Cantilever motion -OT

I know this is off topic, but I am looking for some help. We have a machine that we would like to build that requires a cantilever XYZ motion. I am looking for vendor that would sell this type motion. I would take care of the controls, motors, and everything else. I am just looking for the rack and pinion XYZ motion. We have used Gudel before, but they will not quote a system for us this time.

Spec. 12' x 4' X & Y motion
10" Z travel
Approx. 100 lbs on the head.
Speed for X & Y = 1000 inches/min
Acceleration = 300 in/sec/sec

Anybody know of a vendor that provides this sort of machine.
Thanks

What's the application? Are you doing a stroage & retreaval? Is X & z horizontal and Y vertical?

The application is a Foam dispensing machine. We build machines for own own use and we have 4 other foam machines that we built. This time the business unit wants a cantilever type machine. In the past we have built 4 post ganty systems and we can not persuade them to go that route. The XY are horizontal and the Z is the vertical stroke. The machine would be run like a CNC type of machine. I am looking for just the mechanical motion, rack & pinion, bearings, rails, ...

Thanks

Curious, what happened with Gudel?

you could try Ewab in IL.

another gantry supplier may be Lado or Lido. I don't know the exact spelling but if I find it I'll post it.

I'm just starting work on a cuttng table. I plan on using slide guides and pulling the gantry with two fixed servos or steppers via a set of timing belts. I've done a "concept" drawing, I'll post later, (its on another computer).

The 300 inches/sec/sec with approx. 100 lbs of weight hanging out on the end scared them. We are using their 4 post gantry systems, but with these accelerations they are not going to quote the cantilever style system.

Since we build our own machines in house, we have talked about building our own gantry, but the 300 inches/sec/sec scares me two. I need this acceration with out hardly any defelection and I know of no way to test it with spending a lot of money.

I will check out ewab. If you find Lado's number, let me know.

Thanks

To put it in perspective, that's almost the acc. rate of a falling object. (30' sec/sec). Can I ask why? Any time made up for production would likely be lost through maintenace & shutdowns, not to mention the initial cost.

Eng. Economics 101. Increased productivity - (the cost of the gantry,+ service issues)

When a company whose business it is to build these machines tells you that your spec is unreasonable, it's generally wise to pay attention.

For a given deflection, a cantilevered structure is going to require more mass than a structure supported at two points. To accelerate that extra mass at your specified rate will require a larger motor which will probably require larger drivetrain components (more mass that needs to be acclerated).

The end result will be a machine that is substantially larger and more expensive than its 4-post equivalent.

Time to start thinking outside of the box. Presumably The Powers That Be want a cantilevered structure for maximum flexibility of access to load the machine. Instead of mounting a 4-post machine on the floor, is it possible to suspend it from the ceiling?

Feel free to ignore this post if I've managed to completely misinterpret your needs.

To answer elevmike first:

The acceleration is needed because we are dispensing a liquid around corners. With a slow accel & decel, the liquid will "pool" in the corners. One solution is to adjust the dispense rate at the corners and the other is to make sure the time stopped in the corner is very small.

To answer Steve:
Yes, I agree with you totally. We have come up with many different designs and are pitching them to the Powers That Be. I am also concerned with a cantilever design and that is why I will not let our Mechanical Engineer design a cantilever system without proof. What I would like to do is send my request to another vendor and see if they give me the same response.

Thanks

Providing a variable dispense rate would be a lot less expensive and easier to control.