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Induction brass annealer redux

Awesome, thank you itchy. I'd like to make a bit of a smaller coil to compromise between 7.5x55 Swiss, 303 British, 6.5 Creedmoor, and..... 223 Rem. I was thinking of a 5/8" or 3/4" coil that is double wound similar to VenatusDominus. The inner 3.5 turns would only give me about 0.15uH so I would need a much larger outer 1 1/4" outer coil with 5 turns to reach the 1uH (I'm simplifying double wound to two series inductors)
 
I would strongly suggest getting some
3mm high temp silicone fiberglass sleeve to slide over your tubing before winding. Uxcell on amazon had it but the 3mm appears to be out of stock. You may be able to find a replacement.
 
I have some 3mm Uxcell sleeve on order but it hasn't arrived yet. I will likely need to go back to 1/8" instead of 4mm OD copper tubing unless the sleeve can stretch over a 4mm tube. It's easier to find the metric tubing (at least for me) in Canada
 
oliverpsmile said:
Mr. George F. Vander Voort did the same (see my post 3,245). His 30 minutes @ 1200 F experiments gave me the idea to "excommunicate" the 1.88 sec Reese gospel.
Click to expand...
If you look at the Vander Voort graphic and look for the levels of hardness that Norma produce to or AMP work towards then it's more like 30 minutes at 700F. Using Reese's formula that implies more like 1s at 1000F (0.9s if one insists on one decimal place).

That too is much more consistent with Reese's own results which he published in his latest video. While he specifically notes that he doesn't know the exact temperatures the brass got to I think we can assume he was at least trying for 1000F as he specifically tested 1.9s. His 1s results were much closer to levels of hardness targeted by Norma and AMP. More accurately, the resulting hardness he achieved in 1s (119) was a bit higher than Norma/AMP targets (circa 100-110). Maybe he didn't achieve quite 1000F - we don't know. 1.5s was too soft (90). And 1.9s was very, very soft by comparison (66).

The bottom line is that without hardness testing for a specific setup we don't know what hardness/softness is being achieved. Of course, even if we did there would remain a debate over what level is appropriate. The 'good news' is that I think the cursory testing done by Reese gives me greater confidence that trying to target something like 1s at circa 1000F is going to be closer to the zone to which Norma and AMP operate.

(Anyone with a less sophisticated setup might well just punch through to briefly 'touch' 1200F. Three one hundreds of a second using Reese's formula and 30'@700F as t1/T1.)

Lastly, it is worth commenting that the slope of the softness vs time of Reese's results is still very steep. The delta between 0.5s and 1s was 20 (but the brass was still too hard vs Norma/AMP). The delta between 1s and 1.5s was 39 (with the latter softer than Norma/AMP). And lastly the delta for the shorter time interval between 1.5s and 1.9s was 24. If one seeks something like 100-110 you're not really dealing with a particularly flat time-softness response (as can be observed by looking at the Vander Voort graphic as well).

(Note also that in Reese's testing the only part of the case that softened was where he measured on the case "mouth". Also, resizing after annealing returned the hardness at this point back to its pre-annealing starting point. Obviously I'd anneal after sizing.)
 
itchyTF said:
3mm sleeve won’t go on 4mm tubing if it is the silicone impregnated fiberglass stuff.
Click to expand...
Get the expandable stuff. A bit more fragile but fits snugly. I used Insultherm® Ultra Flex® - 8 AWG - Natural, 25 ft cuts, from Wirecare.com. There are different sizes.
 
Just finally got my annealer all put together.. first coil ID was 1” 8 wraps pulling 20+ amps at 46.3v can’t turn psu down any further, second coil is 1.3” ID 8 wraps pulling 14amps empty.. should I try going to 10 wraps with the 1.3 coil?
 
Can’t seem to get dialed in still reading about 4 amps high.. I used a 50a/75mv shunt from another reader and looking in what I ordered it’s should be a 100a/75mv shunt.. would this be my issue?
 
itchyTF said:
How are you scaling the reading?
Click to expand...
Once I popped the meter out it had the 100/75 colored in so I ordered that shunt cuz the one I had was a 50/75.. I made the 1 1/8 8 wrap coil and was only pushing maybe 9amps at 45.7v, had to calibrate the voltage as well
 
SGK said:
If you look at the Vander Voort graphic and look for the levels of hardness that Norma produce to or AMP work towards then it's more like 30 minutes at 700F. Using Reese's formula that implies more like 1s at 1000F (0.9s if one insists on one decimal place).

That too is much more consistent with Reese's own results which he published in his latest video. While he specifically notes that he doesn't know the exact temperatures the brass got to I think we can assume he was at least trying for 1000F as he specifically tested 1.9s. His 1s results were much closer to levels of hardness targeted by Norma and AMP. More accurately, the resulting hardness he achieved in 1s (119) was a bit higher than Norma/AMP targets (circa 100-110). Maybe he didn't achieve quite 1000F - we don't know. 1.5s was too soft (90). And 1.9s was very, very soft by comparison (66).

The bottom line is that without hardness testing for a specific setup we don't know what hardness/softness is being achieved. Of course, even if we did there would remain a debate over what level is appropriate. The 'good news' is that I think the cursory testing done by Reese gives me greater confidence that trying to target something like 1s at circa 1000F is going to be closer to the zone to which Norma and AMP operate.

(Anyone with a less sophisticated setup might well just punch through to briefly 'touch' 1200F. Three one hundreds of a second using Reese's formula and 30'@700F as t1/T1.)

Lastly, it is worth commenting that the slope of the softness vs time of Reese's results is still very steep. The delta between 0.5s and 1s was 20 (but the brass was still too hard vs Norma/AMP). The delta between 1s and 1.5s was 39 (with the latter softer than Norma/AMP). And lastly the delta for the shorter time interval between 1.5s and 1.9s was 24. If one seeks something like 100-110 you're not really dealing with a particularly flat time-softness response (as can be observed by looking at the Vander Voort graphic as well).

(Note also that in Reese's testing the only part of the case that softened was where he measured on the case "mouth". Also, resizing after annealing returned the hardness at this point back to its pre-annealing starting point. Obviously I'd anneal after sizing.)
Click to expand...

You are missing my point. Your post is related to applying fixed level of heating power with at cutoff time to prevent melting with the hope that certain level of hardness will be achieved..

In contrast, with my closed loop temperature control system, I'm heating the brass at mentained 1000-1200 F for an extended period of time (longer that Reese formula sugstes) without any damage to the brass. It provides, for sure, ample time for a full annealing (the lowest level of hardness). The assurance comes from the experiments of Mr. Vander Voort and your "case study".

I agree with you, that the brass annealing should follow the resizing of the brass. The hardness will increase, to certain level, during seating of the bullets. As long as this level is consistent the accuracy would be guaranteed.

I'm planning, with a friend (number of world records - bench rest), to conduct accuracy/longevity test with a rail gun and at least 25 reloading-annealing cycles. The brass will be thoroughly measured every time.
 
So I ended up using the 1 1/8 coil.. just used one of my 6.5 creedmoor cases and amps went to around 13 at the end of cycle.. max amps my power supply is rated for is 12.5, should I worry about running this at 104%? Or should I try to wrap another coil slightly bigger then the 1 1/8?
 
No. We can each do exactly the same thing. As I have noted previously, I have implemented VenatusDominus's version as well. The technique is still dependent on accurately reading Tempilaq to "calibrate" a sensor ill-suited to the task (albeit the most economical solution we've found so far). None of our implementations include a hardness tester to verify results.

(I merely mention that those who haven't implemented this slightly more sophisticated version of the GinaErik annealer might well be advised too target a simply touch of a much higher temp than 750F, something like 1200F.)

I'm just suggesting that both (a) Vander Vort's work, when combined with Reese's formula, and (b) Reese's own actual hardness testing suggest that 1.9s at 1000F is highly likely to yield brass much softer that what Norma's production lines do and softer than levels targeted by AMP. Each point to a time about half of that. And so maybe that's a better guess than 1.9s at 1000F.

Because we haven't done any hardness testing with our own systems, we don't actually have any idea what softness is achieved by whatever settings we choose to work our annealer's at and until we do we never will. Nor do we have a good understanding of what level is ideal. The only useful guidance I've seen in this are is the work done on Norma brass and AMP's work.

Good luck and let us know the results of your testing.
 
Michaelt said:
So I ended up using the 1 1/8 coil.. just used one of my 6.5 creedmoor cases and amps went to around 13 at the end of cycle.. max amps my power supply is rated for is 12.5, should I worry about running this at 104%? Or should I try to wrap another coil slightly bigger then the 1 1/8?
Click to expand...
I wouldn't
 
Michaelt said:
So I ended up using the 1 1/8 coil.. just used one of my 6.5 creedmoor cases and amps went to around 13 at the end of cycle.. max amps my power supply is rated for is 12.5, should I worry about running this at 104%? Or should I try to wrap another coil slightly bigger then the 1 1/8?
Click to expand...
You need a supply with more headroom (power).
 
Michaelt said:
What do you mean? So it adjusts further down? Or higher max amp? I was looking already but I think I’ll use this one until it pops. Lowest it will go is 45.7v.
Click to expand...
Higher max amp. 1,000 watts should provide what you need with reserve. 36v would provide more current (27A).
 
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