"Tuning" a balance beam

[hoz53]

I got obsessed with this friggin scale tuning experiment and went at it again today to do more refinements. I have now quit before my wife hauls me off to the psychiatrist. Pretty much have it to estimated .01-0015g off zero repeatability under load measuring 50 times by lifting the pan and resetting. And now 100% of the time it will noticeably register one kernel drop of varget which is .020. Trickle test worked great.

The main thing I learned from this exercise is to never use a balance beam for accuracy weighing without having check weights. Forget the zero when empty...just dial it in close and then use check weights to match your desired powder weight and then zero it. If you want sartorius style repeatability to the 10th of a grain every time then you need to zero at the pressure the knifes have on the bearings at the load you are weighing. At least thats what I believe and am gonna do from now on.

Thats interesting. Thanks for all the info. What material did you use for the pointer?
Looks like aluminum. How did you fasten it on there? Some guys believe you should use a nonmagnetic pointer. AL is I know.

 

[Tesoro]

I raided my wifes sewing stuff and found an appropriate sized ss sewing machine needle and cut it to size. Used gorilla super glue.
The beam is steel so needle metal shouldnt make any diff?

 

[Homerange]

If you want sartorius style repeatability to the 10th of a grain every time then you need to zero at the pressure the knifes have on the bearings at the load you are weighing.

Have you tried some sort of dry lube ?
Powdered graphite would be my choice.

 

[1066]

I raided my wifes sewing stuff and found an appropriate sized ss sewing machine needle and cut it to size. Used gorilla super glue.
The beam is steel so needle metal shouldnt make any diff?

The beam on the M5 scale is some sort of aluminium (non-magnetic) however the little stud that the auxiliary weight hangs from is steel. This is not normally a problem but if you are planning on uprating the damping by exchanging the original magnets for stronger "rare earth" magnets then, if you don't use the 500-1000gn range, you would be better off removing the stud and replacing it with a small brass nut and bolt of similar weight.

I always use non-magnetic material for the extended pointers I fit. Usually brass or copper.

 

[hoz53]

The beam on the M5 scale is some sort of aluminium (non-magnetic) however the little stud that the auxiliary weight hangs from is steel. This is not normally a problem but if you are planning on uprating the damping by exchanging the original magnets for stronger "rare earth" magnets then, if you don't use the 500-1000gn range, you would be better off removing the stud and replacing it with a small brass nut and bolt of similar weight.

I always use non-magnetic material for the extended pointers I fit. Usually brass or copper.

ya this is what I thought. I was going to try a nylon bristle from a brush but I think the copper or brass would be better.

 

[Tesoro]

my scale works just fine with the ss needle. I had some weird floating going on yesterday and took me a few to realize it was the am/fm radio I had too close to the scale! They say fluorescent work lights can create a mess also. I have led flourescents and they dont effect it.

I dont know about messing with the magnets on the m5. check out what they look like!

 

[Tesoro]

Have you tried some sort of dry lube ?
Powdered graphite would be my choice.

I tried pencil lead for the heck of it. No diff and I think when you have your knife edges just right then lube can only hinder it and not help.

 

[fguffey]

I have repaired a few balance beam scales. I start with lead shot, I crush the lead shot with a hammer then slice the thin shot into strips. I also have a bag of lead shot from RCBS that is used when repairing a balance beam scale, I cut the smallest shot into strips.

F. Guffey

 

[1066]

I tried pencil lead for the heck of it. No diff and I think when you have your knife edges just right then lube can only hinder it and not help.

Yes, no lube of any kind needed.

 

[1066]

ya this is what I thought. I was going to try a nylon bristle from a brush but I think the copper or brass would be better.

A piece of copper wire from ordinary mains cable works well - To get a nice stiff straight bit, cut a length of a few inches and clamp one end in a vice, hold the other end in the chuck of your electric drill. Give it a spin and you will have a dead, straight work hardened length of copper wire.

 

[hoz53]

my scale works just fine with the ss needle. I had some weird floating going on yesterday and took me a few to realize it was the am/fm radio I had too close to the scale! They say fluorescent work lights can create a mess also. I have led flourescents and they dont effect it.

I dont know about messing with the magnets on the m5. check out what they look like!

first -yes I took mine apart some time ago to look at the magnets. There were guys on here claiming the magnets could move and cause problems.
Mine could move in the holder so i silicon caulked them.

Second. Tell me isnt so---One of the reasons for a balance beam instead of an electronic is to not worry about lights-radio waves ect. Ahhhhh it cant be can it

Third--And as far as the pointer---Being an obsessive means its never good enough doesnt it

 

[Tesoro]

HAH if its good it can always be better!!!

I had my portable radio turned on about a foot from the scale..I was using it as a breathing shield for the pan. when I turned it off all went back to normal. I read somewhere that overhead flourescent bench lights can also interfere too. probably if they are real close liek on an adjustable arm. Also I had my computer right next to the scale using it to see the pointer and didnt phase the balancing.

A tip - if you have any little 22 shotshells then the shot works great for final balancing. Also if you pop the stars out of primers they work well. Can clip the little arms off for micro adjustments too.

good idea I will change mine to copper. Will give it the matching classic look!

 

[500Stroker]

I just did a test weigh on my batch on my digi and it came out to .29gr per kernel in averaged in a grain. And then cross checked on my balance with the same kernels and then substituted kernels for a 1g check wt. What I learned is my digiscale - with reported .03 gr accuracy - would be off by one kernel but still read the same but the balance beam would show the difference immediately. However I am not getting obsessed over weighing to one kernel!

I dont know if I have been staring at my scale too much recently or what but when I look at the needle in the attached pick it hovers slightly!!

I like the pointer on your scale. Is that the stock setup or did you add it?

 

[Tesoro]

I like the pointer on your scale. Is that the stock setup or did you add it?

Its part of a ss sewing machine needle and a dab of gorilla glue

 

[Schutzen2]

I solicit used parts that reloaders have replaced and no longer need to donate to new loaders. Scales always need a good tune-up and I have done quite a few. Cleaning solves most problems but getting rid of friction caused by wear is usually necessary. I have test weights that go from 5 to 500 grains and found it necessary to test with full scale range to insure linearity. Sensitivity requires that the scales pivots never bind but they almost always do. That is why it can take several grains to get a beam to move from its rest position at the top and bottom of the beams travel. I don't know how anyone can do this work for money and charge less than the price of a new scale. I do it for free to get new people involved in the hobby. I also have refurbished presses, dies and powder measures.

Quick shameless ad: I am always in need of equipment so if you have any old stuff you don't use let me know!

I have a complete rcbs 5-0-5 you can have if you want it. I have a tuned 10-10 and an m5 now so I'm pretty sure I'll never use it again. Be glad to donate it to someone who could use it

 

[hoz53]

HAH if its good it can always be better!!!

I had my portable radio turned on about a foot from the scale..I was using it as a breathing shield for the pan. when I turned it off all went back to normal. I read somewhere that overhead flourescent bench lights can also interfere too. probably if they are real close liek on an adjustable arm. Also I had my computer right next to the scale using it to see the pointer and didnt phase the balancing.

A tip - if you have any little 22 shotshells then the shot works great for final balancing. Also if you pop the stars out of primers they work well. Can clip the little arms off for micro adjustments too.

good idea I will change mine to copper. Will give it the matching classic look!

Hi Tesoro. Just saw your reply to my post. Say have you noticed the agate bearings can move around in their holders. Wondering if you addressed this issue? On one hand they can self align which is probably good but on the other I see them moving when using the scale so this could cause inconsistencies. Whadya think?

 

[Tesoro]

Hi Tesoro. Just saw your reply to my post. Say have you noticed the agate bearings can move around in their holders. Wondering if you addressed this issue? On one hand they can self align which is probably good but on the other I see them moving when using the scale so this could cause inconsistencies. Whadya think?

I think more important to make sure your pivot beams are both wiggling evenly when your pan is slowing down from swinging. I think the agates moving help things out or they would have made them fixed.

 

[Tesoro]

I have a complete rcbs 5-0-5 you can have if you want it. I have a tuned 10-10 and an m5 now so I'm pretty sure I'll never use it again. Be glad to donate it to someone who could use it

Have you tried putting the 5-0-5 pan on the m5? its nicer as contoured. I am going to swap pans from my 5-0-5 to my m5. the 505 pan is too heavy empty of counterweights but it looks like might be able to clip a portion of the wire hangar under the pan to lighten it up. i havent tried yet.

 

[Schutzen2]

Have you tried putting the 5-0-5 pan on the m5? its nicer as contoured. I am going to swap pans from my 5-0-5 to my m5. the 505 pan is too heavy empty of counterweights but it looks like might be able to clip a portion of the wire hangar under the pan to lighten it up. i havent tried yet.

I did not think to even compare them but I will now. Unless it's considerably better I probably won't go through the process of trying to adjust the weight to get it to work. Thank you for the heads up.

 

[1066]

Hi Tesoro. Just saw your reply to my post. Say have you noticed the agate bearings can move around in their holders. Wondering if you addressed this issue? On one hand they can self align which is probably good but on the other I see them moving when using the scale so this could cause inconsistencies. Whadya think?

The agate bearings are designed to move about. Ohaus patented the floating bearing system in 1928, it was a significant step in the development of the mechanical balance.

The bearings sit on a small domed pillow allowing them to self align and help reduce friction.