Effective Date: 09/25/08 Page 5 of 9
ATS Systems
Form
Subject: Ultimate Chuck Install & Training Checklist
Doc. No. FM 9-112
Rev.C
- The chuck actually breaks at some critical component either because the drawbar pull is way over the maximum
rating, or the chuck is used and fatigued for an extended time at a drawbar pull that is perhaps only 20% over the
maximum rating.
Now that I have your attention, we will go step by step through the safe operating practices of the Ultimate Chuck.
Note that all of what I've just said about the hazards and what I will now say about how to deal with them applies to
all jaw chucks, not just the Ultimate Chuck.
I have attached this maintenance and safety decal to your lathe. It summarizes the points I will now cover and
I encourage you to review it regularly.
This is the Installation, Operation and Maintenance Manual. It contains all the information I am going to
present and more. Please read it carefully and pay special attention to safety items in sections 1.1 through 1.3.8,
safe jaw positioning in section 4.2, calculating safe operating speed for different top jaws in section 4.4, and
proper lubrication in section 5.2.
My training will now cover the following topics:
1. Safe chuck speed.
2. Changing, positioning and mounting jaws for safe operation.
3. Proper chuck lubrication.
4. Hydraulic pressure and proper drawbar / drawtube pull.
5. Chuck inspection and some miscellaneous safety instructions.
Safe chuck speed (RPM) is greatly influenced by the top jaws used. The maximum rated speed of this chuck is
____ and applies only for normal chucking applications using the maximum rated drawbar pull and only for
standard top jaws such as our Deep Bite Job Shop Jaw. For any other top jaws or conditions, speed must be
reduced. (Manual 2.2)
Always use the smallest, lightest, shortest jaw possible, and position it as close to centerline as possible.
Centrifugal force pulls on all jaws and reduces actual grip force. The further out from centerline and the
heavier the jaw, the higher the centrifugal force. When you do use oversize jaws or even standard jaws if they
are positioned very far out from centerline, you need to determine a safe operating speed. You can either do
this by using a dynamic grip force gauge and slowly raise the RPM until 50% of the initial grip force remains,
or you can weigh the master base jaw and top jaw combination and make some simple calculations as shown
in the manual section 4.4. Demonstrate how to remove the bolted together base and top jaw, to weigh it, to
balance it in a knife edge to determine and mark the center of gravity, to reinstall the jaw and measure the
distance from centerline to the CG of the jaw assembly when the jaw is in the proper position for the
particular job, and how to make the calculations by taking them either through their actual setup or examples
#3 and #4 in the manual section 4.4.
4.4
Note that you can also use this technique and formulas to calculate the approximate safe speed of standard
chucks, but you must weigh and measure not only the top jaw but also the master jaw, bolts and T-nuts as an
assembly. If you don't include the master jaws you will calculate a speed that's way too high. Of course, this
requires you to disassemble the chuck which is impractical. (Another selling benefit of the Ultimate Chuck.)
Are there any questions?
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