Homemade PCP receiver

[KWK]

Tapping with mill = great. Looking good. Holding endmill with chuck is a little dicey, collet is more rigid. Can't wait to see end reault.

Exactly, drill chuck shanks have Jacobs taper and not reliable for side loads when milling. Don't
Another thing, don't run a keyless chuck in reverse. It will get tight as a bull's arse. You'll have fun getting your chuck loosened.
Nice work, M

 

[bsahogger]

Exactly, drill chuck shanks have Jacobs taper and not reliable for side loads when milling. Don't
Another thing, don't run a keyless chuck in reverse. It will get tight as a bull's arse. You'll have fun getting your chuck loosened.
Nice work, M

Ok ok, collets only from now on (or I'll crop the chuck outta the pic if I use it again )

 

[sb327]

Ha! Don’t worry, I do it from time to time myself out of convenience and I seem to be getting along just fine, lol. You do you.

I think if you come up with a tubular solenoid, you could design to be able to switch between spring/solenoid type hammers. Solenoid city has the best selection, albeit pricey.

Dave

 

[HogKiller]

Tapping with mill = great. Looking good. Holding endmill with chuck is a little dicey, collet is more rigid. Can't wait to see end reault.

Agreed, I'm a huge fan of chucking reamers also, if you have them, rigid is good, keeps the runout down.

 

[HogKiller]

Ok ok, collets only from now on (or I'll crop the chuck outta the pic if I use it again )

I'm not a fan of the chuck but if you checked the TIR of the chuck first with a ground dowel rod you should be 'ok'.

 

[hotspark]

Cool project! Following for results and ideas!

 

[bsahogger]

Got going on the bolt today. I decided to use a Crosman bolt that comes with their steel breech, since it fits the back of the barrel that I'm using. Quick drill & ream into the main bolt:

Cross drill/tap for the bolt handle (no collets for tapping! I prefer it if the tap can slip in the chuck if things awry):

Decided to give the front part of the bolt a little set screw:

Bolt complete for now, I'll make a fancy knob for it at some stage:

With bolt in place gun can now shoot. I flick a 1/4" rod into the back of the receiver to hit the pintle:

First group at 7yds, already looking better than my FX Dreamline. One pop with the 1/4 rod, bottom hole, then a harder pop, top hole:

Small issue which ended shooting session, the second shot went through the 3/4" plywood. I'll have to rig a decent back stop:

Sorry, but if your manometer doesn't glow in the dark we can no longer be friends:

 

[JohnTaylor]

After my recent horrible experience with FX Dreamline POI shift issues I decided to build a receiver which I could clamp in a bench vise, then insert the FX barrel assembly so that I could see what's up with these liner/shroud set up's (ie. why the annoying POI shifts) independent of the rest of the FX rifle & the shooter. Anyhoo, in the meantime I figured out what the issue at the heart of the FX Dreamline accuracy is: it has no barrel. To make this gun shoot, the .177 version anyway, is as simple as throwing the stock straw/noodle/liner or whatever you call it in the trash, along with the flimsy little wagon wheels spacers & the shroud. Then, buy a real barrel & have someone machine it for you so it fits the FX receiver, problem solved!!!
I had already started machining my homemade receiver though so I thought I'd finish it up & post some progress. Caution: I am not a machinist by any standards! I am a tinkerer, go ahead & criticize my methods & machining standards all you want, I am always willing to learn!

I grabbed a piece of 6061 billet & drilled two holes all the way through with a long 1/4" drill bit from the hardware store:
View attachment 489155

Enlarged & reamed top hole for an 18" Crossman barrel that I have lying around:
View attachment 489156

Removed some material ahead of the lower hole so the valve could fit in there;
View attachment 489157

Used a boring bar to enlarge bottom hole to .788" to accept valve:

View attachment 489158

Test fit el-cheapo Amazon valve. Right after I bought this I saw one in Fleabay that comes with a regulator. I may upgrade to that if this receiver turn out ok, the front parts are the same:
View attachment 489159

Plunging the transfer port, I used an end mill since I was drilling through the barrel channel, drill bit likely would've walked:
View attachment 489160

Drilled & tapped some holes for a pic rail, you know, in case we wanna scope this sucker. Machinists may scorn me for tapping with the mill: I'm lazy ok, if it's faster I'm doin' it:View attachment 489161

Scope rail holes & transfer port plug tapped:
View attachment 489162
I always consult my meticulous technical drawings before I cut:
View attachment 489163

Time to cut the loading port:
View attachment 489164

Little more room:
View attachment 489165

Test fit barrel, valve & tank:
View attachment 489166

Sorry for the lengthy thread, when I have more time I'll do more work on the thing& see where it goes (cue your words of encouragement here).

Very cool!… I tap on the Bridgeport too…always square, and works great!…looking forward to seeing the finished product. John

 

[bsahogger]

Didn't have much time today but did manage to get the pic rails on. Got some tubular solenoids on order, once they come in I'll bore the hammer port larger to accept said solenoids, then the experimentation with the electronics shall commence.

 

[Airgun-hobbyist]

With a metal working machine or two at your disposal, why not take that experiment a little bit further and press fit the FX barrel liner in a machined aluminum tube (with the end machined to the barrel's o-ring and receiver specs)? That would eliminate barrel liner whip and allow it to attach to the experimental receiver and also the Drreamline.

 

[KWK]

Looking good

Very cool!… I tap on the Bridgeport too…always square, and works great!…looking forward to seeing the finished product. John

Who doesn't?

 

[bsahogger]

With a metal working machine or two at your disposal, why not take that experiment a little bit further and press fit the FX barrel liner in a machined aluminum tube (with the end machined to the barrel's o-ring and receiver specs)? That would eliminate barrel liner whip and allow it to attach to the experimental receiver and also the Drreamline.

I personally don't know of anyone that would be able to machine (ream) the inside of an aluminum tube over that length to that kind of accuracy. Also, the FX 'liners' are twisted so the OD is not smooth, that would make a press fit difficult.
Bottom line when it comes to FX Dreamline POI shifts is this: FX made the thing as cheaply as possible, worse than low end guns like Marauders. The gun does not have a barrel, it has a flimsy little tube, supported by comical little plastic discs. I've even read reports of the .177 barrels being cracked open the inside due to the tight twisting when they form the grooves. Rip the whole barrel assembly out, toss it, fit a steel barrel with at least a 5/8" OD & you'll shoot dime size groups at 50yds all day, no POI shifts.

 

[JohnTaylor]

Looking good

Who doesn't?

My thoughts exactly..

 

[Airgun-hobbyist]

I personally don't know of anyone that would be able to machine (ream) the inside of an aluminum tube over that length to that kind of accuracy. Also, the FX 'liners' are twisted so the OD is not smooth, that would make a press fit difficult.
Bottom line when it comes to FX Dreamline POI shifts is this: FX made the thing as cheaply as possible, worse than low end guns like Marauders. The gun does not have a barrel, it has a flimsy little tube, supported by comical little plastic discs. I've even read reports of the .177 barrels being cracked open the inside due to the tight twisting when they form the grooves. Rip the whole barrel assembly out, toss it, fit a steel barrel with at least a 5/8" OD & you'll shoot dime size groups at 50yds all day, no POI shifts.

I wouldn't necessarily go for superior straitness or precision press fitting. Just a decently strait and tight enough sleeve fit that the application of sleeve adhesive would lock up both metals rigidly upon curing. I'd bet that it would be comparable to these guys putting FX liner's into these carbon sleeves, whose internal straitness are not precision ground like the outside dimension, or the gunsmith who reams out an old barrel for a new liner. Can't be any worse than the factory straw...

 

[thumper]

I personally don't know of anyone that would be able to machine (ream) the inside of an aluminum tube over that length to that kind of accuracy. Also, the FX 'liners' are twisted so the OD is not smooth, that would make a press fit difficult.
Bottom line when it comes to FX Dreamline POI shifts is this: FX made the thing as cheaply as possible, worse than low end guns like Marauders. The gun does not have a barrel, it has a flimsy little tube, supported by comical little plastic discs. I've even read reports of the .177 barrels being cracked open the inside due to the tight twisting when they form the grooves. Rip the whole barrel assembly out, toss it, fit a steel barrel with at least a 5/8" OD & you'll shoot dime size groups at 50yds all day, no POI shifts.

Bingo.

FX peddles cheap junk for exorbitant money.

They used to make guns with real barrels.....

 

[bsahogger]

Bingo.

FX peddles cheap junk for exorbitant money.

They used to make guns with real barrels.....

Yep, they figured out that if you make a quality rifle folk will have no reason to buy another. Now they make as many models as possible (more than any other manufacturer), engineered as poorly as possible, then regularly bring out a "new" version of each model (Mk1, Mk2, Mk3 blah blah). So you have a current version of a model & you realize it has flaws, but hey you can't wait to sell it in order to buy the "new improved" version. Hey as long as folk fall for it & they sell lotsa their junk rifles, good for them.

 

[bsahogger]

Busy week, just now finally having time to bore out the receiver to accept the solenoid which arrives today. Think I know how I'm going to do the stock, that'll probably have to wait until next week.

 

[OC_]

Whats the stock going to be made out of?

 

[Scotchmo]

You discussed an electronic hammer. I’ve done a few builds with electronic hammers and settled on a circuit configuration that I now use on all of them. I use solenoids from Circuit City (Magnetic Sensor Systems). My circuit design is shown below and a link to the solenoid that I prefer:
SOTUH02305106P - -S-20-90-22H

The circuit that I use is analog (no computer). The hammer strike can be controlled three ways. A mechanical stroke adjustment can be built into the design. Stroke of 1/8” to 1/2” is a good adjustment range. A higher energy hammer strike with the longer stroke might use more capacitance. Increased capacitance can also increase dwell. For on the fly hammer adjustments, the dc-dc boost converter has an output voltage adjustment pot.

By default, the circuit allows multi cycling, like a semi auto, but unless we have an auto loader mechanism, we don’t want that. So I have an electrically latched relay in the circuit so that the on/safe switch must be cycled each shot. It’s like an auto safety so that you can’t accidentally fire it multiple times.

Tubular Push Type Solenoid S-20-90-H 0.90"(23.0mm) DIAx2.00"(50.8mm) LENGTH

Tubular Push Type Solenoid, 2.00 in (72.4mm) LENGTH x 0.90 in (23.0mm) DIAMETER, MSS S-20-90-H

www.solenoidcity.com

 

[bsahogger]

Whats the stock going to be made out of?

Thinking of attaching an AR folding stock adapter, then fitting a Magpul PRS fully adjustable stock.