My first effort

This entry is in response to all the forum members on many of the forum boards who have helped me with my first foray into CNC machining. Help with Inkscape, Gcode, general cnc nomenclature and setting up of my desktop cnc router/mill/engraver has been greatly appreciated. So attached is the logo for the Oxford Mammal Group (my daughter is the secretary) showing a Harvest mouse on a wheat stem with Ox M G text around - just needs a bit of surface polishing

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Glad to see your on your way!

Rick G

nice effort , your on your way , dont stop now

Looks good!!

I just did a TEXT project but ran into a snag... the text always OUTLINES when I export it. (Grumble...)

Now as you know I'm no expert - but I think the reason you get an outlined TEXT is because you need to use special engraver fonts rather than the normal fonts that most software uses. Inkscape (which I am using for quite a lot of my graphical work as it has a direct Gcode conversion routine) has another extension that provides Hershey Text fonts which are engraver fonts. You get this as a function within the EggBot extension downloaded from egg-bot.com

Micromet wrote:

Now as you know I'm no expert - but I think the reason you get an outlined TEXT is because you need to use special engraver fonts rather than the normal fonts that most software uses. Inkscape (which I am using for quite a lot of my graphical work as it has a direct Gcode conversion routine) has another extension that provides Hershey Text fonts which are engraver fonts. You get this as a function within the EggBot extension downloaded from egg-bot.com

Thanx, I'll check it out.

I do have Inkscape, but I don't know much about it. Case in point: I didn't know it could G-Code! (I've been saving them as SVG files...)

While my first effort seemed to go OK - it was probably beginners luck - as I have had problems since in making multiple copies of the Harvest mouse keyring.
I'm not making it easy by trying to engrave stainless steel - which I now know is probably the hardest surface to engrave. And while production metal suppliers will tell you which type of Stainless Steel you are getting, many suppliers of these type of trinket items probably don't even know that there are different stainless steels. Anyway it seems I would be best if I used 416 stainless steel, then 430F, 303, 420F, 430, 304 and finally probably avoid 420.
On the tool front - I began using 30 deg x 0.1mm single flute carbide cutters that I sourced from ebay. Why? Because I knew no better and they were cheap. It seems I should be using 45deg x 0.1mm quarter-round micro-grain carbide cutters as these are less likely to fracture at the tip - which is something that was happening often as soon as the narrow angle cutter touched the stainless steel surface. I'm awaiting some of these micro-grain carbide cutters - but they are not cheap.
I was also running too fast a feed rate (400mm/min) and plunge rate (100mm/min). Again didn't know any better at the time - have now reduced that to 250 (feed) and 40mm/min (plunge) - seems to work better. And while I should be machining at something like 20-30,000 RPM or higher, my CNC machine has a maximum rpm of 15,000 (as shown by my excellent laser rpm meter - I recommend these to anyone who wants to calibrate their lathe, mill or cnc machine (less than £10 from Amazon - search digital laser photo tachometer)
I've also taken to covering the disc with a layer of 3-in-1 oil as a lubricant/coolant - I'm using Newplast modelling clay to act as a "bund" around the disc to keep the oil inside.

If any one has any comments to improve my current machining protocol - I'm as always - all ears

My inkscape is not the latest - I'm using version 0.48. You need to install gcodetools as an extension - don't be put off by the Russian links -it's quite safe. Go to - github.com/cnc-club/gcodetools and download the ZIP file on the right-hand side, unpack that and follow the Install instructions at the bottom of the page. If you need any further help get back to me - but remember I'm no expert on INkscape either.

Micromet wrote:

My inkscape is not the latest - I'm using version 0.48. You need to install gcodetools as an extension - don't be put off by the Russian links -it's quite safe. Go to - github.com/cnc-club/gcodetools and download the ZIP file on the right-hand side, unpack that and follow the Install instructions at the bottom of the page. If you need any further help get back to me - but remember I'm no expert on Inkscape either.

I had .48 as well and saw on the 'Evil Mad Scientist' wiki that I should update to .91 Granted that was for the actual egg bot kit, but I figured I would be a good idea to update anyway, so I did. Check it out!! Under '[Extensions] there is a Gcode category already built in!!! (whoo-hoo!)

Next up; download the Hershey Text via Eggbot extension...

My Mageia 4 Distro hasn't yet upgraded to the latest version of inkscape and trying it myself - I ran into a lot of dependency problems - which I didn't get with installing the Gcodetools extension. So I went down that latter path because I wanted the gcode function rahter than any new Inkscape options. But I have a warning - while the gcodetools extension worked perfectly, there were problems with how Inkscape appears to work that caused me some headaches. See www.inkscapeforum.com/viewtopic.php?f=31&p=74792#p74728 where I recount the problem and various replies as to the cause. I'm not sure even now whether I have found the solution which does seem to be bound up in some way with the ability of Inkscape to preserve history for the "undo" function.