Hi,
Trying to decide if the MPCNC is right for my intended use: guitar building. Will it be able to carve a ~20in20in2.75in guitar body in hardwood without turning the body, using a Dewalt 660 (would certainly consider a different spindle if needed, but I have this one on hand so it’s preferred)? Speed isnt really important to me, but convenience (eg, no turning) and consistency are.
Magnificient product in either case, btw 
Thanks a lot!
What do you mean by “turning”? as in flipping the body over or rotating it to fit the cut? You can build it more than large enough to carve a guitar body.
Sorry, I realize I wasn’t clear. Yes, I meant turning the body over in order to achieve the necessary depth; I would like to avoid that when I don’t need to carve both sides of the body. So you don’t see any problem achieving ~2.75" of depth in hard wood with the 660 and (I would guess) a 1/4 bit? Thanks.
That depth will need the Z axis to be spot on perpendicularly. (Is that a word?) If it is at all off, you are going to have rubbing of the bit as it goes deeper if you don’t use a bit with a 2.75" flute length. Also, you are going to need a longer tool, probably 3.5" at least, which may be hard to come by in 1/4" shank at a reasonable price. Not entirely un-doable, but it would be a lot easier if you were only cutting 1-3/8".
Also from experience and reports of others here you will likely want to use an 1/8" bit if you can get away with it. You could use 1/4" but you will likely need to make light passes. The bigger bits tend to chatter, especially when cutting a slot. So it may be OK once you get past the first pass and are not cutting the full width of the bit. Just going to have to play with it an feel it out to see what works best. And if you have to flip it, its really no big deal. You are going to have to sand the body anyway, so even if there is the smallest misalignment once sanded you would never see it.
If you don’t need to carve the other side of the body, and are doing like a telecaster body, you can always cut as deep as you can, then finish off the rest with a regular router and flush trim bearing bit.
I think it will be very capable of cutting that deep with no problem just watch the speed and feed
I accidentally ordered a long 1/4 in mill and it is 4 inches and I only have 4 inches under the 660 so I can cut paper or real thin foil at some point it will get used but I was bummed when it showed u p and it was so long but only 18$ I think, amazon delivered in1 day but 
since I started using speed control 1/4 inch is no problem can’t wait for the PID for 660 Peel pocketing works great 4-8mm dc and 800mm/m (probably would work even deeper I just have not had a opportunity to try it) slotting not so deep 4mm good 8 bogs down PID may help that this MACHINE is incredible find your sweet spots with the material and it is a dream come true I love my MPCNC The Low Rider 2 may be in my future also ;-0
I’ve got a similar project on the go (that means drawn up in CAD, waiting for a bit of time) Because I hate the idea of tonewood on an electric guitar and most of my favorite guitars are made from it, I tend to go for plywood. My plan is to do it in 3 pieces the front 2.5d, middle 2d and back 2.5d, I don’t think it’s going to be too difficult to align the pieces but yeah, thats my thought.
I’m excited to see how you get on with your build.
Just to let you know, you guys convinced me, I have the mpcnc parts waiting for me to find the time to assemble it Thanks!
Initial build done (I guess I’ll probably shorten the Z based on what is considered best practice; currently at 6”, X and Y are 30” and 24” work area). Seems to work allright
(I intended to have a picture of the test here, but it looks like the attachments I add are not kept; no error or anything, they just don’t appear; you can see the picture here meanwhile: https://photos.google.com/u/2/photo/AF1QipP8MmZ5OnQDz-158WrTkuX9LRJSRWIzwHnoBuo ).
Used Fusion 360 to work on the model and create the tool paths. All done with a 1/8" end mill; one Adaptative Clearing, and 2 parallel cutting 90 degrees from one another.
I’ll work my way up to hardwood from there to see how it goes with the current build.
Yeah, it should be possible to mill any depth provided you have a long enough bit and correct feed rates.
But I’m not sure why exactly don’t you want to flip the work? It’s almost a no brainer if you have the endstops. The CNC will pause the job, go back to home position and then you only have to flip it the right way and press a button to continue milling the other face. It’s not difficult at all.
Maybe you can try doing that with some foam or polystyrene to get more confidence about how its done.