Adventure With a 4-Jaw Chuck

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Nyala said:
My thanks to all for your quick response and suggestions. I posted here because I didn't want this thing to beat me but I seemed to be at a dead end.

I started watching Blondihacks videos about 2 years ago. She was very interesting but lately she seems to be on a kick of making models. I don't do models or work in miniatures. I'm not that skilled. As a result I unsubscribed from her channel. She is currently on Episode 34 of a model build. Same with Joe Pie. Too many models. I'll go back and watch her earlier videos.

Abom79 has become a walking commercial for everything from factory sized CNC machines to spray cans of cutting oil, and everything in between. I think that he has become geared for professional machinists than a hobby guy like me. Unsubscribed.

I'll continue to search around for additional help but you all have given me a start to help me conquer this thing. Thank you all for your time and efforts.

Denny
Click to expand...
Best thing to do is just walk away for a bit.
I had my 4 jaw chuck gifted to me ( Thank You!!!) for over a year.
I had t learn how to make adapter plate , hole lay out , making custom transfer punches . What took a long time was getting the material !!
Thats expensive and frustrating to find also!


adjusting a 4 jaw is not hard. Its just frustrating but I assure you with a little time it goes quickly.

This video pretty much got to me to the “ah ha “ moment .
 
Nyala said:
My thanks to all for your quick response and suggestions. I posted here because I didn't want this thing to beat me but I seemed to be at a dead end.

I started watching Blondihacks videos about 2 years ago. She was very interesting but lately she seems to be on a kick of making models. I don't do models or work in miniatures. I'm not that skilled. As a result I unsubscribed from her channel. She is currently on Episode 34 of a model build. Same with Joe Pie. Too many models. I'll go back and watch her earlier videos.

Abom79 has become a walking commercial for everything from factory sized CNC machines to spray cans of cutting oil, and everything in between. I think that he has become geared for professional machinists than a hobby guy like me. Unsubscribed.

I'll continue to search around for additional help but you all have given me a start to help me conquer this thing. Thank you all for your time and efforts.

Denny
Click to expand...
I hear what your saying about the you tube videos. Those you mentioned are heavily invested in trying to monetize their videos. So they need constant content.
Although not always easy to watch you can pick up methods tips and tricks watching them make a model steam engine.
I just gloss over anything that is long winded. I also play with you tube search feature to find less popular videos .
I like Mr pete , joe pie, TOT , and several others. I pick up tid bits and eventually piece them all together.
 
I do a coarse alignment using the jaws as center indicators. With the chuck rotated so one jaw points straight up, I roughly center the work front-to back relative to that jaw, then close the front/back jaws to hold the work in place. Rotate the chuck 90 degrees and do the same thing. It can be difficult to figure out what you need to adjust If your dial indicator executes several complete rotations as you rotate the work, so the rough alignment helps there.

Also, if the indicator stops moving that means it's not touching the work. You can adjust the jaws to bring the work back toward the indicator stem, yet another rough alignment scheme.

Don't forget that if the DI needle moves "X" amount when rotating the chuck 180 degrees you need to adjust the jaws so the movement is reduced to no less than X/2. Correcting too aggressively is what leads to the chasing-your-tail chain of adjustments.

Using chuck keys on opposite jaws can make it easier to make adjustments in a controllable manner. I made one with a longer-than-standard stem because I kept bumping into the dial indicator when it was close to the chuck, and knocking it out of kilter.
 
I didn't read all the responses so this may have been covered already.

First thing is you need to learn what your indicator is telling you.

Place your indicator where it is easy to read between you and your part. Slowly push on the tip and note which way the needle is moving.

If that was your part that moved the needle it would be high, or closer to you.

The first thing I did was label each jaw with a felt tip pin.

I do my rough in by measuring how much jaw is sticking out from the chuck. I do this rougly with my finger and try and get them the same. You can use a rule of some sort of you want to get it close.
Then i move to the indicator.

Mount the dial indicator so that when you take a reading it is in line with a jaw, say jaw 1, pre-load it say half way and bring it to zero. Now move to the opposite jaw, jaw 3 and take a reading. If need be write it down. Also note when you do that which way the needle moved. You can also note movement of the plunger, did it move in or extend.

Now, you need to move half the distance. Let's say the part was closer to you at jaw 3, you will need to loosen jaw 1 and tighten jaw 3.

At the same time you also need to dial in jaw 2 and 4, your almost always going to be dealing with opposite jaws.

Looking forward to your progress.

Tim
 
You can pull on the back of the dial indicator stem, And that will show you direction, (Up or down) Won't work on a dial test indicator like that but just use a standard dial indicator until you get it down.

When you are dialing in slightly loosen one jaw and you will also see it move slightly and that will tell you which way you need to go.

I have zeroed the bores on hundreds of barrels using a 4 jaw. Once you use it a few times it will become second nature and you will be able to dial something in a couple minutes or less.

Edit to add:

establish a center on the work by scribing it etc. Then push your tailstock up to the part in the chuck and adjust it close to your live center on your center line you scribed before you put the indicator on, That will give you a head start.
 
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A big thank you to everyone. I watched a couple of videos, read all the replies, and now understand (maybe???) what I might have been doing wrong.

The Abom video was the most confusing and the most helpful. Does that makes sense? He would find the low spot on one side, flip to the opposite side and say "look for the low". I thought he should have been saying "look for the high" but now I understand what he was looking for - which was something that I wasn't looking for. I also didn't know that you needed to align the stock squarely in the chuck.

It looks like I still have a lot to learn but if I follow your directions I just might be able to conquer this.

I genuinely appreciate your help. It has been most useful and I will continue to use your suggestions in my learning process.

Denny
 
Nyala said:
My thanks to all for your quick response and suggestions. I posted here because I didn't want this thing to beat me but I seemed to be at a dead end.

I started watching Blondihacks videos about 2 years ago. She was very interesting but lately she seems to be on a kick of making models. I don't do models or work in miniatures. I'm not that skilled. As a result I unsubscribed from her channel. She is currently on Episode 34 of a model build. Same with Joe Pie. Too many models. I'll go back and watch her earlier videos.

Abom79 has become a walking commercial for everything from factory sized CNC machines to spray cans of cutting oil, and everything in between. I think that he has become geared for professional machinists than a hobby guy like me. Unsubscribed.

I'll continue to search around for additional help but you all have given me a start to help me conquer this thing. Thank you all for your time and efforts.

Denny
Click to expand...
It would be good to watch her mill and lathe skills videos.
 
Nyala said:
I also didn't know that you needed to align the stock squarely in the chuck.
Click to expand...
One of the great advantages of a 4-jaw is that it can accommodate work that is NOT square, as well as doing things like boring holes that are not centered in the work. I had a problem with the x and y axis bearing blocks on my mill, they were making very annoying screeching sounds when I turned the handles. Examination showed a couple of things -- one of them had paint in the bearing pocket, and the ID of the other pocket was too small. Those pockets weren't centered on one axis of the block, but that was no problem with the 4-jaw. A few passes with a boring bar, problem solved.

Making eccentrics is another application. They are used in some QCTP designs to lock the toolholder in place. Or a quick-release tailstock clamp.
 
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