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Get FreeCad, the first step in learning it is a bit steep but stick to it and once you get the gist of it then you will discover at how powerful this thing is!
It will generate CAM files also, with G-code etc..
It is no more a 'hobbyist" level software since I think it is now maintained by CERN (not sure about that) and it integrates very well with KiCad which is developped by the CERN (that I am sure! :) )
I used to work (since DOD 3.3! ) with Protel for electronic schema/PCB but can not justify the cost of it anymore as I am retired, I hated KiCad for many versions but since now it is under the CERN it has become very stable, and very potent and I actually like it!
My two cents :)
 
I'm not so convinced with FreeCad.
For 2D work, which front panels are, I think Autocad (or one of its several free clones) is a most adequate resource.
For 3D, I'm a convinced user of Design Spark Mech.
I think both offer a HI that corresponds to a typical workshop workflow.
FreeCad, OTOH seems to be guided by its will of becoming the ultimate tool, able to answer all demands and being compatible with all manufacturing/machining processes, at the detriment of being rather arcane to people who had formal training in drafting, mechanical design and machining, which I am.
Being designed by committee, I see it as the ornithorynx of CAD.
 
im a hobyist. im also retired and dont have the cash for big software packages
I use Nanocad (one of a number of free Autocad 2D clones) for creation and SheetCam (£110) for G-code processing. Before Sheetcam, I used HeeksCad, which was quite cheap (£10 IIRC) but is now free, and doesn't seem to benefit from help by the designer any more.
So no big cash involved here. Sheetcam is one of the most expensive software I have bought recently and I don't regret a penny of it.
 
Fair enough, I didn't really say what's going on. I'm doing okay with feeds and speeds. Gotten some decent results. My trouble is something in one of the free softwares is causing problems. My machine is going idle mid cut, and I have to manually intervene and babysit hours long jobs. The other thing, sometimes when I try to abort a job to reset, it drives my bit straight into the material destroying everything. I'm pretty sure these things are software related, but I cannot complain to anyone because they're free.

So I started researching other CAD programs and everything I've tried is so complicated that I haven't gotten anywhere. The ones I mentioned above look easy comparatively, I just haven't gotten used to the idea of paying yet.
Hi,

I was reading your message again and several things struck my mind:

First, you're talking about hours long job?! What's the dimension of your attempts? Is it for milling? What are your feed rates?

Second, if your machine goes idle in the middle of a job, it's often caused by a not recognised or misinterpreted GCode. What's your machine running as software?

Same goes for the problem with abort job. This is probably the controller / gcode sender sending wrong commands.
Having a emergency switch which will cut power to the motors is really helpfull.
And sometimes, you want to pause rather than stop a job.

What is your complete software suite at the moment?
For CNC, you need 4 softwares (some can do more than one task).
1. CAD soft (2d or 3d) to basically design your panel.
2. CAM job generator. To transform lines and curves in gcode that can be interpreted by your machine.
3. A Gcode sender. This is the software running on your computer connected to the machine. It also allows to control the machine manually, set zeros, start a homing cycle...
4. A GCode interpretor. That is the software embedded in the microcontroller of your machine. It will translate gcode in machine motion, handle limit switches... This one will probably determine part of the chain above becaus eof compatibility issues.

This is mine at the moment:
1. QCad for designing the panel (but anything that would export .dxf would do as well)
2. FreeCAD to generate CAM jobs. I basically import the dxf from QCAD, make it a 3d panel and select forms to machine.
I also use CAMBAM for engraving at the moment because i didn't figure a proper way to do engraving in freeCAD.
3. bCNC allows me to control the machine, probe the surface for flatness...
4. My machine runs grbl on an arduino UNO.

The interpretor might not be compatible with all existing GCode commands, that's why you need compatible CAM generator / GCode sender.
If it receives a command that it can't interpret, it might lock itself (safe), miss the step and not properly do what you intended (not very safe) or go crazy (unsafe).

If your job always stall at the same moment, you might want to dive in the gcode and look which line caused the problem.

Also, i strongly advise you to cut your jobs in smaller ones, at least until you get confident in your machine abilities and your skills.

For example, for my first panels, i had 8 channels of preamps on one panel, i cut it into 24 different jobs. 3 per channel (drill, mill, engrave).

It will be a fair bit longer but it's more forgiving. And don't hesitate to home your machine regularly (i do it between each jobs). Small machine often use stepper motor that might miss a step once in a while. This is not a big problem (only slightly less accurate) until missed steps accumulate and grow in bigger error. Unless you have a servo loop built in your machine, the only way to be sure of where your tool is is to home it.

Oh, and I always closelly monitor my machine. I don't have built-in vacuum or coolant, so I tend to lay a few drops of cuting oil on the surface, this does the job for now. And with some compressed air and my shop vacuum cleaner, i regularly get rid of accumulated aluminum chips.

Hope all this makes sense and helps

Thomas
 
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The other thing, sometimes when I try to abort a job to reset, it drives my bit straight into the material destroying everything.
I broke a number of tools when aborting a job, because when you ask "Go to zero", it doesn't raise the tool before moving. I do it with a RF remote controller, similar to that one https://fr.aliexpress.com/item/1005...!sea!FR!747477913!&curPageLogUid=jrRmtj7cXiiO
I'm pretty sure these things are software related, but I cannot complain to anyone because they're free.
I concur with totoxraymond that you must split jobs in separate operations.
I have as many drilling jobs as different diameters. After the first drilling job is done, I screw the stock to the spoiler board, using teh holes that have been drilled, so it gives less warping.
By separating jobs you can analyse the G-code (open with a basic text editor - not Word).
It's not too difficult.
 
Thanks for the thoughtful responses @totoxraymond and @abbey road d enfer

I was definitely exaggerating when I said "hours long jobs". There was one cutout I set really really slow, just to make sure it could be done, and this was the first time I had the idle error. I took almost 2 hours for that one, because it kept freezing and I had to manually intervene.

I've been designing in Easel, converting to gcode there, and using Candle to send. I tried many others but couldn't get anything to work right. I'm working on Fusion 360, but I'm not even close to ready with it.

Yesterday I installed a spoil board and drilled it in UGS. My machine didn't freeze once, but it was somebody else's code. So my problem was either Candle, or possibly the post processor in Easel. However I made a test in Front Panel Designer, exported svg, brought it into Easel, created gcode and sent it with UGS, and had no problems. I think I'm going to stay away from candle now, even thought I really wanted to height mapping capability.

Turns out I do need to work on feeds and speeds, ran another cut and some letters are warped. I think I'm pushing past the flex limits of my rig.

I do plan on splitting my jobs up, if I ever get that far.
 
Even though it might be counter intuitive, running slower isn't always better in the CNC world. Getting the right relative speed between the bit and the stock is the key for a nice job.

Too fast, the tool will try to remove too much material at once, it will overheat, your spindle will force and overheat and your motors will force and overheat... You might even break something, probably the bit.

But too slow, you're making dust instead of chips, this dust can agglomerate with the coolant, get stuck in the bit... Your bit might overheat and get dull.

What you want is to get nice, even chips out of the material and this requires the bit to be set at the right speed. This way, your machine will be happy and sing through the material, you will get nice smooth cuts, and all will be optimal.

If you want to go easy with the machine and bit, reduce the cut depth, make more passes. Generally you'll read that the cut depth should be equal to the tool diameter, i tend to cut that in half on my machine.

I'll link the spreadsheet i use later today, i'm on my phone right now.

Thomas
 
attached is the spreadsheet i use to calculate spindle speed and feed rate.

I got the formulas and tables from my bit provider and it gave me good results so far.

I translated it as best as i could from French, units are metric.

Bests,

Thomas
 

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  • Feed Rate calc.zip
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