GearHeads Forum

Hopefully the 90 degree v bit will come in the mail tomorrow, then.  Thanks, Art!

Kirk

i just tried a guiloche on a scrap piece of flammable building cladding .
[platicised rocket fuel sandwiched between two aluminium sheet with a uv plastic exterior coating,  think granville tower]
might be a better use for the stuff other than making high rise roman candles.

this scrap was a bit damaged and the camera flash shows every defect nicely
made with aforementioned springy engraver tool [3040 mill @20000 rpm 1000 mm/minute]
needed a couple of passes due to surface dints.  the edges have very little burring

That looks great!

Is that the aluminum/plastic/aluminum sandwich board the signmakers like.  I've seen it sold as omega sandwich board, and it goes by other names.  Another version, alumilite (sp?) has a corrugated core and might make a better rocket fuel.  Nophead's Mendel90 3D printer used it as a frame.  I got quite a lot of it as scrap from a couple sign shops, with a solid (what looks like) polyethylene) core and it cut very nicely on my ZenBot mini; made a set of gearotic gears with it and planned more before the 3D printer obsession intervened.

My guilloche book just arrived, have only skimmed part of it but know how I'll be spending the afternoon.  The 90 degree two flute bit arrived at the same time but that'll wait until tomorrow when I can sit in a regular chair longer (PT today...).  Stumbled across a comment about 0.2 to 0.3mm mm spacing in the book and covering the entire surface, might try that tomorrow too, see what it looks like in metal.  Wonder how spinning bits (or even dragged v cutters) relates to the more conventional ground lathe bits used in classic style machines.

Discovered Amazon has lots of round circles, found them called "stamping blanks" in aluminum and brass, then there's round wooden coasters.  Unlimited pre-cut material to work with, maybe could try the metal ones as ornaments on top of a turned wooden box and make more use of that new Jet wood lathe.  A jewelry box for Mrs. Moose...

Art, if you get bored    do you want to think about adding radial (starburst) and then maybe hypotrochoid (etc) line types?  Vexx's multi-sided eccentric shapes already add a unique, from what I've found so far, aspect to guilloche, although thinking about the math to combine that with hypotrochoid makes my eyes water.

Kirk

Richard, how do you like that 3040?  Is it the parallel port or USB version?  One, with an 800W spindle and 4th axis was on my short list but I cheaped out.

20 pages into the guilloche book, history of schooling in the late 18/early 1900s in Switzerland.  Don't think I'd have the patience for a 4 year course.  At that time the art/craft/skill/trade of guilloche was closely held, like trade secrets today, and was learned through an apprenticeship program.  Little was written down, and a lot of skills were lost when masters with few apprentices passed away.  There was a small (2 to 10 students/year) university program for a while.  When the author approached the school (School of Applied Industrial Arts in La Chaux-de-Fonds, Switzerland) she was told they'd never taught guilloche.  It took searching through the school records to determine that they had a program until 1932 when it was interrupted by the war and never restarted.

Someone who works in guilloche is a guillocheur or guillocheause.

End of today's history lesson...  I haven't made it to geometric, eccentric, and elliptical chucks, straight line and brocade machines, rose engines, etc. another 120 pages to go.

Kirk

Is that the aluminum/plastic/aluminum sandwich board the signmakers like.

that was the first time i have experimented with it , my first thought was wow this stuff would be excellent for signs/instrument panels etc
so it probably the same stuff.
just need to figure a way to remove the al chips [caustic bath may work]

Richard, how do you like that 3040?  Is it the parallel port or USB version?

i have had it for several years it was the ball screw version , since upgraded to  usb,vfd spindle.  pokeys
as it was delivered the x axis was not parallel to the table ,it needed some work to true it up.
the z axis is now showing some backlash that will need attention. overall its held up well and made lots of chips

i dug in a bit deeper here completely through al layer

these spring loaded v-bit holders need a bit of thought when you use them .
its my experience that the bit will retract into the holder when under load but it will not spring back until the bit is lifted from the work.
so it works best with lots of short runs.
getting the spring tension correct is a science thats beyond my comprehension
i wind the tension up till the bit just penetrates the surface when z is zeroed to surface and doc set to 0.1mm for aluminium . this does not give much dynamic range and may require multiple passes with progressively deeper cuts  , but i don't bust too many bits .
unfortunately this does not work too well when the surface is harder than the core eg pcb material
getting things mounted flat [within .05mm for a nice pcb]  over big a area on my mill is problematic i find

My 3018 also has an extruded aluminum table, it was out of level about 0.3mm and a little dippy too.  I double side taped down 1/4"/6mm mdf and surfaced it in 0.1mm steps until it just skimmed the whole table.  I'm concerned about moisture in this damp tropical climate but so far it's held OK.  I'm doing 0.1 and 0.05mm cuts without problem.  In the first picture the ds tape wasn't all the way under one side and the sheet must have dropped down a little, but since then it's been nice and even.  I started off at a higher speed, think it was around 300mm/minute, but since slowing down to 100 it's been cutting a lot cleaner.  This spindle is only 7000 rpm with a one flute bit, perhaps the 2 fluter will go faster.  I keep telling myself that with all the screw turning, clicking, and multiple narrow passes it's far slower on a rose engine.

I'm going for the shallow engraved style, going to try closer together tomorrow with the 90 degree bit.  Maybe if I'm really lucky I can get a barleycorn effect but that might be dreaming.  I've seen pictures of the same pattern both v cut and done with a diamond drag, and while I like the diamond bit think that v cutting is closer to the historic appearance.  Those old machines could use asymmetric bits with different angles on each side, but that's going to be harder to do.  Grinding bits out of drill rod so they swivel in the spindle might be getting too carried away, particularly when there's lots of basics to sort out first.  Plus no drill rod, or grinder, or way to harden it down here.

I like the black background against the top layer in yours!  It took me a while for your rocket fuel comment to register.  Things that look great in the lab don't always work out in real life, sometimes with tragic results.

Kirk

I double side taped down 1/4"/6mm mdf and surfaced it in 0.1mm steps until it just skimmed the whole table.  I'm concerned about moisture in this damp tropical climate but so far it's held OK.

yes i have done similar things, in the end i found milling pcb's on fibreglass substrate was best done with oil/water mist spray to eliminate dust
mdf did not appreciate that. so i got a A4 sized vacuum table,went to great lengths to trim it to machine  . nature still seems to conspire against
flatness at every opportunity

It took me a while for your rocket fuel comment to register.

its created a shitstorm here in australia over who is going to pay for it removal after a series of fires

this one shows the issue with my setup ,  @the 4 oclock position
not sure if the missed cut is z backlash,or the bit stuck up the holder or something else

forgot to add
i fount the high angle bits >45 deg create more burring than the low angle bits ,  10 deg break too easy ,30  is my fav
i just get cheap ones and expect to much i think

Thanks for the feedback guys, well appreciated.

Cheers
Bob