[Mountaincraft]

I posted these two posts over at the vectric site, and I wanted to ask here too... As there is more activity here...
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So, I'm about ready to take a stab at this.. I bought some led strips (various colors) and power supplies a few weeks ago, got them out this morning and wired them and made sure it all works... I have some 3/16" and 1/4" scraps of acrylic to practice on.. All I need to do now is decide on the bits, speeds, and feeds, and then a design..

I have various bit.. The only bit I have that is 'made' for plastic is an amana 1/8" single flute up spiral...

But I have a 45 and 60 degree miter fold bit, a couple 90 degree carbide bits, some 1/8", 1/4" 3/8" end mills, some radiused, 1/16", 1/8", and 1/4" ball nose..

and I also have these tiny 1/8" 20 degree 1.5mm engraving bits.. I'm wondering if those might be good to use for this..

Anyways, with what I've listed as in my bit collection, would like to hear what you guys suggest I start out with, and what DOC, speed, and feed rates I should use..

I'll be using V Carve Pro to create the tool paths.....

Thanks,
Mark

[Mountaincraft]

Okay.. These engraving bits are 1/8" diameter, 20 degrees, with a .004" engraving tip...

My test Acrylic is 3/16" thick...

Here is a rendering of the file I want to run...

I currently set it up to 'V Carve' with a flat depth of .0325" a start depth of .005" spindle speed of 10K, feed rate of 100 IPM, pass depth of .025, step over and clearance pass step over of 40%

The outside profile pass is currently set up with a 1/8" acrylic upspiral bit (single flute), spindle speed of 5K, feed rate of 100 IPM, Pass depth of .035, 3D tabs .5" long by .075" thick..

Will take over an hour to carve according to VCP...

Should I use a different bit for the logo? Are my settings appropriate?

Thanks..
Mark

[jjacstcy]

I do quite a bit of acrylic at work on a Multicam 3000. The best bits that I have found for acrylic are from Hartlauer. The bit I use the most is the 65-023. Its a 1/4" bit. I run the spindle at 28500 rpm's with a feed rate of 120 imp. The only thing I have noticed using router bits is that it will leave tool marks in the flat of the acrylic. If I route a project my depth is never over .005". I perfer using the router to just cut out the sign blank. I always use a vegetable based coolant and always use cast acrylic. The edges of my signs come out almost crystal clear. After cutting I wet sand the edges with some 400 grit wet/dry paper then flame polish the edges. I sandblast all copy, I get a more even finish with no tool marks. You engraving doesn't have to be vary deep, just enough to catch the light. I think you would be better of using one of your engraving bits at .005 depth, 120imp, try 15,000 rpm. Cast acrylic is better if you can get it. Really nice looking logo you have there!

[Mountaincraft]

Thanks for the input... So you're saying that I am good to go with the engraving bit, but I should just cut much shallower? Maybe up the spindle speed some?

What about the profile cutout? Feed and speed and DOC good?

Also, thanks for the props on the logo...

It's hard choosing something to represent 'myself'.. The more I play with design, the more I'm beginning to appreciate the beauty of 'simple'... Whenever I am struggling, I find the best course is to start removing complexity...

[txcncman]

I plan to do some of this in the near future. While I can't speak directly for cutting edge lit signs, I do have some experience machining plastics.

The thing I would point out to you is to as precisely as possible, locate your material square on the table and be able to relocate the X, Y zero point at another time. Then route your image shallow and test it. If you are not happy with the results, you can re-machine the pattern deeper and retest.

[jjacstcy]

I cut out 3/4" acrylic in 2 passes with the 65-023 bit at 120ipm and a spindle speed of 28500. My table has a 5 hp motor on it so it helps out when cutting the thick stuff. You could cut your 3/16 or 1/4 acrylic in one pass maybe at 60imp 15,000rpm using your amana bit. Wet sand your edges to get the tooling marks out. Maybe even try a little flame polishing on some scrap!

[Mountaincraft]

I plan to do some of this in the near future. While I can't speak directly for cutting edge lit signs, I do have some experience machining plastics.

The thing I would point out to you is to as precisely as possible, locate your material square on the table and be able to relocate the X, Y zero point at another time. Then route your image shallow and test it. If you are not happy with the results, you can re-machine the pattern deeper and retest.

My table auto homes accurately, and I have built a nice jig that the software knows all about, so repeatability is not a problem.. I am most concerned with breaking bits, melting plastic, etc...

Of course, once I cut out the outer profile, all bets are off.. But I could always cut a custom 'holder' for it... But I'd rather not go through all that...

So perhaps I'll try a real light pass first and see how it goes...

But I only have 'one' of the amana plastic bits, and they're expensive.. Already broke it once, and fortunately all the business end was still left so that I was able to still use it.. I don't want to ruin that bit..

Breaking bits sux... LOL

[DeadTom]

Here are a few of mine that I cut a couple a years ago for Christmas one for my youngest daughter for her wedding.

[ssutton]

Tom could you tell us about the base that you are using? Di you make them or buy them? Is it pre-lit with LEDs or how exactly did you light them, they are very cool.

Thanks,
Scott

[vtx1029]

I got some of these Acrylic Color Changing LED Light Plaque Decoration its hard to beat the price!

And cut some things for my son and nephew's for Christmas. I think it looked the best when I reversed the image and cut the back only. I just used a 60* v bit and cut it .015.

[DeadTom]

Tom could you tell us about the base that you are using? Di you make them or buy them? Is it pre-lit with LEDs or how exactly did you light them, they are very cool.

Thanks,
Scott

Scott,
The bases are made from oak, the slot was cut with my table saw. I then drilled a hole in the bottom and slotted for the cord to fit through. The led's are from the auto parts store, they come in various colors and can be cut to different lengths and they run on 12vdc so I made up some battery packs that will plug into the lights and if one so desired they can get a wall wart pack to operate them on AC.
the led's are then hot glued to the bottom of the slot and then some felt is added to the side of the slot to protect the acrylic that slides into the slot. So you can have one base and many different signs/plaques to put into the base.
I will post some pics tonight when I get back home.
Tom

[sirkossorg]

I posted a small gallery of engravings in the LazyCam forums if you want to see some others.

My only real advice is, don't go too deep. As previously mentioned, you probably want to reverse the image and engrave the back.

There are many ways to edge-light.

Have fun, and please post pics.

[Mountaincraft]

Here are a few of mine that I cut a couple a years ago for Christmas one for my youngest daughter for her wedding.

Nice..

What bits, feeds, speeds, and DOC did you use on them?

How thick was the acrylic?

[DeadTom]

Mountaincraft,
When I get home this evening I will pull up the files and list the bits, feeds, etc. for all to see what I used. I will also try to remember what also went wrong so as not to repeat the mistakes of melting the acrylic.
Tom

[Mountaincraft]

Mountaincraft,
When I get home this evening I will pull up the files and list the bits, feeds, etc. for all to see what I used. I will also try to remember what also went wrong so as not to repeat the mistakes of melting the acrylic.
Tom

That is what I'm trying to avoid.. Melting acrylic = broken bits...

[DeadTom]

I did not break any bits on the acrylic but I sure did melt some before I got the right combination of bit, feed and speed. A real pain to get off the bits and not to mention the waste of the acrylic.

[Mountaincraft]

Alright, so I got brave and tried it...

At first it was skipping places, so I deepened it, then again, and again for good measure..


I probably cut in about 25-30 thousandths...

I deepened it by changing the Z offset... So forgetting to change it back after the engraving, the sign started coming loose during the profile cut, so now I'm holding it in place with my hand while it finishes cutting the profile.. hence the chips on the edge (chair)

Anyways, a decent first try.. I may try a different bit next time, or at least a roughing area clearance bit....

I need to get some soft cloth to dry with after I wash it.. I think the tee shirt I used scratched it some.. Or brushing away some plastic while carving, may have scratched it.. I can figure all that out later...

Anyways, the speed on the engraving was good, the feed rate on the profile was a little slow, as it was starting to melt.. not bad, but enough to cause chips to stick to each other... So bumping the feed rate up from 100 IPM to say 125 IPM or maybe more will probably be good...

I'm happy enough with the first attempt, that I feel confident to order some more lighting stuff and start making some bases... A couple more test runs and I should be able to make something pretty hi-quality...

Anywho.. Here's my first attempt...

[DeadTom]

That looks just fine for your first attempt, it's all a learning experience but when you get the combination down for your machine it is so simple.
Keep up the good work.

[Mountaincraft]

I think I'll set the pocketing pattern to raster next time too..

[DeadTom]

What cam package are you using for your work?
I currently use MeshCam, Vectric's Cut2D and Vectric's Photo VCarve for all of my mechanical magic.