Air Gun Home :: View topic - micro-gtx - i homemade one and now i got an update!!!!

BEANER · Member

I went to a gunsmith and a hardware store, both guys said that the http://www.pspairguns.com/id14.html bolt and the nut dont fit each other. the 2-56 bolt doesnt fit a 5/32 nut. Weird huh? So i did get a 2-56 1/2 inch bolt and 2/56 nut that fits it. i think that was the nut, but the gunsmith said it has 56 threads perinch as does the bolt. I wanted this for finer adjustment. I bought the spring too. I also bought the dowel cause i have a crossman/chinese phantom which they say it would need. Well that dowel is huge compared to the original pin. So i grinded the pins just enough for the bolt to fit inbetween the stock ones. It is a thumbnail worth gouge out of the pins needed only. Also the nut has to have opposite sides grinded down to fit inside the trigger cause it was too wide. My bolt ended up exactly where the x-ray picture shows and when you go to install it into the gun, the trigger pin with e-clips on it is blocked by part of the bolt? So i had to grind down the end of the bolt, just enough to take threads off the end for the pin to even fit.

Now the gun did what the bottom of the page described, it had 3/4 smooth pull then the rest is when the gun fires. So i take it all apart and lube it with moly/oil. Its all smooth. I go to shoot the gun and the first stage is nice and smooth, barely there and then you feel some resistance then pop. Im thinking perfect. But the trigger stays all the way back. I load it and go to shoot it and no smooth pull just a pop.? So i take the trigger and have to manually after every shot pull it forward til it stops in order to get the first smooth stage. If i dont then all i get is a pull 1 mm then pop. They said to leave the blade spring off and not to use it.. I used a stiff spring on the actual bolt insert. Then i tried to change it to a soft spring, but the trigger still will not return itself after being fired.

Anyone have any ideas? Im thinking i need to install a light spring between the back of the trigger and the rear trigger gard. I guess im just going to have to spend 30 for tunas trigger when i have the cash.

This little mod works great if it would return the trigger each time. I thought maybe i put too much grease in there, so i cleaned it all out and still nothing. I have taken this gun aprt three times not and im pissed. Im good at mechanical things, it just seems like there needs to be a return spring in there. So if you goto that website i listed i did everything to the tee. Help!

AirGunEric · Site Admin

Todd Cooper used this setup (this is also his picture):

He says he used a 2-56 screw and nut, a spring from a ball-point pen and a 0.125" spring pin was made from a 1/8" drill bit (0.26" long).

I can't even read the instructions on the PSP site (way too small)- so I don't want to comment on anything there.

Can you post pictures of your setup so we can see?

Mar · Veteran Member

Who are they???

You're gonna make me look for this trigger mod now, aren't you. Smile

OK, just had a quick look in my bookmarks and seems like I'm not seeing it but give me a bit of time and I will find something about it.

There is someone here or on Canadian airguns that could help you though as he did it.

BEANER · Member

well, maybe i got confused a bit about this part "two supllement springs are included with the kit, 1 is stiffer and 1 is soft. They are called strut springs and they also call them compression springs. they go inbetween the sear and the strut at the rearmost part in the casing. It says nothing about the springs size in any doc on their site or any other website showing this mod like here http://www.network54.com/Forum/479035/message/1161226712/
http://www.network54.com/Forum/479035/message/1158803309/
http://www.network54.com/Forum/479035/message/1175653014/You+can+make+your+own+insert%2C+Larry.
http://my.tbaytel.net/~coopers@tbaytel.net/QuestPhantom/#PARTSDIAGRAM
http://www.network54.com/Forum/479035/thread/1187367985/The+Bling+is+Back!

so if anyone knows, i will appreciate it. Thanks. And its also future info for other homemade type deals for others.

BEANER · Member

by the way phtoshop sharpens the psp website enough to say on the picture the bolts and screws needed here they are
1.#2-56x0.5" fillisterhead screw, it diesnt have to be fillister.
2.5x32 brass nut , The gunsmith and hardware store says this nut and the 2-56 dont fit each other cause the threads are different.
3. 0.125" od spring. That did work. but a ball point spring is easier to find
4. 0.125" x 0.25" (smaller pin to the left of the bolt micro-gtx bolt in the pics)"replacement size in chinese versions such as quest /phantoms among others---its way too small. Its very loose in there. I would try something larger or grind a little notch out of it and the 2nd stage pin they call it, (which is to the left of the pictures with the micro-gtx screw installed)its the larger pin.

sorry while i was typing i didnt see two people had posted. Sorry i didnt take pics. And the psp website i tried to put it in photoshop to sharpen and do everything under the sun to try and read and look at the pics but photoshop cant even do it.

So just take your two pins that the screw goes into and gouge a tiny groove on each one for the screw. Then grind the side of the main trigger holding pin so the so the screw doesnt have to be grounded down about 3mm from the end. Im not talking about cutting the screw down but making the diameter smaller cause you can see threads when you look through the trigger e-clip pin hole if you dont. Dont worry about the threads your shaving off cause adjustment doesnt need all those threads.

Now i guess i have to take it apart again and put a unknown size spring inside that sear. It would have been nice if anyone would have added that info. But when the psp said it wouldnt need the triggerblade spring because the micro-gtx fixes that problem , that is what made me believe the trigger would somehow reset itself. So i guess my mistake will help lots of others. Cause as of now,,,its a great cheap alternative and works very well if you get the right parts. and you have a file to grind down what is needed. But forget about there instructions about crossman needing that .125 pin. That is comlpetly wrong. And it doesnt hurt taking a sliver of metal from those two pins inbetween that 2/56 bolt. That bolt almost fits through them, you just need to give it a little extra room. And maybe they sell brass nuts that arent as wide, cause i had to buy a stainless steel one. Maybe somone could email tuna guy and ask him to micrometer the width of the crossman trigger internal slot where this nut is supposed to fit.

AirGunEric · Site Admin

BEANER · Member

no the trigger blade spring isnt needed, thats what they say,,,i did however find that a spring is needed above the sear. That is what no pictures show. So i guess a little tiny spring is wedged inbetween the sear and the strut. The sear is what the trigger actually moves to the point where it falls off the edge of the strut and that is when the gun fires. So now i have to figure out what size spring is needed in there and where im supposed to put it and also how its supposed to stay in there.

In everything i have seen and read both with the micro-gtx and the gtx trigger, the leftover parts for the phantom and the quest are the blade spring, and the plastic adjuster housing and the plastic adjusting screw, So tomorrow when i take it all apart i will take pics for everyone!

BCSteel · Member

23ib0d0n · Moderator

Be very careful with this tigger modification. Since the tolerances for a 2 stage trigger are so tight, with just a tiny amount of wear on such a miniscule surface, you have an unsafe trigger on your hands.

I have read that the wear on this modification releases the sear without touching the trigger after just a few hundred shots. Please use extreme caution.

BEANER · Member

ok, so this is the update. I went to a different hardware store and bought new screws. I bought 1 2-56 round head philips by 1/2 long,(I happen to find this one by accident cause i was looking into the metric machine screw boxes)this screw wasnt in with the 2/56's either since it was a philips and the 2-56 were all standard. I bought 1 2-56 nut and 3 more 2-56 screws 1/4 inch long,3/8 inch and one 1/2 inchall with bigger heads and one with a flat -standard head top. I then bought smaller diameter metric bolts (compared to the 2-56, i think they are 4-40? with round type standard heads in 1/4 1/2 and 3/8. The metric nut was also significantly smaller compared to the 2-56 one. So if you read earlier how i had to file both sides of the 2/56 nut to fit into the trigger that this metric might not be a problem.

Well I also stated before that the 2-56 bolt wouldnt fit inbetween the two pins show here in this picture http://www.network54.com/Forum/479035/message/1161226712/ so i had to grind gouges into them. Well for some reason after trying all these different screws i just bought, the one that fits perfectly is the weird philips headed one that happens to fit 2-56 nut but the store doesnt sell 2-56 bolts that are philips(it was also in the metric bolt box like i said earlier. So i had to spin the trigger pins which i earlier grinded because the bolt fit without those grooves. The new 2/56 nut i bought still wouldnt fit so i had to use the old one i grinded.

Now i also told you i couldnt fit the trigger holding pin(the one that holds the trigger on and has e-clips on both sides) because the previous 2-56 bolt was long and was in the way of the hole. So i ended up shaving off the threads on the end. Well i found this site---- http://www.network54.com/Forum/479035/message/1161226712/ and read what was said. The part that says "Rotates the screw around the point of nut/pin contact, holding the screw against the pivot pin" Now the holding the screw against that top pin is what got me thinking. I shouldnt of had that screw threaded to the point it was up there. Cause when you finally install the trigger pin, you then start tightening the screw until it "holds itself against that top pivot pin". So after i installed the pin and thre the e-clip on, i started turning the screw, turning then checking the pull of the trigger, and turning and checking etc. Well now the trigger pulls back to a a nice stop with virtually no resistance until it comes to that perfect spot, you can release the trigger without pulling it more and it will pop right back . It is soooo perfect. I have this nice smooth feather light pull and then maybe the resistance of hmmm, im not sure how many ounces but it is just perfect. Its enough for it to not be an accidental discharge but its just a great feel. Im frustrated all the work i had to do in order to get the right screw and grind the nut down. But it is absolutely worth it 100%!!!

So if the screw doesnt fit your crossman or phantom, keep looking , one will. Do not buy that pin they say is needed for chinese and crossman models, even when i had the screw that didnt fit and stuck that pin in, the slop on either side of that pin is huge. And the screw will not tighten up that metal dowel they say in the instructions on the psp site and the net. It will fall right out. The nut ,, like i said, from the gunsmith and from both hardware stores say that 2-56 screw does not fit a 2-53 nut. Im not sure about this, and i couldnt find a 2-53 nut to try either. So maybe it does i dont know. But it doesnt take long to file down a 2-56 nut to fit tightly inside the trigger. The spring is correct in the instructions. I dont have a ballpoint pen or else i would have used that, but i had to buy a stiff spring and cut it to about 1/4 inch and bend the end that butts up against the head of the screw so its tight right there. I think if i do it over then i would add a washer on the side of the spring that touches the pins. Just so it stays tight or something doesnt go awry. Dont file nothing, the first phantom i owned i sanded the trigger sear a tiny bit and it was real touchy. Its good enough from the factory, its smooth and after you mod the trigger you will put plenty of rounds through the gun from the fun to wear the parts in.

Accuracy has already went up also which i always wondered why i had heard about better triggers doing that. I think its cause your alot more prepared for when the shot is going to happen. But, i hope this helps people out. If i had this info before i started then things would of went alot faster!