[4]

Boring head.

  • Thread starter Deleted member 43972
  • Start date
[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!
D

Deleted member 43972

Guest - Please Register!
Guest - Please Register!
#1
Okay, now I'm just peeved off... This is just right silly.

I got a boring head for Christmas with the matching 1/2" boring bars.
The gosh forsaken boring head is a a right hand threaded attachment to the arbor. Okay, fine. I modified an arbor to thread on. Done, perfect. Go grab a boring bar, fresh from the package, wipe the gobbity-goop off, spend 20 mins touching up the grind, toss her in, "ooh wow, no deburring to speak of", I say aloud. Fine, I'll deal with that.

The Gat-Darn, McFreaking, SOB, boring bars want to be turned counter clockwise in the side holes.... With a right handed threaded arbor attachment... it'll just spin right ofd the second I touch the work...

I'm trying to cut a concave gullet in the side of a surface guage base. Thought, what a perfect time to whip out this new boring head.

For Chris Snakes....


Edited *not edited* for language. I assure you, my garage was not PG-13 just now...

Just a long line of dissapointments today.
IMG_20180204_222440.jpg
 
Last edited by a moderator:
D

Deleted member 43972

Guest - Please Register!
Guest - Please Register!
#2
I guess I'll turn the bar and bore up instead of down... But cooome onnnnnn....
 

Technical Ted

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Nov 5, 2016
Messages
645
Likes
614
#3
Yeah, with that bar probably you'll end up turning the bar 180 degrees and bore from the bottom up instead of the top down. There's more than one way to skin a cat!

Those bar are better suited to be used in the end holes when boring straight down.

Ted
 

bluechips

Active Member
Registered
Joined
Dec 19, 2017
Messages
44
Likes
17
#4
How about a little thread locker on the mounting threads.
 

mikey

Active User
H-M Supporter - Gold Member ($25)
Joined
Dec 20, 2012
Messages
4,381
Likes
4,742
#5
Shawn, you need a left hand bar to use in the horizontal position of a boring head, with the tip on the other side of the head. Sorry you had such a bad day.
 

Chipper5783

Active User
H-M Supporter - Gold Member ($25)
Joined
Sep 25, 2014
Messages
724
Likes
558
#6
I guess I'll turn the bar and bore up instead of down... But cooome onnnnnn....
Sure. Figuring out how to get the task done with the tooling and equipment that you have is called "machining". It really does not matter how well your shop is set up, or how extensive a tooling collection you have - eventually (frequently) a job/operation will come along that you don't have the ideal arrangement for completing.

Machining is just another of those things which provide one the opportunity to practice & develop patience. If that is the sort of thing that gets you all torque'd up - then I predict you will have opportunity to grow your patience.
 
D

Deleted member 43972

Guest - Please Register!
Guest - Please Register!
#7
Yeahhh I know. It was just one of those things...

In hind sight, I should have just taken the time set this up on the rotary table and used an end mill. This 1/2 boring bar is singing like a convict in the interrogation room begging for a plea bargon!
 
D

Deleted member 43972

Guest - Please Register!
Guest - Please Register!
#8
Oh. Well. I'd that wasn't enough, the 2hp motor on the head just blew up in a cloud of smoke... The capacitor blew. And there may be something wrong with the drum switch too.
In the panic, I turned the motor off.... It kept running. So I pulled the disconnect beside the mill... Let that be a lesson... ALWAYS have another means to disconnect all phases as close to the device as possible. Don't rely on a breaker however far away... I let the motor stop, turned the drum switch off, plugged the disconnect back in, and it hums. It'll start when I turn the switch on, but loud humming... Pulled the disconnect....

I'm going to bed. This sounds like a job for tomorrow Shawn....
Good night world! Thanks, and screw you.
 

bfd

H-M Supporter - Gold Member
Staff member
H-M Supporter - Gold Member ($25)
Joined
Sep 9, 2016
Messages
421
Likes
245
#9
pin the adapter to the head. go right thru the threads along the axis of the threads once it locks together it will not unscrew . bill
 

cathead

CATWERKS LTD
Registered
Joined
Feb 7, 2013
Messages
928
Likes
1,109
#10
I had the same dilemma so started making my own boring bars with carbide tips. That way you can orient the
cutter in the configuration to your liking. I have been using some scraps of H-13 material and adding some weld
for a place to hold the carbide. The carbides can be silver soldered on quite easily with a gas torch. For bolted on
carbides, I use a softer material than the H-13 as it has an extremely hard surface and makes threading an arduous task.
Most new boring bars need to be fine tuned anyway so one might as well make his own.
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,451
Likes
1,829
#11
A note regarding the use of harder stronger materials for such things as boring bars; it makes no difference in ridgidity using alloy steels, hardened or not, all steels have very nearly the same modulus of elasticity; a full hardened alloy steel is no stiffer than soft mild steel. The only way to increase stiffness to the diameter (in this case). As an example, increasing a boring bar or arbor from 1" to 1-1/4" diameter increases its stiffness by a factor of 5.
The job shown is clearly not a job for a boring bar of the type shown. One writer suggested pinning the threads to prevent the head from threading off; this would be next to impossible, as the boring heads are quite hard, besides which, I would suspect that the threaded part would be inaccessable for drilling.
 
D

Deleted member 43972

Guest - Please Register!
Guest - Please Register!
#12
The threaded portion of the head and arbor is quite short. Only about 1/4"-3/8" worth of engagement. Drilling a hole and pinning it could quite possibly weaken the structure too. I ran the bit in reverse from the bottom up for this operation. I got the job done. I realize none of this is designed for this operation, especially with cheap tooling.
The alternative would have been to take the time and set up the rotary table. But I saw a short video Tom Lipton did where he did the same thing. Albiet, a MUCH better mill and boring head.
 
Last edited by a moderator:

petertha

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Jan 15, 2016
Messages
590
Likes
399
#13
Even in upright mode, I've had good success with using insert style boring bars in the head. I turn the (16mm) OD shanks down to 0.500" bboring head hole & mill a flat for the setscrew. Just get your self a lefty, they are a whopping $10 on AliExpress.
 

Attachments

Tozguy

Active User
H-M Supporter - Gold Member ($25)
Joined
Feb 15, 2013
Messages
1,712
Likes
1,118
#14
Put a set screw in mine, no problem drilling or tapping the boring head. I do not intend to rely on the set screw however if it can be avoided. It is better to run the boring head CW with the right tools.
 

Attachments

Last edited:

petertha

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Jan 15, 2016
Messages
590
Likes
399
#15
Or, can you raise your work off the mill table with sufficient clearance, turn the boring bar 180-deg to how the picture is shown & cut from bottom to top in the conventional direction?
 

KBeitz

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Apr 17, 2018
Messages
395
Likes
196
#16
Quote....full hardened alloy steel is no stiffer than soft mild steel .

I beg to differ... Pump shafting of the same size is much stiffer than
most other steels.
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,451
Likes
1,829
#17
Quote....full hardened alloy steel is no stiffer than soft mild steel .

I beg to differ... Pump shafting of the same size is much stiffer than
most other steels.
You are quite mistaken; do some research on modulus of elasticity, I got it from "Tool Steel Simplified" and had it confirmed by a professional mechanical engineer. Increased modulus comes only with change in material, such as carbide. The modulus varies with alloys of steel by only a tiny insignificant amount.
 

Chipper5783

Active User
H-M Supporter - Gold Member ($25)
Joined
Sep 25, 2014
Messages
724
Likes
558
#18
I am one of those "professional mechanical engineers" and I would side with Ben. Hardened steel tools are nice, they don't get beat up as much, they would typically be professionally made, everything fitting nice and looking good - but they are not any stiffer. I have a number of mystery metal boring bars, that are not hardened and of magnetic material which will rust. They work fine.

Now a solid carbide bar - that's a game changer! It has a significantly higher modulus of elasticity, and you can really tell. It is crazy what you can tackle with a solid carbide bars. David
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,451
Likes
1,829
#19
I am one of those "professional mechanical engineers" and I would side with Ben. Hardened steel tools are nice, they don't get beat up as much, they would typically be professionally made, everything fitting nice and looking good - but they are not any stiffer. I have a number of mystery metal boring bars, that are not hardened and of magnetic material which will rust. They work fine.

Now a solid carbide bar - that's a game changer! It has a significantly higher modulus of elasticity, and you can really tell. It is crazy what you can tackle with a solid carbide bars. David
I seem to remember that carbide has something like 3 or 5X the modulus, is that right? HSS or any steel boring bars are limited to about 5 times the diameter to overhang to work with effectiveness; carbide extends that limit greatly.
 
F

f350ca

Guest - Please Register!
Guest - Please Register!
#20
I agree on the modulus of elasticity for any steel, but lower strength steels will bend due to the lower yield strength. Hopefully your never reaching that point on a boring bar though.

Greg
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,451
Likes
1,829
#21
Yes, steels whether hard or soft bend equally until the elastic limit is reached, at that point, the soft steel will take a permanent bend, where the hard steel will spring back, and yes, this has nothing to do with boring bars.
 

Silverbullet

Gold
Registered
Joined
May 4, 2015
Messages
3,419
Likes
1,665
#22
I know it would take time but he could have made a boring bar and used a carbide lathe tool bit.
 
[6]
[5] [7]
Top