What's new
What's new
By:
Advanced search…

SK or TG collets?

M

mort210

Plastic
Joined
Aug 30, 2011
Location
TX! USA
Which collet system is superior or am I comparing apples and oranges here? Looks like the SK system may be a tad better on run out but the design of the TG system looks more rigid for milling? Any collet system here anyone prefers for heavy milling over these two?
 
sk and tg are similar angles.... similar clamp forces. It comes down to what is made for your toolholder. In cat 40 you can get both... big plus cat may be different
 
Use an endmill holder. No other tool holder system will allow you to get as short gage length as a CAT40-EM.750-1.75. Its all about gage length. Even if rounout is a few tenths worse it makes no difference in a 3/4 or 1.0 end mill. But a few tenths better runout and gage length is 1.0 inch longer tool will not perform as well.
 
Yep, what frank said. Every single time I have ever had chatter issues, it could be solved with a side-lock holder.

Even better would be an integral-shank insert tool. Finish with an end-mill if needed.
 
mort210 said:
Which collet system is superior or am I comparing apples and oranges here? Looks like the SK system may be a tad better on run out but the design of the TG system looks more rigid for milling? Any collet system here anyone prefers for heavy milling over these two?
Click to expand...

.
most collet runout in my experience is a used collet gets rusty or dirty over time. hard to keep collet and matching taper on tool holder clean
.
hard to beat a set screw for holding a end mill. if they slide or move length wise they are limited by weldon shank. many a end mill roughing can easily start moving in collet tool holder it can be bad when they pull out of tool holder deep into part. i have seen even drill bits held with a set screw holder. drill bits with a weldon flat. they may move a little but cant move much length wise.
 
I have some Kennametal TG holders, but I'm not thrilled with them. Unlike ER or SK holders, the face of the collet is inset from the face of the nut, so you end up needing to stick the endmill out an extra 1/4" on a TG075 or 3/8" on a TG100.
 
DanielG said:
I have some Kennametal TG holders, but I'm not thrilled with them. Unlike ER or SK holders, the face of the collet is inset from the face of the nut, so you end up needing to stick the endmill out an extra 1/4" on a TG075 or 3/8" on a TG100.
Click to expand...

Just wanted to say, this isn't always the case. Seems like half of our TG100 nuts are like you say, recessed about 1/4 inch, but the other half have the collet about flush with the face of the nut. Depends on the manufacturer.
 
Yeah it definitely seems to be the consensus that end mill holders are about the most rigid. I was just more curious as to everyones opinions about the sk and tg collets. Thanks for the input!
 
This brings up another question. Since everyone loves end mill holders, and people tell me that 3/8" is often the best size for HSM toolpaths, why don't 3/8" endmills come with flats? 1/2" sometimes do depending on the manufacturer (the MariTool/HTC ones do), but I've never seen one stock on a 3/8".
 
Frank I agree on the endmill holders and gage length being the most important factor, I used to rip material with a stubby 3/4 cat 40 holder. Beat the crap out of a milling chuck all day.


Do you balance your end-mill holders on a cylindrical shank, weldon flat, or an average screw position between the two?
 
Most end mills can be ordered with flats for an extra $5 or so, usually with a 1 day lead time. Theoretically collets will have less runout than side locks. In the reality of my shop what I see when I indicate tools is about .0001" better than side locks with my best collets, which usually have .0002"-.0003" tir, all Maritool holders.

Frank, just wish your BT30 SK10 holders were shorter like some of your ER holders.
 
DanielG said:
This brings up another question. Since everyone loves end mill holders, and people tell me that 3/8" is often the best size for HSM toolpaths, why don't 3/8" endmills come with flats? 1/2" sometimes do depending on the manufacturer (the MariTool/HTC ones do), but I've never seen one stock on a 3/8".
Click to expand...

I just spent a few buck on a "green-wheel" and lick a small flat on by hand when i want to really lean on a tool in a side-lock.
I really need a diamond-wheel though, as that green-wheel is bouncy, and wearing quick.
Regardless, my spindles live @ 12k RPM, and I can not feel a difference in vibes between a collet, and home-brew flat in "good" side-lock.
No, I do not have a balancer. But, I do have good ears, and sensitive touch, LOL. And, my spindles seem to last a long time.
Even the one dip-shit crashed, that I thought would be dead a year ago, is still going.

BUT! For a 3/8" tool? I seriously doubt you will see a benefit going to a side-lock from an ER32 or TG75. 3/8" is tiny.
I go as fast as a HAAS super-speed will go with 3/8" S-carbs daily (2-300ipm all day long) in ER32, and they don"t make a peep, and last seemingly forever.

As a matter of fact, the S-carb I am running right now has filled over 40 55gal drums with 6061 chips, and still going strong, in an ER32.
 
Neither SX25 or TG100 collet systems are a good application for a 1" EM in 4140HT and 17-4 but it really depends on what you are doing with it and how much gauge length (for clearance) you need.

I would be in a side lock first then a shrink. Like Frank said, the gauge length is a killer. A short side lock always out performs a longer shrink.
 
wheelieking71 said:
I really need a diamond-wheel though, as that green-wheel is bouncy, and wearing quick.
Click to expand...

Little diamond thingy.. Dress it... AAAAANDDD..... NO bounce.


I've got one kind of like this, dig around, you can get 'em cheaper.

Hand Diamond Dresser Dressing Wheel Tool for Bench Grinding Grinder Wheel | eBay

I've never seen these before, anybody know if they dress a green wheel worth a shit??

US Diamond Grinding Disc Wheel Stone Dresser Tool Dressing Bench Grinder New | eBay
 
You must log in or register to reply here.

Similar threads

TAIWA NUMBA WAAN
Are milling chucks obsolete?
3 4 5
Replies
90
Views
8K
DouglasJRizzo
DouglasJRizzo
M
Wanted: Vertical Milling Head (Burke?)
Replies
1
Views
452
bobbyf
B
B
TREE Journeyman 250 mill
Replies
10
Views
963
Metalurgent
M
O
machine recommendation big VTL with milling
Replies
8
Views
1K
ondori
O
604Pook
Breaking 1/32 end mills in 6061-T6
2
Replies
24
Views
2K
rjwalker1973
rjwalker1973








 

ABOUT PRACTICAL MACHINIST

With more than 10.6 million unique visitors over the last year, Practical Machinist is the most visited site for metalworking professionals. Practical Machinist is the easiest way to learn new techniques, get answers quickly and discuss common challenges with your peers. Register for the world’s largest manufacturing technology forum for free today to stay in the know.

Learn more about us.

STAY CONNECTED

Facebook Instagram YouTube LinkedIn Pinterest Twitter Tiktok

Register Become a forum member. Register today.

Sign Up Sign up for our e-newsletter.

© 2024 Copyright Practicalmachinist.com. All Rights reserved.

Back
Top