GemPro 250 and a stable zero

[dstoenner]

I have had my Gempro now for a while and it gives better readings than my RCBS 750. But the zero wanders a little just like my RCBS scale. What I do to mitigate it is ever 5 rounds (1 line of my 50 round block) I re-zero both the RCBS scale and the Gempro and go again. But I started noticing that if I loaded the whole block in one setting, I would notice that the "zero" weight with the pan only would get smaller and smaller till at the end it hardly changed.

So I got an idea. Since I turn off the RCBS scale till the next loading, I just moved the pan of the RCBS to the Gempro, zero'd it and left it there till the next time I was going to load. Now I was getting mostly 0.00 grain zero weight and no more than +/- 0.02 when I went to zero it. Like no drift at all. It seems that the circuitry recognizes that there is 0.00 on the scale and it keeps dynamically adjusting to hold zero which then sets up a series of weighing with a stable zero weight. I have now been doing this for a month and even as the temp changes getting hotter in the garage, it is still working.

Thight I would pass this on for you guys with GemPro 250.

David

 

[L.Sherm]

I dont have any problem with my Gem Pro drifting if I atleast turn it on the night before I wanna use it.

 

[FURMAN]

When I was still using mine(I've switched to the A&D) I just left it on. It is a great sale in my experience. Too bad they don't make it anymore. The replacement is not as good.

 

[JohnKielly]

I was taught to add the powder to the pan on the scale, not drop a filled pan on it.

 

[dstoenner]

I was taught to add the powder to the pan on the scale, not drop a filled pan on it.

You can’t trickle into a GemPro 250. It won’t tolerate any small additions. That is why i use the rcbs to trickle the first level and then use the gempro to get to within +/-.02gn. I also place the pan not drop

 

[dstoenner]

When I was still using mine(I've switched to the A&D) I just left it on. It is a great sale in my experience. Too bad they don't make it anymore. The replacement is not as good.

Mine has been on since i got till we have a power failure and i have to turn it on again. That didn’t keep it from drifting a lot when i would have it zeroed with nothing, then add the pan and zero again.

 

[gambleone]

You can’t trickle into a GemPro 250. It won’t tolerate any small additions. That is why i use the rcbs to trickle the first level and then use the gempro to get to within +/-.02gn. I also place the pan not drop

I do something similar, only instead of RCBS scale, I use a Redding master balance to get close, then set pan on gempro. I do turn the gempro on about 3hrs before use. About every 10 loads I'll re zero the scale just to make sure. Works well this way.

 

[Straightshooter1]

You can’t trickle into a GemPro 250. It won’t tolerate any small additions. That is why i use the rcbs to trickle the first level and then use the gempro to get to within +/-.02gn. I also place the pan not drop

I also found this to be true about trickling onto my GemPro 250. Upon developing a method for getting my GemPro to get the weight I was after (like within +/- .02 gr), I found it was as accurate as my FX 120i (see pic below). . . .however, it takes substantially more time to get my desired weight with the GemPro than with with the FX. Part of the my method had to do with keeping the GemPro from drifting over extended loading periods where I'd return the pan to the scale after emptying it each time then throw a charge in the pan and trickle up lifting the pan up and back down until I got the weight I was after.

Now that I have an FX, I'm keeping the GemPro as a back up, just in case.

 

[46and2]

I also found this to be true about trickling onto my GemPro 250. Upon developing a method for getting my GemPro to get the weight I was after (like within +/- .02 gr), I found it was as accurate as my FX 120i (see pic below). . . .however, it takes substantially more time to get my desired weight with the GemPro than with with the FX. Part of the my method had to do with keeping the GemPro from drifting over extended loading periods where I'd return the pan to the scale after emptying it each time then throw a charge in the pan and trickle up lifting the pan up and back down until I got the weight I was after.

Now that I have an FX, I'm keeping the GemPro as a back up, just in case.

View attachment 1265706

In your chart are you comparing what is weighed by your Charge master to the other scales?

 

[Sundown]

I have a GemPro 250 which works fine. Every so often it wonders a bit. This means there's some noise on your lines that's causing interference. I've had to shut off my dehumidifier and that stopped it. Florescent lights causes interference also. Your next door neighbors wife may be using the Mixmaster to make bread. Try turning off some things and see if that helps. Wait a while and see if it stops or wait until later in the evening.
Good luck!

 

[Straightshooter1]

In your chart are you comparing what is weighed by your Charge master to the other scales?

Yes.

As you can see, the GemPro 250 measurements were very, very close to what the FX-120i measurements were. And I found it interesting how in the last group on the right, my little Frankford Arsenal DS-750 measurements were right there with the Charge Master's.

 

[JohnKielly]

You can’t trickle into a GemPro 250. It won’t tolerate any small additions. That is why i use the rcbs to trickle the first level and then use the gempro to get to within +/-.02gn. I also place the pan not drop

Try using separate pans, leaving one on the GemPro on tare & moving the powder to it in one hit.

Incidentally, you can trickle if you irritate the scale each drop by touching it moderately with a feather or slip of paper to overread then come back.

 

[D-4297]

Have had my Gem-Pro 250 for about four years now . Set it up as instructed , and have had little to no trouble with it . Drop charge from the RCBS measure , and place pan on scale . Trickle using a RCBS Trickler to final weight . You do sometimes have to wait for scale to "read" the change , so being in a hurry isn't conducive to accurate loads . I'll keep my Gem-Pro as long as it keeps weighing solid loads . As with all things mechanical and electronic , OPERATOR REQUIRED . Personally ; I think the Gem-Pro scales got a bad rap because many did not know how to correctly set-up and properly use the scale . Not because it was a bad scale . Every time I checked it against a 120i , or my "Bud's" Chargemaster , it's never more than .01 off . And that's one kernel of the powder I use . ONE ! So how much more accurate do you want to be , anyway ? Somebody pass me the X-acto knife , so I can cut a kernel in half .

 

[BTHP52]

I know I'm jumping in on an old thread, but looks like there may be some members with more in depth knowledge on the Gempro.

I'm curious if there's a way to override the "lock on" max weight/toggle off display stability. I found there to be some instructions on my Hornady auto dispenser to change several internal variables by entering different button sequences, just wondering if Gempro might as well.

thanks

 

[Konocti's Wigwam]

@BTHP52 I have used a Gempro and still own one, but recently got an RCBS ChargeMaster Supreme.

The Gempro is very sensitive, but it has more precision than you need. I would say that the Gempro is more accurate than the ChargeMaster Supreme, but it is way more difficult to hit my loads without going over. The ChargeMaster Supreme does go over from time to time, but is easier for me to use. With the Gempro I use an RCBS trickler.

I do not completely understand the "lock on" question. Hopefully it makes more sense to others. As far as I know there is no secret spy ring or handshake. One thing is you should leave it turned on for at least 15 minutes before using it, if you can.