Question for panel makers - engraving.. how do you do it?

[metalnwood]

Just ordered and onsrud cutter! Looks nice!

 

I cant wait to give it a whirl!

 

 

Steve, here is a program with a months free trial. As you get familiar with feeds and speeds it will give you an excellent idea of what to use for different cutters on different materials.

 

http://www.cnccookbook.com/CCGWizard.html

 

It can certainly help you save that small bit that run to hard and at the same time let you run that small bit as hard as it will go without breaking it. A lot of people are fairly timid on the speeds they go for after breaking a bit or two but then they never get the idea chip load either.

[Warhog]

Thanks for the quick reply, Stevos758! Those links are very helpful. And now that you mention it, the ability to do more with a CNC compared to just a laser engraver is very appealing as well. I certainly don't have a budget for both machines at the moment.

 

I think that's an excellent reason for going with a CNC mill. That precisely why I purchased a mill. Mind you that was a long time ago. Just recently though, I was very seriously considering buying laser but when I asked myself what I would do with it after I finished my panels... well I didn't come up with much.

 

I may however purchase another machine...a dedicated rotary engraver. It is less expensive than a laser, no special ventilation requirements and no special cooling system required. The advantage for me is the large bed they have. Hobby type CNC mills are small and as such have a small bed. I can engrave all my A10 panels with it but I have other panels, much larger, that I would like to engrave and the bed I have is too small.

 

The quality of rotary engraving is excellent for our needs but I would have concerns with the Shapeoko for doing fine engraving like we are doing. The spindle looks to be like a dremel tool and the run out on those things are terrible. I couldn't even drill holes in a PCB (0.03" dia drill bit) with mine using a drill press holder. The bit visibly had to no fixed end point you could see because the run out was so bad. All of these machines require a certain degree of precision and that unfortunately costs money to obtain.

 

As Metalnwood said you don't need coolant for acrylic. Just a constant stream of compressed air on the end mill with good feeds and speeds gives me excellent cuts. I too use a mister for milling aluminum and although I do have a flood cooling system in place, it rarely gets used.

 

Whatever you decide it must have precision and consistency. Without either of those attributes you will have wasted a lot of money.

[metalnwood]

I had a play on one of my machines just now. Here are the results…

 

Against advise I might have said in the past I now don't have any hesitation about doing rotary engraving for panels compared to a laser, once again this is because of the generally small type we are using without large fill in areas.

 

So Steve, here is the output I achieved doing a couple basic steps…

 

One, surface an area so that there is a properly flat pice to put your panel on. Any variation in height can show up as uneven text in the engraving. I just run a small pocket routine and then put some double sided tape down to hold the piece.

 

I used a cheap engraving tool that you would buy in packs of a dozen or so. 1/8th" shank, 0.02" radius on the end.

 

I attached a full size of the result. These are letters for the CDU so they are the actual size of cdu letters, slightly larger than panel text.

 

The bottom three lines are done with a depth of 0.2mm or 0.008", they are a bit too deep for keys because you can feel them. The top line is 0.05mm deep or 0.002" deep. The result is good but you can see the circle around the W is not quite perfect, this is because at this depth I am finding the unevenness of the surface. 0.07mm wold probably do fine without looking like the engraving is deep.

 

So yeah, if you think you can get more from a cnc router then go for it, the engraving should be fine.

 

[Warhog]

Im in the process of moving, about 2 weeks until exchange of contracts and its at the tense moment.

 

Youre dead right about the flying bit, and actually ive had to pack up the sim PC. Right DC Industries is focusing on software development. Ive been working on my personal version of a UDP Bridge since i started my tutorial on it and its nearing completion. Right now ive got a working import of all the LUA files that allows me to browse all the objects, kind of an interactive database of the cockpit panels.

 

Metalnwood ... What font are you using? Is it a stick font or a TT font? That blowup of the engraving is pretty much what I get. Nicely done.

 

Now for great backlighting I would take that piece, flip it over and create a pocket 0.035" deep behind each line of text assuming the work piece is 0.06" thick. If you use a several lengths of strip LEDs from China ($15 for 5m length of 5050 LEDS) in an enclosed space behind the panel it will have a beautiful green glow with no hot spots.

 

For work holding I have experimented with maybe 8-10 different types of double sided (DS) tape. I find ds tape to be the most effective means of keeping the work piece in place. Scotch DS Poster Tape is the best I have found to date. Tuck that bit of info away for when you start engraving as it will save you needless hours experimenting with all sorts of tape.

 

One more bit of info...CamBam is an excellent little CNC package that you should try out. First 40 uses are free. That will give you a lot of time to decide if $150 is a good price for a way to draw what you want to make, select multiple types of milling actions, set cut depths, speeds and feeds and then output the Gcode to Mach III to cut your work piece.

 

I've had an opportunity to try out several similar type packages and in terms of value, this program was on the top of my list. It is perfect for beginners and easy, very easy to use.

[metalnwood]

John, that is the MS33558 mil spec truetype font.

 

Because of the small engraving bit I programmed the engraving via pocket operations, at most it was just two passes to fill in the area.

 

Aint double sided tape our best friend :) It pretty much gets use on the router, the lathe, the mill, pretty much anything :) It's excellent stuff for the cnc when you don't want or cannot have something holding the work getting in the way. My router has a vacuum table but if you want to do any reasonable cutting operation the pice has to be at least ~300x300 to hold well enough.

 

It is over a 2500x1300 bed though, in the future I might make a small one to hold things like this as well.

[Stevos758]

That looks nice! I'll play with it when I get my Onsrud cutter. I'll try using some shallower depth cuts.

 

I already have G wizard! Sill learning it but it had helped me so far.

 

This kind?

 

http://www.staples.com/Scotch-Removable-Poster-Tape-3-4-inch-x-150-inch-1-inch/product_916223

 

I messed around with cambam for a few minutes. Ill check it out again.

 

Right now I have cut2d and meshcam art. That seems to be working out for me now.

Edited May 29, 2014 by Stevos758

[geneb]

It's likely the font that Derek Higgs made for simpits.org back in 2000.

 

g.

[metalnwood]

There is nothing for panel building I can think of that you cannot do with cut2d and cut2d is really easy to use.

 

You are using the onsrud cutter for engraving? If you are talking about the o-flute you will need a much smaller one than they make for doing the lettering. One like I posted or some v cutter will get you the best results on small fonts.

 

Are you going to try the engraveable laminate? One sheet for under $100 will do the who cockpit, seems cheap to get the best results after spending so much on a CNC to be able to make them :)

[Stevos758]

There is nothing for panel building I can think of that you cannot do with cut2d and cut2d is really easy to use.

 

You are using the onsrud cutter for engraving? If you are talking about the o-flute you will need a much smaller one than they make for doing the lettering. One like I posted or some v cutter will get you the best results on small fonts.

 

Are you going to try the engraveable laminate? One sheet for under $100 will do the who cockpit, seems cheap to get the best results after spending so much on a CNC to be able to make them :)

 

I had meshcam before for other projects. Bought Cut2d for sign making and engraving. I really enjoy both programs. They both have their place.

 

I have hte .006 tip V engravers already. Just waiting on the onsrud to cut them out.

 

I'll just play with acrylic for now. I will check into the other stuff when I am done playing around! : ).

[Stevos758]

But really is this the kind of tape you guys are referring too?

 

http://www.staples.com/Scotch-Removable-Poster-Tape-3-4-inch-x-150-inch-1-inch/product_916223

[metalnwood]

Looks ok, just make sure you don't use any foam tapes, they need to be thin.

 

It is quite a small roll though, I would buy it in a much larger roll as you will get through it. $5 is a good way to see if that one works though, then you can get a larger roll.

[metalnwood]

I had meshcam before for other projects. Bought Cut2d for sign making and engraving. I really enjoy both programs. They both have their place.

 

I have hte .006 tip V engravers already. Just waiting on the onsrud to cut them out.

 

I'll just play with acrylic for now. I will check into the other stuff when I am done playing around! : ).

 

 

I used the .02" tip. Which onsrud can you use for engraving? Have you modelled it in cut2d? Even the 0.02" head was too large to get in to do some text so I can't imagine any o-flute doing panel engraving on 4mm high fonts unless they are stick fonts and really fat.

[geneb]

He may have missed the part about the O flute cutters being really only used for pocketing operations.

 

g.

[Stevos758]

Sorry, I have a cheapy ebay V cuter with a .006 tip for engraving and an 1/8" onsrud O for pocketing on the way. I understood everything I just must have misworded it.

[metalnwood]

These are the kinds of cheap engraving tools I am using, you can grind/round of the end or also get some with a radius on the end.

 

http://www.ebay.com/itm/10xCarbide-PCB-Engraving-Bit-CNC-Router-Tool-30A-0-3mm-/130422956140?pt=LH_DefaultDomain_0&hash=item1e5dd0606c

[Hempstead]

I bought my laser cutter specifically for engraving panels. But then came to use it for making the PTFE rings for Warthog. What I find it most useful is to cut templates.... No more going to my drafting table then jig saw the templates very carefully, then sand them to size! Draw the design in CAD, laser cut whatever template I need on a thin sheet of plywood, then plasma cut made easy!!! No more wiggly cuts due to trembling hand or sneezing!

 

I also use it to cut and actually pocket (rough multi-pass engraving) the Hall Sensor base I am making. I used to make this w/ a 3d printer, but found the el'cheapo 3d printer I have very temperamental and unreliable.

 

Well, instead of silk screening, you can laser engrave rubber stamps for lettering on curved surface, cut complex masking for spray painting/decal.... numerous uses!

 

If you ain't got a hammer, nothing looks like a nail!

 

 

I think that's an excellent reason for going with a CNC mill. That precisely why I purchased a mill. Mind you that was a long time ago. Just recently though, I was very seriously considering buying laser but when I asked myself what I would do with it after I finished my panels... well I didn't come up with much.

 

I may however purchase another machine...a dedicated rotary engraver. It is less expensive than a laser, no special ventilation requirements and no special cooling system required. The advantage for me is the large bed they have. Hobby type CNC mills are small and as such have a small bed. I can engrave all my A10 panels with it but I have other panels, much larger, that I would like to engrave and the bed I have is too small.

 

The quality of rotary engraving is excellent for our needs but I would have concerns with the Shapeoko for doing fine engraving like we are doing. The spindle looks to be like a dremel tool and the run out on those things are terrible. I couldn't even drill holes in a PCB (0.03" dia drill bit) with mine using a drill press holder. The bit visibly had to no fixed end point you could see because the run out was so bad. All of these machines require a certain degree of precision and that unfortunately costs money to obtain.

 

As Metalnwood said you don't need coolant for acrylic. Just a constant stream of compressed air on the end mill with good feeds and speeds gives me excellent cuts. I too use a mister for milling aluminum and although I do have a flood cooling system in place, it rarely gets used.

 

Whatever you decide it must have precision and consistency. Without either of those attributes you will have wasted a lot of money.

[DerekM]

This thread just keeps on giving! :thumbup: I still think I'm pushing towards a CNC-type machine as I think I can get a lot of use out of one. A quick question - do any of you guys create PCB's with your machines? If so, is there anything in particular to look for when buying; what's the PCB quality like, etc. I'm an electronics engineer so if I could make up simple PCB's I'd be happy as well.

[Stevos758]

I have the stuff to make one I just haven't tried it out yet. I am "not" an electrical engineer so that is my hold up. : )

 

Here is someone using the machine I have to do them.

 

 

And someone using the autoleveling feature that would come in handy with panel making too?

 

https://www.youtube.com/watch?v=3sWVY89B7Gs

 

Looks like they turn out ok.

Edited May 30, 2014 by Stevos758

[geneb]

There's a free add-on for Eagle called "pcb-gcode" that does great isolation routing for boards.

 

g.

[Hempstead]

I do use a CNC to do PCBs for the Cougar DiH hall sensor. It's a SOIC 8 chip. Works just fine. 10 mil trace, no problem.

 

However, I have to tell you that for finer pitch... tough... It wouldn't be easy to do 0.5mm pitch for, say, Atmel SAM4S with LQFP 0.5mm (not impossible). And the flatness of your table and fixing of the PCB has to be absolutely flat that it's not easy for large format. A vacuum table would be great, but for small PCBs, I mill some aluminum hold down for them (just a flat plate of aluminum with a rectangular windows on it and another milled flat backing plate to clamp the PCB flat). And obviously, your machine be better trammed perfectly... or you will end up one side cut too deep, one side no cut at all. This is mainly why larger PCBs are very difficult. Professional PCB milling machines solve this problem by using depth sensor, which you would not have with a regular CNC mill/router.

 

Also, your machine backlash better be tightly controlled. See, if your machine's backlash is 5 mil and your trace width is 5 mil... you might end up with no trace at some places.

 

A tip for after milling the PCB... you will end up with some copper burrs that you need to clean up. I find that using a fine grit Japanese water stone for knife sharpening works perfectly. Wet the stone with some water, press the copper side down, run a couple of passes and all the burrs are gone. A good blast of compressed air.... and you are good for soldering.

 

Also, if you use Windows EagleCAD's PCB2GCode to generate the GCode and your mill is using Linux EMC... you'd need to run dos2unix on the generated GCode to translate the Windoze CRNL to NL, otherwise Linux EMC will err out and spit out some weird/confusing error messages.

[Stevos758]

There's a free add-on for Eagle called "pcb-gcode" that does great isolation routing for boards.

 

g.

 

Yes! Its pretty amazing. I have messed around with it and you can make pretty much anything you can think of as far ac PCBs go.

 

PCB G code has a built in auto leveling G code.

[DerekM]

Thanks for the replies guys. I wasn't really expecting super precision with PCBs and I thought even 10 mil would be difficult. But it sounds possible with some attention to detail. Cheers.

[Warhog]

This thread just keeps on giving! :thumbup: I still think I'm pushing towards a CNC-type machine as I think I can get a lot of use out of one. A quick question - do any of you guys create PCB's with your machines? If so, is there anything in particular to look for when buying; what's the PCB quality like, etc. I'm an electronics engineer so if I could make up simple PCB's I'd be happy as well.

 

 

How's that for a quick and dirty PCB? The holes are 0.03" diameter.

 

 

 

Yes they do have to lie perfectly flat and those copper clad boards have a bias in them so they always bow in or out or whatever. Pain in the ass. But that's where the double sided poster tape comes in. Give the board a bit of a bend to get it close and then cover the whole thing with tape. It sure as hell will lie flat after that. Feeds and speed need careful attention here as well and depth of cut is absolutely critical. It should be just shallow enough to break the copper. I set my cutting depth and then cut a little circle beside my work as a test. I throw on a ohm meter to make sure it actually broke the copper. If you go to deep you might need to reset to zero and run the gcode again. It cleans up some of the crappy edges if you went to deep and burrs.

 

@Metalnwood... I couldn't live without Scotch Double Sided Tape.:smilewink: Nothing else that I have tried works this well. And they must know that because it costs a small fortune.:cry:

 

@Stevos...I couldn't see the product since I'm in Canada and Staples only lets you see their products from a Canadian site. But fear not, if all else fails go to the Scotchbrand web site. Product No. 109. Its realty thin tape.It holds well and it won't damage anything. When your good enough you can set your cutting depth so that you just cut through the work and not hit the table as the tape is just thin enough to act as a buffer.

 

http://www.scotchbrand.com.au/wps/portal/3M/en_AU/APAC_ScotchBrand/Home/Products/Catalog/?PC_Z7_RJH9U5230G7N10I6F2EBGJ1O03000000_nid=VLBGMC8S77gsP628PQJ3NLglT1NWM3L5MKbl

 

I have some pics of a recent engrave I did on acrylic that I will post shortly so you can see what to expect. It is recommended that you use a ball nose cutter for engraving acrylic. I use a 0.10" ballnose and I always run the gcode twice.

[Stevos758]

Thats the same tape I posted! Good. I ll pick some up asap!

[Warhog]

This is my Caution panel.

 

 

 

 

Actually it's my second caution panel as I wanted to implement some of the tricks I learned from doing my first set of panels. Its still a works in progress but it is .117" Lexan. I did all the horizontal and vertical lines with a .0625" 2 flute end mill to a depth of .040". It was then sanded with 800grit paper after which I did a cleaning on it and then I airbrushed several coats of Tamiya semi gloss black paint. Let dry 2 days and then engraved it with a 60 degree .010" ball nose cutter. Ran the code twice to clean up the edges. Now it's ready to be cut to size to insert into the frame of the caution panel. Next I will design a PCB for SMD LED's and some 32 pin connectors on the back for the ribbon cable.:)