[Pretzel]

In my quest for testing everything, I wanted to know which of my regulators was better; the gold standard Redline SFR, or the P* MR Gen 2. So I shot about 50 times into my BB trap to get the bucking warm, then put 20 rounds each through the chronograph at about 2rps with first the MR then the SFR. Here's the data (which indicates, huh, MR is actually slightly better for this application!):

I forgot to write down one round for the MR somehow, but... good enough.

Looking at these numbers further, perhaps a total clean and rebuild of the SFR would improve it, because it has strings of identical fps shots, but the strings themselves have "large" jumps, while the MR has shot to shot inconsistency, but in a smaller range overall. Still, while I'm not netting +/- 1 100% of the time, 90% of my shots are +/- 1.4 on both regs, and 80% do fall inside the +/- 1 range, which I think is pretty decent for an AR.

Going to try with the one larger metering screw and re-test consistency, then print a spacer and boost the PSI just a smidge as apparently that's the solution, and see what I get for consistency then.

Accuracy testing tomorrow hopefully!

 

[SiliconeSword]

That's kinda interesting, I'd consider sending you my MRS to compare if you were interested in that

 

[Pretzel]

That's kinda interesting, I'd consider sending you my MRS to compare if you were interested in that

Probably not worth it, plus once I have this thing tuned I'm probably not going to want to touch it again in terms of any testing of anything haha.

Ran the tests with a 1mm and 2mm spacer in the kythera, used the SFR because it was still on the tank. Pressure was adjusted between spacers to maintain... similar FPS.

TL;DR: DON'T USE SPACERS ON THE KYTHERA.

I "knew" that from earlier testing, but I didn't have 20 shot strings of data with too much math in a spreadsheet. Now I do, and yeah... spacers suck. It might be worth trying a like... 0.5 spacer, but again... why bother at that point.

It only improved literally one point, and that was from 2.35 > 2.00 +/- on the 1mm, but the 2.35 is because I had one singular BB randomly go yeet and clock in at 334. Once you trim out one each of the highest and lowest it's no question, spacers are bad, at least in my build.

Now time to test the slightly larger screw for consistency!

Or all of my tanks could be out of air, sure why not... I don't think my gauge seals perfectly, my 15ci lost 1,000psi over dinner so I'm out of air... damnit. Gonna have to pump a few of the 13s up tomorrow by hand...

 

[SiliconeSword]

Check the fill fitting on your tank, it may be covered in white junk, and I'd just take the whole thing apart and clean it too. I imagine it's a First Strike, so you'll want a GOOD FITTING Allen key to take off the fill fitting or upper part.

 

[Pretzel]

It was the digital gauge inline that was the issue I think, just a slow leak over time, probably didn't screw it in tight enough when I assembled it (or the gauge itself has a leak...).

Thankfully no cocanium in my tanks currently, had that issue once and blew the airline clean off my F2 when the dust got into the SFR and made it creep to well over 180psi at a game. Glad I took a few test shots first before I started blowing holes through things (I was supposed to be at ~80psi to get 1.85j, no clue what I was hitting at 180psi, but saying it was loud is an understatement).

 

[Pretzel]

One of 6 filled... Not looking forward to the last one! At least 2 are only 9ci... And I can probably skip those for now. Two 13/3k, one 15/4500 (can only fill to 3 because I'm not heavy enough to compress the pump past that...), And one 48/3k. Wonder what exercise I should mark this as in my activity tracker

Hopefully able to test accuracy before sun down... Thanks daylight savings I guess?

EDIT: 48ci filled... If I keep doing this I'll be able to wrestle a bear and win. I'm also slightly concerned that if I drop another 20lbs I won't actually be able to fully compress the pump.

 

[Pretzel]

Testing delayed due to my trigger jamming up and wearing weirdly... guess there's a reason P* advises not to use Maxx triggers on a Kythera 🙃

Speed trigger on order, hopefully be here Thurs or so. Weds if lucky.

In the mean time, I'll work on making a selector bar so I can have ambi B.A.D.A.S.S levers working, because at least that's being productive with my time while the gun's taken apart waiting new parts... Also polish the spool, sear, and disconnector for better/smoother trigger pull. looks like at some point I removed the washers from the trigger spring, so I need to find those and put them back in too 😅

 

[Pretzel]

Updates ahoy!

Speed trigger installed, tuned.

Heavy spring installed, tested, ripped back out and replaced with the light spring. I'm not saying it was terrible (or even actually bad), but the light spring is a tiny bit more consistent for me, and also considerably quieter on trigger reset. Newest results at the bottom of each reg, grey is before the rebuild, blue is today:

Going with the P* MR still, that most recent result is really nice!

Other changes:

Upgraded my mag release so it's no longer part of the gearbox, now I can pop the lower out without needing to unscrew the release etc etc. even more stable then before, so win-win:

Also, the selector switch! It's now Ambi! No gears means no worries about mill going brrrrr and just... punching a whole right through reality. Blue stuff is just marking fluid I couldn't be arsed to clean off:

Trying to get to accuracy testing today but people have decided to use the backyard and I really don't feel like being swatted by using the front... Gods I miss living out in the country

 

[Pretzel]

Accuracy update:

Not great, workable.

Using a hard nub with the 3mm silicone squishy bit replaced with a 3mmx4mm brass rod has me flying tolerably straight at least (the soft nub had a solid left hook on both the SHP and the TNT buckings). Also: holy sweet hell, hard nubs are SENSITIVE to pressure. I was dialing in the max with rotations of no more than 3-5°. I need to print a low slope wheel I think!

125' (measured with a laser rangefinder) 170' (am bad with rangefinder, see later post lol) lets me hit a 9" wide target... ish. Or at least around it.... Height is pretty variable, but it's what it is for now. People tend to be tall, and this is for more CQB environments. Part of the height issue is it's really hard to get it dialed in with the hard nub as I said above, which means I can either get too low or too high currently. Going with 0.36s may help...

The post in the center of the picture was my target (the buildings behind it are another 100' back and there's brush and scrap piles etc, so it was as safe as possible*, as well as the solid fence directly behind the post):

Somehow I've never actually cracked the code for an accurate airsoft gun... I was hoping this one would do it... but despite perfect alignment, +/-2 fps at the outside, good BBs, a great barrel, and everything totally locked down, I'm still hardly above stock gun. Might be worth trying the TNT again tomorrow with the hard nub... and seeing if I can make a better hop wheel for the MAXX so I have more adjustment range.

Or I might just leave it and call it good enough for now because I only have one more weekend before the game...

Yes, I'd prefer to be in the middle of nowhere again where I could just flat out call it safe because there's nobody else within half a mile, but my partner declined to have a 1 hour commute to work, so... At least I have a backyard in our new place.

 

[SiliconeSword]

I think that part of your issue is likely due to HPA engines kicking BBs into the hop chamber harder than some AEGs, so I'd experiment with bucking lip tension and different buckings to try and put more resistance on the BB to slow it down.
Also try and glue a BB to the end of a rod and put it in your gun to feel the empty space between your nozzle and hop patch, and try to reduce that empty space as much as possible by moving your nub further back or by even moving your hop chamber back with an O-ring or shims if you aren't 100% seated against your gearbox. Your engine may also not be 100% forward in the gearbox.

 

[Pretzel]

The nozzle is moving slower than most AEGs at this point using the 0.015 screw, it's slow enough I can even watch it move forward, so it's unlikely to be that.

I'll double check bucking tension, but it felt pretty good; and both buckings I tried it was doing similar vertical wise. Might try another but I'm going to see if the enhanced hop wheel helps first. The engine is very, very seated against the hopup, with about 15lbs of force holding it there. I think it may be worth trying the 0.36s, I might just have too launchy of a rubber atm for 0.32s.

New hop wheel has been designed and printed, it has the same adjustment range as 0-3 on the Maxx hop, but over the whole wheel (and it's a bit tighter too, so it has less chance of moving):

 

[Pretzel]

Hopefully the last build log update (but probably performance analysis post game):

JBwelded the brass nub in place for improved consistency as it was able to wiggle for and aft a bit, seems to have helped my vertical consistency somewhat:

Also realized I'm bad with laser rangefinders - that fence post is somewhere between 51-53m (167-173') not 125', and the tree I started plinking at is at around 42m, so ~135' or so.

With the SHP5 at the tree most of my BBs are within a few inches of it on either side. At least when the wind isn't gusting. Still a fair amount of +/- on vertical. Acceptable for a lightly tuned gun, but not what I want.

Swapped out for the TNT and during the cumulative ~20 seconds of "not 20mph winds" I was able to hit the post at 170' fairly reliably, and was getting probably 8/10 hits inside the circle of my scope crosshairs on the tree at 135' (math says that's a ~9" target at that range).

My hopup is only at ~22% on the new wheel, so it would be right around 0.96 stock (and now you see why I needed a way finer wheel!). I was only at about 35% on my new wheel with the SHP, so I could drop that significantly again for even finer adjustment ranges... not going to bother taking it back apart however, it works and I don't want to touch it!

Solidly good enough for a ~1.65j system, I could turn up the psi more but I'd have to put the heavy spring back in and radda radda radda. Going with 0.36s would probably yield better results than an extra 0.15j power all things considered.

Here's a pic of it assembled and being it's beautiful self:

I don't think I mentioned the QD mount stock spacer I designed and printed to give me 17mm more LOP so the stock sits better, and allows me to have sensible QD points instead of the terrible one on the bottom of the stock. It's on there and fits well. Flashlight is nice and bright and the whole system is reasonably quiet.

Putting the gun away for now, will test it the weekend of the 1st at the game down in PA. Bringing a spare AEG though because I'm not dumb... have a Cyma Platinum MP5 inbound tomorrow from taiwangun, which I'm looking forward to.

 

[Leo Greer]

She's a beauty!

One side note on accuracy tuning, which may or may not be useful to you... More and more I'm finding that creating good components fitment is actually the key, rather than simply using a better or different rubber or making everything more stable. Of course, those are still huge factors, and shouldn't be ignored, but as I try out more and more combos and get a "feel" for everything, I've found that some combos simply seem to "work" rather than needing to be cajoled into performing well. The point of this post being; I would start looking for tolerance and fitment issues to diagnose your seeming deficiency of accuracy. Also, someone correct me if I'm crazy, but is +-2 FPS a bit much for an HPA engine like the Kythera? Increasing the speed of everything takes consistency down, of course, but it's not unusual for me to get +-0.5 or +-1 from a lightly tuned AEG (good stock gun, not crappy stock gun, of course).

 

[Pretzel]

I would start looking for tolerance and fitment issues to diagnose your seeming deficiency of accuracy. Also, someone correct me if I'm crazy, but is +-2 FPS a bit much for an HPA engine like the Kythera? Increasing the speed of everything takes consistency down, of course, but it's not unusual for me to get +-0.5 or +-1 from a lightly tuned AEG (good stock gun, not crappy stock gun, of course).

Accuracy seems to be fixed for the most part with the TNT and solid nub, I know that could be better but it's solid enough for a short gun with "lighter" ammo and lower power (for this region anyhow). It was also turbo windy yesterday, so I may be doing better than I think haha.

I'm personally of the opinion that it's easier to get an AEG consistent than HPA.

AEG has 3 moving seals, and a spring. Assuming your piston, nozzle, and nozzle to bucking interface seal well, you should have essentially the exact same amount and "power" of air each shot.

Just the Kythera itself has 2 moving parts internally with at least 8 seals among them, plus a spring... and a metering screw. Then you have regulators to consider, which as my charts show, literally changing nothing in the gun but swapping regs (and having them within 1psi of each other) can change the consistency...

I think HPA is easiest to get within +/- 3 or so (as it essentially does that by default unless you have a shit hop setup), then AEG, then bolty for sub +/-1.

Which makes sense if you look at the complexity of each system, HPA has less wear parts and overall things to go wrong, but it is for sure way more complex in terms of how it does it all (espesially for a system like the Kythera, where if you miss-adjust one screw it literally goes into full auto) the operation than at least an AEG.

Which also stands to reason why the Electric Wolverine Bolt is incredibly consistent, it's just an air spring essentially with a really accurate release mechanism. And due to being a dump chamber design and the "long" time between shots, even a slightly inconsistent regulator has time to equalize and fill the dump chamber. Kythera is also a dumper, but there's a lot more going on there

I also need to test my consistency with my TNT bucking, all those tests were done with the Begadi SHP5. May do that this evening. Who knows, it might be terrible, it might be +/- 0.5... tune in whenever I bother to do that and post about it 😅

 

[Leo Greer]

I'm personally of the opinion that it's easier to get an AEG consistent than HPA.

Very interesting! I've always heard the mantra that HPA is more consistent than AEG, but to be fair I've never chronoed an HPA gun myself. I hadn't thought of an HPA gun actually having more seals and not less than AEG. I will say that there are some more obscure factors that affect consistency that HPA doesn't mess with, such as piston weight, cylinder head buffer shape, piston head porting shape and size, etc, but having eight different seals to work with will certainly do it. I have a GATE Pulsar on order, so I'll have to do some work and figure out what I can do with it.

 

[Pretzel]

It depends on what's consistent for you I guess.

A lot of AEGs are... Not great out of the box.

Hpa can get you in the top 10% of performance just by dropping in an engine, but AEG is going to take a pretty major rebuild and knowledge to get it past that... But if you know what you're doing, like I said, I think it's easier. I know the Inferno Gen 2 is stupid consistent, as it's delayed open bolt and it has only 4 moving seals if I remember. It's a give and take for sure of less seals = less to be inconsistent, but turbo fast nozzle open bolts make their own consistency hell (see SMP and Gen1 inferno/hydra accuracy struggles people were having).

I will say that there are some more obscure factors that affect consistency that HPA doesn't mess with, such as piston weight, cylinder head buffer shape, piston head porting shape and size, etc, but having eight different seals to work with will certainly do it. I have a GATE Pulsar on order, so I'll have to do some work and figure out what I can do with it.

While those do affect it, they should be affecting it identical each time, as they're fixed points. In theory anyhow.

A different reg is like somehow spinning your motor so fast the pistons momentum brings it back a random extra 0-3mm from the normal release point...

I'm interested in hearing how the pulsar works, I'd love to see the internals, there doesn't seem to be any breakdowns of it online yet!

 

[Leo Greer]

In theory. In practice though... it's airsoft.

I can make that happen for ya--40K motor, 12:1 gears, sub 1J spring... It won't be too hard to put together. Only to clean up after it explodes.

I think I saw one breakdown, but it was not in English, and I don't know a crazy amount about how HPA works, so I really couldn't tell ya much--I think there's only a couple of moving parts though. The guy basically just unscrewed the top cap, removed the nozzle, and that was it.