Hello all
About 6 month ago I did build my MPCNC.
It is a bit different than other builds I think, so I though it would be interesting for some of You to see?
Working area aprox. 1160 mm x 760 mm
Thank you Ryan for all your hard work 
/Michael
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That’s a lot of mpcnc right there :). Looks neat.
Thank You jeffeb3 
That’s really something. Double supports of Z that way should be quite good at minimizing Z tilt. Minimum would be twice the stiffness but I would think it would be significantly more than that.
@jamiek
Yes Z tilt was a problem due to the large machining area (and heavy spindle). double Z axes make a big difference. But double X and Y also helps a lot in terms of deflection. My 2.2 kW spindle weighs about 5.5 kg.
I use Ø25x4 mm tube on X and Y which also gives extra strength.
I have seen double X & Y done only once before although the arrangement was quite different, using double the motors on X and Y (meaning 4 each, 8 total) and a single motor for Z.
The MPCNC is very cost effective but if someone is wanting increased stiffness for a bit more cost, there are not many options that make sense. Yours is the exception. I think this is a great design for a stiffer machine for not too much more cost.
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Thanks Jamie. i’ve seen another solution with double X and Y (single Z). I do not think it is quite as effective at reducing Z tilt, but still a great design.
@jamiek
I was watching your YouTube channel. Your double decker provides greatly reduced Z tilt even at very high Z clearance. I like it
What was the purpose of having it so when the workarea height is a quarter of that?
The upper gantry prevents tilting but if it is not very tall, it could have a multiplier effect that increases the lateral load on the lower gantry. The logical consequence of minimizing the “leverage” is to make the upper gantry as high as possible.
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So how stiff is it? Can you post a video of it cutting through steel or diamonds? 
(I’d settle for aluminum.)
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well, with pipes that are 45" long in X and 61" long in Y then it is obviously not the most stable MPCNC built 
As I wrote earlier, it was not rigid enough, so I came up with the idea of double X, Y and Z.
It mills plywood, MDF and DELRIN without problems, but I am not sure it can mill Aluminum.
But I will try, and give you some feedback
Can you give me some recommended cutting speed and feed for the MPCNC in Aluminum?
I did some testing today.
3 mm carbide 2 flute.
Cutting speed: 226 m/min
Feed: 500 mm/min
DOC: 3 mm
Cooling: Air
I must admit that it did better than expected, and I think I can get more out of it
But I am more than happy right now 
Rough cut:
Final cut (200 mm/min 0.2 mm):
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