Prebuild question- Would this setup make sense?

Mostly Printed CNC - MPCNC Advice
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Hey there! My name is Frank and I am from germany. I have been tinkering around with 3D printers for over 2 years now and I get usable results.

I really like this whole project and decided to build a MPCNC for me. I already have a small homebuilt CNC since around 15 years, that I used to mill balsawood and thin plywood. It gets barely used recently since it is too small for me. Its about 35x25cm.

So i came across this project and thought this could be very useful for me and I have a lot of parts laying around that are leftover from some 3D printer projects.

This will most likely end up in a learning project, but I wanted to ask some questions first before I start ordering material. So here is my loose plan, that I could build like that with minimal investment. But if components seem to be a waste of time, I would of course swap them out before I start building.

Main use: mainly Milling, maybe adding laser.

Priority for Materials to mill: 85%Wood, 10%Acrylic, 5%maybe aluminium, but only very slow and low priority

Print Material: ASA (recently got gifted 2kg and currently don’t know what else to use it for and it seems to be very strong mechanically)

Router: A M3700 Makita is cheap and easy to get for me and I can swap it out later on (Europe, no DeWalt) its 530W. Too low? The 3710 is about 20€ more, but has the same power.

Size: I would love to go for 1x1 m object size. So I thought about 1.2x1.2 to have a bit more than I need, just in case - And add mid supports.

Rails: (I am in Europe) 25mmx2mm Stainless Steel

Board: I have a Ramps left over with A4988 drivers. Does it make sense? I would prefer a board with a removable controller, instead of a all in one. I fried too many controllers on my 3D printer by stupidity and was lucky to be able to swap them out.

Motors: I have 4 Nema 17 clones from China Printers left over, I am sure to find another one somehwere.

PSU: 900W Server PSU

Baseplate: Wood, I don’t know the english name, I would use that brown coated plywood that trailerfloors are made of.

Mounts: Aluminium rails inserted to the baseplate for T Nuts.

 

What do you think, does this make sense? Which components should I most likely swap out? Thank you for your help!

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Nope, that should work fine.

 

Does it need to be square, making it smaller on one side would really help if/when you get to things other than wood. Every little bit helps, adding extra just in case is a choice that effects every cuts time and accuracy, for a just in case.

 

Everything else looks good as long as the steppers are 42oz/in or preferably larger. We use 70+.

 

 

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Hey, thanks for your quick reply! I will fire up my printer now!

I could actually live with 1.05 x 0.7m.

My motors should have 0,34Nm which converts into 48oz/in, but… china… who knows…

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Everything seems fine, no problem.

If you can, use a higher power motor for the Z axis, and if possible a better driver.

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Thanks for reminding me! After reading your post, I remembered that I also swapped out the Z drive on my small mill, because it was getting too hot all the time.

What Drivers would you recommend? I currently have the TMC2208 on my printer, mostly for noise reduction, but thats kin dof nonsense on a machine with a router.

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you need 5 motors and I can recommend you to buy 5th motor of nema17 8401 size (it’s 48mm length) and install it to Z. you don’t need too much work torque for Z, but more detent torque of longer stepper can be helpful - then it will be less probability that your spindle will slide down after you power off steppers
and my opinion that you don’t need to spend money to something more expensive then drv8825

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Hey there and thank you all for the feedback. In the meanwhile I found my 5th Nema motor. So I will build the CNC with those 5 and then swap out the Z motor when I start upgrading or if this one doesn’t do the job. But I have it here and its free, so I will give it a try.

I have been printing the parts, but it takes forever. That ASA stuff is a bit tricky to print for the larger parts, but it is so damn tough. I think I could park my car on those parts!

Next week I will order the Rails and all the little mechanical stuff like belts, bearings, pulleys and stuff.

 

Is the Ramps way better than the CNC shield for the UNO? I have a lot of UNOs here and a Ramps, but no Megas left over. So it wouldn’t make much of a difference for me. I have just seen alot of people using the CNC shield for the UNO.

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There isn’t a Marlin build for the Uno, I think. If you’re using an Uno, just get the cnc shield and run GRBL. lots of support for an Uno and CNC shield. I would stay away from a ramps board, to be honest, unless you’re getting the one from Ultimachine. The Rambo board and estlcam will be just fine to start with and figure out what you need.

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But isn’t the ultimachine just the same as all the other Ramps boards? Other than an arduino, there are no logical parts on the board, so its just a breakout board with some mosfets and fuses. I really like the development of parts and are willing to honor it, but 80$ for a breakout board is a bit over the top for me.

I think I will try the CNC shield + Uno +GRBL since this seems to be the easiest way to get it running fast.

I had ESTL on my old CNC, I think I have the original Floppy disks somewhere around here ;-D It was a way more complicated back then :smiley:

 

 

 

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The ramps is better because you can connect up to 5 motors on it, so you can use some functions like the autosquare thing.

Also you can hook up the screen with the SD card reader, so you won’t have to plug your computer to the machine whenever you are milling parts. In my opinion it is far better than the CNC shield for a very slightly higher price.

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Price doesn’t matter, it really just is a few $ difference. What Firmware are you running on the ramps?

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I have 5 ultimachine RAMPS (not Rambo) boards and 17 import Ramps boards. All 5 of the ultimachine boards are doing just fine, and of the 17 imports, 4 work with no issues.

 

It’s also worthy to note that Ultimachine are the people that developed the RAMPS board in the first place.

 

Like I said, I would stay away from the ramps board, unless you’re getting the ultimachine one, or a known good seller. That is not a recommendation to get the ramps+mega setup, what I’m saying is that if you go that route, going ultimachine is a sure way for it to work. Rather, I would recommend getting the Rambo mini for about the same price from V1 and just have it work.

 

If you’re familiar with setting up stepper drivers and grbl, the grbl route is very cheap, but the Rambo solutions from Ryan are already present for current and firmware. Plug and play.

 

 

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Wow, thats interesting. I set up 2 of my own printers and 3 for friends using Ramps (clones) and fried some arduinos but it was all caused by my own mistake. I infact had one Ramps bord that died at some point, but I can’t really tell if it was my mistake or bad luck. So maybe I just got lucky with my boards so far (always had the red ones). Thats also the reason why I wanted to avoid the Rambo boards. I like the idea of the exchangable arduino. It makes things cheaper when I accidently fry one :smiley: And believe me, I am good at that.

 

But I am curious, which clone boards did you get? I never thought about the possibility of having them fail, since there is nothing special on them. I would have just bought any one. Now I totally need to check which ones exactly I bought.

 

 

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I just checked, mine were 1:1 clones of https://reprap.org/wiki/RAMPS_1.4 , they eaven have reprap printed on the (red) pcb. All looks pretty well soldered, no exess flux or anything.

But I should also mention, that they never had to handle alot of power in therms of a heated bed, I always used a mosfet for the bed and bridged both power inlets.

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Ultimachine has made it hard to fry anything on the Rambo, and the drivers are properly cooled as well.

Of the 35 printer kits I put together for some local schools, the ramps boards that didn’t fail were Ultimachine and zyltech. These kits were assembled by students and teachers at the schools, and we’re very much like a Prusa kit.

 

I’m not saying it’s impossible to get a good ramps board, many here have them on their machines, as do I. If you just want it to work so you can start making stuff, get the Rambo. Otherwise, get Ultimachine ramps or zyltech probably.