Submitted: May, 2005

We are having trouble with Date Wheels not turning properly during the production run. We've tried loosening them, however they lock up again during the next run. A flat screw driver is all we use to try and turn them. Any ideas? Typically it is the month date wheels we have to move.

1. One root cause could be that there is too much or too little clearance of the Insert O.D. to the Holder I.D. against the tolerance they were manufactured to. If that is not the case, it could be possible that there is too much press fit on the assembly.

2. When you 'free up' the wheel, is there any plastic between the insert and the holder? Flash in this area would indicate TOO much clearance. 

3. What resin are you molding? In some cases, different types of Resins have been known to cause these types of issues.

4. What is the Mold Temperature? Some molds run really hot at 150 deg. F, while some run at 45 deg. F.  Both extremes can affect how much clearance there is while molding.

5. How many cavities does the problematic mold have? Is there one Date Wheel/Stamp per cavity? If there is a 16-cavity mold and three of them are not turning, one can now begin to look for differentiation between those that work and those that do not and know how many are failing in total.

6. Are all the inserts in the mold sticking or is it certain cavities? Having only a couple out of, say, 8 would lead us to believe that it may be a possible manufacturing problem.

7. Are the inserts close to the gate and are they on the A or B side? If they are close to the gate, heat is higher and may be affecting the movement.

8. Make sure to check the sticking wheel in the press before  pulling it out to inspect the problem. This is an odd issue, so it would be a great advantage to attempt to address the issue in the press rather than after it's been pulled.

9. When a Date Wheel/Stamp is not turning, and one is turning them back and forth to loosen them up with no resolve, then it's possible it is the tool. However, this is difficult to diagnose without actually viewing the application.