Tuning Cutting Springs

[dormitionskete]

I've often heard some of you advising people to cut 1 - 1 1/2 coils off a spring to bring the power level down. If a person was to do this, how would he close or flatten the end? Just grind it to be a ground open end?

Or do you you just leave it open? (That sounds barbaric to me.)

I searched on YouTube, and all of the solutions I found there required special machines.

This page has some interesting ideas:

How do you mash the end of a spring?

I have (4) Delta high speed drill presses, all substantially identical in construction. I am getting OLD and hate lifting the head/motor/cast iron pulley cover - 67 lbs.- on the column! For a counterbalance, I purchased some springs and other parts from Delta to install on each one. The...

www.practicalmachinist.com

How or what do you folks do, or recommend?

--

Full Disclosure: I'm not likely to actually ever try this. But even as a boy, I wanted to learn machining and metal work; but I was too proud to pursue it. Life has humbled me a bit, thank God, but now I'm in a situation where I'm not likely ever to be able to pursue that. But I still find things like this interesting / intriguing ... and I'm curious.

Thanks for bearing with me.

 

[AirShot]

I use a cutoff wheel on a dremel tool. Then heat just the last coil and flatten. Grind smooth with a belt sander then polish smooth with a large cratex wheel.. Been doing it this way for over 40 years. Takes about 15 minutes.

 

[dormitionskete]

I use a cutoff wheel on a dremel tool. Then heat just the last coil and flatten. Grind smooth with a belt sander then polish smooth with a large cratex wheel.. Been doing it this way for over 40 years. Takes about 15 minutes.

I could probably do that! I think we have everything necessary to do it this way. Do you put the spring in a vice to heat and flatten it? Or are you able to just hold onto the spring with your other hand, since you're only heating the last coil?

 

[thumper]

Cut the spring with a cutoff wheel of whatever sort you have on hand.

Heat the last 1/2 coil and simply press against the floor or workbench or whatever. You can do the whole operation without a vise.

Then grind the end flat. Don't waste your time or effort polishing it, as it will be against a thrust washer or have a tophat or guide inserted into it anyway and won't make any difference whatsoever.

Just pay particular attention to the pointed end of the cut coil, and make sure it's rounded off so not to dig in to whatever flat surface it's against.

 

[dormitionskete]

Thank you both very much! I could probably do that. And I may do that, if I decide to tune our ProSport down -- which I'm not sure I want to do. I haven't completely decided yet.

But I have a broken Weihrauch spring to practice on, so the risk is minimal, I think.

I might try it on the broken spring just for the fun of it!

Many, many thanks!

Much appreciated!

 

[Mycapt65]

I use a cutoff wheel on a dremel tool. Then heat just the last coil and flatten. Grind smooth with a belt sander then polish smooth with a large cratex wheel.. Been doing it this way for over 40 years. Takes about 15 minutes.

Do you quench or air cool the heated end when done?
Thanks

 

[marflow 777]

so, i am going to disagree with not polishing the spring end
if you can get the spring to never bind i feel it is better
if you are hoping the spring is going to turn the top hat and spring guide it would be better if that could be done with less friction
i add 2 thin stainless washers at both ends if possible if the spring picks up the washer, the washer will spin on the second washer
washers polish the end of the spring with a drill and a disc pad start with 400 and you will be done in a few minutes
https://www.ebay.com/itm/164573184907?var=464175123552

is it right or wrong or overkill, i don't really care, it is what i do and it works very well for me and what you do is none of my business

 

[Sqwirl57]

I polish my spring ends as well although I agree that it probably doesn't matter. Once on the top hat/washer guide that who assembly should rotate freely. It looks cleaner, takes 30 seconds, and adds an additional bearing surface so I just do it. Also don't forget to round off the INSIDE edge of the cut end as that tends to stick in some and will dig into a tighter fitting guide. I quench with vegetable oil.

 

[Chuck-in-Ohio]

Canola oil or Parks 50 for a quench if you wish.

 

[KWK]

Heating a spring does weird stuff to it. The temper next to the area heated for colapsing is altered and the area you're taking to cherry red before quenching doesn't receive tempering. So that little bit on the end could be brittle. Oils or brine?
You're really in over your head when you attempt to heat treat a spring in the basement. Check this out

Can You Trust Your Magnet During Heat Treating? - Knife Steel Nerds

Many knifemakers heat treat with nothing but a forge and a magnet. Is that reliable? What does it mean when the steel is no longer magnetic?

knifesteelnerds.com

I just heat it quickly and colapse it and forget it. Finish the end on the side of the bench grinder wheel (where it is not recommended to grind) and it comes off pretty smooth. Deburr. If you have delrin guides you're good to go because delrin is excellent bearing material. Lubricated polished metal guides and washers are better than spring ends too. Molybdenum disulfide or space grease is slick as eel ........................you know

 

[SpiralGroove]

Do you quench or air cool the heated end when done?
Thanks

Quench in oil to case harden .... standard procedure on screws/springs.
Not in Water .... hardens metal making it too brittle ................

 

[Chuck-in-Ohio]

I have never heat treated one myself, my suggestions above were for anyone so inclined.

I would rather have a softer end transitioning through the heat affected zone to the tempered spring section.
The softer section will be the last coil resting on your thrust washer, so the cyclic stresses are less in that area I believe ?

I flatten the end on a disc grinder once collapsed, then finish with 600 grit for a polish.

 

[Mycapt65]

Thanks all. I've cut and closed dozens of spring ends and never had any problems until lately. I normally let them air cool. I have recently quenched a couple in oil. I had one low use spring that broke at the edge of the discoloring. Unfortunately I can't remember if it was air cooled or oil cooled. I'll have to take better notes.

When finishing ends I don't go too nuts on them. I slowly step use a belt sander and continually dip in water between steps to prevent over heating. This method I've used all along and am fairly confident because I used to sharpen twist drill similarly on a good grinding stone with good results.

 

[AirShot]

Do you quench or air cool the heated end when done?
Thanks

Just wave it around for a minute or two to get the worst heat out, then quench to finnish. Some guys don't bother polishing the ends of the spring but I always have and found longer life from it, but to each his own..

 

[Berserkeley Mike]

I could probably do that! I think we have everything necessary to do it this way. Do you put the spring in a vice to heat and flatten it? Or are you able to just hold onto the spring with your other hand, since you're only heating the last coil?

I used a glove to hold the spring. That way I could hold it closer to the heat to keep it from wobbling around. It doesn't take much of a torch to get it soft enough to bend flat.

 

[AirShot]

Quench in oil to case harden .... standard procedure on screws/springs.
Not in Water .... hardens metal making it too brittle ................

Your not tempering or hardening the spring, just removing stress from that coil after flattening..

 

[KWK]

Just wave it around for a minute or two to get the worst heat out, then quench to finnish. Some guys don't bother polishing the ends of the spring but I always have and found longer life from it, but to each his own..

That would be ok. Keeps the residual heat from affecting the temper because it can. 400 degrees affects temper

 

[KWK]

When I make a spring out of music wire which is already hardened and tempered it's bent beyond it's limit to form the spring. Then to stress relieve it I bake it at 350 for an hour. Doesn't take much heat to affect the steel.

 

[SpiralGroove]

Yeah, sometimes we get too caught up in (details) doing the "perfect job", when just doing a reasonably good one is a 99% cure.
Whether you oil quench, air temper or do whatever likely changes nothing, but we all need to follow our ways.

PS: I do polish my spring-end, but that may not improve performance much -> but it makes me feel better.

 

[dormitionskete]

PS: I do polish my spring-end, but that may not improve performance much -> but it makes me feel better.

Awh... You made me laugh on my B-Day! Danke.