Why I get these Lines on my Cuts?

[Janderso]

Wait a minute. What speed are you running for the diameter of your tool?
The last pass depth?
A good quality, sharp 4 flute end mill at the right speed on aluminum produces dang near a mirror finish on my Bridgeport.
By the way, nice job!

 

[oskar]

You are to be complemented on building your own tool holder for a Taig Lathe. I started out doing Hobby Work on a Taig lathe set up for milling and it's fun, but a very lot of work.

Thanks for the compliment and indeed it was a lot of work to make the tool holder (BTW it was a video / drawings I was following) but to my opinion the only way to learn, that’s to follow a project.

Regarding the speed I’m running I have a VS Sherline DC motor and I selected a speed which was comfortable to my beginner’s skills. Perhaps wrong but I don’t like to have the spindle running too fast right now. I would guess I was at about 1K RPM and the end mill is new 4 flute

 

[Rooster]

I for one like the tool marks left on some projects, it leaves a nice pattern.

 

[T Bredehoft]

I would guess I was at about 1K RPM and the end mill is new 4 flute

1/4" tool in steel (drill or mill) should run at 900, in aluminum 3 or 4,000 should do well. I learned that 1/4-900 figure abut 40 years ago, it stuck with me.

 

[Charcole]

Change in tool pressure. Tools don't really cut. Look at the shiney side then look at the backside. The backside tells the story.The material is nearly molten. Very little is actually being cut.

I would take a indicator to the surface and measure for ridges. Just because you do not feel anything doesn't mean the tool isn't deflecting.

 

[12bolts]

....Tools don't really cut. Look at the shiney side then look at the backside. The backside tells the story.The material is nearly molten. Very little is actually being cut......

What do tools do to remove material if they "dont really" cut? I'm at a loss here. Could you expand on this?

Cheers Phil

 

[Mystery1]

Great result for a first project.

Surprisingly, end mills are not generally intended to be used as you did. They work best by using the sides of the cutter. Depending on how rigid the machine is you will still get artifacts from the cutting operation.

Rubbing the part on some sandpaper (wet & dry) or emery cloth with some oil will get rid of the marks. Also using some WD40 as cutting fluid (for aluminum) helps the cutter do its work.

 

[KBeitz]

If you don't like mark use cutters with rounded edge.