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Calling engineers and mechanical folks, need a spring.

akmike47

Rumpleforeskin King of the Poors
Full Member
Minuteman
  • Feb 23, 2013
    11,331
    43,352
    Picked up a trigger shoe and it came with a reset spring so heavy it made my trigger twice the pull weight(5lbs). I did the “Bobby pin mod” and now have a 2lb trigger pull(I modified internals). I don’t really want to keep it half ass long term as I don’t like how it torques another spring. so I need to make a 1/2lb or maybe 3/4lb torsion spring(measured by trigger pull when only trigger and reset spring is installed)

    How do I go about figuring out the wire diameter needed, is there a formula or have any of y’all done this before?

    the company who made it doesn’t seem to understand what “the springs too heavy” means so I guess I’m on my own. I’ve been googling but it’s all crap for garage door springs.

    Posted here since more people will see it, any help is appreciated.

    Here’s the spring I need to replace
    909FF02C-5166-49F0-8208-347A6CC74A9D.jpeg
     
    Measure the wire diameter.
    Buy some 01 or *maybe* 1095 or similar tool steel.
    Bend the fucker up.
    Heat to mid'ish red glow.
    Oil quench......just drop it in, do NOT draw back via temper.
    Play around, should be pretty cheap, is really simple.
    You won't get it the first time but if you pay attention the first time will show you what you did wrong.
    Apply appropriate mods to correct.
    Profit.

    Edit.
    Use micrometer to measure wire diameter.
    Use same to measure *ring* in spring (measure inside diameter).
    Anneal tool steel wire by heating to mid red and dropping onto pile of kiddy playground sand and leaving to cool.
    Do that 2-3 times to be sure of anneal.
    Bend around drill bit to get correct size ring.
    Then quench for hardness/springiness.
     
    Last edited:
    Measure the wire diameter.
    Buy some 01 or *maybe* 1095 or similar tool steel.
    Bend the fucker up.
    Heat to mid'ish red glow.
    Oil quench......just drop it in, do NOT draw back via temper.
    Play around, should be pretty cheap, is really simple.
    You won't get it the first time but if you pay attention the first time will show you what you did wrong.
    Apply appropriate mods to correct.
    Profit.

    Edit.
    Use micrometer to measure wire diameter.
    Use same to measure *ring* in spring (measure inside diameter).
    Anneal tool steel wire by heating to mid red and dropping onto pile of kiddy playground sand and leaving to cool.
    Do that 2-3 times to be sure of anneal.
    Bend around drill bit to get correct size ring.
    Then quench for hardness/springiness.
    Mostly good advice however hardening such a thin spring will be an absolute pain in the ass if they have no experience with heat treating.

    I'd simply take the existing spring that came with the trigger and run it through tempering colours with controlled heat like an oven, testing at each colour range, the spring is not going to be used otherwise so it's hardly a waste if it gets fucked.
     
    Mostly good advice however hardening such a thin spring will be an absolute pain in the ass if they have no experience with heat treating.

    I'd simply take the existing spring that came with the trigger and run it through tempering colours with controlled heat like an oven, testing at each colour range, the spring is not going to be used otherwise so it's hardly a waste if it gets fucked.
    Hold in tweezers or needle nose, heat with propane torch.
    Open tweezers/pliers to drop in oil ?

    How is that difficult ?
    Are you a gen z'er ?
     
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    Measure the diameter of the wire and hit up a hobby store for some music wire that's smaller diameter than the spring you want to replace. It's cheap enough you could get a few sizes, and make a few springs to see what works best. Shouldn't be any need to play with the heat treatment, just wrap it around something a bit smaller than the coil is now to account for spring back of the wire. I've also made a couple trigger springs from safety pins when I didn't have any music wire on hand.
    Kristian
     
    Hold in tweezers or needle nose, heat with propane torch.
    Open tweezers/pliers to drop in oil ?

    How is that difficult ?
    Are you a gen z'er ?
    Proper heat treating window for something like 1095 is less than 40 degrees C, uniformly heating a piece of wire with a torch to the correct temperature is finicky enough let alone the instantaneous temperature drop that will happen as soon as the heat is removed, even simply dropping fine wire a short distance into quenching medium can result in a failed heat treat. This is even assuming @akmike47 can identify the right temperature to heat treat.

    I guess it's the difference theoretical and practical knowledge.
     
    There are different types of torsion springs. The one you are working with is considered a single coil straight torsion spring. For a torsion spring, the applicable formulas are shown below along with the symbol notation. This information is from the Machinery's Handbook. Similar information can be found in Mark's Standard Handbook for Mechanical Engineers. As a side note, these two books are great reference tools for anything mechanical.

    Edit: To find the diameter of the wire you will of course want to solve for "d" in the first row, first column. However, before you apply the formula you will need to determine what steel you want to use. When selecting the steel be sure to consider environmental conditions, e.g. temperature, salt air or corrosive environment, etc. along with number of cycles, preferably to solve for infinite life.

    Torsion Spring Formulas.jpg
     
    Last edited:
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    Multiple ways. Find a spring, and use 2 sets of needle nose pliers. Bend it to your will. You now have a template of what shape / wire diameter is needed.

    Another way is to lightly remove some material. Belt linisher works great. Find what works, then send it to a custom spring maker. Spend $25, get a new custom spring.
     
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    Why did you buy a shit trigger?
    Just needed a shoe, but this one also set the trigger face farther forward which I needed. I didn’t expect it to come with such a heavy reset spring either.

    Most 10/22 triggers sit way in the back of the trigger guard which forces me to use the tip of my finger to pull the trigger.
     
    Last edited:
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    There are different types of torsion springs. The one you are working with is considered a single coil straight torsion spring. For a torsion spring, the applicable formulas are shown below along with the symbol notation. This information is from the Machinery's Handbook. Similar information can be found in Mark's Standard Handbook for Mechanical Engineers. As a side note, these two books are great reference tools for anything mechanical.

    Edit: To find the diameter of the wire you will of course want to solve for "d" in the first row, first column. However, before you apply the formula you will need to determine what steel you want to use. When selecting the steel be sure to consider environmental conditions, e.g. temperature, salt air or corrosive environment, etc. along with number of cycles, preferably to solve for infinite life.

    View attachment 8039724
    I feel like I could fuck this up fairly easily 😆
     
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    When I see such threads I remember this episode of the Big Bang Theory...


    Not really the same thing, but get what you're saying.

    Just dont want a halfass trigger spring or have to make 15 different ones till I get the weight I want
     
    Last edited:
    There's some very good suggestions made in this thread, and you've been supplied some VERY good information.

    Annealing the metal to bend it to the desired shape "is a thing"
    Hardening the metal to get it to 'retain' that shape "is a thing"
    Tempering the metal to get it to 'maintain' that shape "is a thing".

    Each of those process's do a specifically different task. Once performed, in the proper order, you can make something that will last for a long time and be trustworthy.

    A "hardened" spring will work great, once or twice.
    A "Hardened" and THEN "Tempered" spring will work great many many MANY times.

    Start with piano wire. Quite often, you won't even need to anneal it. Make yourself a jig, so that you can make 'more than one' and each time you'll repeat the identical process so that you gain the actual goal in the end. 'tweaking' with needle-nose and a screwdriver to get 'good enough',,,,, ain't.

    I forgot to add:
    metal can either be 'hard' or 'tough'. It cannot be both. The harder a metal is, the weaker it becomes. The tougher a metal is, the softer it becomes. This is predominantly why 'heat treatment' for knives is such a 'science' and whatnot. You can have an insane'ly hard blade. But it will be brittle and possibly break/snap at the first twist or drop. You can have an insanely 'tough' blade, but it won't keep an edge worth shit.

    This is the balance that metallurgists play with, when adding other elements to an alloy.
     
    Last edited:
    There's some very good suggestions made in this thread, and you've been supplied some VERY good information.

    Annealing the metal to bend it to the desired shape "is a thing"
    Hardening the metal to get it to 'retain' that shape "is a thing"
    Tempering the metal to get it to 'maintain' that shape "is a thing".

    Each of those process's do a specifically different task. Once performed, in the proper order, you can make something that will last for a long time and be trustworthy.

    A "hardened" spring will work great, once or twice.
    A "Hardened" and THEN "Tempered" spring will work great many many MANY times.

    Start with piano wire. Quite often, you won't even need to anneal it. Make yourself a jig, so that you can make 'more than one' and each time you'll repeat the identical process so that you gain the actual goal in the end. 'tweaking' with needle-nose and a screwdriver to get 'good enough',,,,, ain't.

    I forgot to add:
    metal can either be 'hard' or 'tough'. It cannot be both. The harder a metal is, the weaker it becomes. The tougher a metal is, the softer it becomes. This is predominantly why 'heat treatment' for knives is such a 'science' and whatnot. You can have an insane'ly hard blade. But it will be brittle and possibly break/snap at the first twist or drop. You can have an insanely 'tough' blade, but it won't keep an edge worth shit.

    This is the balance that metallurgists play with, when adding other elements to an alloy.
    Well said. Completely agree.
     
    There's some very good suggestions made in this thread, and you've been supplied some VERY good information.

    Annealing the metal to bend it to the desired shape "is a thing"
    Hardening the metal to get it to 'retain' that shape "is a thing"
    Tempering the metal to get it to 'maintain' that shape "is a thing".

    Each of those process's do a specifically different task. Once performed, in the proper order, you can make something that will last for a long time and be trustworthy.

    A "hardened" spring will work great, once or twice.
    A "Hardened" and THEN "Tempered" spring will work great many many MANY times.

    Start with piano wire. Quite often, you won't even need to anneal it. Make yourself a jig, so that you can make 'more than one' and each time you'll repeat the identical process so that you gain the actual goal in the end. 'tweaking' with needle-nose and a screwdriver to get 'good enough',,,,, ain't.

    I forgot to add:
    metal can either be 'hard' or 'tough'. It cannot be both. The harder a metal is, the weaker it becomes. The tougher a metal is, the softer it becomes. This is predominantly why 'heat treatment' for knives is such a 'science' and whatnot. You can have an insane'ly hard blade. But it will be brittle and possibly break/snap at the first twist or drop. You can have an insanely 'tough' blade, but it won't keep an edge worth shit.

    This is the balance that metallurgists play with, when adding other elements to an alloy.

    Agreed. Cliff notes version of Materials 101 right here... ;)
     
    This......
    Maybe if you read the thread....

    Kind of hard to make a shit trigger shoe, the spring is the issue. Also pretty much half off helps.

    Volqaurtsen and I made the important trigger parts it's a mix of my work and there's they made the hammer, but I worked everything.
     
    Last edited:
    There's some very good suggestions made in this thread, and you've been supplied some VERY good information.

    Annealing the metal to bend it to the desired shape "is a thing"
    Hardening the metal to get it to 'retain' that shape "is a thing"
    Tempering the metal to get it to 'maintain' that shape "is a thing".

    Each of those process's do a specifically different task. Once performed, in the proper order, you can make something that will last for a long time and be trustworthy.

    A "hardened" spring will work great, once or twice.
    A "Hardened" and THEN "Tempered" spring will work great many many MANY times.

    Start with piano wire. Quite often, you won't even need to anneal it. Make yourself a jig, so that you can make 'more than one' and each time you'll repeat the identical process so that you gain the actual goal in the end. 'tweaking' with needle-nose and a screwdriver to get 'good enough',,,,, ain't.

    I forgot to add:
    metal can either be 'hard' or 'tough'. It cannot be both. The harder a metal is, the weaker it becomes. The tougher a metal is, the softer it becomes. This is predominantly why 'heat treatment' for knives is such a 'science' and whatnot. You can have an insane'ly hard blade. But it will be brittle and possibly break/snap at the first twist or drop. You can have an insanely 'tough' blade, but it won't keep an edge worth shit.

    This is the balance that metallurgists play with, when adding other elements to an alloy.
    May end up being more work than thought. I knew I'd have to hear treat it but maybe $5 worth of bobby pin springs will last a lifetime😆

    Would be easier if Tandemkross customer service wasn't so insistent I did something wrong....pretty hard to fuck up gun legos and obvious when you do. I've given them way more info than they need to prove it's the reset spring.

    There's no reason I need a 2.5# plus reset spring, Its a half pound of pressure on the trigger (only the trigger and spring in housing) to move this jerry rigged one and it functions normally with a 2# trigger pull fully assembled.
     
    Last edited:
    Proper heat treating window for something like 1095 is less than 40 degrees C, uniformly heating a piece of wire with a torch to the correct temperature is finicky enough let alone the instantaneous temperature drop that will happen as soon as the heat is removed, even simply dropping fine wire a short distance into quenching medium can result in a failed heat treat. This is even assuming @akmike47 can identify the right temperature to heat treat.

    I guess it's the difference theoretical and practical knowledge.
    I've read stuff but never put anything into practice, I'm just getting tired of the company CS turds BS
     
    I've read stuff but never put anything into practice, I'm just getting tired of the company CS turds BS
    Heat treating is not super complicated but it's easy to fuck up.
    If you don't want to muck around too much with the existing spring, take a lighter or small torch to it and stop applying heat once the metal reaches a dark blue or even grey would be alright. This is the softest state you will get the spring while still being properly head treated.
     
    I'd suggest that you get yourself some piano wire, and conscientiously form the wire into the spring shape that you want. Take your time, do it 'right' and put effort into making it as perfect as you can.

    If you like how it turned out, put it in your trigger and see how it feels. If you don't like that, then make yourself another one, 'version 2'. Do better than you did with the first one. For the cost of a piece of piano wire, (less than 5 bucks) and investing a bit of time.... you can actually make something of your own.

    And then the 3rd one will be even better. Pay attention to what you're doing. As I said earlier, make a simple jig so that each move is repeatable. You'll be surprised as to what you can accomplish. If you only 'bend' the piano wire into curves (circles/loops) you can get away with a lot of things. It is where you make 'sharp bends/corners' where things break the most, and the fastest.

    You can accomplish a LOT with piano wire before you even have to THINK about purchasing 'spring stock'. That is a whole other world, as has been alluded to, above.
     
    I'd suggest that you get yourself some piano wire, and conscientiously form the wire into the spring shape that you want. Take your time, do it 'right' and put effort into making it as perfect as you can.

    If you like how it turned out, put it in your trigger and see how it feels. If you don't like that, then make yourself another one, 'version 2'. Do better than you did with the first one. For the cost of a piece of piano wire, (less than 5 bucks) and investing a bit of time.... you can actually make something of your own.

    And then the 3rd one will be even better. Pay attention to what you're doing. As I said earlier, make a simple jig so that each move is repeatable. You'll be surprised as to what you can accomplish. If you only 'bend' the piano wire into curves (circles/loops) you can get away with a lot of things. It is where you make 'sharp bends/corners' where things break the most, and the fastest.

    You can accomplish a LOT with piano wire before you even have to THINK about purchasing 'spring stock'. That is a whole other world, as has been alluded to, above.
    Spring stock, to my knowledge, was never mentioned.
    You can buy tool steel rod at most any metal yard....it comes in tons of different alloys and tons of diameters.
    From my last experience about 3-4 years ago it was in the $5 range for something like the .040-.070 range he would need in a 3 foot length.
    You can maybe make more than 1 spring with 3 foot of material.
    The rod will come annealed but it doesn't hurt to normalize it a few cycles just to be sure.
    Machinists use it to make tools and *stuff*.....like, you know....springs.
    Piano wire is available, but will be harder to find, especially the thicker diameters that don't normally break on a piano and the size required would be somewhere on the very lowest register of the piano keyboard.

    Here....
    .069 rod, 3 foot length....
    $3
     
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