Lyman 1200 Electronic Scale Problem


March 5, 2008, 09:13 AM
Here's a note of caution for you!

I had received a bulk purchase of pulled military bullets, and last night I started weighing a sample of 100 to determine weight variances before reloading. I zeroed my Lyman 1200 DPS without the pan, and carefully placed each bullet in turn on the pan rest, immediately getting the bullet weight to the nearest 0.1 grain, placing the weighed bullet in numbered envelopes. I was very careful not to jar the scale and to deposit and pick up the bullets gently.

About halfway through the batch I noticed the scale momentarily flash a negative 0.4 between bullets. I rezeroed the scale, and got a plus 0.4 grain reading on the last bullet I had weighed!:what: Retested a few of the other weighed bullets, and virtually all were off. :eek: Dumped them and started over, being even more careful and rezeroing after about 15 bullets each time...and found that I was still off by 0.1 or 0.2 gr before rezeroing.:banghead:

This shook me...I've lost my faith in using the DPS for my normal powder charge dispensing. I'm going back to my trusty mechanical powder measure and old practice of checking every tenth dump on my beam scale until I get this resolved.:barf:

Is there something wrong with the way I used the DPS? What to do? I am contacting Lyman about it...:confused:

(By the way...the bullets passed with flying colors...167.5-gr avg. plus or minus 0.5 gr.:p)

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March 5, 2008, 11:39 AM
Just finished studying the DPS instructions...on the last the very end...the last item under "Suggestions/Tips" says:

"The 1200 DPS has a drift warning. If anything causes the readings to drift over 0.3 grains, the scale will beep. The scale should be re-zeroed by pressing the "CAL/ZERO" button." (Now, get this!) "It is a good idea to press the "CAL/ZERO" button after every 5 powder drops to be sure no drift has occurred.":what:

:cuss: Why in Heaven's name didn't they put this very important information in the "Use" part of the instructions? Why put it at the very end as an afterthought?:banghead: I've loaded a huge amount of ammunition, several hundreds of rounds at a setting...without doing complete confidence my DPS remained accurate.

BIG lesson: Dont Assume Your Expensive Electronic Powder Dispensors Remain Accurate for More Than Five Charges!!

March 5, 2008, 11:51 AM
It's not just your Lyman scales.
Electronic scales have to be warmed up to operating temperature before using them. If you don't turn them on at least 1/2 hour or more before use, they will continue to drift off zero as they warm up.

I often try to remember to turn mine on the night before I intend to use them.
Or just leave them on all the time.


March 5, 2008, 04:51 PM
Letting the scale warm up 20 minutes plus is critical. Once the scale warms up the drifting of my scale stops. I've also noticed it will drift when the outside temperature drops and the house cools slightly and the furnace runs more. Not a air current influence but temperature changes. Also I've had problems during storms involving high winds. Since the scale needs consistant voltage, I figure the voltage to my house fluctuates slightly as a result of the storm. I have a Lyman check weight set and it will give you confidence that your scale is weighing correctly. I highly recommend a scale check weight set for any electronic or balance beam scale. Takes away the nagging doubt and the distrust of whether you're accurately weighing charges.

March 5, 2008, 04:52 PM
That info is in the "Use" part of the instructions. When you turn the Lyman DPS there is a 30-min warm up period, complete with countdown on the data screen. The unit had been on for nearly an hour when I found my "drift" problem. Drift is not mentioned any where in the user instructions...

March 5, 2008, 05:33 PM
There are a few things that will cause your Lyman or any electronic scale to go haywire. Make sure there is no drafts like air conditioners, heat ducts, or open door ways. Cell phones and wireless networking are a huge problem. Fluorescent lights can also cause problems and last but not least entertainment systems like a loud radio or boom box.

I have a Lyman 1200 and I works great. I double check all of my powder dumps on my 505 just in case and they are almost always dead nuts.

March 5, 2008, 06:14 PM
I have a 1200 and just leave it on all the time to avoid the warm up period. I still get drift from time to time. I must say after using this scale for a few years I absolutely hate it. :barf: Dumping the powder just plain sucks. They should string up whoever came up with that rear dump design. :fire:
But they have my money, so I'll keep using it until I can budget to replace it with something like a PACT or RCBS.

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