Spoolies modded for sprung bolts

[JCC]

Ok, so I need a replacement bolt tip/cap for old gun and started me searching for a source. Ended up coming across some spring mod bolts which I was aware of, but never paid much attention to. The idea is basically using a spring to help push the bolt forward allowing for a decrease in electronic dwell in replacing it with mechanical dwell. And I am left wondering why? I do see how it may help with FSDO in guns that have that issue, and you can turn your electronic dwell down to a crazy low setting for the gun but really your dwell is staying the same your just changing the manner that you reach it from electronic to mechanical. Anyone have a clear picture of why this would actually help anything?

Then here is my thought on what would actually help. You need to spring the bolt in the opposite direction. Most of these guns can cycle at 20+bps while only needing to cycle at 10bps. Adding a spring in front of the bolt to slow down how quickly it comes forward would be softer on paint. Yes you would need a higher dwell, but with fixed volume bolt systems it does not matter how long dwell is as long as bolt goes forward and there is enough time for all air to be dumped.

Does that make sense? Mechanically slowing down the bolt speed of the gun so the mechanical limit is closer to the electronic limit in order to be softer on paint. Sadly, adding a return spring is likely near impossible for most guns.

It would have to be built into the "bolt keg" or whatever different manufactures call the piece the bolt slides through. Hell, maybe there are already guns built like this and I am just unaware as I have only had a handful of more modern guns since coming back from a 15+ year break a couple years ago.

Slower bolt movement to be soft on paint while still allowing the standard 10.5bps seems obvious though so would not be surprised to hear its been done. Seems way more effective the slapping a soft tip on a bolt.

[kyote]

My anecdotal wxperience with my former enmey was after replacing the original valve with the "HE" valve, it chopped paint a lot more frequently.
Could be due to short stroking, my bad, but I feel like it was likely related to the QEV on the forward stroke increasing bolt speed and force.
So just remove the QEV on forward stroke and problem solved?

[JCC]

That makes since to me. I mean a gun that has no issue cycling as fast as you can pull the trigger why speed up the forward motion of the bolt? Just increasing the force it strikes the ball with. Now the return speed? Sure, speed it up. Faster the bolt gets back the longer another ball has to feed before it comes forward again.

All that being said I have a pair of enmys one the original body and one the new, but believe both have been updated. I never had an issue breaking paint with them. Now my RSX CVO I did chop paint if I short stroked it. Not sure why enmy never gave me trouble and RSX did since they are very similar in function.

[ChuckLove]

From what I remember the purposes of the spring modes bolt on a SFT shocker was to help prevent bolt stick as well as improve the efficiency. With that being said, my one attempt at trying said modification was not successful.

[dano_____]

The spring mod is done to help with bolt stick and fsdo. You can reduce the electronic dwell a little typically, but that has nothing to do with the bolt dwell. The electronic dwell is only how long the solenoid is energized. The bolt will still have the same set mechanical dwell. Depending on the gun your air supply will be cutoff when fired or not. You'll see an increase in efficiency if you can run a shorter dwell with the latter. Putting a spring on the front side is relatively pointless. You are better off regulating the air as it is exhausted to actuate the bolt. This is as good as a mechanical spring and is actually tunable. Planet eclipse did this with their geo 3 platform.

[imped4now]

The SFR is still utilized in the CS1/Geo 4 platform, as well as every LV model. The Dye DSR+ also has an SFR, although it performs a slightly different role as that's a "fill to fire" marker vs. a "vent to fire" like the Geos.

[Magmoormaster]

On DMs, springing the bolt allowed you to drop the LPR pressure substantially. This made it smoother and gentler on paint.

But in most cases, yeah FSDO, bolt stick, and efficiency are the primary reasons. It's worth noting that most if not all modern spools are now sprung in some way.

[JCC]

This is a good point. If the gun has a separate LPR for bolt movement the full pressure from the HPR holds bolt back, but the LPR is what moves bolt forward. Having a spring would help you reduce LPR in that case, and the benefits that come with the lower LPR. I was looking a non-lpr markers.

[imped4now]

In just about all modern cases, the valve is sprung (be it breech-sensing or chamber-sensing), not the bolt itself. The Empire V16 utilizes a pneumatic spring to aid in the cycling reliability of the forward stroke, which is a very nice little trick.

[JCC]

but that has nothing to do with the bolt dwell.

Lost me, "dwell" as set electronically is how long the noid is energized. The actual dwell is how long the valve is open allowing air to propel the ball. Which in reality is less then the electronic dwell as there is always some lag in the system. Adding the spring should allow you to get your actual dwell and your electronic dwell closer to same # as bolt will move forward quicker and hold there till noid is switched off again and air pressure moves it back.

There are some guns now that bolt moves back once dump chamber is empty even if noid is still energized. Maybe, that is where your coming from with the "bolt dwell" would be the same as the bolt will always return once enough of the pressure behind it has been removed. In those guns dwell really does nothing and I am not even sure why anyone needs an adjustment for it as its mechanically controlled to always release the pressure from dump chamber then return, and electronic dwell setting just has to be enough to give bolt time to reach forward position then pneumatic/mechanical control takes over.

Now in a non-fixed volume setup dwell has huge impact on efficiency and consistency. In those types of markers higher dwell kills efficiency but helps consistency. Why old days some went as far as high dwell for front players to maximize consistency between shots as they did not need the quantity and lower dwell for back players to help them dump a case a game on single fill. More of a poppet valve use of dwell, but true for non-fixed volume spools as well.

For this conversation I was assuming a fixed volume spool without the self-returning feature (not sure if that has a name). Meaning the noid has to be de-energized before the bolt resets. So a dwell of 20ms would hold bolt forward for 20ms not just the 10ms needed to dump the fixed volume chamber and bolt already began to reset before noid was off.

[imped4now]

I think you're trying to describe the PE Gamma Core in part of your example. In that case, the bolt, valve and solenoid are all effectively decoupled and the system is entirely pneumatically sequenced, initiated by the solenoid venting the chamber behind the switch to kickoff the cycle. The bolt return is handled by a constant rearward-acting supply from the shot chamber known as an air spring.

[Hellion360]

This modification is largely to prevent bolt stick and the resulting FSDO. It was super popular on the shocker lineup and is incorporated into the bolt designs of the shocker's descendants.

You mentioned springing the other direction for gentle paint handling. Most spool bolts are already designed to move forward gently, this is why early iterations had issues with FSDO and bolt stick. As weather became colder it required more pressure to overcome the friction from the grease thickening up. The spring added that little extra push to overcome the stickiness and complete the shot.

Some folks have experimented with spring tuning in blow forwards like the automag, axe, and mini to improve paint handling. Stronger springs make the bolt gentle but slow it down. Overall these efforts usually introduce more problems than they solve.

[imped4now]

As an FYI on the Axe/Mini, I'm only aware of aftermarket springs that are lighter, not heavier than stock-rate. I always suggest sticking with the factory spring. Additionally, while the spring does play a part in the paint handling of that system, the forward bolt acceleration is largely a function of the first stage orifice diameter. Like the PE Gamma Core, the first stage of the bolt is low-force thanks to the small supply orifice and then opens up to an unrestricted supply for the remainder of the cycle. Both of those systems are fairly high-force (pressure x surface area), but slow speed. That explains why they're so much more reliable than older spools that throttled force to control bolt speed....incidentally, those are the systems that benefit from forward acting springs that the high-force systems don't need.

[Tracker]

to piggyback on helion, the easy way to overcome the slower bolt is to hold the noid open longer, but that reduces your efficiency and slows your ROF down. the other option is to run a higher pressure, but that kinda defeats the purpose

mainly the guns that need springs getting involved are spools that lack LPR's because you dont have a way to control the cycle pressure, your cant "turn it up" to overcome bolt stick.. old shockers, macdev, bob long insight.. the insight it was such a benefit they re-designed the engine to incorporate it for the next year and called it the onslaught

[imped4now]

Good comment. A couple points:

1) Holding the solenoid open doesn't impact systems that shutoff the supply when the bolt is forward *as long as* it's not a system that relies upon chamber trapping to yield its efficiency advantage - ala, Insight. For example, the PE IV Core spools are all over-dwelled for cycling reliability, but since the solenoid selectively fills the chamber (shuts off during the venting portion of the cycle) and the breech-sensing valve shuts off the shot chamber to prevent full dump, efficiency and dwell really don't share a relationship.

2) The Insight/Onslaught system is a bit of an oddball, and an interesting one at that. Since the forward stroke isn't fully pressurized (it's vented through the small holes in the back cap after the first ~1/2" of the stroke), it's more sensitive to friction/lube/temperature conditions than most others. The spring added to the Onslaught does seem to help "kickstart" the ram/bolt in cold conditions and also acts as a return damper. I've done a ton of seal testing with the Onslaught in an attempt to vastly improve reliability - U-Cups, X-Rings, and different seal materials. I've had the best luck with X-Rings and cast urethane seals (ram sails + shutoff). I really wanted U-Cups to work but between the groove specs not being correct for them and some blowby I believe was occurring, I couldn't get them to cooperate in the real world.

[imped4now]

Then here is my thought on what would actually help. You need to spring the bolt in the opposite direction. Most of these guns can cycle at 20+bps while only needing to cycle at 10bps. Adding a spring in front of the bolt to slow down how quickly it comes forward would be softer on paint. Yes you would need a higher dwell, but with fixed volume bolt systems it does not matter how long dwell is as long as bolt goes forward and there is enough time for all air to be dumped.

Does that make sense? Mechanically slowing down the bolt speed of the gun so the mechanical limit is closer to the electronic limit in order to be softer on paint. Sadly, adding a return spring is likely near impossible for most guns.

It would have to be built into the "bolt keg" or whatever different manufactures call the piece the bolt slides through. Hell, maybe there are already guns built like this and I am just unaware as I have only had a handful of more modern guns since coming back from a 15+ year break a couple years ago.

Slower bolt movement to be soft on paint while still allowing the standard 10.5bps seems obvious though so would not be surprised to hear its been done. Seems way more effective the slapping a soft tip on a bolt.

As I've alluded in other responses to folks in this thread, this isn't needed in just about any remotely modern marker, especially those that use inlet flow restriction to control the bolt's acceleration profile. At the end of the day, if you did this, you'd likely just kill reliability since the bolt would have to overcome and increasing spring rate and most systems don't have the shift force to do that.

The Axe/Mini (mechanical spring) and all Gamma Core markers (pneumatic spring) do this - the spring is there to return the bolt, the shift force is relatively high for cycling reliability and the bolt speed is slow due to inlet restriction.

[JCC]

Just for full transparency the marker I was working on that started me down this path was an old MacDev droid. Have the Clone GT/GTi bolt in it so it has bolt face comparable to lot of modern markers. Broke the tip and started searching for a replacement without having to pay $10-20 shipping for a $10 part. Still looking btw. Have something new on the way, but this is actually my newest electronic gun (not counting a DM12 I used twice before trading). I play mech way more then I play electronic anymore.

Awhile back I had some paint left overs from a mech tourney that was fragile to begin with and now stupid fragile to point it would break from knee high easily 9/10 times. Had 3/4 of a case and ran most of that through emek with no issue. Switched to Droid to run some airball with guys practicing that needed another body, and could not even chrono the gun in as it broke first ball. Few attempts to clean up and keep going, but it would break more then it would shoot. This is a good shooting marker that previously had ran fresh tournament paint for me without issue this paint was just brittle. Switched back to emek no more breaks. Looking at where the paint was breaking was easy enough to tell it was not chopping, but was breaking on the face of the bolt so when the bolt struck the ball.

The idea of adding a spring to help push the bolt forward when you can not adjust lpr down or anything else to counteract the extra force your adding just seems like a bad idea for paint handling. Which is what had me thinking it should really be occurring in opposite direction to lessen that impact. I had not looked into the modern stuff enough to realize they had already done so through pneumatic springs and flow restrictions, but seeing how much better the emek handled the same paint makes a lot of sense.

[imped4now]

It's interesting to hear that you had paint handling struggles with the Droid + GT bolt, as that's a pretty nice combination. Just to rule out something weird, have you checked to make sure that paint is dropping into the breech freely? The bolt face isn't slightly overhanging into the breech and disrupting the ball's path? And once in place, the ball should have little to no movement between the face and detents.

Given the pressure and surface area of the Droid (and all balanced MD spools), ~100 psi and a 016 sail seal, that's hitting a pretty nice spot between cycling reliability and paint handling - you shouldn't need to do anything to improve either one, aside from maybe bumping up the dwell a bit in cold temps and giving it some nice fitting seals. Personally, I've setup many Droids/Clones and have settled on cast urethane seals for all dynamic areas. This gives the bolt assembly a satisfyingly glassy feel that keeps things running reliably in cold temps and I also don't recall the last time I had a ball break in one. I fear that you may be looking in the wrong place for the issue - I'd take a look at the detents, the eye delay setting and ensure that the bolt face is playing nicely in the Droid. If you've got a stock/Gold bolt you can try, I'd also be curious to hear the results with some fragile paint.

[JCC]

The Droid has no issues with other paint. This stuff was as brittle as it gets. I actually had fully expected to throw it out and buy new that day, but gave it a shot through the emek before doing so which worked perfectly. Not that this says much, but I also put some of that paint in my old Airstar Nova with the same results as the droid. Broke way more then it shot, but the Nova was like that with all tournament paint so it was not surprising. This paint was to the point that dropping it into grass often resulted in a break. The fact that the Droid had issues was not the surprise as much as the fact the emek was able to shoot it was really more surprising. I had 1 pod left a couple weeks later I put through a RSX with CVO frame, and it broke 2-3 out of the pod. Not as bad as the Droid, but not as gentle as the emek.