My engraving nose

[riche543]

Thanks Hessel, yep had no luck finding anything with single line , Amazing that no one has converted more fonts for single line , anyway will have to experiment with tool settings etc. Thanks again
Cheers
Riche.

[jonesthesoftware]

Hi Richie
I don't know what software you are using for engraving, but I use Autocad to design everything and then import that .dwg file into Artcad for engraving and generally generating the cnc files. When I import the text from .dwg into Artcad it ends up with single line text which can then be engraved by using the "follow a vector" tool. You can also draw single lines to make your own text and cut using the same tool. Of course you will not then have "aircraft" style fonts as Hessel says. What is wrong with your text engraving? Too wide fonts? Are you cutting too deep with the wrong tool? Wrong tool specified in you cnc software?

regards
geoff

[Hessel Oosten]

Hi Rich, Geoff,

To menstion another possible option:

In an older toolpath generator I used (RAMS3D) I imported a double line dxf from AutoCAd.
In RAMS3D I choose a (fictive) mill diamter which was just about 49 % of the width of the double lines. Generated a toolpath which, of course, is than a single line just in the mid.
That line could be exported as a normal toolpath but also as ... a *new* dxf. That *new* dxf can be used for generating a single line toolpath. How complicated can you go ....-).
The double lines are no problem for me.
Geoff, I searched for the artcad you mentioned on Google but found nothing waht resembled a graphical program. Did I understand it well that when using that program no aircraft like-fonts (e.g. Futura MdBt etc.) are possible ?

Hessel

[jonesthesoftware]

Hi Hessel
the programme is ArtCAM see here
http://www.artcam.com/

Yes it has the full range of fonts, whatever windows fonts you have on your computer. I just mentioned the peculiarity of the programme that when it imports from Autocad, text comes across as single lines which I then have to delete and substitute with Futura Ltcn Bt(this is the narrowest of the Futura fonts).
I think engraving for backlighting must be the most difficult and frustrating task so far in cockpit building.
I've encountered so many problems in engraving with a cnc machine, table flatness, material flatness (acrylic is only within 0.1mm and paint is about 50 micron), blunt tools, paint not properly dried so not a crisp edge, speed of engraving, blowing, clearing/cooling of tip to prevent paint melting and sticking to tip etc, etc. I think I've just about got it all sorted. Only problem I haven't cracked is white text when the backlight is not on. I use opal acrylic, painted and engraved through, but it's a sort of grey text without the lights. I tried spraying white then brown and tried to engrave only through the brown but you need flatness of better than 50 microns or thereabouts. Can't get that without dedicating my cnc to engraving only. Of course I use it for everything else including making furniture, so I use sacrificial mdf sheets on the base table which again aren't flat.
AH the joys of cockpit building!

regards
geoff

[riche543]

Hi Geoff / hessel

I'm using vectric vcarve , I did find using futura LT came out ok , but still doing outline, It's a shame we couldn't get futura md bt one stroke straight out of windows fonts as it seems like lots of messing round just for text engraving.
Vcarve has a couple of single line fonts built in one being a futura font, but few letters don't come out very good

Riche

[riche543]

Looking on the net there seems too be some font design software out there , is it possible too use these to make one stroke futura md bt font for windows?
Don't think I'm smart enough too do this , just asking if it's possible?

Riche.

[jonesthesoftware]

Hi Riche
are you using the correct font because Futura Ltcn Bt is a narrower font than futura md bt?
regards
geoff

[Perik]

Hello

I have a short video showing 0,4mm Single Flute Endmill inside contour engraving session over here:

http://www.youtube.com/watch?feature...&v=2Ps87U2nOEE

I've tried different approaches but this is for me the best. An alternative for the brittle 0,4mm endmill,
you can try to use for instance a 15 degrees V-cutter with a flat tip of 0,2-0,3mm.
The clue is to take one "word" or small section at a time and lowering the tool step by step until
you take out just the paint.
Remember - this is not mass production ( I hope ) and the time used for engraving is just a blink
of an eye compared to the overall spent time.

Concerning material I find that white PMMA (casted) or Hesaglas - for instance:
http://www.peerless-coatings.co.uk/acrylic.html give the best result.
I believe Hessel use ~1mm Hesaglas glued on top of transparent acrylic.
I use 6mm PMMA pocket milled from the back to get the appropriate thickness.

Anyway this is just my experience and without a huge investment in
a Laser “Turbo GT Plus”, I feel this is about as close as we can come
with a “mechanical” approach.

Happy millling

[jonesthesoftware]

Hi Per-Erik
thanks for that. I've just watched your youtube videos. Beautiful work, you have even more patience than I. Yes I am going to try both the hesaglas approach and 6mm white PMMA milled from the back. I already mill from the back but I used Opal acrylic because I didn't realise that the white had any transparency at all.
I use the 30deg V cutters and can get good results down to 3mm high text. Haven't tried any smaller yet. Because I was still learning the cnc and broke quite a lot of cutters in the process I bought chinese 30 deg V bits because they are cheap, but it took a while for me to realise that they were part of the problem. When I really looked at the tips some were broken and some of the edges weren't sharp. Changing to a better quality cutter made a world of difference.
ah well live and learn!
kind regards
geoff

[riche543]

Hi Geoff / per-erik
Geoff for me the futura md bt comes out too thick , even using 0.2mm 40 deg bit , maybe it's vcarve software making them too wide.?
Vcarve has option for fill or outline , fill would give me slightly narrower but takes such a long time just for one letter. I will take some pics of how they come out.
Per-Erik great video , what font are you using for that engraving?
The engraving nose I built for mine was proberly the best thing I've done, because I don't have too worry if material is not within 0.2 flatness, will always engrave same depth.
If your cnc can cut aluminum , you should think about making one ,
Cheers
Riche