Is ChiliPeppr right for noobs?

CAD & CAM Tool Chain ChiliPeppr
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Is ChiliPeppr right for noobs?

I’m new to CNC and am building my own CNC router and PCB diller.

My main concern is getting myself into frustrating corners with something new rather than super-established and lots of online tutorials and support (like anything with Mach3, etc). Because I’m new, I wont know, when I encounter issues, whether it is because of me, or the software.

I’m just barely getting my head around all the components that get me from design to final product. I’m using OnShape (free/non-commercial) and FreeCAD (for projects that need to be commercial). I’d use Fusion but I find parametric drawing and constraints insanely easier in OnShape. I can export STL, assuming that is the way to go. Then I realized I need to produce GCode and need CAM, which I guess means CAMBAM or Fusion 360. Does ChiliPeppr play nice with these (as graceful and gotcha-free as Mach3 or other known, matured systems)?

Lastly, I don’t mind cloud based software, but I hope to run the machine without a PC connected. This is what started me down the path of Tinyg G2 and Arduino Due, and then discovering ChiliPeppr. But… again, to me it means going off the rails even more, into the realm of introducing even more potential issues for a noob, rather than just getting the latest known-good off-the-shelf controller (eg: what is the problem? my driver/controller hardware, or my driver software (ChiliPeppr, Mach3, UNCNC, whatevs), or my CAM output, or my OnShape CAD design?). Aack!

Is GRBL as stable, reliable, issue-free? Some folks say Arduinio for CNC is a joke, not powerful enough. But I think that is referring to Uno, not Due, and even better would be Raspberry Pi (is there a rPi Controller that works with Chilipeppr?)

I dig open hardware, and open software, but not at the expense of finding myself constantly tinkering with the software/drivers rather than just getting machining done.

Any advice from this group is appreciated!

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Hi @David_Pugmire_dapug ​, there is a lot to say about this. To me it seems you need a real time OS (or no OS at all) to control a CNC, so an Arduino or LinuxCNC or… A Pi will probably not be a good choice because of this, unless you use a special kernel.

Then the software, the Uno is limited to Grbl, lots of people use it without problems though. The Due is much more powerful allowing G2core, which has more advanced and therefore smoother motion profiles.

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If you’re doing PCB drilling then ChiliPeppr’s Eagle BRD widget is amazing to use.

You can run Serial Port JSON Server on a Raspberry Pi 3 so you don’t need a nice computer next to your CNC machine, rather you can use a super cheap device like Raspi.

Search Youtube for ChiliPeppr and you may find more videos than Mach3, so the support is pretty good. Keep in mind, though, it is open source software.

Every time I need to mill, it all just works. The only hard part on milling jobs now is getting the CAM right in Fusion 360.

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@Menno_de_Graaf you don’t. With MACH3 you can have cheap hardware controller cards do the timing and provide tons of input and output pins as well. From what I see ChilliPepper is limited in file size for g-code.
(Using parallel ports and software timing on regular PCs should have died in 199x)

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@Menno_de_Graaf Thanks, yeah, I was planning on G2 if I go this route. I think I get what you mean about a real OS, but I thought any of the TinyG stuff replaces the direct PC tether.

If I understand correctly, I need a PC with Chilipeppr open, and the PC then sends data to the TinyG controller via Ethernet or USB. Do I have the right?

Anyway, I am not a noob when it comes to electronics, and I just need to decide whether to use rPi or Arduino Due. I’m not a fan of GShield because it does not appear to be Open hardware, and I would like bigger drivers than DRV8818 - more importantly I would like removable independent stepper drivers, like this project:
https://www.amazon.com/Arduino-Shield-a4988-driver-compatible/dp/B016O7TD6O

To my original q:
Please sell me on Chilipeppr. I need more of a value prop than just “cause it’s cloud based” and “cause it uses USB rather than parallel”. There are USB adapters, so that’s a non-issue, and cloud based has it’s downsides. If it is easier to use, modern UI/UX, has great community support (appears to so far), handles popular CAM well, etc - these are bigger factors. Why use this over Mach3, UCCNC, LinuxCNC? And thank you all for your input already!

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Are you just doing PCB’s? Or what kind of stuff are you milling? That always helps figure out best setup.

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@David_Pugmire_dapug , if you are considering g2core, my design for a g2core shield might be interesting for you. With it, you can use external stepper drivers:

https://plus.google.com/u/0/107066771802910612494/posts/XznpRJJrym1
https://plus.google.com/u/0/107066771802910612494/posts/LxBswhdD6Zt

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My main goal is generally learning about CNC. That said, drilling PCBs, cutting foam and wood (2d) is a need.

@Menno_de_Graaf , that design is right along the lines of what I was thinking! Is that project intended as Open Hardware, or did you have plans on selling boards, etc?

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From my perspective as a non-technical person, it is definitely doable, but you will spend lots of time to overcome little obstacles. This is a great resource, the advice I received to my previous posts may save you some time. I always tried to solve the problem before posting here, so there are some things I solved, but maybe not the right way.

For example, in cutting two-sided PCBs, particularly 4"x6" PCBs, it is critically important that the X and Y axises are perfectly perpendicular – otherwise, the traces and holes will not meet where they should. Rather than trying to physically adjust my machine (a Chinese 3040), I wrote some code to adjust the X-axis coordinates to comepensate for the error (at all points on the bottom side, it is essentially off by two times the Y value multiplied by the sine of the error angle). If I ever learn JavaScript, I will fork the board layer widget to add that functionality.

I have also had trouble with PCBs that are not flat. The first thing I found was that my machine bed is not parallel to the spindle, but addressed that problem by milling flat a thick piece of plexiglass.

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@David_Pugmire_dapug , the g2core shield is open hardware in the sense that anyone is free to adjust the design to its own need. At the same time, boards will be for sale for those not interested in making their own.

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@Rick_Obel Thanks. Good tips. I kinda figured it was a matter of drilling 4 mounting holes after the first side so I could flip the board and determine the exact reference from one of those mounts. But maybe it will be more involved.

@Menno_de_Graaf Sounds great. Do you have a site where I can get more info or follow progress?

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A coupla things from my perspective… First, with my kit, it was/is always me that made the mistake. The machine has a sometimes annoying habit of doing exactly what I tell it.

And chilipeppr has been much easier than I thought to get up and running. So very good for noobs.

With regard to CAM, I would wholeheartedly recommend Fusion360. I too use another tool for the drawings, but Fusion360 is actually pretty easy to use for generating tool paths and gcode. And if it doesn’t have a gcode translator for your machine built in, they’ll make one for you for free… But it will almost certainly be there.

It has only taken me 5 or 6 hours to get my machine from the end of characterising and calibrating the mechanicals to moving through my first gcode program. And that incudes the time taken to get up to speed with compiling g2core and driving the cam bits in Fusion360. I will admit though, I was already familiar with the process of programming the arduino due using Atmel Studio and bossac.

Good luck. I guarantee it’s more daunting before you actually get into it…

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I would not recommend Fusion360 yet as a CAM in 2 cases: You work with STL meshes above 10K polygons and you do work with on a rotary axis.

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A good point. I hadn’t considered that Fusion360 might interact differently with stl data.

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You can only CAM from solids and you can only analyse meshes up to 10K polygons to be converted into solids.

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A subtlety we noobs would take a while to get to grips with if it wasn’t pointed out…

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As a noob+ I would recommend starting off slow.

PC+JSON+Chilipeppr+tinyg. This has been a fairly rock solid solution for me.

I have been using Fusion360 for my CAM and its been working. For less complicated CAM stuff I like Vectric tools for flat pattern work.

Once you’ve got it running stable then branch out into the Pi world or whatever else tickles your fancy.

My biggest challenge is making sure i dont tell the machine to screw up

My next biggest challenge is tuning my speeds and feeds for the lack of stiffness of my hobby machine (5’x5’x6" OX CNC)

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@Bryan_Freed , I would be very interested to know what feeds and speeds you use for various materials. I am just getting started (haven’t actually cut anything yet…) with an OX variant. Mine is built with C Beam members and leadscrews, so it’s stiffer than the original OX, but I would like to know what the right ballpark is.

Am happy to take this to another post, but I wanted to pounce on your last couple of sentences before I forget :o)

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@David_Coones There are very good feeds and speeds calculators out there. Myself I’m currencly evaluating HSMadvisor.
You need to know some data about your spindle and the min+max speed and max acceleration of your machine.

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@David_Coones , most of my cutting lately is 1/4 sanded ply at 2"/sec with a 1/16" single flute mill (0.035" depth). Everything else I do is slower. Faster than that and i break the small bit. For large bits I’m machine stiffness and/or hold down limited.

For all using a router with 25000rpm speeds. I highly recommend spending the extra $ and getting SuperPID. I run my router mostly at 8k - 10krpm. SuperPID keeps the spindle speed low enough for a single flute to cut nice and you can fine tune the spindle speed to keep the router quiet and out of resonance

Instead of feed/speed calcs I usually grab some material, throw it on the table and start slow. Evaluate the performance of arcs/straights w_grain/straights against grain as you use the Chilipeppr speed override function to increase the speed until either the OX gets angry or your cuts looks ugly – then back it down to where you want