Re-Grinding a Chuck the MrCrispin way

Comments · 582

• SD

  @sd13900 · 3 years ago

  The "Mr Crispin Jaw Dolly Clamping System" is an inspired work of genius !

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• BC

  @bcbloc02 · 3 years ago

  I have discussed this multiple times and I believe Robin has talked about it too. Scroll chucks are made with a master key. For best results you need to tighten the master with a torque wrench and then grind. The same torque needs to be applied every time to get the best repeatability because the torque deflects the chuck and jaws.

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• DA

  @DavidHerscher · 3 years ago

  The humor in these videos is dryer than a martini. Im here for it.

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• WY

  @wyldanimal2 · 2 years ago

  Non-Repeatability after your regrind.<br>In a scroll chuck, &nbsp;the Scroll is what determines the True Repeatability of the Jaw Positions.<br>Any wear or play between the inner diameter of the scroll, and the Hub diameter that the scroll rotates on<br>will affect the jaw positions.<br>When you use the Key to Tighten the Jaws, &nbsp;a rotational force is exerted on the scroll, but at the same time there is a Lateral Force against the fit of the scroll and the Hub.<br>Depending on which tightening spot you use, the scroll will shift by however much play there is in the fit between the scroll and the hub.<br>And this results in the Jaws shifting around.<br><br>Ideally you can snug up the jaws using any one of the tightening spots.<br>then indicate the runout and tap the part or directly on the jaw at the high spot to Shift the Jaws and the scroll.<br>This will center the scroll, or place it in the position it was in when you re-Ground the jaws.<br>Once you get the best indicated runout, &nbsp;tighten the jaws using all three spots.<br>The Jaws have some spring to them with the fit of the T-slots.<br>When tightened, the spring forces of the Jaw against the T-Slots will hold the jaw in place, so you are not just relying on the scroll fit to hold the jaws in place.

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• KE

  @kenknight4560 · 3 years ago

  All is right with the world, the English Island still exists and Mr. Crispin is back in the shop. &nbsp;God save the King.

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• MR

  @MrAvenger1600 · 3 years ago

  The jaw clamping dowel invention is a brillant idea. Way back when I was being trained I remember our instructor used to always tell us to use all three pinions every time when tightening. To get the work piece more true.

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• DR

  @drevil4454 · 3 years ago (edited)

  you are 100% correct. The scroll wear WILL contribute to runout as well as how much play are in-between the outer surfaces of the jaws. Meaning the non-grooved sides riding in the chuck body. At our company we used to spend a lot of time doing what you do did but soon realized wear plays too much of a factor. Hence we also went the dowel way where we removed the jaws from the chuck and then ground them in a jig. Our dowel jig system held the jaws flat, on their sides but in a circular jig, if you know what I mean.

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• PA

  @paulgammidge-jefferson9536 · 3 years ago

  MR CRISPIN!<br><br>Great to have you back. Hope the absence wasn&apos;t a forced one.<br><br>Informative, educational , and entertaining as usual. Thank you.<br><br>You were missed.

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• SA

  @samshublom8761 · 3 years ago

  Glad to see you back and the project complete. I was beginning to think you had moved on to other interests. I found the jaw loading discussion particularly helpful.

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• CH

  @charlesward8196 · 3 years ago

  Following the example/advice of other content creators, I have moved my angle grinding operations OUT of the shop to a portable work table to minimize the abrasive filth that gets spread around the shop. I also employ an N-95 mask to minimize the abrasive filth that gets into my respiratory system. Nice job on the tools.

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• DA

  @danandersson3556 · 3 years ago

  Good to see you again, sir!

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• TE

  @TerryMartin3428 · 3 years ago

  The best solution to an old &nbsp;problem that I ever saw.