Chuck jaw truing tool

[thehomeengineer]

Hi olderdan
Not a problem to have a backplate slightly smaller. I am a mechanical craftsman and I have always turned the backplate for a new chuck 0.004"/0.008" smaller for the reasons you have made.
Great post. Thank you
The Home Engineer

[PJs]

Olderdan and Paul,

My Heartfelt condolences on your losses. Your stories brought back memories of my Mom's Teacup Poodle, Bear. She name him that because when you looked at him straight on he looked like a mini bear. One of the greatest loving and smart companions I have ever known. Unfortunately at 15 he started having mini strokes and we had to put him down. I find myself thinking of him regularly and the fun and loving times we had together. He could easily jump straight up 3' without blinking, loved to chase golf balls bounced on concrete (true cartoon picture) and would jump up in my lap and snuggle in between my leg and the arm of one my moms rockers while we watched a movie or just talked. Once I thought I could teach him to jump a bar and set up an elaborate rig to work with him. We got up to about 2 feet and when I called/coaxed him to do it he looked at me like "What the...You do it!" I busted up and then he jumped the bar straight onto me and I fell over laughing and him getting all over me. He was great for mom in so many ways over the years and especially in her hard later years. She passed a few years after him.

The best part of the story is about a year after moms passing I was thinking about Bear and Mom and some of those "moments" and when I looked up in the sky I saw this cloud that looked just like Bear chasing a golf ball. That was special and why these wonderful companions bring such a joy to our lives, I think. May your memories fill your hearts with the Joy and Love they shared with you.

~PJ

[olderdan]

Thanks for the sympathy guys, end game is part of having pets and we have all been there, ours are all rescue dogs so at least we gave them a better life and they do reward you for it. We have had Greyhounds in the past but now find smaller dogs easier to manage. Never could figure out why they like us so much, I guess that is part of the fascination.

[Paul Jones]

Thank you for the sympathy. Each dog was a unique personality and both they and us like each other so very much.

We are also fond of cats as well We have had several: lilac Siamese, Mostlys (mostly black with some white furnishings) and Calicos. Each with its own unique personality.They seem to get along very well with our dogs and respected each other's space.

[old_toolmaker]

Hi olderdan,

I really like your method of using a section of tube to simulate the way the jaws clamp on the O.D. of material in the same direction they are used. Your method was new to me.
I also have floated my mini lathe 3" 3 jaw chuck on the back plate and have never had a problem ever. A few years back I also did the same with a 4" 3 jaw that was mounted on a 5C adapter. I could dial that in right on the money and never had it slip.

Dick

[old_toolmaker]

olderdan,

Thanks for posting this.
This is really a great idea to hold the jaws with the the load on the scroll in the same direction in which the jaws will be used. I wish I had thought of it myself!

Dick

[tonyfoale]

Alan,

I use a similar device but with a difference. Depending the amount of wear on the sliding grooves it may produce slightly different results.
I use a tube which is longer than the width of the jaws and cut grooves like yours but to take the full width of the jaws not just the front. This results in a chuck which clamps a bar evenly over the width of the jaws rather than aiming for best results with short pieces.
I have never understood why anyone would expand the jaws into a ring for truing the inside of the jaws, and vice versa.

[old_toolmaker]

I have never found a need to true the jaws by grinding or any other means. That is not to say it can’t be done but any chuck I have seen has never required that drastic kind of surgery.

[olderdan]

I have never found a need to true the jaws by grinding or any other means. That is not to say it can’t be done but any chuck I have seen has never required that drastic kind of surgery.

Agreed a chuck that has been looked after from new should not truing. The 3 jaw I have is an original South Bend about 80 years old and was much abused so this improved it.

[olderdan]

Your way is a definte improvement.