Lyman M-5 Zeros on Anything

[ColColt]

I just bought a Lyman M-5 Reloading scale off ebay. It looks like it was made a few months ago. However, having a hard time understanding why after I zero it according to the instructions(it's different than my old Lyman 5-0-5 in that it has a magnetic dampening system.) I put a small 10 gr weight in my 5-0-5 and it read right on the money. I put the same weight in the M-5 and you're suppose to move the large poise till it drops below zero and then move it back one notch...did that and with the smaller poise on 1.5, it zeroed the load making it off by that amount. I moved the smaller one again to zero and it zeroed itself to that change. I seem to be doing something wrong here. It shouldn't be difficult to adjust a scale but this one has me puzzled a bit.

The instructions that came with the scale indicated to move the large poise to the first notch which causes the beam pointer to drop below zero and then move it back one nothch. then, move the smaller poise to the notch with brings the beam pointer to zero and the combined weight is the sum of the two poise readings. Fair enough but, I didn't have to move the smaller one on another try with the 10g weight as it zeroed itself without moving it.

I tried a powder charge of 7.5 gr and dumped it into the pan of the M-5 and both large and small poise were set at zero and it stayed the same. I moved the larger poise to ten and it dropped below zero so, I moved it back one (five grain position) and it zeroed with out having to move the smaller one. What gives?

[1hole]

Not sure I follow you. You "zero" any beam with the empty pan in place and both poises on "0." Then the left side notches equal 5 gr. and the right side notches equal .1 gr.

[bbqncigars]

Make sure that there's no crud in the bearings (where the beam axle rides). Inspect the axle. It should have a sharp angle on it. Rounded edge=problems. I wouldn't use anything more aggressive than a brass brush on either part.

[ColColt]

The scale is clean and looks nearly as new. Maybe I didn't explain things clearly before. Here's what's throwing me off. I put a charge, measured with the other scale as 8.0 gr of powder, in the pan of the M-5 and with both ends(large and small) on zero, it never moved off center of the pointer. I moved the large slider down toward 5 from zero, still set with the pointer on zero. I moved it further to 10 and it bobbled down. I then moved it back one notch(set on 5 now) and it showed a true zero. Well, that was only 5 grs...not 8 as measured with the other scale. So, I moved the smaller tin poise down from ) to 1.5 grs-nothing. I moved it all the way to 5 which is at the far end and it bobbled downward. I kept moving the poise back till finally got to 8 on that scale and it zeroed there. Seems like a lot of unnecessary work to see where you're at.

Bottom line is the pointer never rises above zero like my other scale. I added a dime to the pan and it still didn't move off zero and should have moved downward even with the 8 grs of powder in it. It only moved when I moved the larger poise downscale to a heavier setting and then moved it back(as the instructions say to do) one notch at a time. It's a PITA if you ask me and for the moment, I'm sorry I bought it. This is what it looks like per the same photo on the site I bought it. The photo doesn't do it justice as it looks completely new. Even the plastic cover looks pristine.

http://i180.photobucket.com/albums/x220/ColColt/Misc%20Stuff/ScreenHunter_01Mar241937.jpg

[jaguarxk120]

Check the magnetic damping paddle for rubbing or binding. If you touch the beam it should swing freely the come to rest at "0" after a few swings.

Make sure the knife edges are centered on the bearings and nothing is binding or rubbing.

[462]

Are you sure your house isn't haunted? This scale and the newly acquired Lyman 55 have been giving you fits.

Have you set the poises to "0", with the pan and its hanger installed, and adjusted the leveling foot so that the pointer is reading "0"? Have you cleaned the pivots and their seats?

Seems to me that you are not "zeroing" the scale, to begin with, or the pivots are not moving freely.

Try this test -- stolen from Lee Precision. Cut a piece of printer-type paper 1/16" square. After zeroing the scale, place the piece of paper in the pan...the beam should move down and indicate that the paper weighs about 1/10 of a grain.

[ColColt]

Are you sure your house isn't haunted? This scale and the newly acquired Lyman 55 have been giving you fits.

Have you set the poises to "0", with the pan and its hanger installed, and adjusted the leveling foot so that the pointer is reading "0"? Have you cleaned the pivots and their seats?

Seems to me that you are not "zeroing" the scale, to begin with, or the pivots are not moving freely.

Try this test -- stolen from Lee Precision. Cut a piece of printer-type paper 1/16" square. After zeroing the scale, place the piece of paper in the pan...the beam should move down and indicate that the paper weighs about 1/10 of a grain.



Haunted? I know-I think it's vexed by my ex-wife. she hated guns and anything associated with it.


The poises both are set to zero, leveling screw turned till I obtain zero...just like all other scales. the pivot points and their cradle or bearings both have been cleaned with a bit of alcohol on a Q-tip and blown off.

I tried something similar as you mentioned with the piece of paper even before I read this. With a 10 gr check weight in the pan and the pointer on zero, I laid a Q-tip across the pan and the pointer didn't move up or down. My other measure, the Ohaus 5-0-5, would have went skyward with that addition. I would have thought the M-5 would have responded the same way.

[1hole]

"I would have thought the M-5 would have responded the same way. "

It will unless something is blocking it. The only thing 'unique' about the M5 is the extended range to 1005 grains. I got mine new in '65, it's still as 'dead-on' accurate and sensitive as the first day.

[ColColt]

OK-I figured out what the problem is but not sure how to correct it. I got down eye level with the scale and noticed the bottom of the pan is hitting on the table. Not the gold pan but the one it sits in. there's a little nut of a sort that the Phillips head screw goes into and it protrudes maybe 1/16" or so and when you put the gold pan on it's nearly touching the table. Put any sort of weight in it like the 10 gr check weight and it hits the table. this is with the scale initially zeroed. Problem solved but can't understand why it does that since my other scale is about 3/4" or more from bottoming out on the table.

[Char-Gar]

It only takes a very small bit of ferrous metal attached to the magnets to make that thing go wacky. Magnets being well..magnetic..they attract all kinds of little ferrous metal flakes.

[jaguarxk120]

If the pan holder is hitting the table then gently bend it enough to have clearance.
I think that hook is made of aluminum so be very careful.

Don't change anything on the holder(replacing screws,ect.) as that will upset the calibration of the scale.

[ColColt]

I don't know where my head was at. I was a bit reluctant to bend the hook but of course, that fixed the problem. Not sure how it got bent but "bowing" it out a little more gave enough clearance as to not rest of bump itself on the table. Just when you think you've seen and experienced all, something simple stumps you. Fortunately that's all there was to it and nothing wrong with the magnet. So, jaguarxk120, you were right.