Machining question for lynnmor

Pawnee

Well-known member

Equipment
L2501
Jul 1, 2021
340
286
63
Ontario Canada
I'm an amateur machinist.
Sometimes I need to find the center of a boss where I either don't want a mark in the center or it's too late to dimple it on the lathe.
In the attached pic I can use an edge finder to get one axis centered by using the jaw edges but in the other direction I'm not sure.
How would you do it?

Thanks,
Mike
IMGP0981.JPG
 

LostTrail

New member

Equipment
MX6000, LA1065
May 22, 2024
15
8
3
MT
What's the machine? Bridgeport (vertical) mill? When you reference using an edge finder, are you meaning one of the chuck loaded that has the spring end that 'pop' off center when spinning and bumping the piece? If so, once you find center of the jaws (Y-axis, I assume?), you could then raise the quill (Z-axis) and find center on the perpendicular (X-axis). Just a thought, not knowing what all your using.
 

InTheWoods

Active member
Premium Member

Equipment
B7510/FEL, B7100D, ZD18, ASK-R130
Nov 17, 2023
101
59
28
Indiana
I put a 'swing-down' stop on the left side of my Kurt vise. I can easily use my edge finder to locate the back vise jaw as you describe, and them similarly locate the inside edge of the stop. Then the work goes in pushed against the stop as I tighten the vise.
 
  • Love
Reactions: 1 user

Sidekick

Active member

Equipment
RTV-X, BX3260, Z726XKW-3-60, Deere 4100
Jul 29, 2023
275
220
43
N.Y,
I put the round in a collet if it's under an inch and a collet block on the bottom for clamping in the vice. Then move the vice until the square block kisses the fixed jaw then lower into the vice and clamp. Loosen the collet and replace with a drill chuck.
 

barts

Member

Equipment
4wd B5100, FEL with Piranaha bar, box blade, log arch, 3 point hitch adaptor
I bought a co-ax indicator on sale, but there are a lot of ways to do this. Blondihacks goes through a bunch of them here:

She does a great job on these videos; clear, calm and focused.
 
  • Like
Reactions: 1 user

Pawnee

Well-known member

Equipment
L2501
Jul 1, 2021
340
286
63
Ontario Canada
What's the machine? Bridgeport (vertical) mill? When you reference using an edge finder, are you meaning one of the chuck loaded that has the spring end that 'pop' off center when spinning and bumping the piece? If so, once you find center of the jaws (Y-axis, I assume?), you could then raise the quill (Z-axis) and find center on the perpendicular (X-axis). Just a thought, not knowing what all your using.
It's a knee mill, Bridgeport style but Chinese.
Yes I use that kind of edge finder.
It doesn't work on a curved surface.
 

Pawnee

Well-known member

Equipment
L2501
Jul 1, 2021
340
286
63
Ontario Canada
I put a 'swing-down' stop on the left side of my Kurt vise. I can easily use my edge finder to locate the back vise jaw as you describe, and them similarly locate the inside edge of the stop. Then the work goes in pushed against the stop as I tighten the vise.
I don't have a Kurt but I'm certainly jealous.
i like your stop but I can't always have the work pressed against it, the rod was just an example.
 
  • Like
Reactions: 1 user

Pawnee

Well-known member

Equipment
L2501
Jul 1, 2021
340
286
63
Ontario Canada
I put the round in a collet if it's under an inch and a collet block on the bottom for clamping in the vice. Then move the vice until the square block kisses the fixed jaw then lower into the vice and clamp. Loosen the collet and replace with a drill chuck.
I've done similar but don't have a collet block. That would work in this case but it's just an example, I don't always have a rod to find center of.
 

Pawnee

Well-known member

Equipment
L2501
Jul 1, 2021
340
286
63
Ontario Canada
Thanks for the replies guys.
Wow, Blondi has come a long way, I haven't watched for quite a while. She has better equipment now and has learned a lot.
 

lynnmor

Well-known member

Equipment
B2601-1
May 3, 2021
1,381
1,086
113
Red Lion
I would mount an indicator in the spindle and swing it in similar to what Blondi did at approximately 9:40. Of course she had way too much problem since she can't divide by two. Hopefully you have an indicator so you can tram the milling machine head in and indicate the vise.
 

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
7,633
3,801
113
Myersville, MD
windyridgefarm.us
I'm an amateur machinist.
Sometimes I need to find the center of a boss where I either don't want a mark in the center or it's too late to dimple it on the lathe.
In the attached pic I can use an edge finder to get one axis centered by using the jaw edges but in the other direction I'm not sure.
How would you do it?

Thanks,
Mike View attachment 131641
With the sàme edge finder used to index the jaw on the vise.

if you dont already have one invest in one of these - they make things a LOT easier and faster. You can get a cheap one for half the cost of that the Fowler and probably just as good.


Dan
 

BXHoosier

Well-known member

Equipment
BX24
Jan 21, 2018
465
524
93
Indiana
If you don’t have an indicator, put a square against the back jaw and slide it against the side of the pin and pick up the square blade with the edge finder and move over half the diameter.
 

Bugzilla46310

Active member

Equipment
2022 BX2680 198? AC 916H
May 22, 2022
138
142
43
Demotte, IN
If you are wanting to find the center of a circular shape, the center finder, v shaped item, is what you need. Scribe 2 lines, where they cross is the center.

1720525130836.jpeg
 

Pawnee

Well-known member

Equipment
L2501
Jul 1, 2021
340
286
63
Ontario Canada
If you don’t have an indicator, put a square against the back jaw and slide it against the side of the pin and pick up the square blade with the edge finder and move over half the diameter.
I had not thought of that, it works well, thanks.

Also, I've got an optical/audible edge finder on order from China. I'll see how it works on a radius - Thanks Dan
 

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
7,633
3,801
113
Myersville, MD
windyridgefarm.us
I had not thought of that, it works well, thanks.

Also, I've got an optical/audible edge finder on order from China. I'll see how it works on a radius - Thanks Dan
You are welcome. If you expect to do a lot of this (I do) invest in a cheap (or high dollar) 3 jaw and clamp it to the table like this.

For initial setup you can quickly center it using a piece of round stock mounted in the spinde as shown. Set the chuck on the table, run the jaws in on the piece of stock and the chuck will self center. Then clamp it down to the table and zero your readout/dials. Its fast and GI proof. I keep that piece of 1" TGP round bar mounted in that collet chuck for just this purpose.

Using that work holding scheme you can chuck up round workpieces one after another with no further setup.

Dan
 

Attachments

  • Like
Reactions: 1 user

Pawnee

Well-known member

Equipment
L2501
Jul 1, 2021
340
286
63
Ontario Canada
Well, I got the electronic edge finder, it's enormous! I knew it had a 20mm shank but didn't realize the overall size. It needs 3V to work properly, an AA fits Ok but then only the audio works, no light. I'll cobble up something with 2 button batteries. I also have to make a sleeve for the 7/8" collet or buy a 20mm.

Record shipping from China, 8 days.
 

Attachments

  • Like
Reactions: 1 user

Sidekick

Active member

Equipment
RTV-X, BX3260, Z726XKW-3-60, Deere 4100
Jul 29, 2023
275
220
43
N.Y,
Well, I got the electronic edge finder, it's enormous! I knew it had a 20mm shank but didn't realize the overall size. It needs 3V to work properly, an AA fits Ok but then only the audio works, no light. I'll cobble up something with 2 button batteries. I also have to make a sleeve for the 7/8" collet or buy a 20mm.

Record shipping from China, 8 days.
I tried one of them a couple years ago and it was off by .0004 when verified on a CMM. Mine was .500 diameter and took AAA batteries. They do make it easy.