2 Pound Halfblock

[Dees_Troy]

Last year when I first ordered my delrin turtle body, my goal was to come up with a 2 pound cocker at "shooting weight" or basically including everything but the hopper, paint, and air tank.  I was at about 2 pounds 2 ounces for a while, and I finally found an ASA that is lighter than anything out there: the Empire Nano rail-mount ASA at just 0.8 ounces.  Combined with a few other minor changes, the whole setup including the barrel with the smallest bore (heaviest) insert it now weighs just under 2 pounds.

As a side note, I noticed that the feedneck wobbles a tiny bit with a hopper installed.  The delrin turtle bodies use the same style press-fit feedneck that regular cockers use only it is helped by a couple of set screws to hold it in place.  Since the delrin body doesn't have the sight rails on the top, there's at least 1/4 inch of extra height to the feedneck that doesn't need to be there.  I ordered a spare feed tube from turtle innovations (let's see how long that takes to arrive) so that I can make a shorter feedneck and still have the stock original if I mess it up.  My goal is not only to come up with a shorter feedneck, but to also to set it up so that the threaded feedneck sits right on the top of the body to help keep the feedneck stable with a relatively heavy, fully-loaded hopper.  Anyway, pictures will come once I have completed the feedneck change.

[rlong]

It went out on Tuesday so it should be showing uup today or Tomorrow.  The tracking number if you didn't get it from paypal is
9101 1501 3471 1791 1751 96  We have been making the new ones that they sit right on top of the body and also been coming up with an all one body and feedneck that will use the same clamping as the EGO's.

Also if you know what Blackbean had to do to those couple bodies that would be great.  Wondering so we can fix the problem before the go out.  We sent him a couple e-mails but no response.  Thank you.

[Dees_Troy]

Hopefully I'll receive the feedneck soon and it's good to hear that you are continuing to make design changes to improve the body.  The wobble isn't bad at all, but I notice that the feedneck moves everytime I shoot meaning that the bolt is rubbing the feedneck enough to move it.  The feedneck doesn't move without a hopper but does move with a hopper and load of paint.  Something about the weight of the hopper I guess.

I haven't contacted BlackBean since November or so, and I haven't seen him on the forums here in a while.  You might try sending him a PM through these forums if you still can't get hold of him.  I know at one point in time, the email link on his site wasn't correct.

[rlong]

Tracking number said it was deleivered today just checking to make sure it was.

[Dees_Troy]

Yes, both packages I was expecting from you arrived just as you said.  +2 for rlong.  Thanks.

[rlong]

Not perfect but getting better.

[Dees_Troy]

Pictures and specs on both of my halfblocks linked below:

http://www.geocities.com/dees_troy/paintball/delrinturtle.html
http://www.geocities.com/dees_troy/paintball/martin.html

[Temerity]

I love that delrin one man.

[rlong]

Been fightingthe Velocity problem on the delrin Cockers for some time.  Never thought of the Cocking mass being to light.  Thank you Will start looking into that.  It makes sense now.  We have another one in the shop right now that we are having troublem breaking the 260 mark.  Have a couple Ideas to add a little weight to the Bolt with out changing to much.  I thank you for putting that in there.  We want things to be perfect and all help and any Ideas to make it better are welcome.

[drg]

Dees - you mentioned raising the LPR pressure to try to counter the low velocity problem ... did that solve it?

I just find it somewhat odd. I would think that a decent LPR pressure should make this impossible no matter what the cocking assembly weighs.

[Dees_Troy]

Increasing the LPR helped some.  At first I couldn't get over the 240s.  I cranked up the LPR and got it to 260s, but cranking it further and further didn't help.  Running a high LPR pressure is more likely to damage or wear out parts anyway, so I don't want to run it too high.  KAJohnson said he had some ideas, but that he couldn't discuss them with me and that the added weight is obviously what I needed.  I've done everything else that I can to eliminate the problem except try a different ram.  I'm not sure a different ram would help though as rams like Moody's (MPP) are designed with a smaller 'closing' surface and larger opening side.  Presumably, most cockers need more pressure to open the bolt due to having to push the spring loaded hammer to recock while a lesser closing force is more likely to pinch.  In my case, I need more closing force to keep the bolt in place.

[drg]

Couple random thoughts...

Could it be a timing issue, with the light recip. assembly being more responsive (perhaps CDEL?)?

So if you put your thumb on the back of the block and apply some pressure
during firing, velocity is normal?

I wonder if removing one QEV (rear I think) could help?

[Dees_Troy]

I'm going from memory on my timings as I haven't had to work on it in a while.

CDEL was raised to the max allowed on the E2 board (19.9ms I think) and then lowered until the velocity dropped and raised back up to the point where it didn't drop.  CDEL is set roughly to 8ms.  SON is 3.2ms.  HPR pressure is set a little lower than the point where it leaks to get 290s and then lowered from there as dictated by the field's limit.  Higher SON times don't increase velocity any.  Lower pressure and higher SON time doesn't help either. I have tried with and without the white spacer on the plunger on the MQ with no change.

Last time I did any testing, I had unplugged the cocking solenoid so that the back block stayed in the forward position completely eliminating timing issues except for SON.  To reload, I pulled the pull pin and moved the bolt by hand.  Using this setup, but holding the bolt with my thumb, I can get almost 320fps but without my thumb its 290s.  Change the bolt pin to the Slik delrin and it's 260s.  I tried a number of different bolts as my brother has quite a number of compatible Bushmaster bolts.  I think we tried 5 or 6 including one with dual O-rings.  We tried no O-rings, front only, back only, and both.  The O-rings made the bolt have quite a bit of friction with the breach, but that all made no difference.  I also tried the bolt in my Martin which weighs more than the delrin turtle bolt and that worked pretty well.

The ram is the WGP MP4 with built-in QEVs.  I can't remove them.  The MP4 shaft is pretty narrow and the inside bore is about average.  The best kind of ram for this setup would be a narrow shaft, large bore, providing the most surface area for the LPR pressure to close with.

I have no audible leaks of any kind.  It seals perfectly.  I don't have any blowback, even when shooting paint.  I tested blowback with a kleenex over the feed tube while firing paint.  The MQ is installed correctly and I checked to make sure that the valve holes line up vertically with the MQ valve body all the way up to the hole in the bottom of the bolt.  This same MQ worked trouble-free in my Martin just before it was swapped to the turtle.