Sacrificial Plates on Zero Point Systems?

Hi everyone,

I've been looking at filling my machine with a LANG or 5th axis 'zero point' system. No more setting datums, standardised set ups and fast set-up changes!

That's all great for jobs that are held in a vice or on a dedicated fixture. But what about all the one-off, large plate work? I don't see how these systems accommodate for that?

The best option I can see at the moment is to make my own sacrificial plate that fills the machine table (maybe out of 3x separate pieces for ease of loading), and mount studs to the bottom of it so it can be mounted on top of the zero point system. I think that would work well.

So then I started looking at sacrificial plates, but there isn't really much info out there! I want something that does the following:
-Has threaded clamping holes.
-With precision c'bores for locating.
-Has plugs over the holes to block swarf building up.
-Can be drilled into and tapped into (but not milled into - I will stay off 0.05mm)
-And if possible, be able to minimum clean up the top surface whenever it gets knackered.

So my question is, what do you guys use as a large sacrificial plate? Any pictures would be very helpful!

Thanks,
Joe

SMW makes fixture plates. They're not really intended to be sacrificial, but he has "plate savers" that are. They go between the workpiece and the plate. He has plugs for the holes available as well.

SMW Fixture Plates – Saunders Machine Works

Look into a vacuum fixture like Pierson for plate work. You can put studs in that to quick mount on your Lang plates.

Here's our quick change plate on a Lang setup. 1.350in thick with a 3/8-16 grid on 1 inch spacing. I built this about three years ago, and keep asking the guys to make a better version - it's been replicated several times, but never really improved upon. Pretty good for quick and dirty jobs on the five axis. I get super annoyed when I see it in use on the vertical, which is usually an assembly stack that looks like:

sub plate -> lang adapter -> lang grid plate -> lang riser-> "sacrificial plate"

All so they can hold something down with toe clamps.

Quick change fixturing can definitely make you lazy.

boosted said:

Here's our quick change plate on a Lang setup. 1.350in thick with a 3/8-16 grid on 1 inch spacing. I built this about three years ago, and keep asking the guys to make a better version - it's been replicated several times, but never really improved upon. Pretty good for quick and dirty jobs on the five axis. I get super annoyed when I see it in use on the vertical, which is usually an assembly stack that looks like:

sub plate -> lang adapter -> lang grid plate -> lang riser-> "sacrificial plate"

All so they can hold something down with toe clamps.

Quick change fixturing can definitely make you lazy.

View attachment 335512

Click to expand...

This looks pretty good for what I'm after. I have a few questions:

Do you allow the guys to drill and tap through the job and into the part slightly?

Do you have plugs for the holes? If so how do they fit and what are they made from?

Can you take a minimum clean up on the top surface once it gets worn out?

Thanks for all your responses!

The plate gets drilled into occasionally. Usually if we are going to drill/tap though, we just make a fixture plate. That's the whole point of the Lang system. Make a designated fixture, and throw it on the shelf. Next time the job comes back, setup is about 5 minutes.

The holes are punched through so coolant drains out. It works okay. We have tried plugging with set screws, and that's more PITA than it's worth IMHO.

The plate can be skimmed, but I'd rather throw it away once it gets worn out. Again, the whole point here is quick-change, so as soon as something doesn't match the CAD model, it looses a ton of value.

We have an Orange Delta pallet with a bunch of tapped holes and dowel holes, works good for plate stuff that I don't expect to return. It can be skimmed as needed, not a big deal. But like Boosted said, if it's reoccurring I like dedicated fixtures.