ICD Lasoya Promaster - build thread

[Myrkul]

Makes sense removing the spring dropping the fps. It's likely there to overcome static friction of the ram seals.

That is absolutely why it's there. I recently had a rebuild where someone had shaved 1/2" off the spring and the first shot drop was horrible on it, like a good 40 FPS. A new spring from ICD got them sorted.

It *IS* possible to delete the spring completely though. I believe it was either Dyn2liv or Vaporworks who modded the B2k ram on the left here. The back cap was also filled in with JB weld. This was off a Defiant. The gun has no ram spring, but also experiences no FSDO or other issues. No way my hands are that steady or I would have attempted to duplicate it.

[latches109]

fsdo can also be overcome with software, add a dwell increase n on the first shot if the marker has sat for n time.

[latches109]

I was thinking about filling the void to have the chamber fill faster. a delrin plug would be the best.

[Myrkul]

I've definitely seen delrin plugs made before, I think the ones I saw had an two "o" ring grooves in them to secure it in place so it's not rattling around in the ram.

[Frmrspec]

Did you check between the stock valve and the Lazarus to make sure they are getting the same amount of valve lift?

[Frmrspec]

Then your findings make sense.. you cut the mechanical dwell time..

I think most people with balanced valves found that they really couldn’t drop the LPR pressure much with reliable results. Instead they could get away with super light reciprocating mass…

I haven’t compared but one of my favorite things about the morph valve was it had a fairly long valve stem/potential valve lift… alien put a bumper in the cap but I yanked that out and had much better luck. Of course this was in a slower/softer mech setup

[tyronejk]

Agreed. To be clear, I haven't tested this yet. Only latches has a prototype so far. I sent him an aluminum hammer too, so I'm expecting/hoping to see that produce the same velocity as the steel hammer but with reduced reciprocating mass.

[latches109]

Frmrspec there is plenty of valve lift. We increase pressure for short dwell times. The hammer is making contact with the valve body. This is the same if not more than my autococker. I have the hammer off and will test the aluminum ones hopefully today.

[tyronejk]

I realized my original replacement rammer wouldn't work well, since it doesn't have much rearward force to reset the bolt, so I redesigned it and a new housing. I still intend to try a Laz valve in here but that design is pretty much fixed, due to the dimensions of the other parts of the valve, so hopefully the reduced weight and forces of this rammer will still work.

I modeled it after an Ego rammer including the rammer oring sizes and locations and the Zick cushion feature. The design is constrained by the body of the Promaster, which is why there's that weird routing in the rear of the rammer, but I think this should be manufacturable on my manual lathe. But please point out any potential issues or pain points if you see any. The feedback is greatly appreciated.

[latches109]

Okay, good results today.
the piston it’s self was not long enough to reach the valve stem so I added a cocking rod end to help. With this set up I hand loaded and held the bolt closed for each shot. I tested with and without the spring, spring was not needed. I was able to get the marker to fire 280fps @ 160psi & 300-315 at 190-200PSI




PSI floor to make it cycle and shoot (LPR)




310 fps at 45psi (LPR)


HPR pressure


dimensions

[latches109]

Next I tested the aluminum hammer tyronejk sent me.
This test I kept the HPR pressure the same and experimented how LPR pressure would affect the FPS. To get back to the 300PFS the LPR pressure increased to ~62psi. I forgot to weigh the bolt and pin. I'll change the HPR pressure tomorrow and test again.

[latches109]

all in all it felt really nice with the lighter 17g ram only test. zero kick and responsive to LPR pressure. I had thoughts of a fun electronic closed bolt, bolt action first strike build. I'll continue testing and add dwell into the equation later. If you are curious when the LPR pressure increased too much the FPS would drop. For example the pressure in the first test without a hammer the FPS was at 290FPS @55psi LPR pressure. yet 310 at ~45psi.

you need 65psi to compress the ram spring. Definitely did not have a benefit. Making a ram housing with minimal air loss would be fun to test. We do not need a heavy rammer for the ICDU variant. I have an idea to connect the bolt to the cocking rod end and get a shooting video. I will at least take one with the aluminum ram and a stock ram side by side.

[tyronejk]

Are those tests using the aluminum hammer with or without the ram spring? I'd be surprised if you needed more LPR pressure for the aluminum 22g hammer than with the 17g cocking rod.

[latches109]

Without the spring. Probably won’t when the bolt and pin weight are considered.

[tyronejk]

Gotcha. So the aluminum hammer should work then as a drop-in solution. Maybe it could be made lighter, but I'm not sure how to calculate that.

[latches109]

Look at the NDZ impulse hammer for Inspiration.

[Frmrspec]

Interesting that higher LPr meant velocity loss.. usually means that the pressure holding the bolt back at rest isn’t venting fast enough… isn’t there a qev at that location? Or was it only at the rearward travel?

[tyronejk]

There's a QEV to vent the air in the rear (I.e. faster bolt return) but no QEV to vent the air in the front.

It may be feasible to swap the QEV position around. The only constraint is packaging in that area, although I think it's doable.

[Frmrspec]

lol derp… I completely forgot there’s images directly above… don’t mind me…

[latches109]

The ICD valve chamber is larger than the autococker yet needs higher HPR pressure. I realized the vasa supply hole is only 5mm versus 2x 5mm ports on a 2k+ cocker body. So I drilled my body and vasa .5mm larger and sure enough my HPR pressure dropped 10psi.

HPR - 190psi
LPT - 60psi
aluminum hammer
305fps

I want to get to a similar 10mm supply, any ideas?

[Frmrspec]

Custom VA? Or maybe an LPR extension to increase the valve chamber… similar to what SP did for the nerve

[tyronejk]

I considered an LPR extension but since it would require some air passage to supply air to the LPR, it would be either complex, limited increase in volume, or both. But considering this small change resulted in a 10psi drop, maybe just a little extra volume is all that's needed. It's something to consider for sure.

[Sneak Miester]

I thought the idea of a new ram was to service it out the back?

[tyronejk]

Yeah, that's the plan for my own Promaster. The new ram would require a lot of parts so I don't think I'm going to make extras to share for testing.

[tyronejk]

I had some time to do some machining and got a couple parts done. The bolt is a modified (shortened) stock Ressy bolt. The valve is the same Laz valve body that latches109 is testing, but very slightly simplified. (Don't worry, Myrkul, I still remember you want some!) By the way, if anyone else wants these, let me know. It's a little time-consuming to make these, so I don't want to make too many manually. A small number (<10) would be fine. If there's more interest than that, I'd be happy to share CAD files if anyone can find a real machinist to do a small run of these.