Saweet! Thanks Rod. I will give this a shot as well.
Posting useful info and pics I found at a two year old DAR thread:Quote from: Gertrude on August 03, 2018, 02:46:55 AMHere' 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 longQuote from: Gertrude on August 01, 2018, 05:28:09 AMok, 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 surfacesQuote from: Gertrude on August 04, 2018, 05:09:52 AMQuote 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]
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
I think that the regulator shown is for a .25, if my memory serves me.
Mine are all Gen II and I don't see any differences with the naked eye nor would I think there is. They all supply regulated air to sit in the plenum (same size) until it's dumped into the TP. The reg then opens and recharges the plenum. The adjustment screw was definitely set differently but the rest looks to be the same.(nevermind the black screw, that's just there to pull out the assembly)
Quote from: Firewalker on December 11, 2021, 02:03:47 PMMine are all Gen II and I don't see any differences with the naked eye nor would I think there is. They all supply regulated air to sit in the plenum (same size) until it's dumped into the TP. The reg then opens and recharges the plenum. The adjustment screw was definitely set differently but the rest looks to be the same.(nevermind the black screw, that's just there to pull out the assembly)I would guess they are all the same and just set at different pressures for each caliber. The reg setting was written right on the side of my 25 dar. Just can’t remember what it was. I assume the 22 maybe is just set slightly lower.
With mine the poppet issue was cured by lapping the poppet against the valve face using a cordless drill at slow speed.
Quote from: singleshotcajun on December 02, 2021, 12:50:37 PMWith mine the poppet issue was cured by lapping the poppet against the valve face using a cordless drill at slow speed. If it is practical you might be better off lapping valve seats "without using" power tools. Out in the real world in critical use situations valve plug and seats are almost always lapped through rotation by hand. Too easy to do too much, too quickly or develop galling or produce an "out of round" condition in the seating area.
One thing always bugged me about the DAR, only one action screw and my air tube was not floated. I finally did something about it. Friday I bedded the action on my Suhl 150 .22LR olympic style rifle. I always waste some Belzona metal epoxy when I do one so I prepped the DAR. Hogged out the fore end plugged cracks,creases and holes in the receiver with modeling clay then painted it with grease. Both jobs turned out great. Wish I had took pictures but I almost never take time to do it. The DAR now has 90% contact receiver to stock out to the flange of the air chamber and the air tube is floated. Got a little hairy removing it after a twenty-four hour cure, love taps with a rubber mallet to the trigger guard got it out. Before it shot Crosman domes better than CHPS but I get no fliers with them now and the shot cycle sounds “right”.
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