Hello I have recently been researching the MR-1 however I have some concerns about the aluminum base plate cast in concrete along with the steel anchors in the aluminum. I am concerned about galvanic corrosion and very concerned about the obvious no-no of aluminum in constant contact with concrete.
Am I missing something?
I have one of the first machines and zero galvanic corrosion issues. You are overthinking this thing.
You aren’t missing anything. There will 100% be corrosion under the plate since its not pure aluminum. I suspect though it will take many years for there to be any significant amount to start affecting performance. Plate lifting will be the first sign of issues.
Yes, there will be galvanic corrosion. But he is still overthinking this.
There are lots of conversations on this subject. I read a little and looks like Steel in aluminum in concrete is the worst scenario. Be interesting to see if this becomes a problem over time as the MR-1 has not been around that long.
All the hardware used to anchor that baseplate can be purchased in aluminum if it keeps people up at night. You know I bought a car once and to my surprise after ten years it started to rust. Sarcasm, I’m genuinely sorry.
I get your point, but I also get theirs! If I had designed something and had made a mistake that could effect the longevity I would like to know. Or have we all gotten used to the throw away society?
I would just like some type of timeline…how long until problems can occur? Should I expect x years of service from the initial base and or concrete?
Has langmuir any info? Every search on the subject online is adamant about avoiding the following…
Aluminum in wet concrete
Aluminum and steel in concrete
Aluminum in rewetted cured concrete
This purchase cost may be more trivial to some, but it isnt to me.
I don’t know that it would be much different if longevity is a concern, but the epoxy granite for a base might be more what you’re after.
I don’t know who has the longest time with an assembled machine on the forums, but it would be a reassurance if they commented on any signs of galvanic corrosion.
I’m a little over 1.5 years of operation with my machine and haven’t had any signs of it being a problem.
Ive actually read up on Epoxy granite a bit and that does seem to be a better way to go, not sure why langmuir chose the concrete route, maybe cost and process, I know that epoxy granite can be more complicated and hazardous up front.
They didnt use epoxy granite because it would add many thousands of dollars to the price. You have material costs, which are not insignificant, but more importantly you would have a more difficult “DIY” project. If you remove the “home built” aspect of this machine, the price and lead time goes up because LS will most likely have to make every one of them in house. At typical labor costs, the “prebuilt” option for the MR1 right now is probably not making LS any money anyway. Im sure they are doing it to cover the handful of folks who cant or wont go the homebuild route, for whatever reason.
As for the plate, eh, its a replaceable component. I kind of agree with Bigdaddy here – its not worth worrying about. All of the cost advantages this machine has are based on the application of that concrete. As mentioned earlier, if the cost was a major factor to you in making your decision to purchase this thing, then this whole concrete question is irrelevant – you wouldnt be able to afford any other mill that has this performance. Im not saying that to be an ass, Im just saying that there isnt anything even remotely close in price. The machine really is a bargain for what it does. I personally had been dragging my feet on getting a CNC due to the price hikes from Tormach prior to this thing coming out. Then I lurked here, read about the problems and the issues, and made my decision. It has no less and certainly no more issues than the Tormach 440 and 770.
Out of pure curiosity, I would be interested to know if the concrete has any effect on the plate as well, but its not important enough to me to take a peek at the underside in another year or two. There are some variables here you dont have with other aluminum / concrete applications. For one, it uses much less water than a typical concrete pour. Most of the guys will tell you they didnt notice much heat coming off the concrete when it was poured. I certainly didnt. Also, Quickrete and whatnot has different consistencies and different aggregates than bulk concrete. I dont think anyone could say for a fact that this baseplate will react in a similar fashion to other aluminum case studies. Hell, it could be worse. Only one way to find out. 
If everything that is in contact with the concrete is replaceable then I would not be worried either.
Could any of the components be painted or powder coated to help with possible problems.
One of the selling points of bonded powdercoat systems is corrosion resistence. Non-bonded powercoat can and will flake off if any part of its application or environment is not correct. Ive seen that myself.
I dont know whether the y axis rail supports were painted or powdercoated.
I had never heard of bonded or non bonded P/C. So how does non bonded cure?
Who sells non bonded?
I would be more concerned with the dissimilar metals creating a galvanic situation. That’s why retrofitting the steel hold-down bolts and couplings to the aluminum versions would eliminate that for the most part… As for moisture reacting to the aluminum, it is enviable. Aluminum being so low on the galvanic chart will always be an issue. The epoxy sounds like a great idea, but where do you stop? It’s still the best value in the industry. I believe with all my mods and upgrades, I’m at $10k. It’s still $25k cheaper than a $35000 Haas. Buying a used machine like a Haas is like playing Russian roulette. Very rarely do they sell machines that work correctly. I realize they are out there, but they are still $20K.
Im sure there is a reason, but why aluminum at all? Why not a steel baseplate? Decking would be slower but the machine is able to handle it right? It wouldnt have to be “1/2 thick either i would imagine.
Stainless steel would be best
Yes perfect, dimensionally stable, corrosion resistant.
The problem will be getting a base plate made of stainless steel that has been laid out and drilled. This is overkill. I understand Buttttttt.
If I ever get to the point I need to replace my table I had thought about machining either steel or stainless plates to go back in with. Go up to some 3/8-16 and 1/2-13 holes for fixturing. The 1/4-20 thread size has been a bit of a hinderance with some of my existing tooling and fixtures.