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Posted: 11/4/2023 6:04:22 AM EDT
[Last Edit: Blowout][Edited]
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I did the following steps to improve the performance of my LEE Perfect PM so it throws within +/- 0.2gr consistently. About 90% is +/- 0.1gr. This was with IMR4895. 1. Test what you have to determine if anything needs to be done before spending time making any changes. Also provides a baseline to quantify the improvements made a positive change. 2. Disassemble the rotor/body assembly by removing the Rotor Tension Adjustment Screw shown in the below pic. Attached File 3. The body (non-moving portion of the PM) needs to be inspected for any flash created in the molding process. Using 220grit or finer sandpaper or a fine grit file to break the inside edges of the port as shown below. Only the port without the elastomer wiper needs to be cleaned.  Initial sanding  Final result  4. Use same technique to clean up the port edges on the rotor. Before cleaning port edge:  After:   5. Reassemble rotor and body. From the Lee PPM manual: "To get the proper tension on the screw that holds the rotor assembly to the base, place the lever in the up position and tighten the screw until you cannot move the lever up and down. With an empty powder measure, begin loosening the screw until the lever begins to move downward. Once this occurs, you have achieved the correct tension. " 6. Use fine graphite powder (used for locks that can be bought at hardware store, Amazon or ebay) to season the PM. Put a small amount in the hopper and cycle it through same as dispensing powder. I do this about 5-10 times reusing the graphite powder. 7. Retest to determine if it made a difference. I did quite a few after dispenses to feel confident the PM throws +/- 0.2gr or less, but didn't document the before measurements. I made a baffle for this PM but it had a negative effect on consistency of dispense so I removed it. I only use the Lee PM for extruded powders. Spherical powders it doesn't do as well and leaks occasionally. |
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I've done this quite a few times with mine. As the instructions say, fine powders (like H-110) will eventually leak a little bit. At first, after the polishing there were no leaks but eventually it did. So now I only use it for coarser powders and I'm pretty happy with it. I have had this measure since the early 90's and I hate to throw away anything that still works. |
Global Warming Hoax Skeptic before it was cool
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Originally Posted By maximumtorque: I skipped the graphite and did 3 coats of finishing wax on mine, waiting until each coat was completely dry before applying the next. Smooth as butter now I've used Johnson's paste wax on a Redding PM, but those parts are made of metal. I wasn't sure of the outcome using it on the nylon that the Lee PPM is made of. I followed what Lee has in their service articles: Bumping against the stops when dumping and filling the metering chamber usually causes inconsistent loads with the Perfect Powder Measure. Be gentle at both ends of the stop when charging powder. Also failure to condition the measure by running a pound of powder through the unit will cause inconsistent charges. You can speed the conditioning by dusting the metering surfaces with powdered graphite. Powdered graphite is available at most hardware stores (often used as a dry lubricant for locks). Empty the powder from the hopper of your perfect powder measure. Remove the screw from the crank plate and remove the rotor from the body. Apply some powdered graphite to the inside of the body and work it in with the rotor. Repeat this until you get an even coating of graphite on both the rotor and the body. Re-assemble the the powder measure. The powdered graphite will make the mating parts slide past each other a lot easier. Lastly some powders do not meter well, Unique powder is one example that meters with "casual uniformity." Another service article with similar information: To eliminate leakage, disassemble the measure and clean thoroughly. Dust with powdered graphite or mica, and re-assemble. Powdered graphite is available at most hardware stores (often used as a dry lubricant for locks). Work the lever back and forth to spread the powdered lubricant over the mating surfaces. Disassemble and observe the wear pattern on the cone shaped mating surface between the metering chamber and body. There should be even wear across the whole surface. If not, dust with lube and try again, with the tension screw slightly tighter (or looser, depending on the appearance). If you can't get an even wear pattern return the measure to the factory for repair/replacement. Our address is: Lee Precision Inc, 4275 Hwy. U, Hartford, WI 53027. To get the proper tension on the screw that holds the rotor assembly to the base, place the lever in the up position and tighten the screw until you cannot move the lever up and down. With an empty powder measure, begin loosening the screw until the lever begins to move downward. Once this occurs, you have achieved the correct tension. |
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Originally Posted By s4s4u: Appreciate the 411. I have one of these and it has never performed well. I may strip it down this weekend and put this to use  Originally Posted By s4s4u: Appreciate the 411. I have one of these and it has never performed well. I may strip it down this weekend and put this to use I just use mine for extruded powder. My Redding PM was cutting those powders and weights were all over the place. Hope it helps give your PM some new life. Originally Posted By CRNUMBER: I've done this quite a few times with mine. As the instructions say, fine powders (like H-110) will eventually leak a little bit. At first, after the polishing there were no leaks but eventually it did. So now I only use it for coarser powders and I'm pretty happy with it. I have had this measure since the early 90's and I hate to throw away anything that still works. Can you help explain the polishing comment? What did you polish? I didn't touch the mating surfaces with sandpaper because I thought I'd just screw them up. Originally Posted By dryflash3: Nice thread Blowout, I'm going to set the archive toggle on this thread to keep it out of the archives. Thanks! Hopefully it will help some get better performance out of their LEE PM. Also hoping there are some other ideas/improvements I can pick up too. |
Global Warming Hoax Skeptic before it was cool
Joined:
Jun 2007
Posts:
67158
EE: 100% (1)
WA, USA
Global Warming Hoax Skeptic before it was cool
Joined:
Jun 2007
Posts:
67166
EE: 100% (1)
WA, USA
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Originally Posted By Stump70: After pouring in my powder, have found that tapping it for a few seconds compacts the powder and seems to settle on charges quicker. Thanks for the info. Will check for rough edges. Part of what I call "good technique" when it comes to good PM operation. How I get PM's to throw exact charges with powders others say won't drop accurately. Like Unique. |
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