Results 1 to 7 of 7

Thread: DIY servicing the Norica Quick

  1. #1
    Marksman

    User Info Menu

    Default DIY servicing the Norica Quick

    A few days ago my Norica air rifle's trigger started feeling very light on some shots and it began breaking at a different point than I had become used to. I ignored this for a few shots as it otherwise seemed to be shooting just fine. A few more shots on, I started noticing that the rifle was taking two or three tries to catch at the end of the cocking stroke and it began to dawn on me that this was probably the start of a major problem. A few more shots later and the trigger was slipping on every cocking stroke and it was clear that to try and continue would be dangerous.

    Once inside, I removed the stock and a glance at the trigger revealed that the plastic spring guide at the trigger end of the spring was deformd backwards in a v shape at the point where the trigger engaged the piston to hold the spring in the cocked position. The spring guide is part no. 715 in the diagram below:







    With the action out of the stock like this and without removing the trigger unit and spring, I could see that the reason for the spring guide deforming was that the steel washer (part no. 213 in dagram) was missing from the rifle, so the end of the plastic spring guide was bearing the spring tension of every shot unsupported against the trigger assembly.

    I had bought the Norica second hand and I had it taken apart and lubricated by a local guy who knows some gunsmithing; I'm guessing that this is when the washer was left out. So now having seen the cause of the malfunctioning trigger, I had a choice from two options, either take it back to this guy or do the repair myself. It was an easy decision to do it myself. Just by looking at the plastic spring guide I could tell that the spring and trigger should never have been assembled without a supporting washer and I couldn' take a chance that something else might be mucked up again this time.

    It took me about a day to figure out my spring compressor layout, made from a car jack and a sawn-down crutch with some inelastic cord and cellotape. By some great luck I managed to get a replacement Norica piston seal and spring,after months of waiting, the day after the trigger started malfunctioning. As it turns out my repair guy didn't notice the rip across the side of the piston seal, and his solution to the honking sound the seal was making was more grease and motor oil on the spring, piston and seal.






    Yellow arrow- broken off piece of the spring guide. Red arrow- the tool I had ground to compress the spring with.

    The end of spring guide was in two pieces when I got it out, I got a qoutation from a machinist to have a steel spring guide made for B$10.00, about 195 rand, but I opted for them to machine a washer for instead for B$2.00 which I then bonded to the spring guide pieces with epoxy glue. I was worried that a metal guide would change the rifle's vibrations and recoil possibly damaging the spring as well(?). In any case I was in a bit of an anxious state about my favourite rifle and didn't feel like experimenting at that particular time.









    The original spring top, new spring below; new washer at left, old washer at right note the burn marks from over lubricating on the old seal, Norica don't recommend oiling their seals through the transfer port. The original spring guides at right, the plastic rear guide now has the steel washer bonded into place. The (somewhat heavy weight) piston bottom left.


    I decided to use the original spring on reassembling the Quick because both the spring guides fit more tightly to it than to the new spring. The rearward end of the spring was slightly bent due to the flexing of the previously unsupported rear spring guide, so I reversed the spring to have the bent end in the piston since there is a metal spring guide in there. I put a quarter teaspoon of green lithium grease inside the piston and on the guide to (hopefully) compansate for putting the bent end in there, and light coatings of the same grease on the piston and spring.

    I finished the assembly at around 9 pm, and I simply had to try out the rifle right there and then, so I loaded a pellet and went outside. Instanltly I could feel that the cocking stroke was smoother and quieter than before. The trigger also engaged the piston firmly without any sloppiness. The trigger pull was rather firm, something the Norica Quick is infamous for, and it now broke with a reasurring crispness. The sound of the rifle on firing is best described as a pleasant, light phooosh sound, with just the lightest of recoil,which came as just the greatest of suprises to me.I didn't need to test fire a second time, I knew from that one shot that this repair had gone quite well.

    I may eventually take up the machinists offer to make me a set of steel spring guides in future, to snugly fit the new spring but for the moment I'm just enjoying the rifle as it is. If anyone has any doubts about doing some work on an air rifle you just need to do your research and have a plan before going in; I won't say that it's the easiest thing to do, but does add greatly to the satisfaction and enjoyment of our sport.







    Some disallowed "targets" have been coloured over.
    Sign Up To Air Rifle SA Forums

  2. #2
    Inactive Member

    User Info Menu

    Default

    Well done. A very good DIY.
    Looking at the photo it seems as if the new spring has a noticeably smaller diameter than the old one. Is the problem with the new spring that it fits very tightly over the guides? If so, then very good. A spring that anchors on the guides will give a smoother and lighter recoil than one that fits loosely and that follows the piston on the firing stroke and then jumps back to give that double direction recoil that destroys scopes. On compression the spring expands in diameter so it will not bind on the guides. Just lube the guides to ensure smoothness. The tighter fit the better as the spring will last longer. After fitting the new spring it is good practice to "set" or also called to "scrag" it to delete the manufacturing coiling memory before putting it to work. This can be done by cocking the gun and leaving it cocked for 4 hours and then releasing the spring. This will "set" the spring to optimum working length which will be similar to that of your exiting spring.
    Regarding the old spring that you turned around. Springsteel builds up a "memory" Turning it around might cause it to break soon. When cocking the gun, listen very carefully for any scraping noises. If heard, rather replace the spring before it causes damage inside.
    Heavy pellets love a heavy piston.
    Beautiful gun though.
    Sign Up To Air Rifle SA Forums

  3. #3
    Marksman

    User Info Menu

    Default

    Hi. Thanks for the post, I can see how the bits about scragging and spring memory are especially useful for breaking in replacement parts.
    I had browsed some posts about guide fit on the forum and in some youtube videos but since reading your post I have been looking into the area a bit more and seen quite a few approaches the getting rid of spring twang and promoting smooth shooting.On youtube especially I've seen some tutorial videos on shimming the inside of the piston.
    I then found this scholarly article: https://www.researchgate.net/publica...Piston_Airguns , stating that it's best to have a tight fitting rear spring guide; and that you can basically ignore the piston end if the rear guide is a tight fit. To confuse myself a bit more I then saw some other youtube videos of Weihrauch's that very clearly had rather loose front and rear spring guides but were presumably smooth shooters (maybe loose spring guides are ok on lower power springs?).
    Going back to my rifle, the new spring had the same number of coils as the old one, but both top and bottom guides fit quite a bit more loosely in the new spring than in the old spring. This was the deciding factor in my using the reversed old spring, but I didn't know then what I know now.
    The new spring was sold as being for high-power Norica's (300 m/s or 1000 fps) models so I did not want to risk loose fitting guides causing problems. Now I'm not sure if fitting the new spring would really have caused any issues. The new spring had a slightly larger inner diameter but it's outer diameter would be slightly larger too meaning a tighter fit in the piston, which may have the same effect as the shimming of the inner piston fix some tuners use. This would still leave the rear guide loose, but loose fitting guides didn't seem to cause any issues in the Weihrauch's I saw on youtube.
    With all I've seen; I think that when I do fit the new spring I want to have both spring guides as tight as I can get them. What I could understand of the scholarly article in the link above, makes clear that this is best for spring life and smooth shooting.
    A post on this forum advises, fixing loose fitting plastic rear guides by bulking them up with heated cling film (doesn't the heat deform the plastic guide?). Apart from that method or having a fully machined metal spring guide made; I wonder is it not possible to have a slip-on plastic or metal insert over the existing rear guide anchored by the spring and a washer to the spring guide?
    If there are other solutions to get tight fitting guides please let me know. Thanks again.
    Sign Up To Air Rifle SA Forums

  4. #4
    Sharp Shooter

    User Info Menu

    Default

    Quote Originally Posted by Outoppie View Post
    Well done. A very good DIY.
    Looking at the photo it seems as if the new spring has a noticeably smaller diameter than the old one. Is the problem with the new spring that it fits very tightly over the guides? If so, then very good. A spring that anchors on the guides will give a smoother and lighter recoil than one that fits loosely and that follows the piston on the firing stroke and then jumps back to give that double direction recoil that destroys scopes. On compression the spring expands in diameter so it will not bind on the guides. Just lube the guides to ensure smoothness. The tighter fit the better as the spring will last longer. After fitting the new spring it is good practice to "set" or also called to "scrag" it to delete the manufacturing coiling memory before putting it to work. This can be done by cocking the gun and leaving it cocked for 4 hours and then releasing the spring. This will "set" the spring to optimum working length which will be similar to that of your exiting spring.
    Regarding the old spring that you turned around. Springsteel builds up a "memory" Turning it around might cause it to break soon. When cocking the gun, listen very carefully for any scraping noises. If heard, rather replace the spring before it causes damage inside.
    Heavy pellets love a heavy piston.
    Beautiful gun though.
    Just be very careful with scraging. I scrag-ed a brand new Vortek spring and it failed after only 4000 shots. I contacted Vortek and told them what I did. The reply was that there springs are set before leaving the factory. The next Vortek I fitted is still running good after 8000 shots. Chris Pope from V-Mach told me the same thing.
    Sign Up To Air Rifle SA Forums

  5. #5
    Sharp Shooter

    User Info Menu

    Default

    Sisuphos, I think you are a very good gunsmith. I see that hammer lying on your workbench and I knew. My dad told me," Never ever took on a job without a hammer, not even working on a watch"
    Sign Up To Air Rifle SA Forums

  6. #6
    Marksman

    User Info Menu

    Default

    Quote Originally Posted by Deon.hopefield View Post
    Sisuphos, I think you are a very good gunsmith. I see that hammer lying on your workbench and I knew. My dad told me," Never ever took on a job without a hammer, not even working on a watch"
    You're right there about the hammer. I've rarely encountered a problem that a good whack won't fix...
    Sign Up To Air Rifle SA Forums

  7. #7
    Inactive Member

    User Info Menu

    Default

    Ah Ok. So the new spring is a "hotter" one than the old one. To be "hotter" it would either need to have larger diameter wire or a different metal compound to deliver more N of force than the old one for the same number of ACTIVE coils.
    Some of the important factors here are:
    1) whether the wire diameter (thickness) is identical. If the newer spring has a larger wire diameter it will also have a longer "solid" length which might then not be able to accomodate a full cocking stroke of the piston and you might have to lose a coil or two before your trigger sear will engage. In your case this might not be a bad thing as it would reduce the N force which from what you have written is what you want.
    2) if the spring OD is larger than the old one then at solid (full) compression it might not fit inside the piston because a spring expands in diameter under compression. As most Springers work on the basis of "over shaft and inside tube" I judge this factor in my spring design so critical that I have made the formula for this calculation my Avatar
    So best is to add an accurate tape measure to the hammer on the table to determine things such as available length inside and length of piston stroke

    Building up the synthetic rear guide with heated clingwrap should not be a problem if a hairdryer is used with caution. Just how effective the grip of the spring on the guide will be with this material is debateble or if it is even desirable with a synthetic rear guide. I doubt if the rear guide would have the tensile properties to control the spring forces without breaking or at the very least deforming. If I were in your shoes I would not risk this and live with the spring's performance until you can have a Steel rear guide made.

    Factory Setting of springs is the exception and not the rule due to the cost of extra time and handling in the production process and is most unusual. I would rather Set than taking the risk. After-market sales of spares is a great motivator for most producers and mostly trumps production of things that last forever. The acceptable benchmark life for a spring is between 3000 and 4000 shots. I make my springs last much longer by overdesign and working them way below the fatigue failure limits. Something similar to idling a large engine in a small car.
    Last edited by Outoppie; 18-08-18 at 18:38.
    Sign Up To Air Rifle SA Forums


Similar Threads

  1. Fitting a gas ram to the Norica Quick
    By Sisuphos in forum Airgun Discussions
    Replies: 5
    Last Post: 22-05-18, 15:49
  2. Norica Quick vs Gamo CFX
    By jkkelbrick in forum Airgun Discussions
    Replies: 10
    Last Post: 30-10-09, 19:03
  3. Norica quick
    By breeknek in forum Airgun Discussions
    Replies: 3
    Last Post: 16-03-09, 14:26
  4. Servicing help needed
    By knormoer in forum Airgun Discussions
    Replies: 7
    Last Post: 23-05-08, 20:09

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Friends of Air Rifle SA