Self Aligning Clamp Pad

[Toolmaker51]

Secure clamping relies on directing pressure quite figuratively 'through' the part to an opposing fixed surface; as in moving and fixed jaws of a vise. And whether vise, clamp, or hold down; they like parallel surfaces best.
Frank S and I directed attention to one remedy, a semicircular adjustor that compensates misalignment of shaped parts between parallel jaws. http://www.homemadetools.net/forum/v...-do-more-49490
Here's another using a swivel action, for tapers, curves and compound surfaces, as in cast or forged parts. Self adjusting, it uses less space, advantageous when a vise is used.

This is a lathe or mill project, or combination of the two. A little planning will allow making two at a time. Test fits while work proceeds. Heat treating is not needed, or recommended.

The physical size isn't critical, use steel an adjust to suit material available. Procure two bearing balls, example uses .75/ 19mm. This block is about 2 1/2" long, 1 5/16" high, and 1" deep. The radius inside block [not through] and chord is 1". Allow .002-.004 clearance on one side. The chord has two pockets bored to slip fit the bearing balls. Ball end milling can be used, but isn't required. If pocket is ball-milled, pilot drill around 1/4 ball diameter and somewhat beyond 1/2 ball diameter. Seat depth is .020-.030 deeper than 1/2 the ball diameter. Before assembly, grind flats with any manner at your disposal. Lightly stake the balls in place to be retained, not locked. Top edge of chord is grooved for a roll pin pressed into the top plate. In the groove are 2 roll pins at 45* to keep the chord from swiveling out of the block. .
Top plate is countersunk for 2 #10 flat head screws, tapped in block.
jjr2001's post has a similar aspect, and some good building techniques. http://www.homemadetools.net/forum/w...se-balls-50698
This works in vises, hold-downs and a variety of fixturing.
If any amplification is needed, feel free to post or email questions.
And for Ralphxyz here are 2 shots, to represent use. Only have one suitable casting at the moment, and about a 5" stub of round stock. Casting's the 'apron' from a manual form bender being modified. Round is just a drop from our saw.

[DIYer]

Thanks Toolmaker! We've added your Self Aligning Clamp Pad to our Workholding category,
as well as to your builder page: Toolmaker's Homemade Tools. Your receipt:

Self Aligning Clamp Pad by Toolmaker51

tags: bearing, clamp, holding

[Frank S]

TM51 Thanks for posting.
I made something similar to that a long time ago I found that bu placing the .75 bearings .050" apart with a .150" grind to them this gave me a .600 dia flat surface. also by making the pocket to a depth that allowed for .150" of the ball to remain above the surface I had .450" embedded. This made the diameter of the ball at the surface .018" smaller than the major dia. More than sufficient for staking in place. This gives better than 23° of angularity per bearing meaning a .312" dia cylinder could be clamped
I guess now I will have to make a couple of new models mounted in the corded cylinder as you described I hadn't thought of that one Brilliant.

Eddited reply here is a sketch showing the angular possibility

[Ralphxyz]

I'd like to see it being used clamping something.

Ralph

[billster]

Simply brilliant.

[Ralphxyz]

Wow,thanks, now if only I could find this again when I have time to make up some!

Ralph

[Jon]

More workholding tools from Toolmaker51:

Mill Vise Clamping Aid by Toolmaker51

tags: vise, holding

Mill Vise Edge Clamping Aid by Toolmaker51

tags: vise, holding

Turret Mill Clamp by Toolmaker51

tags: clamp, mill

[Ralphxyz]

Again WOW, thanks!!

Ralph

[Ralphxyz]

Thanks for the pictures, added to my list!!

[billster]

Since I've put aside my metalworking for a while, and am concentrating on woodworking (guitars, ukuleles, basses), I decided that hardwood and plastic (Delrin, nylon, urethane) clamp pads of this design would be helpful in those builds.