So to be clear, I started this adventure in October 2019. I new nothing, and I mean nothing, about 3d printing or CNC.
Here are a couple things that I learned as a newbie. I will of course try to answer your questions, but I think there are a couple good nuggets below. Anyone else reading is free to correct my misunderstandings.
Summary of Advice
I expand on each topic below, but here is the summary. I encourage you to review the details.
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Additional Components: IMHO if you want a sleek MPCNC setup, you will spend more time on the additions than the original build of the MPCNC. Just an FYI.
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Sizing: Really spend some time reviewing the sizing of the machine. Foot print and work area are of course not the same thing and affect the amount of belt you need to order. It tripped me up.
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Board & Dual End Stops: I choose not to use dual end stops and ordered the basic mini Rambo. However, I think that this may have been a mistake. I think it maybe too much work to change out now. It might be wise just to go with the “full meal deal” and order what you think you eventually want and do the work up front to get it going.
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Computer: Dedicated laptop/desktop.
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CAD/Drawing: I am using TinkerCad, , GIMP, and Inkspace
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CAM/GCode Player: ESTLCam, cncjs
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GST: I had to pay on my order when it was delivered to my door.
Current State Of My Project
So here is a picture of of MPCNC which is about 75% done I think. I post it just for reference for what will mention in the following sections.
Additional Components
Here is something to consider.
I suppose it very much depends on your personality, but I found the original MPCNC to be pretty quick to build and get operational. Maybe a weekend or a week of nights once you have your parts and kit. However, once you build it, you soon start looking at all the pictures of what others have done and added on. Then you start trying to do the same. For me, this is super fun, but that process takes 10 times as long as the original build. What do I mean? Once you build your MPCNC here are things you start researching: tables, cable management, dust collection, enclosures, lighting, spoil boards, hold down clamps, bits, v-carving, masking, etc.
For some of those, you might end up doing the following, which was true for me on numerous occasions:
- Searching thingiverse and the internet forever to find a solution.
- Printing things to try out and finding them not to work out.
- Trying to design something yourself.
- Trying and printing your design until it works.
My point is, in my opinion looking back, the MPCNC was the easier quick thing to build because there is a pretty clear road-map for that. The other stuff takes way more time.
If Later You Decide To…
So to be clear, I took the approach, “let me start small and improve things later if required”.
I think that may have been a mistake.
On many topics (or any topic maybe) I would see some advice that basically said “you can upgrade that later if you want”. Certainly, that is possible. However, I think you need to know your personality on this. I lied to myself and thought I would upgrade things later. Look at my current project. Am I really that likely to change out my controller board now? Knowing me, probably not.
Sizing
Really think about sizing. I mean really look at every result of the calucator. Here are a couple gotchas related to that.
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The community here (I think) talks in foot print dimensions not usable work space dimensions (i.e. how big of an area can you cut). This was a bit confusing to me and I did not notice that at first.
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Because of the above, when I ordered my kit from V1 Engineering, I did not get enough belt. There is a note on the order page that says ”GT2 Belt enough for any combination of 48" of X and Y axis length, if you would like a larger machine please see this for how much extra belt and rail you will need. If you need more add it to the cart at the same time and it will be combined.” I made the mistake of thinking this was usable workspace dimensions not footprint dimensions.
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Why would I make that mistake if everyone talks in footprint? Well, I wanted to make sure I did everything perfectly. So I basically just started my sizing journey with the calculator link on V1 site and really only looked at that (https://jscalc.io/calc/QHWZUpKFJzyGVS2D). This calculator starts with “work width” not “foot print width”. As such it tripped me up.
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Finally, it’s not that major, but if you add dust collection to the MPCNC you might loose additional working area. This was not obvious to me at the start. The reason being that that dust hood on the tool no longer allows (or may not allow you) to get the tool all the way back to the X/Y origin. This might not be a problem for those with a “tall” MPCNC, but it was for me.
Board & Dual End Stops
Because I took the approach “let me start small and improve things later if required” I happened to purchase the “Mini-Rambo Series Wire Kit”. This might have been a mistake because I cannot use dual end stops.
Does it matter? I am not sure yet. I read a lot of older posts that said you don’t need them. However, I get the feeling that the current way of thinking is they are a good idea. I have not done that much cutting but I use the following to help me manually put the gantry at the origin:
Computer
I use a dedicated laptop to control my MPCNC. Here is how I came to the conclusion of doing that. It just so happens that before I started these projects I had a spare desktop and a spare laptop.
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When I first started 3D printing, I used the LCD and an SD sard on my AnyCubic Mega. I used this to print all of my MPCNC parts. However, this got old quick. I saw many people use an OctoPi but I though why do I need another piece of hardware. So I setup my spare desktop to run OctoPrint essentially using these instructions (https://youtu.be/XvzSxbD_dkc) and (https://community.octoprint.org/t/setting-up-octoprint-on-windows/383/22)
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For my MPCNC I simply decided use a dedicated laptop to run it.
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In both cases the advantages for me are that if needed, I can install any type of software that may be additionally convenient to have (7Zip, Inksacpe, whatever), easy access to all my network shares, and easy access to the internet.
CAD/Drawing Software
I am using TinkerCad, ESTLCam, GIMP, and Inkspace. I am not very good with them but learning.
I get the impression that if you want to do thing “professionally” or want to interface with the professional world, Fusion360 is the way to go but harder to learn.
Lars Christensen (https://www.youtube.com/user/cadcamstuff) seems to be a good and fun teacher for Fusion360.
CAM Software
I switched to CNCjs the desktop app (https://cnc.js.org/). Here is why, at least for me. I personally think this is very important but maybe others have a better explanation or solution.
After much searching, at least without end stops, the concept of starting your MPCNC job is:
- Move your gantry (typically manually) to what you want to be the origin.
- Tell the system that you are now at the origin.
- Start the job
Frankly, I could not reliably figure this out quickly in Repetier. In theory you would issue the following to “tell the system that you are now at the origin” see (https://reprap.org/forum/read.php?267,120561):
G92 X0 Y0 Z0
or
G92 X0 Y0 Z0
@isathome
I could not get this to work and also saw this post that made me switch (starting job: G92 doesn't work in Repetier so I disconnect/reconnect)
The G92 X0 Y0 Z0 command works fine for me in CNCjs.
GST
I had to pay this to Canada Post at the door.
