Well I received my 2 flute mills and decided to take the plunge at cutting aluminum. Since I am currently limited to a spindle speed of 5000 there was a bunch of experimenting with feed rates and depth of cuts. I eventually got things to work somewhat and took a whack at it.
I did learn a couple of things. First, make sure to not get too lazy and be judicial at removing the cutting chips. Second, don’t use a backer piece that has a sticky protective coating. This is especially true when using a 1/32 end mill. You probably guessed what happened. I went to get something and when I came back things didn’t quite sound right. There was the machine happily cutting air due to the fact that the mill had snapped off. I regrouped, figured out where I had screwed up and the second time through went without a hitch.
My project was a face rendition of a BBS rim with a diameter of right around 5/8th inch. It’s a little rough, but I think it came out OK for a first attempt. The code wound up having 3 tool changes and included pocketing, drilling and profiling. If I were to actually make some “working rims” I would machine up some blanks on one of my lathes (Unimat 3 for little stuff, an old Atlas for medium and the Logan for big stuff). Then I would CNC the spokes into the blanks.
Here is a photo of the freshly cut practice piece.
Thanks for the kind words.
Yes, I am thinking about both slot cars and RC as well.
Just playing around with the concept. I could either purchase solid blank rims or make up my own. Then perform a little cncing on them to come up with something different....
Thanks for giving details on this, I am building a CNC 3 axis that is similar in size and construction to a Zen toolworks 12" and I plan to use it for aluminum. If you don't mind, what kind of RPM and feed rate ended up working out for you, and with what size end mill?
Sorry for the delay at getting back to you.
I seem to be more into projects than scoping out the forums.
Latest is a pendant kit that is almost done. No more goofy positions.
Anyway, on cutting aluminum my little machine does have issues. There just is not enough rigidity to the unit and one will get lots of chatter. I have had success on thinner aluminum running a .0625 bit at around 7K with a feed rate of around 6. The thickness being like .032 on the aluminum. I have tried cutting half inch and I get too much chatter. I vary the rpm clear up to 10K and move the feed rate all around, but still have not found the magic combination. One thing I still have to try is to cut a clearance path outside of the main one. Thinking on this is you give your cuttings somewhere to go and you help keep the bit from binding up some especially on the corners.
Unit works great with wood, plastic, phenolic, thin aluminum and brass.
That looks great CanAM1! I've been looking at getting the Zen but probably the 7x7 to start but I do want to eventually mill a bit of aluminum and have heard that rigidity is an issue.
What spindle did you use and did you have to strengthen your Zen? The spindle for the Zen seems so quiet but it's currently out of stock so I'm hesitant to buy my first machine when I'm sure all the support is for the spindle they sell. Any thoughts?
I think the complete packages still have the spindle available. You can ask Xin through the customer support.
The kind of spindle does not have anything to do with the support of the machine. The normal DIY kit does not come with a spindle, only a tool plate to mount one. Some use a Dremel, others use the ZTW spindle or another brand. As long as it can mount onto the tool plate and not too heavy, any spindle will work
Thanks for the kudoos.
The Zen machines are great for learning the CNC process. Rigidity is the main issue when cutting metals with these machines. My setup has the Zen spindle on it, but I did pickup a 0-50 volt power supply to power it. The stock chuck that comes with the spindle kit I replaced with a Jacobs. Other than that my machine is stock. I have done a ton of measuring and tweaking to get the accuracy better.
I have had great success on thin metals such as .032 brass and .125 aluminum. The trick here is to slow the feeds down and crank up the spindle speed. I have tried cutting .5 aluminum and the chatter is terrible. The poor little machine is just not heavy enough to support normal milling of the thicker metal. I have not given up and will continue to see if I can find some happy medium for the thicker stuff. I am sure it will have slow speeds in the process when and if I do find it.
Cal is right from the standpoint of any motor that is not too heavy can be adapted to mount on the Zen. I would say that one with a collet type chuck would be more accurate from the get-go.
Can the 7x7 and/or the 12x12 cut 360 Brass/free machining brass and copper?
Such as in blocks like the size of 1-2-3 blocks?