Litho Using Ballnose Bit

[davemartin88]

Based on some feedback and other posts, I bought a 1/16" ball nose bit and used it for the first time today on this lithopane. It's about 3"x6" and took about 3 hours to carve, had about 1100 lines. I've previously used an engraving bit and I think the ball nose gives a smoother finish. The puppy is "Sparky", a Shetland Sheep Dog that we fostered last year, he was really hard to let go and our entire family loved him a lot! I decided to leave some background in the picture although it was closely cropped.

[woody53]

Looks great , Dave. I use a 1/32 tapered ballnose on my litho's and always look good ( but time consuming, 8 hrs for a 5x7 with lost of detail.) . I have a couple of 1/16 ballnose, I need to try one. What are your other particulars ? I use 10 % stepover @ 100 inches a minute, .120 deep.

Dave (too)

[davemartin88]

Here's the setup from Photocarve. My feedrate is only 50 inches/minute but guess that is highly dependent on material and bit geometry. I'm using a Shark Black Diamond CNC with a Porter Cable 890 router- not sure how much I could increase the feed rate but since I only have one bit at this size, didn't want to push it. The feed rate certainly would make a dramatic difference in the carving time. I guess the step over is about 10% since it's a .0625 bit moving .006 inches between lines? Looks like it was 995 lines, thought it was closer to 1100 but looked okay. I got some feedback from Tony in another thread to shoot for options that result in about 1000 lines and that guidance has been very helpful working in this size range for carvings.

I'd be interested to see a comparison of a photo that was cut with a 1/16 versus a 1/32 bit. When I compare this carving to the original photo, it seems to me that I capture more than enough of the detail but may depend a lot on the actual photo? This was the first time I used the tapered ball nose, the other carvings I've done were with a 1/4" engraving bit- the main thing I noticed different under a magnifying glass was the smoothness of the surface. I have some friends that have seen these and want me to do a photo for them so really looking to get the right balance between carving detail and time to carve.



Thanks for the feedback, hope this is helpful.

[martin54]

Looks good Dave, had a look & compared Tony's settings from your other post with yours & his feed rate is double yours & spindle speed a bit faster at 16,000rpm.
Thing that stuck out the most though was that yours was 2 passes & Tony's is a single pass so looks like you could shave the time down quite a bit once you have played a bit more & honed your settings a bit. Makes it difficult to try & push it a bit when you only have one bit at that size doesn't it plus I hate breaking bits anyway the price some of them are lol.

Still haven't got round to trying one of these myself but enjoying watching others making progress.

[davemartin88]

My router as actually set at about 16000 rpm, the setting in the tool database wasn't update it when I added the bit. I may try upping the feed rate a bit as it really does make a big change. As for two passes, from watching during the carving, the amount of time the bit has to mak a second pass doesn't seem excessive but seems like a deeper allowed depth of cut would be possible. Given the small stepover, wouldn't be removing very much material? Might buy an extra bit first though.

Having said all this, I usually start the carving and then move on to other projects as I'm retired so not in any kind of production mode. Don't want this to turn in to work, lol!

[tonydude919]

Dave,

It turned out very nice. Just play around with settings to see what your machine is capable of and you'll come up with a basic starting carving and move up from there. Glad everything worked out good for you.

Tony

[pops1964]

Turned out very nice. What kind of 1/16 bit are you using I have a 1/8" that steps down to a 1/16"ball nose cutter . I quit using and stick with a 1/16" tapered ball nose a very sturdy bit I"ve run it at 21,000rpm for 12hrs on large lithos , but really works well at 16,000 I use this bit all the way down to small night lights. And with speeds from what your doing to Tony's numbers.

[davemartin88]

Thanks pops1964 for the information. The bit I have is an Amana, 1/4" shaft, 4 flutes, 1/16" ball nose, with a ZrN coating- it's a carbide cutter. Here's the one I have:

http://www.toolstoday.com/p-6225-solid- ... ords=46282

Will up the speed a bit on the next carving and see how it does, thanks for the feedback.

BTW, showed this one to the Sheltie Rescue group we work with and have been asked to do one of these for a raffle winner at our upcoming picnic- they would supply the photo of their own Sheltie- should be fun.

[Xxray]

I use a 1/16 bit for all my lithos.
If you elect to go 1 pass, which you should, use a 45 angle. Not sure at all what the dynamics or reason is for a 315 angle, but a 45 starts you off at the bottom tip of a corner so you easily work your way into the longer cuts, whereas if you started with 0 angle you would do a full horizontal line which just might stress out the bit and/or material.

[calgrdnr]

315 is still 45 degree cut .. just starts at x0 ,y0 if something happens right away you don't waste to much material

Cut the dog with 30 degree or 45 degree Vbit at setting of 0.031 will take twice as long but the resolution is fantastic...

Some lithophanes work great up to .125 bit and I am sure the larger the lithophane the larger the ball nose

Vbit used for the strength I cut 1 pass 0.21 deep no problems

45 on left 30 degree on right
https://www.flickr.com/photos/17611327@ ... 3vH-gLamvS

1/8 inch both lithophanes at least 10 in
https://www.flickr.com/photos/17611327@ ... 823140977/

https://www.flickr.com/photos/17611327@ ... 823140977/


1/16 - .0625 on left 30 degree set at .031 on the right ...

https://www.flickr.com/photos/17611327@ ... /lightbox/

[davemartin88]

calgrdnr- thanks for the photos, those are really nice!

Not sure exactly what setting you're talking about on the 30 or 45 degree bits? Where would I see the .031 measurement? The engraving bit I used originally had a 22.5 degree angle so would be similar to the 30 degree vbit I believe but not able to carve as quickly as a vbit? I don't have a 30 or 45 degree bit at this point.

[calgrdnr]

I use 30 degree V bit but lie to the software and assign it as a .031 ballnose
I have had success with same settings on liner bit

http://www.amazon.com/s/ref=nb_ss_?url= ... &x=9&y=20

https://www.centuriontools.com/router-b ... s&pid=363

http://forum.vectric.com/viewtopic.php? ... ighlight=

[calgrdnr]

Sorry links don't work above will try again ...


http://www.amazon.com/s/ref=nb_ss_?url= ... +&x=9&y=20


https://www.centuriontools.com/router-b ... ts&pid=363

http://forum.vectric.com/viewtopic.php? ... highlight=

[calgrdnr]

Fun way to display on web It is explained somewhere in the forum how to do it If I find I will post link look at image for at least 5 seconds

Birthday image. http://forum.vectric.com/download/file. ... &mode=view

Birthday Lithophane original post http://forum.vectric.com/viewtopic.php? ... gif#p54263

web site you can make gif's on http://gickr.com/

I used Photoshop many ways to do it . Google can be helpful sometimes

[davemartin88]

Thanks for the links and explanation.