• We want to encourage those of you who ENJOY our site and find it USEFUL to DONATE and UPGRADE your membership from active member to donating or premium membership. If you want to know the differences in membership benefits, please visit THIS PAGE:

    https://www.hobby-machinist.com/premium/

    Donating memberships start at just $10 per year. These memberships are in fact donations that help pay our costs, and keep our site running!
    Thank you for your donation, God Bless You

  • As some of you know, I have wanted to stop managing H-M for some time. It's a tremendous strain on my personal life. I want to set up my own shop. In September, September 15, to be exact, it will be 8 years that Hobby-Machinist has been in existence.

    I have been training VTCNC to run things here. Dabbler is going to learn too. I feel that they are ready to start taking over the operation. I will be here to help in case they need, but I don't think they will. Tony Wells is and will be here also to consult with. I will be doing backups, upgrades, and installing addons. Other than that, I will not be around. I am leaving this place in good operating condition, and financial condition.
    --Nelson
[4]

Why I get these Lines on my Cuts?

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

oskar

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Nov 24, 2013
Messages
123
Likes
46
#1
Just finished my first project on my mini Taig Lathe but in all my cuts I get these lines as shown on the picture. Rubbing my finger on the surface I don’t feel anything, surface is smooth, but I was expecting a uniform looking surface.

The cuts are made with a 1/4” end mill and each pass is about 1/32” to 1/64” at very low feed rate
 

Attachments

markba633csi

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Apr 30, 2015
Messages
2,651
Likes
1,373
#2
Those are perfectly normal "beauty lines"- the surface is not perfectly smooth at the microscopic level
Mark
 

darkzero

Global Moderator
Staff member
H-M Supporter - Gold Member ($25)
Joined
Nov 27, 2012
Messages
3,028
Likes
1,878
#3
That is known as tooling marks. There are ways to improve surface finish but tooling marks will always be present. Even on high quality CNC machines you will still get tooling marks. To get rid of them (or should I say minimize) you'd have to tumble, surface grind, sand, polish, etc.
 

Ray C

H-M Supporter - Sustaining Member
Staff member
H-M Platinum Supporter ($50)
Joined
Nov 16, 2012
Messages
5,215
Likes
1,403
#4
Good question Oskar!

BTW, you get the same tooling marks on a lathe but they're harder to see. On a lathe, the tooling mark is a single line that makes spirals all the way around the part. No matter how fine the Inch Per Revolution setting is, the line is always there. When held in the correct angle, you get the same rainbow effect that you see on a milled part.

Ray
 

chips&more

Active User
Registered
Joined
Mar 19, 2014
Messages
2,426
Likes
1,741
#5
I know a few machine shops that no longer need to grind any of their lathe parts if surface finish is critical. They can turn it just as good maybe better than grinding it.
 

mikey

Active User
H-M Supporter - Gold Member ($25)
Joined
Dec 20, 2012
Messages
4,008
Likes
4,312
#6
That is known as tooling marks. There are ways to improve surface finish but tooling marks will always be present. Even on high quality CNC machines you will still get tooling marks. To get rid of them (or should I say minimize) you'd have to tumble, surface grind, sand, polish, etc.
+1. If you want it to have a uniform finish right off the mill, fly cut it.
 

dlane

Active User
H-M Supporter - Gold Member ($25)
Joined
Sep 27, 2014
Messages
2,901
Likes
1,353
#7
Bead blast then away
 

oskar

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Nov 24, 2013
Messages
123
Likes
46
#8
Now I know what “beauty marks / tooling lines” are. They don’t bother me so no problem here. I thought I was doing something wrong.
Thanks
 

machinejack

Registered
Registered
Joined
Mar 27, 2014
Messages
52
Likes
40
#9
My first part for NASA at my new job was a bracket for the space station. I worked hard at polishing the tool marks out made it look perfect. Boss comes by later and says nice job on that part BUT they want the tool marks left on. Go figure that one out. I personally like fine tool marks they show a bit of skill of quality of work when they are uniform. You would not be leave how many grades of aluminum for different components that is required. All work carried a packet of certification papers that follow the parts around the shop.
 

T Bredehoft

Active User
H-M Supporter - Gold Member ($25)
Joined
Dec 27, 2014
Messages
2,588
Likes
1,992
#10
as shown on the picture
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.
 

Janderso

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Mar 26, 2018
Messages
546
Likes
289
#11
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

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Nov 24, 2013
Messages
123
Likes
46
#12
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

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Apr 4, 2017
Messages
99
Likes
68
#13
I for one like the tool marks left on some projects, it leaves a nice pattern.
 

T Bredehoft

Active User
H-M Supporter - Gold Member ($25)
Joined
Dec 27, 2014
Messages
2,588
Likes
1,992
#14
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

Swarf
Registered
Joined
Jun 5, 2013
Messages
19
Likes
6
#15
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

Global Moderator
Staff member
Registered
Joined
Apr 23, 2011
Messages
1,967
Likes
423
#16
....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
 

GinStC

Registered
Registered
Joined
Aug 29, 2017
Messages
56
Likes
34
#17
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

Registered
Registered
Joined
Apr 17, 2018
Messages
184
Likes
108
#18
If you don't like mark use cutters with rounded edge.
 
[6]
[5] [7]
Top