HAAS Maintenance

We decided this afternoon to pull the aluminum sacrificial plate on the HAAS this afternoon.

Lets just say it was bad. As a result the plate is off until we can get the plate, table, Tee nuts & spacers cleaned.

In addition I added some Whamex XT to the coolant to get the nastiness under control. The filter is also damn near clogged but we have some on the way.


What’s the coolant situation at the moment? Seems like y’all are running the skimmer a lot more often recently?

No difference than that of the past. The skimmer was running previously 24/7 as well, you just couldn’t see it. That’s as far as the Skimmer goes. We want to get whatever “Crap Growth” under control.

Edit, This Whamex XT can be in the loop during machining operations.

I’m not part of the HAAS community, so I know next to nothing around this. I don’t have a dog in the fight., but is this normal?

Nope. We dont want it to propagate & get out of hand.

I will add we did not pull the sacrificial plate when we did that maintenance a few months ago. We should have but we ran out of time & Volunteers.

The debris/gunk was so built up we had to use a stud & deadblow to get a majority of the Tee nuts & spacers out.

Yes if you don’t clean for 5 years.

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yes very normal. If only you’ve seen what I’ve seen. we’re good.
btw - that was fast. I removed and cleaned under the slab several months back. smelled good I’m sure.

So is the plan to not put the sacrificial plate back on?
That would be signing the death warrant for the steel table.
Just sayin’

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Is the plate just to protect from people that send tools crashing into the surface?

I think @TBJK’s original post was that the sacrificial plate would be reinstalled after the plate and all fixtures were cleaned. Even with the short list of authorized users, we don’t need makers to be makers with that steel table.

Not just crashing - for machining that intentionally cuts all the way through without crashing. Some parts can’t be held suspended off of the bed.

Also a sacrificial “mill tooling plate” like this typically has a bunch of threaded holes to make “clamping” parts on easier than just relying on the slots in the bed.

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I think there needs to be discussion about the plate. Some feel it should be left off & others feel it should be on.

Yes, but also traditionally you use it as a surface you can tap to screw down fixtures and plates.

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My input to the discussion: I do not recall a factory that did not have sacrificial plates. The plate that makes up the bed is generally equal to a tool grade surface plate for flatness then the ways are machined into them.

We have sacrificials on vises, even the Sherlines. Why would we not protect the CNC bed? Want help with the decision: contact Haas and get a cost for a replacement. But just a Steel replacement fixture sub-plate (not the actual bed) is about $2,000 vs $500 for a new sacrificial. Assuming the existing one can’t be skimmed again.


What are the arguments in support of removing the sacrificial plate?

How about a compromise. If you want it on for your work, put it on. Otherwise leave it off.
If you insist on it being a permanent fixture YOU do it properly. Install thread inserts, counterbore the face install bolts with seals to keep the holes clean. And remove the plate monthly for cleaning and inspection. Then replace it all.

So both sides of the coin are.

The sacrificial plate does save against major crashes against the table.

Keeping the the plate on harbors debris, promotes growth of bacteria & can rust the table out/make the table pitted.


For reference, this is what I’m used to seeing for a fixture plate

I haven’t noticed any in the job shops I’ve been in, but I can see the utility (and protection) it brings in our case. This style seems much more useful than what’s on there now.

Competence addresses item 1.
There is an actual benefit to using sacrificial fixtures in the industrial environment.

My vote is we keep the sacrificial fixture. I agree with previous mentions of implementing numerous tapped holes for clamping of fixtures. As mentioned, we could put the threaded inserts into the aluminum and install threaded bolts or 3D printed pieces to block off the holes to mitigate the flow under the slab. Here is another NYCCNC video of a DIY fixture plate we could take notes from.