Fun with fragile 1/32″ bits

Carvey is a really powerful machine, I’d say, but not so smart though.

For this project, we were tasked to CNC mill nice figures with Carvey. Everything was pretty easy before the actual cut. The Detailed Preview feature is one thing that I like best about the entire experience. Being able to see your cuts before actually cutting help a lot in modifying your ideas. For instance, 0.02″ cut is a good enough  depth for most of the projects. Cuts over 1/4″ are just a waste of time and normally entail higher risk of breaking the bit. Don’t ask how I know it : )

One thing I wish Easel could improve is that it would be really helpful if I can group paths together. It wasted me a lot of time selecting everything I wanted.

Cutting was the most challenging part. Due to the details I had on my design, only a bit smaller than 1/32″ would work, but Easel does not have settings with 1/32″ bits. And here came the fun time. Initially, I lowered every rate by 4 units from the recommended settings for 1/16″ bits. And apparently, I was too naive. The bit broke half way. It some how makes me feel “better” to see an entire set of broken bits … We really should post recommended settings for those tinny bits.

Oh, by the way, don’t drop any bit thinner than 1/16″ on the ground….

So what I found is that there is a setting you can use to change the feed-rate at any point during your cut

And this was the final feed-rate I ended up using, and as I broke the 1/32″ bit, I was using a 0.025″ bit. How I decided on this rate was that I kept monitoring the bit as it cut and I lowered the rate as soon as there’s any abnormality.

If you are careful enough, you can notice that the bit was as little bent under this feedrate (9 in./min), and it started to perform perfectly fine after I changed it to 7 in./min. (It did took a much longer time to finish). I initially thought I could finish in an hour, 1.5 hr max as I estimated from the time estimation on Easel. However, it took 3 hours, 3 hours, 3 hours! And not surprisingly, I ended up sleeping in OEDK again. I did find a more comfortable way to sleep tough, that was a very useful lesson: the bean bags work much better than the couch.

After that, it was just post-processing wood. Carvey gives a lot of wood splinters, and they are hard to remove with sanding. So I used a carving knife, it worked really really well, the wood got cut like a piece of paper. P.S. Paint brushes work really well when you try to remove the sanded wood dust.

When I was using the belt sanding machine, I accidentally sanded too much and got an angled edge on the right side. As it forced me to make modifications, I actually got a better design.

Using the table saw and sand papers, I got what I wanted.

And as always, wood-protection oil! This time I used Tung oil, and to reach down to the deeper cuts, I used a small pipe brush. They also worked pretty well when I lubricated my mid-term project.

And this is my final product

Easel Project link:  http://easel.inventables.com/projects/9HAdCciual0zLsgHc_NWXQ

 

Print Friendly, PDF & Email