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  • #1153
    mark
    Participant

    Hi
    First let me say what a fantastic quality of workmanship you guys turn out.
    Secondly all the guns seem to be based around one design,am i correct in asuming this?
    Thirdly i really want to build my own pcp field target rifle to use here in England can anybody provide drawings for me.I have my own small workshop complete with Lathe,milling machine and drill press and the know how to use it.
    Heres hoping someone is kind enough to help yours Mark

    #30567
    blodnob
    Participant

    Hey marc.
    I have a full step by step set of plans to build a pcp rifle similair to an Air Arms if they are any use to you. Its not very Stealthish but would be a very good FT rifle and you could bullpup it.
    Sean.

    #30568
    blackops
    Participant

    Hey Mark I’m sure someone will chime in with some thoughts on the subject…there are some amazing machinists/engineers on here.

    I’ve been pondering a project like your thinking as well for a while myself but havn’t started on one yet… here’s some info on the USFT guns I’ve looked at…

    Great Article about 1/2 way down the page… http://images.search.yahoo.com/search/images/view?back=http%3A%2F%2Fimages.search.yahoo.com%2Fsearch%2Fimages%3Fei%3DUTF-8%26p%3DUSFT%2520rifle%26fr2%3Dtab-web%26fr%3Dyfp-t-501&w=357&h=89&imgurl=www.pyramydair.com%2Fblog%2Fimages%2FUSFT-web.jpg&rurl=http%3A%2F%2Fwww.pyramydair.com%2Fblog%2Farchive%2F2006_12_01_pyramydair_archive.html&size=4.5kB&name=USFT-web.jpg&p=USFT+rifle&type=jpeg&no=1&tt=1&oid=4ee25a5458f7fa2e&ei=UTF-8

    – Air Chamber: Large(650-1,000CC) low pressure(2,200 psi or less) air chamber with no regulator. Unfortunately I have found VERY little info on air chamber creation as it is a VERY dangerous venture to make your own unless you know what your doing(I don’t). I bought a couple Luxfer 1,000CC 153BAR/2,216 psi tanks Model # M006 I wanted 1,000CC it was dumb luck these are similar to what the no holds barred FT guns use!

    -Barrel: Long .177 barrel. Most seem to have or agree a 24″+ barrel is good for efficiency on the .177 BUT this is at 19ft lb guns… I’m currently working on getting a 24″ or 26″ barrel to test at both 19 and 11.5 fpe then cut off 1/2″ test again and see what the optimum barrel length is for each fpe. This will be effected by the psi of your air tank also… From what I’m told all FT winners have used Lothar Walther barrels and FT tuners do considerable prep to them to make sure they shoot there best. I’m startled to find out they are capable of 1/2″ 10 shot groups @ 52 yards…in short they make the crown perfect, lap the tight spots on the bore as well as make the breech(forcing cone) as smooth and perfect as possible. They push pellets in part way etc and then examine with 10x jewelry loop for any irregularities…they also use the loop looking at the crown and breech.

    SCARY assed test target shipped with gun.

    I’ll be really interested to hear what some of the guys who have actually made guns think about your project.

    Some useful Links:
    http://www.luxfercylinders.com/products/medical/specifications/us_metric.shtml stats on the Luxfer Cylinders.

    http://www.network54.com/Forum/79537/thread/1198918843/ short info on guys USFT Carbine

    #30586
    mark
    Participant

    Cheers guys what a couple of fantastic replys to my first question on this forum,far better than i had hoped for 😀
    BLODNOB
    I have sent you a pm regarding the drawings hope this is the correct way of doing things on here.
    BLACKOPS
    What a info packed reply, your computer skills are far superior to mine.
    It appears that im really lucky regarding the reservoir side of the build ahead as i work in a engineering shop where we manufacture hydraulic rams and power packs and im able to test cylinders up to 700 bar on our test rig.Also i will be able to utilise the design teams brains regarding wall thicknesss,burst pressures and the general design requirements to construct a safe unit. Perhaps i can help others with questions of this nature?
    I really do wonder if the preperation some of the field target guys make are really necessary or does it just give them a mental advantage ❓
    Well thanks once again guys for your help and hope to speak again soon yours Mark

    #30587
    blodnob
    Participant

    My pleasure sir.
    I also have some spare seamless stainless tube of the correct WP if you’d like a mtr to play with. Ive had trouble finding the correct ally grade and spec so if anyone has had experiance with this all help would be greatly accepted.
    Atb, Sean.

    #30588
    mark
    Participant

    BLODNOB
    Cheers for your reply once again.
    Hang onto the stainless tube for now,i will have a look at work to see what sizes we have.
    Regarding the alluminium i will have to talk to the guy in purchasing to see what he can come up with regarding suppliers.
    What grade and spec are you looking for?
    I also have a good friend who owns a company called Seadrift and he builds and supplies a lot of equipment to the offshore industry and he might be able to help.
    Yours Mark

    #30589
    buba-b
    Participant

    Hi Mark
    Making a pressure cylinder shoudnt be to hard if youve got the machinery , the problem ive found is getting hold of the materials 🙁 . I got hold of a copy of The Modern Pneumatic Airgun by H M Buckley available from Tideline books ,which has the drawings and info on building a Daystate Huntsman type gun. The book has alot of info on building this basic airgun ,with trigger designs ect. For the cylinder it uses ” 31.7mm x 5mm x 450mm high pressure seamless resiisting tube with a working pres of 300psi and a factor of safty of 3″ alloy ( some have a safty factor of 2 thou , 24 x1.5 threads .It dosnt state which grade thou and trying to get hold of half a meter tube from suppliers is either expensive or impossiable as your not worth the time! you may have more luck. Keep the cylinder under 0.5 cubic liters to avoid having to get it tested (this shoudnt be a problem for you thou). I hate him already…….lol hehe

    #30595
    mark
    Participant

    BUBAB
    Thanks for your reply, if you are struggling for materials i could probably help you.We have a massive supply of cds [ cold drawn seamless] tubing at work all used in the production of hydraulic cylinders.
    The cost of the material is negligible ,the postage cost would possibly be the most expense involved.
    I didn’t realise there was a capacity restriction before you had to have a test cert although as you said not a problem to me.
    Yours Mark

    #30622
    blackops
    Participant

    Hi Mark, Your very welcome brother! I had this info fresh in my head as I’ve spent maybe 100 or so hours here recently looking into the FT stuff. I have much more and detailed info I’ll post later, specifically barrel prep and pellet sorting to start.

    That is FANTASTIC you work in the pressure cylinder industry 😆 how odd is that!!!!! I’ll just go ahead and beg you right now to post some ways of capping/sealing off the ends of the pressure cylinders 😀
    http://talonairgun.com/forum/viewtopic.php?p=11129#11129

    OK back to FT guns….

    AirForce is heading in this direction and this looks like a fine model to base a FT project off of http://www.airforceairguns.com/edge.html

    Pro’s:
    – Simple design and construction. VERY EASY to take apart and work on or make new parts for.
    – Mechanics are all in line with the barrel IE: spring/hammer/breach slide/valve, so mechanically nothing but muzzle blast to change the aim of the gun.
    – This one looks to have an 18’ish inch barrel…prolly what they have in stock 18″ .177…could be 24″ with about 1/2″ space before the end of the shroud.
    – THICK scope rail section looks like it should eliminate any/most flexing of the frame.
    – Short shroud looks an AWFUL lot like the one Tim makes(or used to make? http://www.custombrakz.com/).
    – Nice looking pistol grip
    – Dropped down recoil pad! woot! looks to be adjustable for length and maybe height?
    – Dovetail top and bottom easy mounting of accessories(handles, weights, ???)
    – 😆 h-m-m-m-m don’t see a “safety” on this one…maybe they got rid of it or re-designed it?
    – Looks like there is a “positive” lock with the cocking handle which when adjusted to a very slight pressure when closing reduces valve “bounce” and imroves consistancy. Also a positive lock in the cocked position eliminating the chance of a “misfire” when your finger is loading a pellet!

    Con’s:
    – Tiny assed tank(CO2?) how are they going to get 40-60 consistant shots out of that? might be designed for 12 fpe? or HIGH(4,500) psi? either way I’d stay with stock 490CC or bigger tank. You can’t refill in the middle of a shoot.
    – Barrel bushings are still close together. Amplifies any variance in mounts/bushings. I’d mount the front one near the front of the frame(not in the extended shroud).
    – Maybe not a 100% con but Bodhisdad and maybe others are working on a one piece stock that should elimanate any frame flex. If you pull the gun to your shoulder hard it might be possible to flex the frame? maybe a little???
    – Power wheel is gone? while not essential is does give you another variable to work with in the power/consistancy department. A couple of us have found below PW6 on the SS consistancy starts going.

    Really this seems to be about the simplest and most effective general design for a home built gun. Trigger could use a little help(tighter tolerances and STRONGER parts), Anthony266 looks to have solved that as well as Mark on the home brew guns….

    More in a few I need a break 😆 Jim.

    #30626
    baz
    Participant

    Hi Mark, This set of pictures shows some of the main parts I have made so far in the atempt to make my own pre-charged air-gun. Some of the information came from the plans Blodnob talks about and some from my own knowledge of the workings of an air arms S400/S410. I was abit of a coward when it came to the air cylinder, decided to buy ready made ones. Managed to get 2 FX air cylinders off an air gun forum. But apart from this the parts so far have been pretty much straight forward to make.

    #30627
    blackops
    Participant

    Here is a snap of the Luxfer 1 liter (1,000CC ) 2,216 psi tank next to the factory one. It is a little bigger diameter but is also slightly shorter which when I eyeballed it up they have the same length of pull! They also make this tank wrapped making it a 207BAR/3,000 psi tank with very similar dimensions and a little lighter @ 1.5lbs vs. 2.2lbs for this one. Since the Air Wolf can get 180 19.5 fpe shots and 300+ 11.5 fpe shots from 500CC’s that is what I’m shooting for also! (30 fps deviation from first to last shot)

    Barrel Bushings:
    – I still like THX’s idea of the barrel “floating” on o-rings with the set screws going into larger holes in the bushings so as not to apply any side forces to the barrel. I think there is some good to come from spacing the bushings farther apart though as it will help keep the barrel straighter with the frame as well as lessen the pressure on the o-rings.
    – Vent the first bushing so you can still utilize that space behind it for shroud volume.
    – Put set screws 180 degree’s apart. There isn’t much load at 90 degree screws but it’s just as easy to put them 180 degree’s apart. Especially if your scratch building the gun…and you won’t loose any sleep what the uneven side load is doing 😉 😆

    Frame:
    – They could close off one side of the frame adding some more strength to it. Leaving it open does make it ambi to load but lefties just need to suck it up 😆 and load from the right 😆
    – 1″ ID frame seems to work really good and is easy to get 1″ OD stock and springs etc.

    More later time for the movies! Jim.

    #30628
    blackops
    Participant

    Baz, WHOLLY CRAP that is frigging BAD ASS looking! do you have a sketch of what you want to to look like when finished?

    WOW that is nice, Jim.

    #30762
    baz
    Participant

    not much good at sketching but have look at this early model i sketched you probebly agree that id be better posting photos of the parts as i go along, by the way, who is wholly crap? or did you mean holy crap?

    #30891
    mark
    Participant

    Well a big thanks to Blodnob for sending me drawings of a pcp rifle for home building.
    I have made a start collecting materials for the build ahead,only trouble is my son has jumped in on the act and now wants to help me build two of them and i know from past experience who will end up doing all the work,can you guess who? 😆
    I have got hold of 2 pieces of 38×5 stainless for the reservoir and 4 pieces of 40 mm diameter EN 24 T for the valve bodys at either end of the receiver.
    What really suprised me is the cost of ss tube,whilst obtaining my two pieces i found out the price for 32 x 3 which is £60 a metre 😯 so how much my 38 x 5 would have cost i really don’t know,luckily my piece is just a couple of off-cuts that wanted a good home 😀
    Well nothing else to report yet and as soon as i start cutting material i will get some pictures posted yours Mark
    P.S BAZ
    The part on your drawing which you don’t know what it is yet,i can tell you it is a gigglepin for operating the kerfuffel valve,hope this helps 😆

    #30894
    colinb
    Participant
    quote baz:

    not much good at sketching but have look at this early model i sketched you probebly agree that id be better posting photos of the parts as i go along, by the way, who is wholly crap? or did you mean holy crap?

    where ya manage to find the shoot over hedgey barrel?
    cant find em anywhere on the walther website 🙄

    😀

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