So I go to a high school with a CNC Router. More specifically, the Shapeoko 3. I have been fiddling around with it a fair bit and have had some issues (main one being that it cuts lower on one side than the other even after tramming). Needless to say, I am not very impressed considering the price of the thing (I am a poor high schooler with no money).
So, being the person I am, I have decided to attempt to build my own CNC machine. I have seen that a small build size is required if one wishes to machine metals at some good speeds. My plan is to do mostly aluminum (and maybe steel). Most parts will not go above 1/4" aluminum, but I might go crazy and wanna do a 1/2" part every once and a while.
Also, I am thinking about how I am going to mount this thing to a table. Would it be okay to make a table out of some lumber and call it a day? My plan is to also get a piece of 3/4" MDF and use that as a spoil board, but also maybe machine my own clamps (if this is even possible).
So with all of this in mind, here is some of the stuff I have come up with that I am not sure about (* = parts I already have):
*64oz.in Stepper motors 5x ← Are these ok?
Some 1" OD Conduit from Home Depot ← I heard the finish on these are rough, is this ok?
Dewalt 660 or 611?
12" x 12" x 3" work area. Is this small enough?
Dual Endstop Feature? ← is this really worth it?
How in the world does zeroing work on this machine? On the Shapeoko, it stores your previous zero on your laptop. How would something like this work on this machine?
Does Tube Size matter? I have some older 3D printed parts for this machine that are meant for the 23.5mm tubing. Does larger tube mean more rigidity?
Lastly, what is the best place to order all the nuts and bolts? Amazon seems to have crapped itself because they cant get chinese parts anymore. Best place IMO is McMaster Carr since they are all American stock (and their distro center is almost nextdoor).
Speaking of China, only reason I am doing this now is because I am about to have a few weeks of nothing to do because our entire town is shutting down. Thanks for the help!
P.S. What is a good place to get quality end mills that doesn’t break my wallet? Also, where are people getting their metal from? I can’t find anything reasonable online whatsoever.
I am no expert and still finishing my build but this forum has lots of great people and great advice. Judging from my research and other peoples comments, Stick with the steppers that Ryan sells in his shop, They are stronger then what you are asking about and a decent price. Your build size is perfect for what you are planning on using it for. Larger tube will always be stronger but with the small build volume (and price) conduit is your best option and works with the printed parts you already have done. That is my take but other more knowledgeable people will give you more advice as well. Also keep doing what your doing I wish I would have gotten into this stuff when I was your age.
I went with a 660. It was cheap and since I think the original design was meant for this router I went with it. As such I was able to find lots of addons on thinkiverse if needed. It is pretty loud though.
I think I comment on this in the above provided link. I don’t have them and for me its been working out okay. However, my suspicion is that I should have spent a bit of time installing these.
So this might help (Coordinates - V1 Engineering Documentation) but let me say the following. As a total newbie, after building the machine and doing a test with it, I literally asked the same question to myself out loud. I had trouble finding a simple answer in the beginning. Here is the ultra condensed version that I do (without end-stops or z-probe):
Disclaimer: For safety, always unplug the router. Personally, I don’t have it plugged in if my hands are anywhere near it.
I used CNCjs not Repiter to control the MPCNC. I don’t know why but things just did not work for me with that software. More specifically, any type of zeroing I attempted to do either did not work or made no sense. When I switched to CNCjs it was like magic for me.
Slowly move the gantry to the position you want to be the origin including Z. Normally this will be the lower left corner and the top of the material, but it actually can be anywhere.
Personally, I then issue (through the CNCjs console) the M17 command. This turns on the steppers and for me “locks” the unit in place. I think M18 turns them off. Keep in mind when you turn them off your Z axis usually moves a bit or drops.
Then through the console I issue “G92 X0 Y0 Z0”. This basically says, this is the origin. Normally, set all three to 0.
There is no such thing as 1" OD EMT conduit. It has a nominal size which is loosely related to the inside diameter and the “3/4 inch” EMT conduit is generally 23.5mm OD but you should take calipers to the store and be sure. You can also convince yourself that the “1 inch” conduit is not a size that’s compatible with the MPCNC printed parts.
The rough surface on EMT is not an issue, the zinc wears off relatively quickly and leaves a pretty smooth surface where the bearings roll.
For MPCNC there is no reason to go with 611 or anything other than 660. Even for thick aluminum or steel, the frame will give out (or steppers lose steps) before the DW660 runs out of power, so more power is not needed. The 611 is heavier and you will need to go find yourself a special mount.
12" x 12" x 3" is a good size for stiffness. For smaller sizes, the tube size matters less, because the stiffness of the rails increases dramatically as the rails get shorter. The stiffness of the center assembly, specifically resistance of the Z axis to tipping away from vertical, remains the same regardless of size, so for small machines it is just about the only thing that matters. Only for large machines when the rails get relatively softer because they are longer (and belts too), is it worth considering larger tubes or thick-walled tubes for stiffness.
As for dual endstops, start without it, make some cuts, get the machine dirty, and your experience will either answer the question by itself or provide a good context for evaluating whether it’s worth it.
Lots of good advice here. I will add that Ryans shop sells bundles with the bolts, and after you find all that from mcmaster carr, you would have been better off buying from him.
