Just spent 2 days re-hosting ALL the images that got lost from the build-log a while back. So while we're on a roll... here's a few more... with yet more of the final body-work to come over the next few weeks as we get ready for summer =0)
Upgrades "Mark 2" 2S Battery Pack:
Old-ish news, but on the way to finishing off the build so posting this here for completeness.
* Samsung INR18650-25R's
: 20A continuous current delivery, 2500mAh. A decent solid-perfoming18650 battery. This was the gold standard for vaper's for ages and so is super-cheap and varifiably genuine ones are readily available, and has been a pretty good performer in tthe HushPuppy.
Samsung INR18650-25R test
* Sony VTC5A's
: 25A continuous current delivery, 2500mAh. Harder-hitting and longer-lasting than the Samsung 25R. A bit more expensive, but possibly the best 18650 battery around for this application.
Sony VTC5A test
Turnigy Graphene 65C 1800mAh 3S Lipo test using the same methodology
. 3S rather than 2S, but included here as an "Apples-to-Apples" comparison of Lipo to 18650. Of course it's a MUCH better battery, but the test results might be a bit of an eye-opener for the 18650 nay-sayers out there as far as claimed v's actual performance on a level playing field. For those who want to delve deeper, there's a huge list of other battery tests (3S Lipo's right at the top) on this page.
1. On the right, the HushPuppy's Mark 1 battery pack. On the left, the new and improved Mark 2. And yes... Mark 3 is in developement (think 21700 format...)
2. Mark 1 battery pack - 2x Samsung INR1865025R's in a (cheap) high-current drop-in tray (shown here before the 12AWG wiring was soldered in to connect everything up...). In this set-up, the individual cells have to be removed for recharging. This makes construction really simple, but is a pain to use long-term. Connection between the cells and the output is simply a pressure fit between the contacts - better than coil springs, but still adds a lot of internal resistance to the completed battery pack = less current available at the business end.
3. HushPuppy Mark 2 Battery Pack : 2x Sony VTC5A's welded up into a proper rechargeable 2S pack with a female XT60 output directly attached to the cells via two thicknesses of 0.4mm nickle plate. 22AWG balance taps to the built-in MR30 3-pin female balance-charging connection and a 4-segment LED momentary-switched voltmeter. Better batteries + welded connections (rather than pressure-fit in Mk 1) so lower internal resistance (IR) = better able to dump current out of the XT60 = MOR POWAH!
3a. Mark 2 battery pack - fully disassembled.
4. Mark 2 Battery pack - Internals pre-wire...
5. About to spot weld the second layer of nickel tabbing from the XT60 connector directly to the batteries. A double-stacked tab was spot-welded to bridge the batteries at the other end after this weld was completed.
6. Mark 2 Battery Pack - Internals Assembled
7. MR30-to-JST balance-tap adapter - connects to a standard 3-pin JST balance charger (just like a Lipo)
8. Testing Impedance Meter's internal resistance. To the left is the XT60 female connector with double-stacked nickle tabs soldered on ready to be welded to the 2S 18650 pack.
9. A Sony VTC5A (25A discharge, 2500mAhr. IR Reading: 11.0mΩ (its mate was reading 10.9mΩ)
NB: Older model VTC5's (20A discharge) were spec'd at 13mΩ's so this IR reading for a better performing battery seems on track, plus Mooch's test of a VTC5A
on his gear gave a reading of 11.1mΩ, so these are probably relatively accurate numbers.
10. 2x Sony VTC5A's in series to make a 2S "pack" in the Mark 1 Battery Pack (drop-in high-current tray). IR Reading 33.7mΩ - not brilliant but OK.
11. 2x Samsung INR18650-25R's (20A discharge, 2500mAh) in the same Mark 1 drop-in high-current tray. IR Reading: 39.6mΩ.
Individually, these batteries were reading 14.0mΩ each. A quick comparative calculation with the VTC5A's then puts the additional resistance added by the "tray" part of the pack at ≈11.7mΩ.
12. HushPuppy 2S Battery Pack Mark 2. IR Reading: 18.9mΩ .
I have no idea how this managed to be LESS than the combined IR's of the two batteries (tho these are quick and dirty readings...) but its certainly a marked improvement on the drop-in tray.
13. Just for comparison, a Turnigy 1000mAhr 2S 65C Graphene Lipo
IR Reading: 6.8mΩ.
DAMN, but that's low! Looking forward to seeing how this fares in a comparison shoot-out between all three. Sadly while this little Lipo would be ideal for the Hushpuppy in it's current configuration, it solidly refuses to fit in the existing removable battery-box format. Because of the way the wires run (they're VERY chunky...), even if I trim and re-solder them I'd have to invert the XT60 connection to the blaster (and so the other two battery boxes too...) That'll have to wait till the next build...
Update: Pusher-Box Covers:
Box still waving in the wind... so dressing the sides up. 1st bit is off a Rapidstrike shoulder-stock arm:
Next is chopping into some venerable 6-dart mags:
Caaaaareful glue-up with Devcon. The pusher-box was already held pretty precisely and rigidly by the holes cut in the existing shell, but we didn't want to change that alignment and certainly didn't want to go gluing the box to this new (permanent) part of the shell.
Update: Finalising Sling Attachment-points:
The original sling-points: top one needed a hole filled in the shell under it, and the bottom one... well... just wasn't doing it for me. The velco got in the way and to be honest, ruined the lines of the blaster a bit.
Picking a segemnt of RS shell to colour-match // Cut and filed to fit // Hole filled!
Trialling a Hammershot sling attachment-point. The original idea had this retracting into the shell when not in use. To make the HS sling-point fit though I had to make it permanently extended. // Bent and bogged into place in shell. // Turned out to be too restrictive on the clasp, so looked for an alternative...
Settled on using an aluminium mini-carabiner, and managed to make it retractable this time. Two detent positions (open/closed) provided by filed flats on the tight curved end of the arm. Pushes out with your finger and clicks into place around the internal screw, or pushes back into place and clicks closed:
Greetings, Nerflings - We come in peace. Shoot to Thrill!