GTA
General Discussion To Gateway To Airguns => China Gate => : cpiccolo April 19, 2009, 12:34:39 AM
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Does anyone have some pics about how disasembly a TF-99 (QB-36)? :emoticon: :emoticon:
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Are you already into the process? Pay particular attention to the position of the spring behind the trigger! Once you get it out, it is very difficult to reconstruct from memory how it was placed. It is actually easy, once you know how it is supposed to be.
You will want a spring compressor with this one. Of course you will verify the gun is unloaded and not cocked before beginning!
You will see in the parts diagram, upper right, where the main pin goes through the back of the receiver and the spring guide. You have to get the thing out of the stock, remove the cap on the back, relieve tension on the pin with the compressor, and drive the pin out (it came out easily with the tension off). Thencarefully backthe tension off that long spring to withdraw the innards. I don't recall if you needed to remove the trigger housing but you might as well if you're going that far!
There was a thread on another forum with some good info including trigger pics and parts breakdown. I kept his pic of the trigger layout and I have one I took from the bottom before I removed the spring (good thing).
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Thanks a lot bro... im from venezuela and here its very dificult to find a good air gun the mine in fact was carried by an import agent of a city near of mine. The first thing that i do was polish the anty bear trap hook in the end of the puller rod because i read a lot of post that say problems with the security device, fortunely im a skilled mechanic with a lot of tools and i can do this job.
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I just got finished tuning my TF97 which I believe is just a less powerful version. I think the TF99 and TF 97 are basically the QB36-2 and QB36-1. I took lots of pictures so if you get stuck I've got about 20 reference shots. One thing is that the pins are just floating and held in by the stock. Be careful when you take it out and turn it on its side as a few of the pins will just fall out. Also make sure you keep one finger over the spring when you disconnect the other end so they don't go flying out.
If yours is like mine it was all gunked up inside. It uses a leather seal which I soaked in neatsfoot oil for a few minutes. Upon reassebly it was powerful. Before it was shooting 520-550 fps (.22 cal). The first few shots were 780, 820, 790 and I thought I was too good to be true. Well it was because after about 24 shots it was back down to 560 or so.
I chalk this up to the seal. Guess all the extra oil gave it good compression but once it was all blown out I was back to the old tech being the weak point. I'm going to disassemble and see if I can get a replacement (non leather) seal.
There were no tricks to taking it apart that I can think of.
Good luck.
ANdy
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Thanks buddy its great to talk with guys like you and change points of view, my gun its brand new i just have a pair of weeks with that, about the problem of leather seal i think that you can go up with a nylon seal, just seek a skilled crafstman that can make a good job, but i think that if find a friend with a work shop that borrow you the right tools you can make the seal. (SORRY FOR MY ENGLISH I THINK THAT IT'S NOT GOOD ENOUGH)
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Dave -
Thanks for the good information. I just picked up a TF-97 in .22 last Friday, and was looking for some instruction on tearing it down.
I have a question for you (and for anyone else who's interested) - what's the purpose of the lever behind the trigger? I know you have to depress it to return the cocking lever to its original position, but is it another anti-beartrap device? If so, seems like a "belt & suspenders" set-up.
I don't trust any of it - I hold the cocking lever during the loading process. I haven't shot the rifle much yet, but the additional step needed to depress the lever is already annoying. I'm considering removing the device, but maybe I'm missing some good reason that it needs to stay.
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rr, I have never had the 97 but that is the anti-beartrap release and I would not remove it. The 99 has it so I guess the 97 has the same setup.
Some time ago there was a famous picture of a nearly severed thumb going round the forums. It was a TF97 that slammed home while someone was loading. I don't know whether this additional "safety" was added as a result of this incident, but I would want all the help I could get to keep that spring held back. And then, never trust it. I keep my arm or leg blocking the lever when loading and made a habit ofit.
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I don`t trust too in the bear trap device i hold the lever rod firmly with my arm while y charge the ammo, here im send a pair of pics, one of my hitter and the other its about a trick job that made to my gun, the original breech seal was wrong after few shoots and i replace with a custom made of harder metrial ( Urethane) what made a firm seal and its more durable
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informative and humble, nicely done..
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hey bro, do you have pics of the power plant?
you know the piston an the cilinder, course the seal too.
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here's a few. let me know if you need more shots
Tube
http://i704.photobucket.com/albums/ww46/larspawn/tf97tube.jpg
Piston
http://i704.photobucket.com/albums/ww46/larspawn/tf97piston.jpg
Pin config
http://i704.photobucket.com/albums/ww46/larspawn/tf97pins.jpg
Bugbuster with leapers one piece cantilever mount
http://i704.photobucket.com/albums/ww46/larspawn/tf97bugbuster.jpg
Grouping at 10m
http://i704.photobucket.com/albums/ww46/larspawn/t97_target.jpg
http://i704.photobucket.com/albums/ww46/larspawn/tf79group.jpg
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I want to replace the leather seal for anyone of nylon or urethane, so i need some pics of the seal and if you can, measurement of seal itself.
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It is a leather seal with the hole in the middle. It isn't like an apex. Note the blurry picture. When I took it apart it had leather debris and gunk everywhere. I soaked it in neatsfoot oil and my first few shots were 800 fps, 750 fps, 740 fps. It then settled in at 560 fps with Daisy Precision Max pellets. Oh this is .22
Although some say that you can't use a synthetic seal due to the poor tolerances mine didn't appear to be that bad. I didn't check the diameter when I had it apart but I should have. I plan on replacing my leather seal with a synthetic. I might have to make my own though because I haven't seen a source for replacements.
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Oh yeah. I don't think urethane would work because it is too soft. Nylon or better delrin. You might have to have a custom one made unless you have a lathe.
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You could make a very good seal from a P.T.F.E. rod.
Look on Ebay.
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Thanks for the pics larspawn, i dont saw them hahahahahaha, could you send me if you have it, a pics of the cilinder near to the piston, i think that with a nylon seal the overall perfomance will increase, and i do that near.
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Not sure what you mean? Could you describe more and I'll see what pics I took. I'm going to open it up again soon and try to custom make a piston seal using some PTFE rod. You can buy them at McMasters by the inch I think. If you don't have a lathe you can probably chuck it on a wooden dowel in a drill press and shape it down. Trailing edge should taper in.
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Just a comment to pay attention to the breach seal. On my TF97 I found wear on that seal could mess up the grouping a lot. I ended up using some slightly ground down washers for a faucet. There is a mcari spring that will fit the tf97. My oem broke after maybe 2000 rounds. Same dia spring as a B3 but quite a bit shorter.
Also, to make it easier to latch that sear spring break get a small screedirver and cut a small slit in the end. then that spring will hold in there when you compress it to put it back togther . Otherwise it keeps slipping off there and it casues all kinds of fowl language &^%$ when that happens.
don
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Hi larspawn, i have a B3 modified by miself, i find a good seal of high density siliconed polyurethane, in fact measures of the seal its in milimeters, the inner diameter of the cilinder is about 25 mm ( near to inch ) my B3 was shooted about 700 rounds with no droop in perfomance, i dont have a crhony but i stimate the velocity over 650 fps, the bad thing is that i dont take any pic of the job, ill take pics for my next job, when ill modified my TF-99.
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Hey larspawn take a view of this pics