I got my .25 DAR today... was very impressed with the wood and the overall fit and finish...then I looked at the gauge.Sadness.zero air.SO. I cocked the hammer in case there was preload on the hammer, and began to fill.HISSSSSSSSSSSSSSright out of the breather for the regulator.so then, I thought...hey... I'll fire it into a blanket or what ever that thing was my dear daughter dropped in the corner of the basement when she got home from her COVID infected college....MAYBE if I fire and 'pop' the regulator a few times, it will seat any leaky o-rings. yeah; no.it helped a little. but no. still peeing air out the breather. (along with plenty of some sort of lube)so before I take it alllll apart and reseal it, I'll call our friends on the other side of the continent...and see what they suggest.I think it's just one of those flukes, though. But I'll tell you, 90 duro o-rings are going back in when/if I reseal this. It's what I do on most of the rigs I have.I am a little disappointed that I couldn't just take it out and fire off a couple rounds for effect...but this kind of thing happens. Certainly not the end of the world. I had to smile at the whole thing as THAT is exactly how the last few weeks have gone at work and at home.ya got to have patience and just roll with what is given.I will keep you all updated as I go with this pretty little rifle.Pictures will be added as things progress, too.
My sources tell me you need an 18mmx75 thread to add an adapter to the DAR.
Makes me question now if they're trying to reuse some old parts instead of machining all new pieces.
Here' some more pics of the innards,The Regulator looks to be well built and is externally adjustable for output pressure. I will be adjusting this for a little greater output pressure before reassembly. Unfortunately, I do not yet have a test rig yet for setting output pressure, so I wont know the actual pressure I change it to, and will just have to rely on chrony readings and shot strings. Maybe Bob will be able to apply some mathematical wizardry once I get those numbers to compare to the first shot strings.The Plenum is a simple straight piece of anodized(?) aluminum. It measures .830 ID and is 1.570 long
ok, so I've take the trigger assembly apart to determine if I can do some polishing of contact points. Hopefully some improvement can be made to the feel and weight of the second stage. Since I have not yet seen any good pics of the parts laid out, I took these to share with all who may be considering doing the same thing.Removal of the Cocking Lever Pivot PinPic showing Pivot Pin removed, and small shim (non factory part) used to reduce some of the floppy motion the Cocking Lever was experiencing. The shim was made from a blown burst disk.Remove Trigger Pivot Pin and the Trigger slides out the bottom of the Trigger Assembly.Note placement of the attached Spring. Also note the thin factory Shims on each side of the Trigger Blade. Do not lose these, ... you will need them to prevent the trigger from being too wobbly.You must also remove the Pin that is just forward of the Trigger Pivot Pin.This is to allow clearance for removal of the Sear Catch. Next remove the Sear Catch Pivot Pin, and remove the Sear Catch.Be careful not to stretch the little springs.Next remove the rear plug from the mono block and the Hammer Spring. I dont have a pic of that, but it's pretty basic. The rear Plug just unscrews, and the trigger spring comes right out.Next position the hammer so that You can see the Cocking Pin screwed into the Brass Bolt Body. Remove this pin from the Brass Bolt Body using appropriate Allen Wrench. Loosen the Allen Screw locatedin the rear of to Hammer to allow the Sear Catch Pin to be removed from the Hammer. Remove the Sear Catch Pin and slide the Brass Bolt and the Hammer through the back of the mono block.Trigger Parts Orientation, Now ready for a little detailed cleanup and polishing job of all mating contact surfaces
Quote from: rsterne on August 03, 2018, 05:42:01 PMThanks for the pics of the internals.... It looks like the regulator fits inside the plenum a short distance, maybe 0.2"?.... That would result in a plenum volume of about 12 cc.... Do you have any idea how much volume there is inside the valve, or the back of the regulator, which would add to that plenum?.... That's pretty small for a .25 cal, IMO....BobYeah, I'd guess about 0.2 . Unfortunately, I put the gun back together tonight before seeing this post, so I cant measure it right now. I'll be shooting it tomorrow to test out my polish/lube job on he trigger, as well as my adjustment to the reg. No doubt, I'll be taking it back apart after this weekends testing, so I'll try to get you those measurements next time it comes apart. I did feel the plenum was a tad small too, once I saw it. Here's some picks of the valve before I put it back together.Upon removal of the valve, I did find the Brass Pin Guide to be loose, as well as the Retaining Cap for the Poppet Spring (on the opposite end of the valve). I will be using some blue loctite on reassembly to prevent this happening again. The exhaust port is pretty big, measuring .223 - .224 . Next time I have it apart,I will do a little Dremel work to radius the bottom of the port to the throat of the valve. The valve slides into the monoblock, it i sealed with 2 o-rings, and is held in place with two indexing screws on the lower side. One screw doubles as the Stock Mounting Lug. This makes the port alignment to the monoblock a easy no-brainer. The port in the monoblock meas. .223, and the port in the barrel meas. .221The hole on the "shoulder" of the valve is a pressure bleeder for Degassing. It has a grub screw plug.Nothing exotic going on inside, standard Poppet and Spring. I will say, the Poppet Spring in this thing is SERIOUSLY STIFF ! ! ! (too stiff IMO), but we'll mess with that at a later time. The Retainer Cap (valve inlet) has 4 (small) holes. I think they can be opened up a little more, which we'll also do later. I did notice the Retainer Cap does not have any sort of pin/groove/shoulder/etc. to keep the Poppet Spring on center. I see this as a potential problem as it allows the Poppet Spring to go off-center, and thus, applying a side-load to the head of the Poppet. This could be something that needs to be addressed in future models.Here's a nice little feature,The hammer tube in the monoblock, is "lined" with a hard plastic/delrin(?) sleeve. This prevents the steel hammer from touching the aluminum monoblock. Pretty cool, I think. No internal "marring" or damage to the monoblock, and very slippery slide for the hammer.[/URL]
Thanks for the pics of the internals.... It looks like the regulator fits inside the plenum a short distance, maybe 0.2"?.... That would result in a plenum volume of about 12 cc.... Do you have any idea how much volume there is inside the valve, or the back of the regulator, which would add to that plenum?.... That's pretty small for a .25 cal, IMO....Bob
Guys, if anyone is struggling with a leak, here are my detailed O-ring notes so far. You'll see plenty of improvisation but there are many ways to get air to stay where you want it so by all means experiment with it. This is just what has worked for me.Regulator body: 2ea -117 90 durometer. The original high side O-ring, an M2.5x20 estimated 50 durometer, extruded after a few days and dumped all the air through the atmospheric vent hole.Regulator spool, top: -012 90 durometer, very snug but didn't shear on installation. Original was M1.5x9 and was sloughing off material after ~400 pellets through the rifle. Regulator spool, bottom: -007 90 durometer with OD abraded to about 0.260" to fit inside groove of brass ring. Original is M1.5x4.tube caps: 2ea -117 90 durometer. Others reported using 70 durometer with success; doesn't seem this one is apt to extrude like the ones on the regulator body.air tube (into receiver): M2x14 70 durometer. Originals appear to be M1.5x17 and are a loose fit...didn't feel adequate when inserting the tube into the receiver. The M2x14 stretches a bit to install, and the resulting fit to the receiver is snug. 90 durometer would probably get cut. fill probe: Factory ones are M1.5x3mm estimated 50 durometer. They leak for the first 2 or 3 pump strokes until enough pressure has built for them to seal. A 90 durometer of the same size would probably work _if_ it can be installed without tearing (has to stretch quite a bit...polyurethane might survive). Ended up using -005 in 70 durometer with the ID abraded to match that of the metric. Seals right away.barrel band: M1 x 20fill port: -007 (from memory, maybe -006...original had failed). Bring the tapered screw down onto it with just a slight amount of interference. barrel .25cal (seals to bolt probe): -902 90 durometer (actual dimensions .240" ID .370 OD)Tricky to install. Seated a pellet into the leade, then inserted a short segment cut from a 1/4 dowel to fill the portion beyond the O-ring groove. Then used a pick to work the O-ring into the groove. The 90 durometer seems to be holding up well.
One the Gen 1's some had that straight poppet spring and others had a cone shaped spring. I found the cone shaped spring stayed centered and worked much better. Anyone delve into the Gen 2 that far to see what the internals if the GEN 2 valve look like?
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