and structural work. CVC
President Kevin Martin talks about two parts produced on the
versatile machine - one that takes advantage of the laser's large
bed and the other of the rotary chuck.
What is the steel tubing part (Left & closeup) used for?
Two of these parts are welded together
to make the frame for a litter (bed) for the medical industry.
The material is 2" x 1" rectangular steel tubing, 16-gauge wall.
Before the tube is bent it is 112" long. The web of the litter
frame is 84" and the flanges approximately 12". There are 50
holes in total, in six or seven different sizes, on all four
sides of the part.
How was this part made before you put it on your 3D laser?
Our customer was making this part internally. His process was to
saw the tube to length, form it, drill the holes manually and
then deburr. He came to us because he
wanted to reduce his cost and improve the accuracy to cut his
welding and assembly time.
What problems did your customer have producing this part?
He could saw to length accurately, but then forming was an
issue. He had to make sure his gauging was exactly right. Also
this was a hand drilling process, so with 50 holes of varying
sizes, the operators were constantly picking up and laying down
drills and changing drill bits. Accuracy on hole placement and
size was harder to maintain, too.
How do you make the part on the 3D laser?
We purchase a millrun of the tubing and bring it in here sawed
slightly oversized. Our first step is to form the part. There
are some large holes in the area where the tube is bent, and the
tubing would collapse if we formed it with the holes in there
first. After the part is formed, we laser cut all the holes and
trim the ends on the SpaceGear.
How does the laser machine cut holes on all four sides?
We built two fixtures to hold two formed tubes on the bed of the
laser. During one cycle, we're cutting the holes on three sides
of the part that is in the first fixture while we're cutting the
holes on the fourth side and trimming the ends of another part
in the second fixture. At the end of the cycle, we unload the
finished tube and move the tube that has been cut on three sides
into the second fixture. We load a new tube into the first
fixture.
What are the advantages of making this part on a 3D laser?
First of all, since we bring in a slightly oversized tube, form
the part first and then trim the flanges, the length of the
flanges is very consistent and accurate. The only thing we have
to be concerned about when we form the part is ensuring that the
web is accurate and that we form it up at 90 degrees. If one
flange is a little shorter or longer, it doesn't matter because
we know after we laser cut it, the flanges will be the same.
When the customer sawed the part to length, he could throw off
the squareness. The part we provide makes their fit up easier
and gives them a very good joint to weld. Second, the laser-cut
holes need no deburring, so that step is eliminated completely.
How would you have made this part in your shop if you did not
have a 3D laser?
This part is perfect for the SpaceGear because we need a large
bed to sit the parts on. The formed part is about 8' long, and
the laser bed is 10' long. So we utilize all that space to be
able to cut this part. The other reason this part is a good fit
for the SpaceGear is the fact that there are holes of varying
sizes on all four sides.
If we did not have the SpaceGear, we would have sawed the tubes
to length and used our 2D [flatbed]
laser machine to cut as many holes as we could before the tube
was bent. After bending, we would have drilled the balance of
the holes. Doing this part on the SpaceGear saves us two
operations, and more importantly, the time we save lets us pass
on a cost savings to our customer.
Let's talk about the other part.. What is it and what are the
specs?
This is an inner column support. The material is 6" x 6" square
steel tubing, 7-gauge wall. The part is 15" long, and there are
32 holes of three different sizes on all four sides.
How was the customer making this part?
Our customer went through six operations to make this part. He
sheared the material, punched the holes using a turret punch
press, deburred and notched out the edge. He'd do this again for
another sheared blank. Then he would form each piece into an
angle and weld the legs of the two angles together to make the
square tube shape. And how does CVC make the part?
The part happens to be the shape of available tubing. That was
the key. We buy the tubing cut to a length that is slightly
oversized. We mount it on the chuck of the SpaceGear with the
straight edge against the chuck. By the time the part rotates
three times, we have the completed part - 32 holes and notched end
cuts - all in one operation. We paint it and ship it to the
customer.
How much time do you save making this part on the 3D laser?
The time it takes to make one part on the SpaceGear would be
1/4 to 1/3 of what it took before. The quality of the holes and
other cuts also is more consistently accurate and speeds up
assembly. Most significant, however, is that we have eliminated
the shearing, deburring, forming and welding processes
altogether by using a standard mill tube as our raw material. |