Gempro woes!

358Rooster

358Rooster

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Central Saskatchewan
Just got his shiny new Gempro 250 & it's gonna set my handloading world on it's ear! Right? Errrr, maybe not....

Why is it wandering? I have used check weights for a few years now & the damn things do not change, no matter the temperature, wind, body odour, etc. Why is it that I can check the Gempro after about ten charges and the bugger reads 0.16 different from the last time I zeroed it? Yes, I have done the calibration several times. I think my old Hornady beam is more reliable!

Now, I need to mention that the house's main power feed and router are about four feet from the unit - is this the cause of my angst or have I wasted $200 on what I thought would take me to the next level of precision & certainty?

Please help; yours in Saskatoon & disparity,
Rooster
 
I work with precision scales and for best repeatability, some of the key things to remember are:
Place it on a level surface that is solid and can dampen vibration. A steel plate or small piece of left over granite counter top works well.
Give the scale about 10 to 15 minutes to warm up after powering it up. Load cells will give different readings at different temperatures.
Eliminate interference from the surroundings. Airflow and electronics are the most common.

And just remember, only very light compressed air to clean the scale (not more than 15 psi).
 
You should turn electronic scales on 24hrs before use. I leave mine on 24/7.

Florescent lights can also mess with them.
 
I found when using the scale on the 0.02 accuracy mode as oppose to the 0.05 mode to be frustrating. I figure even at measuring .05 grain accuracy compared to a regular beam scale of 0.1 accuracy that it is more than enough for my skill.

The instruction manual will show you how to change the setting. It has a faster measuring time and seems to drift less in my opinion.

I do however keep the 20grain check weight close by and re-calibrate every 20-25 rounds depending if I see a small shift from when I tared the scale originally with my powder pan.

Its a good little scale, don't give up on it!
 
I am quite disappointed in this scales ability to hold calibration over time for $200 plus not impressed..

I now use an RCBS Chargemaster and a Analog beam scale for backup..
 
I experienced the same issues. What I now do is turn it on 48 hours before my reloading. It is in my reloading room which has no air currents and sits at a stable 15*C. I now get zero wander and my check weight is 20g day in day out.
 
We have quite the time spread in this thread:

Turn it on 10 to 15 minutes ahead of use, 24 hours ahead, and 48 hours ahead.

fwiw, I give my RCBS Powder Pro 20 to 30 minutes warm up time before use.
 
Buys some ferrite snap cores and wrap the powder cord through it once. They could be found at Radio Shack or Source electronic. I bought two and placed them on the wire it helps with some of the magnetic, radio interference. Also if you're using a metal powder pan it could be part of the issue I swiched over to a plastic one and it stablized a little more. I even took the extra cover plate off and just ran it it has stabilized and doesn't drift past much at this time. Temperature seems to be the biggest thing.

Like everyone previously said before keep it plugged in for 24 before use. It's a sensitive bastard however I could live with a tiny drift, than pay $500-2K for a magnetic restoration scale.
 
I also placed mine on a good quality Rubber ( not foam) mouse pad (no static build ups) and used some of those Mylar plastic bags that hard drives come in. Built them into a small shield around the back and sides and part of the top which then seeeds to reduce any electrical interference from my fluorescent lights (one had a ballast that was going which I could tell from the louder humm
 
Thanks for all the suggestions, guys. When I got it, I calibrated after it had been on for about 1/2 hour (already leveled on my sturdy bench & sitting on the pad supplied with the unit). Two days later, I calibrated again and started doing some testing to see what kind of consistency I was getting from my beam scale. The next day is when I started loading and noticed the wandering. So that's three days of the unit being on.

It has occurred to me that my bench is just in a really bad spot - plus, I have a flourescent light over it! I'll try a few things suggested here and hopefully I won't have to relocate & re-furnish!

Rooster
 
This scale is better then most electronic ones, I couldn't use most in my reloading area due to the electronic interference. The gempro does wander as all scales do with temp and air pressure changes. I turn mine on 15 minutes before reloading and have to zero it only after a couple dozen rounds, it will drift +/- .02 to .04 grns. I do check the zero by putting the powder tray back on and letting it settle every couple rounds. I find the scale is fussy about how hard you set the tray down on it when weighing. I have a sagitorious and a rcbs 10-10 and they don't get used much anymore due to the precision of the gempro. I don't find any difference weather it is plugged in or run off of batteries. I have a larger mouse pad under mine and I wipe it down with a bounce sheet if I find the readings goofy. I have found that my velocity spreads have decreased considerable since I started using this scale. I do like the idea of the filter inline for the power supply, I may have to try one of those.
Just what I have seen!!
 
I just got one today. Bought it probably an hour before this post was started lol. I'm loving it so far. The little plastic pan I have measures 60.20gn every time I set it down. Loaded up 50 rounds tonight and after loading the last round I dumped the powder from the first round back in the pan, measured 91.00 just as I wanted (.338 Lapua).

I can see that a larger pad under the scale is warranted. The one they send with it just fits and is slippery. Before loading these last 50 I had 8 rounds with powder in them (but no bullets) that I measured out with my cheap-o scale before it gave out. I dumped the powder from those into the pan on the Gempro and one measured 91.00 and the rest were up to .3 out either way.

Suffice to say I'm happy so far.
 
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