Chargemaster 1500

[CharlieNC]

Everytime you calibrate there is opportunity to induce error, which might be what you are seeing. I keep my 1500 powered up all of the time, and only need to tare the pan to maintain constant results based on check weights and confirmation of charges on another digital, generally +/-.05gr. If you demonstrate a need to calibrate during a loading session(ie a check weight is off), that also demonstrates something is wrong. Otherwise randomly calibrating for no reason may be your problem.

 

[Charlie-NY]

When you change powders, it's not easy to get all the powder out of the dispensing tube. I normally raise the back of the unit and lightly tap the tube with the pan to encourage the remaining grains to fall free of the tube.
While this seems to be necessary, it could cause issues when settled back in place. This is one reason why I re-calibrate in the middle of a reloading session.
How are you emptying the tube?

 

[CharlieNC]

When you change powders, it's not easy to get all the powder out of the dispensing tube. I normally raise the back of the unit and lightly tap the tube with the pan to encourage the remaining grains to fall free of the tube.
While this seems to be necessary, it could cause issues when settled back in place. This is one reason why I re-calibrate in the middle of a reloading session.
How are you emptying the tube?

I empty the bin, then run a charge until the flow stops, then tilt and tap as you do. Try rezeroing then check a weight to determine if it's necessary to calibrate.

 

[Doom]

There should be no reason to recalibrate unless you have a significant change in ambient temperature. The 1500 has an auto zero should be showing up in the top left hand corner of the display.You should see it every time you replace the pan after the display settles to near zero. This is an important feature of the scale and zeroing before every weighing is standard lab practice. I will note also that rezero does not change the calibration. It is simply a tare measurement.

You might want to turn the scale upside down to make sure no powder is in the scale.

 

[Charlie-NY]

There should be no reason to recalibrate unless you have a significant change in ambient temperature. The 1500 has an auto zero should be showing up in the View attachment 1471954top left hand corner of the display.You should see it every time you replace the pan after the display settles to near zero. This is an important feature of the scale and zeroing before every weighing is standard lab practice. I will note also that rezero does not change the calibration. It is simply a tare measurement.

You might want to turn the scale upside down to make sure no powder is in the scale.

I've probably had the CM1500 for 20yrs. I'm sure that kernels have gotten into the scale. Never thought of inverting it. Now you've got me thinking. LOL

 

[CharlieNC]

I've probably had the CM1500 for 20yrs. I'm sure that kernels have gotten into the scale. Never thought of inverting it. Now you've got me thinking. LOL

Take off the pan platen, if you haven't ever cleaned it you will definitely find powder in that hole.

 

[qldreloader]

Based on a recommendation from a friend I tried loading 6.5CM with my old Redding beam scale and a trickler. Results were SDs in single digits (well 9fps so only just single digit) for the first time ever. I could not get that with my Chargemaster. I've given up on strain gauge electronic scales and can't afford Magnetic Force Restoration type scales. I'm going back to the old school beam scale.

 

[Charlie-NY]

Take off the pan platen, if you haven't ever cleaned it you will definitely find powder in that hole.

OK - I carefully inverted the scale and gave it a mild shake. Collected 1.3gr of powder.

 

[Old Navy]

When you change powders, it's not easy to get all the powder out of the dispensing tube. I normally raise the back of the unit and lightly tap the tube with the pan to encourage the remaining grains to fall free of the tube.
While this seems to be necessary, it could cause issues when settled back in place. This is one reason why I re-calibrate in the middle of a reloading session.
How are you emptying the tube?

Caned air will take care of that.

 

[M-61]

I keep my 1500 powered up all of the time

RCBS does not recommend doing that.

 

[Homerange]

RCBS does not recommend doing that.

I agree as it can only accelerate premature aging of its electrolytic capacitors.

I have a later version with a multi-voltage wallwart and only power it ON while I prepare for a charge/seating session then calibrate it just before needing to throw charges.

 

[M-61]

A few years ago I had it rebuilt

Who did you use to ‘rebuild’ it?

 

[CharlieNC]

RCBS does not recommend doing that.

Like me, too old to change now LOL.

 

[jepp2]

I use a battery and it worked very well where it kept the zero more stable (much less drifting).

Do the cables that come with the battery you suggest work with the CM 1500, or do I need to get/make my cable elsewhere? (asking regarding size and polarity)

 

[wkdickinson]

I had lots of similar issues with my charge master and tried static charge mats, line conditioners (ferrites?), battery power and a few other things. The most improvement I made was by replacing all the fluorescent bulbs with LEDs.

But it still wasn’t as good as I wanted. Neil

I did all of those same things to mine also, but would still periodically have the same problems that the OP does, but they were inconsistent. However, the performance of the machine always seemed OK - but nothing to check it against. I solved the problem with the purchase of an AutoTrickler V4 early this year and have never looked back.

 

[yukonal]

Now that I periodically re-calibrate during a single reloading session, I noticed that every time that I re-calibrate and then replace the pan, I get a different weight for the pan. The variance is significant depending upon how long the scale is running. I do zero the scale once the pan is in place but the fact that the pan weighs differently every time is concerning.

Has anyone else noticed this? What are your thoughts.

Occasionally, between loading sessions, my pan will weigh 1/10 of a grain different. But, when you calibrate, then zero your pan, it will come back to zero every time you set the pan on it again...correct? That is all that matters. If the scale is zero with the pan on, the charge weight will be correct every time. No need to over think it.

I leave mine on if I'm doing a bunch of loading in a month. Otherwise, I turn it off between between sessions if I won't load for a month or more. I always calibrate before starting to load...after my unit has been shut off. There is NO need to calibrate during a loading session.

I keep several used drier sheets stored in the powder tube, and one on the pan with the lids closed. I wipe down everything with one of the sheets, at the beginning of each session. I have used this procedure with the same 1500 for over 20 years, and it just keeps working.

If you keep a straw in the powder discharge tube, it will clean out very easily at the end of a session.

 

[Charlie-NY]

Who did you use to ‘rebuild’ it?

These guys have/had a set price for a total rebuild. They were recommended by RCBS.

RCBS Repair

Lone Mountain Communications is a fully functional Two-Way radio communications maintenance facility offering extremely high quality workmanship, done right the first time. Lone Mountain Communications also provides new and reconditioned Two-Way radios, as well as parts, accessories and the...

lonemountaincommunications.com

 

[Charlie-NY]

Here's some interesting info from the site above, They "may" be the only company regularely rebuilding Chargemaster units and they are recommended by RCBS themselves.

WARNING -

The RCBS CHARGE MASTER 1500 digital scale is for use with smokeless powders only. Do not use with black powder (used in muzzle loading firearms). If black powder should come in contact with an electrical spark, an explosion may occur, resulting in serious injury or death.
Check calibration prior to each use of the scale and re-check frequently during use with the calibration weights provided. A spot check can easily be made during operation with an RCBS Scale Check Weight Set. If accuracy is found to be out of tolerance, the scale must be recalibrated as explained in the CALIBRATION section of the instruction manual. A scale with improper calibration will cause an incorrect charge weight which may exceed the maximum recommended load.

CALIBRATION PRECAUTIONS:​

Digital scales are very reliable devices. However, here are some events which may result in an inaccurate reading: * Change in temperature. If the temperature changes more than a few degrees, you must recalibrate the scale. Allow scale tostabilizefor20-30minutespriortouse.* Changes in scale location or an un-level working surface.* Un-centered weights on the platen. * Jarring of the scale during operation.* Use only the two calibration weights supplied for accuracy. *Weight accuracy is crucial. Keep weights clean and carefully stored. If dropped or damaged, have weights inspected against known standards. Contact RCBS Customer Service. * Static electricity can cause the scale to "jump around". If static build-up is evident, wipe scale with an anti-static sheet, or use anti-static spray. Spray on clean soft cloth first. Do not allow spray to get into mechanism. * If powder should get inside the unit, stop operation immediately and do not use scale until it has been serviced. Contact RCBS Customer Service.* Do not press on the platform with your hand. You can damage the load cell.

 

[Straightshooter1]

Do the cables that come with the battery you suggest work with the CM 1500, or do I need to get/make my cable elsewhere? (asking regarding size and polarity)

No cables came with the battery, so had to find and get what was needed to hook up my CM-1500:

Amazon.com

 

[Charlie-NY]

No cables came with the battery, so had to find and get what was needed to hook up my CM-1500:

Amazon.com

View attachment 1472226

I have a similar cable except that mine has right angle plug ends. Someone here provided a link to the battery and cable.