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Popsbengo

Electronic Seating Force Monitor

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I was looking at various arbour press seating force monitors -  all mechanical; either compressing a spring with a dial gauge, or hydraulic with a pressure gauge.  All very expensive and 'analogue" with no recording possible.

It seemed to me that the simple answer was to measure the force applied electronically and then apply that to a data logging app to record and display pressure used to seat bullets.  I've made a force-sensing pad and interface.  Currently 22lb max but I may up that to a higher maximum based on experimenting with various calibres and neck tensions etc.   The force monitor is compressed by the forces acting linearly between the arbour face and the base - the force sensor does not compress so the 'feel' is still the same.

My Sinclair arbour press is unmodified and the force pad can just be lifted out of the way if using a neck die etc.

(The insulated sheet is just temporary to avoid shorting out the electronic module until I enclose it)

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I don't know if this helps or confuses but Litz gave up on a pressure measurement of seating force as it varied wildly based upon how quickly / forcefully you seated the bullets.

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31 minutes ago, DaveT said:

I don't know if this helps or confuses but Litz gave up on a pressure measurement of seating force as it varied wildly based upon how quickly / forcefully you seated the bullets.

No that's no help 😂

 

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47 minutes ago, gruntus said:

Hi Pops,

Targestmaster does these.

G

 

Interesting, bet mine cost less.

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I hope to use it over the next 4 weeks.

Will feed back once I'm familiar with it.

G

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AMP have produced one of these, look at the AMP shotshow 2020 vids on youtube.

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8 hours ago, Popsbengo said:

No that's no help 😂

 

Sir I admire the work you have done. Never in my wildest thoughts would I consider this I do hope it  results in better ammo and groups.

Once again you give me pause to ponder the science involved. My thought is you may be able to improve a consistent pressure while seating. Best wishes for good shooting.

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Popsbengo,

I had a similar, if mechanical, device on an arbour press many years ago to try and define/measure seating force and therefore consistency of neck tension as it made sense to do so.

Gave up after I realised that any seating ‘by hand’ i.e. if it was me pulling the lever on the arbour press, then there was still a variable that negated the data from sexy measuring tools. You might find also, sub consciously, that you start to use the arbour press in such a way that ‘you’ maintain the constant reading

IMHO unless you fit a motor drive to the arbour’s lever that rotated the mechanism at the same speed every time then any measurements you gain can be effected to a greater degree by you as opposed to the operation you are trying to define. I.e. you cannot just look at one variable.

You ‘should’ be able to see large errors, but I could always feel them when using an arbour press without any 3rd party device.

T

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3 hours ago, terryh said:

I had a similar, if mechanical, device on an arbour press many years ago to try and define/measure seating force and therefore consistency of neck tension as it made sense to do so.

Gave up after I realised that any seating ‘by hand’ i.e. if it was me pulling the lever on the arbour press, then there was still a variable that negated the data from sexy measuring tools. You might find also, sub consciously, that you start to use the arbour press in such a way that ‘you’ maintain the constant reading

IMHO unless you fit a motor drive to the arbour’s lever that rotated the mechanism at the same speed every time then any measurements you gain can be effected to a greater degree by you as opposed to the operation you are trying to define. I.e. you cannot just look at one variable.

You ‘should’ be able to see large errors, but I could always feel them when using an arbour press without any 3rd party device.

I appreciate there is an issue regarding the 'visual feedback loop' when using mechanical indicators; that's why I want to chart the resultant force profile;  I don't need to look at the chart whilst running the bullet down so it's similar to "feeling the force" only with a record for comparison off-line.  I had considered making a LED array (like a rev counter) to give a rising force indication but realised that was one of the reasons to not make or buy a mechanical unit.

Regarding motorisation:  That's do-able, there's not much to the electronics, but it means making a motorised arbour press, again easy enough but a faff.  I may investigate especially if justifies my purchase of a milling machine 🤔😁

If the whole thing results in an uncertain data set, so be it:  it started out as a way to evaluate the thin-film force sensor device and application as an alternative to a load-cell (like Targetmaster) and keeping the hand-eye-brain coordinated during lockdown.

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7 hours ago, KABOOM said:

Sir I admire the work you have done. Never in my wildest thoughts would I consider this I do hope it  results in better ammo and groups.

Once again you give me pause to ponder the science involved. My thought is you may be able to improve a consistent pressure while seating. Best wishes for good shooting.

much appreciated thank you.  I don't hold out too much expectation!

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One thing is clear. Whenever you see people using an arbor press with any form of indicator they are very steady and gentle. Yes they might be doing this to note the seating force but I’m sure it makes a difference. 
 

My cheapo machine mart arbor press is too small to accommodate 7mm Rem Mag and I’m about to buy a proper arbor press. 
 

Question is, do I spend the extra and get one with an indicator?

 

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PbG,

Indeed looking at the details is interesting.

Slightly off OP but related, I've always been interested in 'what' goes on between bullet and brass i.e. what sort, if any, of bond starts over time, cold welding? Do you short seat your rounds then then the night before fully seat them? Being able to measure is there is any change in resistance could be good?

I did notice that brass cleaned in a wet tumbler were too clean and had increased seating effort hence I 'regular' tumble in media after wet cleaning (which is now and then) and this restores the smooth feeling during seating.

Also only wire wool the outer neck/shoulder when annealing - do not mind the carbon being baked on, again feel this helps reduce any binding or scraping during seating.

As to coatings, perhaps bullet coatings help? I've seen where graphite in a carrier is applied to inside the neck (never tried it myself). Only thing I do currently is use the Imperial sizing next powder/ball applicator. Seems to do no harm.

Still, gives us things to play with.

Brgds T

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This link is also worth a a watch.

For me I think (?) I just want repeatability and consistency mostly to get a really predictable velocity and it's subsequent reliable vertical placement down range.

As far as reloading progression this is probably just the next step for me (personally) following consistent brass, annealing and powder weighing.

I have a forster press which has masses of leverage but not really ideal for the feel or measuring of bullet seating (but Is often noticable).  By using an Arbor press and a gauge if I can spot an anomolous bullet it will allow me to cull or put aside as clearly there is some form of difference in neck tension and I am keen to observe with this form of measurement if my current annealing process is good enough!!! 😉 I certainly can't justify an AMP! 

I will test and observe the k&m mechanical function and also the targestmaster measuring as well. It will of course take some time but that appears to be the name of the game when it comes to men in shed reloading. 🙂

All of this is just another rabbit hole do go down of course and the real mantra should just be " go out and shoot"!!!🤣🤣🤣

 

 

 

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9 minutes ago, gruntus said:

This link is also worth a a watch.

For me I think (?) I just want repeatability and consistency mostly to get a really predictable velocity and it's subsequent reliable vertical placement down range.

As far as reloading progression this is probably just the next step for me (personally) following consistent brass, annealing and powder weighing.

I have a forster press which has masses of leverage but not really ideal for the feel or measuring of bullet seating (but Is often noticable).  By using an Arbor press and a gauge if I can spot an anomolous bullet it will allow me to cull or put aside as clearly there is some form of difference in neck tension and I am keen to observe with this form of measurement if my current annealing process is good enough!!! 😉 I certainly can't justify an AMP! 

I will test and observe the k&m mechanical function and also the targestmaster measuring as well. It will of course take some time but that appears to be the name of the game when it comes to men in shed reloading. 🙂

 

Yes, I watched the link some time ago and decided to go out and do something 'better' for the reasons mentioned earlier.

To me, the whole point is to improve consistency - neck tension is an interesting area to examine.  Some report (Andrew in the US I think?) that taper crimping is the answer as it 'overrides' any small differences in tension thereby giving an equalised starting pressure.  I want to check this for myself against other ways of equalising neck tension (which is in itself an indirect way of understanding bullet/neck stiction & friction).

I've wondered if the perceived benefits of jamming into the lands is partly down to equalising the release point of the bullet (ie when the bullet first starts to move).

Then there's HBN to throw into the mix - that must reduce the pressure at which the bullet starts to move.   Endless variables going around and around 🤪

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32 minutes ago, terryh said:

Slightly off OP but related, I've always been interested in 'what' goes on between bullet and brass i.e. what sort, if any, of bond starts over time, cold welding? Do you short seat your rounds then then the night before fully seat them? Being able to measure is there is any change in resistance could be good?

I did notice that brass cleaned in a wet tumbler were too clean and had increased seating effort hence I 'regular' tumble in media after wet cleaning (which is now and then) and this restores the smooth feeling during seating.

Also only wire wool the outer neck/shoulder when annealing - do not mind the carbon being baked on, again feel this helps reduce any binding or scraping during seating.

As to coatings, perhaps bullet coatings help? I've seen where graphite in a carrier is applied to inside the neck (never tried it myself). Only thing I do currently is use the Imperial sizing next powder/ball applicator. Seems to do no harm.

I always tumble after ultrasonic cleaning.  I've learnt to do 'just enough' ultrasonic as too much certainly roughs up the brass and doesn't add anything to the clean.  Not sure about the need for wire wool ?   I use my molten salt bath annealer (home made) and dunk the cases into lots of hot water to wash off any carry-over salts - the necks are nice and clean

I have tried leaving lube in the necks, Mv ES goes bad.  I ensure dry, clean and tumbler polished now.

Graphite?  Not sure about introducing yet more carbon.   HBN would be a better option altogether I think although that's more about reducing barrel friction.

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Nice piece of work.  Years ago I engineered something similar for compressing the charge in black powder loads where uniform compression is critical to accuracy. It worked well enough. Later I saw that someone was marketing a gauge that slipped over the ramrod of a muzzle loading rifle to measure charge compression in that venue. Not the same application but similar technology.~Andrew

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2 hours ago, Popsbengo said:

Yes, I watched the link some time ago and decided to go out and do something 'better' for the reasons mentioned earlier.

To me, the whole point is to improve consistency - neck tension is an interesting area to examine.  Some report (Andrew in the US I think?) that taper crimping is the answer as it 'overrides' any small differences in tension thereby giving an equalised starting pressure.  I want to check this for myself against other ways of equalising neck tension (which is in itself an indirect way of understanding bullet/neck stiction & friction).

I've wondered if the perceived benefits of jamming into the lands is partly down to equalising the release point of the bullet (ie when the bullet first starts to move).

Then there's HBN to throw into the mix - that must reduce the pressure at which the bullet starts to move.   Endless variables going around and around 🤪

They call it chasing rainbows 🤪

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I dip my necks in graphite before bullet seating as I tumble brass and I've heard of the "cold welding" being a reality.

I have some HBN sitting on the shelf for testing at some point in the future but just as I was going to go on the journey VarmLR gave me some really sound advice and guidance for brass prep and consistency (which I'm grateful for and what makes this forum such a good place for sharing knowledge). From what I have read on HBN it is definitely worth exploring for consistency of velocity.

@PopsB - Pops wrt salt bath annealing how have you found the salt annealing as a process versus gas torch annealing?  I was very interested previously but got a bit "windy" with the temperatures involved and the potential consequences. * I pictured myself dressed in gauntlets, leather apron and full face mask like a foundry worker to be safe enough! 🙄🙂

I certainly see the benefit of very consistent temperatures and repeatability over gas torch however and the DIY option here on the forum looked really reasonable for the cost involved.

Your thoughts and experiences respectfully requested! 🙂

All the best

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2 hours ago, gruntus said:

I dip my necks in graphite before bullet seating as I tumble brass and I've heard of the "cold welding" being a reality.

I have some HBN sitting on the shelf for testing at some point in the future but just as I was going to go on the journey VarmLR gave me some really sound advice and guidance for brass prep and consistency (which I'm grateful for and what makes this forum such a good place for sharing knowledge). From what I have read on HBN it is definitely worth exploring for consistency of velocity.

@PopsB - Pops wrt salt bath annealing how have you found the salt annealing as a process versus gas torch annealing?  I was very interested previously but got a bit "windy" with the temperatures involved and the potential consequences. * I pictured myself dressed in gauntlets, leather apron and full face mask like a foundry worker to be safe enough! 🙄🙂

I certainly see the benefit of very consistent temperatures and repeatability over gas torch however and the DIY option here on the forum looked really reasonable for the cost involved.

Your thoughts and experiences respectfully requested! 🙂

All the best

Have a gas flame annealing machine which I made, spins the case in the flame and the dwell-time is adjustable.  It works OK but gas pressure varies with temperature and it's difficult to monitor annealing temperature.  Tempilaq is difficult to use and  iffy results requiring constant fiddling so I don't bother with it now.  Induction heating would be better but it's not worth the money to me.

Salt annealing is incredibly consistent and dead easy to monitor temperature.  I have a thermocouple probe in the salt and use a metronome app to time the insertion ( 4sec typically).  It's a bit tedious by hand but I'm not doing thousands. Re safety; 520 Celsius molten salts is not to be taken lightly for sure however it's no more dangerous than handling molten lead (or reloading 😉).  I do wear a leather apron and a face shield visor but no gloves.  I sit the whole rig into a stainless steel tray so any leak will be immediately contained.  I was going to modify the Lyman controller to PID loop control but it doesn't need it,  I'm standing there doing the feeding and timing so I just tweek the stat as required - actually it's very stable once up to temperature requiring very little adjustment beyond a 5min pause at 50 cases when doing .338LM.  A bucket of hot water to receive the cases stops the heat running down the case and cleans the salt off.  Water and molten salt do not mix - splashes must not occur 😳!!

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2
1 hour ago, Popsbengo said:

Have a gas flame annealing machine which I made, spins the case in the flame and the dwell-time is adjustable.  It works OK but gas pressure varies with temperature and it's difficult to monitor annealing temperature.  Tempilaq is difficult to use and  iffy results requiring constant fiddling so I don't bother with it now.  Induction heating would be better but it's not worth the money to me.

Thanks PopsB, 🙂  👍  That's definitely been my experience. I am using a DIY setup with Tempilaq and the Gas torch method isn't 100% rinse repeat enough in my view.  I spend an embarrassing amount of time prepping brass and not being able to anneal consistently like the salt bath doesnt do it justice.

Think I will need to revisit the Salt annealing thread now and start pulling together a kit list for building one.  

I certainly plan on doing the salt bath annealing outside, under cover, no rain and with all the PPE.  Hopefully, the neighbours don't think I'm into some kind of sort of foundry fetish!!!   🤣🤣🤣

Thanks again.

G

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PbG,

gas flames & salt annealing = risky for me. I plumped for an AMP as I can pick up and drop and/or leave unattended to go in for lunch etc.

Gruntus - the K&M + load gauge was the system I tried a few years ago, effective but I was not going to motorise it after seeing it was ‘me’ who could easily vary the measurements by +/-15% 

T

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On 6/14/2020 at 4:35 PM, Popsbengo said:

Salt annealing is incredibly consistent and dead easy to monitor temperature.  I have a thermocouple probe in the salt and use a metronome app to time the insertion ( 4sec typically).  It's a bit tedious by hand but I'm not doing thousands. Re safety; 520 Celsius molten salts is not to be taken lightly for sure however it's no more dangerous than handling molten lead (or reloading 😉).  I do wear a leather apron and a face shield visor but no gloves.  I sit the whole rig into a stainless steel tray so any leak will be immediately contained.  I was going to modify the Lyman controller to PID loop control but it doesn't need it,  I'm standing there doing the feeding and timing so I just tweek the stat as required - actually it's very stable once up to temperature requiring very little adjustment beyond a 5min pause at 50 cases when doing .338LM.  A bucket of hot water to receive the cases stops the heat running down the case and cleans the salt off.  Water and molten salt do not mix - splashes must not occur 😳!!

I did a batch of salt annealing the other week with the hot water in the usual 2l measuring jug on the floor...... which normally results in water splashes all over the floor around the jug, ‘cept this time I gaffer taped a length of rainwater downpipe to the worktop with the bottom end under the water level in the jug. 
Made life a whole lot easier just dropping the hot cases down the tube rather than bending down and aiming the case at the water... as an extra precaution I angled the tube away from the salt annealer. I also halved the time taken by doing 2 cases at a time. 
 

cheers

 

fizz

 

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