• 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
  • June Project of the Month (Click "x" at right to dismiss)
[4]

Boring bar holder

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

chips&more

Active User
Active Member
Joined
Mar 19, 2014
Messages
2,426
Likes
1,739
#2
Looks like a good project, go for it! And show us your pictures, we love pictures...Dave
 

mickri

Active Member
Active Member
Joined
Oct 31, 2016
Messages
173
Likes
93
#3
I am in the middle of making a norman style qctp. So I probably won't make this exact holder. What caught my interest was mounting the holder on the compound in the position that the holder would be used and then drilling the hole for the boring bar with the drill held in a 3 jaw chuck. Doing this would have the boring bar centered with no need for shims. I thought that was a good idea.
 

mikey

Active User
H-M Supporter-Premium Member
Joined
Dec 20, 2012
Messages
3,937
Likes
4,199
#4
What caught my interest was mounting the holder on the compound in the position that the holder would be used and then drilling the hole for the boring bar with the drill held in a 3 jaw chuck. Doing this would have the boring bar centered with no need for shims. I thought that was a good idea.
If the holder is a stand alone holder that bolts to the cross slide then drilling the bar hole this way is not ideal. Tangential forces will push the tip of the cutter down on contact, thereby reducing relief under the cutting edge and causing the tool to rub. You would then need to shim the holder up by 0.005" to 0.010" before using it.

If you make a holder for use with a QCTP then it might work.
 

Rooster

H-M Supporter - Premium Member
H-M Supporter-Premium Member
Joined
Apr 4, 2017
Messages
86
Likes
63
#5
Greetings, the last tool post i made is very similar to the one your referring too. I drilled it the same way and with the flats on the boring bar it puts the cutting edge on dead center, works great. DSCN1352.JPG
 

mikey

Active User
H-M Supporter-Premium Member
Joined
Dec 20, 2012
Messages
3,937
Likes
4,199
#6
Okay, I tried.
 
[6]
[5] [7]
Top